This manual is provided to you in electronic format. It is supplied for
the sole purpose of documenting and supporting Mult-Tech Systems'
products. Any translation, modification, or unauthorized copying of
this manual is strictly prohibited. The information contained herein is
protected by U.S. copyright laws and international treaties.
This text-only version of the MT2834LT manual, P/N 82037101, Rev.
B, documents the MT2834LT and LTI modems as well as PCM Plus
software version 1.04.
1.1 Introduction
Welcome to the world of mobile data communications. You have
acquired one of the finest intelligent PCMCIAÖ data/fax card modems
available today, the MultiModemLT, from Multi-Tech Systems. Your
MultiModemLT (domestic model MT2834LT and international model
MT2834LTI) provides data communication at 28,800, 19,200, 14,400,
9600, and 2400 bps with error correction, data compression, and more!
It complies with the ITU-T (formerly CCITT) V.34 standard, which
includes features such as EIA extended automode, adaptive line
probing, automatic symbol rate, and carrier frequency during start-up.
This owner's manual helps you install, configure, test, and use your
modem, and provides other information as well.
1.2 How to Use this Manual
This manual contains eight chapters. Several appendices at the end of
this manual provide additional information in a more condensed form.
The information contained in each chapter and appendix is as follows.
Chapter 1_Introduction and Description
This chapter begins with a short introduction, followed by a guide
(which you are now reading) to the use of the manual. It discusses what
components are included in the MultiModemLT package. It then
provides a more detailed description of the modem and tells about the
notation conventions used in the manual.
Chapter 2_Software Installation and Operation
This chapter describes the two levels of procedures (Quick Install and
Advanced Install) for installing the PCM Plus software on your system.
It also includes basic instructions for use with the MultiModemLT.
Chapter 3_Hardware Installation and Connection
This chapter covers procedures for connecting the MultiModemLT to
your computer and the phone line.
Chapter 4_Manual Dial and Automatic Answer
This chapter covers some modem operations, but delays discussion of
Command mode operation until Chapter 5. It covers manual dial mode
and answer mode operation in detail, as well as the handshaking
procedures employed between two modems in an auto-answer
application. It then discusses various methods of call termination.
Chapter 5_AT Command Mode Operation
This chapter begins with an introduction and discussion of the
MultiModemLT Command mode fundamentals. A flow chart is
provided to illustrate Command mode and On-line mode operation and
the methods used in each mode. Next, it summarizes the modem's
commands and responses, giving a detailed explanation of each
MultiModemLT command and providing examples where applicable.
Chapter 6_S-Registers
This chapter covers the MultiModemLT's software registers (S-
Registers), which store and/or configure various modem options. It
explains the use of each S-Register in terms of its purpose, valid range
of values, and default settings.
Chapter 7_Testing Your Modem
This chapter covers the modem's test features. The four tests (Power-On
Self-Test, Analog Loopback, Digital Loopback, and Remote Digital
Loopback) let you check that the MultiModemLT is functioning
properly.
Chapter 8_Remote Configuration
This chapter describes how the MultiModemLT Remote Configuration
feature operates. This feature uses a multilevel security system that
involves the use of LOGIN passwords, SETUP passwords, and remote
escape characters.
Appendices
Appendix B_Dial Pulse and Tone Dial Frequencies
Appendix C_MultiModemLT Cables/Connectors
Appendix D_Escape Methods
Appendix E_Programming Reference
Appendix F_PCMCIA Driver Deinstallation
Appendix G_PCM Plus Drivers & Memory Management
Appendix H_Troubleshooting PCM Plus Software
Appendix I_Regulatory Compliance
Appendix J_Technical Specifications
Glossary
Index
1.3 What is in Your Modem Package?
Check your MultiModemLT package for the following before operating
your modem:
* MultiModemLT
* 9-pin to dual RJ11 CoolJaxÖ connector and telephone cord
(MT2834LT), or Line Adapter Module (LAM) cable
(MT2834LTI)
* MultiModemLT Owner's Manual and MultiModemLT Quick
Reference Guide
* PCM Plus software diskette (for DOS and WindowsÖ)
* MultiExpressFaxÖ for Windows diskette(s)
* MultiExpressÖ for Windows diskette(s)
* MultiModemLT protective cover
If any of these items are missing, please contact Multi-Tech Systems or
your dealer/distributor.
You need to install the PCM Plus software provided. It contains device
drivers that your MultiModemLT needs to communicate with your PC.
If you choose to install and use the provided MultiExpress data
communications and MultiExpressFax facsimile software, please refer
to the provided MultiModemLT Quick Reference Guide.
1.4 Product Description
Your MultiModemLT fits into a special slot called a PCMCIA
(Personal Computer Memory Card International Association) socket in
your portable, laptop, and notebook computer. (It can also be used with
desktop PCs and many other applications where desktop modems are
normally used.) Your MultiModemLT lets you take all the features of
your high performance Multi-Tech desktop modem on the road.
The PCMCIA standard specifies a removable PC Card in terms of
physical dimensions, pin assignments, electrical specifications,
protocols, and file formats. The MultiModemLT is a 2.126" x 3.37"
removable Type II (5 mm thick) PC Card.
Within the constraints of the industry standards, we've loaded your
modem with the following: the latest ITU-T's (formerly CCITT) V.34
standard for 28.8K bps, AT&T's V.32terbo standard for 19.2K bps, as
well as CCITT's V.32bis and V.32 standards for 14.4K and 9600 bps
data speeds, respectively; Class 2 Group 3 fax transmissions at 14.4K,
9600, or 4800 bps; error correction; and data compression. The
MultiModemLT is also downward compatible with modems at data
speeds of 2400, 1200, and 300 bps.
Perhaps the most significant features of the MultiModemLT are its
error correction, data compression, and fax capabilities. With CCITT
V.42 error correction, data sent is 100% error free. The V.42bis data
compression provides data compression at speeds up to 115.2K bps
(depending on file content and the receiving modem's capability). With
data compression, your files may be sent up to 400% faster with
V.42bis or up to 200% faster with MNPr Class 5.
The MultiModemLT offers interactive automatic dialing, as well as
Command mode option configuration. Up to ten command lines, of up
to 60 characters each, can be stored in the modem's nonvolatile
memory. The modem uses pulse and/or tone dialing, and can recognize
dial tones and busy signals for reliable call-progress detection. The
MultiModemLT can also detect AT&T calling card tones to access the
user's calling card before creating an on-line connection.
The MultiModemLT is fully compatible with the standard AT
command set, and therefore with all popular communications software
packages.
The MT2834LT comes with the patent-pending CoolJax duplex phone
connector. The CoolJax eliminates messy cables, and allows you to
plug your telephone into one of the RJ11 jacks. Now you can use your
telephone anytime you're not using your MT2834LT modem, without
the inconvenience of swapping plugs.
Important Note to Users of MT2834LTI UK Version Modems
Your MT2834LTI modem is intended for use in a PCMCIA socket with
the following electrical characteristics: +5V dc
(ñ 0.25V) at 150 mA; ripple noise 200 mV peak to peak. You should
ensure that your PC's PCMCIA socket meets the above requirements
before installing the MT2834LTI modem. Your host PC should be
approved for indirect connection to the telephone network under
general approval NS/G/1234/J/100003. If it is not, seek advice from the
supplier of your PC.
1.5 Notation Conventions Used
The following conventions are used to represent commands, defaults,
and instructions that you type or see on your screen when using your
MultiModemLT.
Notation Conventions
YOU TYPE THIS Bold, uppercase type specifies an
actual
command string or other information you should
enter. Spell the entry exactly as shown using
upper or lower case type.
AT Command Bold, italicized type specifies an
AT command.
This convention is used when we do not intend
for you to type it.
O, 0 Both the letter O and the number 0 are used in
the MultiModemLT's AT commands. The letter
O is "fatter" than the number 0. We do not use
the overstrike o to symbolize zero in this manual.
D:\path\filename File name and/or path. In the
following example,
a request for a file path is indicated as:
D:\path\filename
D is the drive and path is the full directory path
where the file is found.
ENTER, <CR> Instructs you to press the Return,
Enter, or
Carriage Return key (depending on how your
keyboard is marked).
CTRL Instructs you to press the Control key. For
example, a Control X (accomplished by pressing
the X key while holding down the Control key) is
written as CTRL-X.
[Options] Replace with option(s) you select.
For example,
replace PCMSS.EXE [Options] with
PCMSS.EXE /RS=0.
Default Value Underlining specifies a default
value. If you do
not provide a value, the system supplies the
underscored value.
2.1 Introduction
PhoenixCARD Manager Plus (PCM Plus) is a software program that
installs device drivers which let you operate your MultiModemLT in
your PC's PCMCIA (Personal Computer Memory Card International
Association) slot. PCM Plus lets you choose the mode of installation
that is suitable to your level of use. Whether you are a novice or an
advanced user, Quick mode installation is fast and simple to use, and
requires little or no knowledge of the technology involved in the inner
workings of the PCM Plus software. To the novice user, PCM Plus
appears almost transparent.
For the advanced user, Advanced mode lets you customize your DOS
CONFIG.SYS or Microsoftr WindowsÖ SYSTEM.INI file to suit your
system's needs. An advanced user should have an understanding of
DOS and Windows, as well as an understanding of PC memory
management, IRQ conflicts, and driver addressing.
PCM Plus provides simple menu selections through either a DOS or
Windows interface. Most PCMCIA cards are configured automatically
by PCM Plus. And if you need to swap cards in the middle of a
program, PCM Plus lets you set up and reconfigure on-the-fly.
2.1.1 Features
PCM Plus provides these features:
* Setup program that lets the novice user quickly and easily
install PCM Plus while also providing a full range of
customization features for the sophisticated user
* Support for the DOS 6.0 Multiple Boot Option
* Easy-to-use deinstallation utility for removing older versions
of PCMCIA software
* Easy-to-use information/configuration utilities for managing
PCMCIA cards in both DOS and Microsoft Windows versions
* Hot insertion and removal of PC cards without the need to
reboot
* Support for Power Management
2.1.2 Document Conventions
The following terms and concepts are used to present the user interface
for the MultiModemLT drivers/utilities described in this manual.
2.1.2.1 Driver Files
Drivers, or device drivers, are programs that connect your PC's
operating system to either an internal function or a peripheral, such as
the MultiModemLT. Drivers are usually included in either your
CONFIG.SYS (DOS drivers) or your SYSTEM.INI (Microsoft
Windows drivers).
You can locate the DOS drivers on any drive. However, you must
specify the full path for DOS drivers not located in the root directory of
the boot device.
Windows drivers must reside in the Microsoft Windows\System
directory.
2.1.2.2 Executable Files
Both DOS and Windows executables may reside on any disk to which
the system has access. For DOS to find and execute a file, the .EXE or
.COM file must reside in a directory specified using the PATH
command or in the current directory, or executed using the full path
name. You may run Windows executables (SYSTEM.INI) from any
directory as long as you specify the full path when running the program
or when creating or defining the Windows icon.
2.2 Installation
PCM Plus software can be quickly and easily installed. Follow the
step-by-step instructions.
Note: Since installing PCM Plus modifies your AUTOEXEC.BAT,
CONFIG.SYS, and/or SYSTEM.INI files, it's a good idea to make
backup copies of these files. You may want the changes made to your
CONFIG.SYS file on a bootable system disk to verify that the changes
work properly.
2.2.1 Preparations
The following lists several pieces of information you need to install the
PCM Plus software.
* Make sure your computer has these minimum requirements:
* 2 MB of RAM memory
* 784 KB of hard disk space
* 80386 or later microprocessor
* Count the number of PCMCIA sockets in your computer.
* Find the full path to which your Windows directory can be
found. If you are uncertain, look for the WIN.INI and
SYSTEM.INI files. The directory containing these files is
your Windows directory.
* If you are using the DOS 6.0 Multiple Boot option, be aware
that the PCM Plus software will be installed for the currently
booted configuration.
2.2.2 Installing PCM Plus
Note: Since installing PCM Plus modifies your AUTOEXEC.BAT,
CONFIG.SYS, and/or SYSTEM.INI files, it's a good idea to make
backup copies of these files. You may want the changes made to your
CONFIG.SYS file on a bootable system disk to verify that the changes
work properly.
Follow these instructions to install and set up the PCM Plus program
quickly.
1. Make a backup copy of the distribution diskette and store it.
2. Insert the distribution diskette in drive A:, type A:\INSTALL,
and press ENTER. The title screen appears.
3. Press any key.
If you have a multiple boot option in DOS, a warning appears.
This screen warns you that the PCM Plus software will install
in the current configuration. To change to a different
configuration, exit the installation by pressing the F3 funtion
key. Reboot you PC and select the correct configuration before
reinstalling PCM Plus.
Otherwise, the following informational screen appears.
4. This screen tells you which PCMCIA controller PCM Plus has
determined is in your computer. Use the help message (press
F1) for information on which controller types are currently
recognized by PCM Plus.
Press any key and the following screen appears.
5. This screen not only lets you specify the name of the directory
you want for the PCM Plus files, it also tells you how much
space will be necessary for the installation. Make sure that
there is at least this much room on your hard disk before
beginning the installation.
Either select the default directory path or type another, then
press ENTER. A screen appears that provides information on
the progress of the installation.
6. When PCM Plus has finished copying all necessary files to the
designated directory, an informational screen appears about
successfully copying all files and automatically updating
others.
Press any key and the PCM Plus setup title screen appears.
7. Press any key and an informational screen about the PCM Plus
setup program appears.
If you see another message, follow the instructions provided.
For more information on messages, refer to Appendix H,
Troubleshooting. If the message instructs you to edit your
CONFIG.SYS file first before continuing with the program,
refer to Appendix F and Appendix H for more information.
8. Press any key to continue. The following screen appears.
9. The "Quick Mode" option is highlighted. Press ENTER to
select the Quick Mode. This provides the shortest method for
installing and setting up PCM Plus. In most cases, the default
values provided by Quick Mode are sufficient.
If you prefer to customize the setup of your system, select the
"Advanced Mode" option. Advanced Mode lets you specify
IRQ and Card Information Service (CIS) Window Address
values, and also specify information for ATA and Flash cards
(if you plan to use either of them).
Once you select Quick Mode or Advanced Mode, the "Socket
Information" screen appears.
10. If the number of sockets is correct, press ENTER. If the
number is not correct, enter the correct number and then press
ENTER.
The sockets are the number of PCMCIA ports that your
computer possesses. Most computers provide one or two of
these ports. Normally PCM Plus senses the number of sockets
your computer has and presents the correct number on this
screen.
The "Microsoft Windows" screen comes up with "Yes"
highlighted.
11. If Windows is installed on your system, just press ENTER. If
Windows is not installed on your machine, use the down arrow
key to move the highlight to "No," then press ENTER.
Note: PCM Plus software only runs in enhanced Windows mode. If
you try to run this software in standard Windows mode, you
get the following error message: PCMCIA card
insertion/removal not supported in standard Windows mode.
12. The Windows path defaults to C:\WINDOWS. If this is
correct, press ENTER. If this is not correct, change it to the
correct path name and then press ENTER.
13. If PCM Plus detects expanded memory on your system, it
displays the EMS Activation screen. PCM Plus can load some
of its PCMCIA drivers into EMS memory, above the 1Mb
address. This reduces the amount of conventional memory
used, leaving more memory for other programs. Select Yes or
No.
14. If you selected the Quick Mode of installation, go to step 16.
If you selected the Advanced Mode of installation, the
"Advanced Setup" screen appears.
15. It includes specific information on the IRQ setting that is used
by the PCMCS driver to determine when a card is inserted or
extracted, the CIS window address you require, the Token
Ring speed you will be using (if you have chosen Token Ring
as your network type), and the Card Settle Time.
Select the values you require. Use the Tab key or the up/down
arrow keys to go from field to field. Type in the values you
require at each field. When you are finished, press ENTER to
accept the displayed values.
Note: If you select a value which conflicts with an existing driver or
device (for example, if the IRQ you select here is already
being used by another device), a conflict warning appears.
Select another value or change the setting of the device that is
using the current value. For more on memory address
conflicts, refer to Appendix G.
The "Flash File System" screen appears with "Yes"
highlighted.
16. If you are going to use a flash card, Microsoft's Flash File
System for PCMCIA memory cards is the best known program
for formatting and maintaining files on the card. Most
unformatted flash cards on the market support this program.
Press ENTER to accept "Yes".
If your flash card comes to you already formatted or if you
plan to use another formatting and file management utility, use
the down arrow key to highlight "No" then press ENTER.
17. The Flash File System path defaults to the C:\PCM31
directory. If this is acceptable, press ENTER. If this is not
correct, enter another path name, such as C:\FFSII, then press
ENTER.
If you select "Yes" and a note like the following appears, copy
the file MS-FLASH.SYS from the distribution diskette to your
Flash File System directory.
The file MS-FLASH.SYS is missing from your Flash File
System directory. PCM+ requires this file in order for the
Flash File System to function. Please copy this file as soon as
possible.
The "Modem/Fax" screen appears with "Yes" highlighted.
18. Press ENTER to use your MultiModemLT PCMCIA
modem/fax card in your computer's PCMCIA slot.
The "Communication Ports" screen appears with COM1
highlighted.
19. Select COM1, COM2, COM3, or COM4 by using the up or
down arrow keys, then press ENTER.
To determine which port designation you should make, check
your computer. Many laptop and portable computers, and most
desktop computers, already have one serial port, usually
designated COM1.
This means that adding a fax/modem board provides a new
serial port which will normally be designated as COM2.
Note: Conflicts can occur between existing COM ports and the
MultiModemLT (i.e., do not assign COM 4 to the
MultiModemLT if it is already occupied).
Also, COM ports share IRQs, and consequently may present
conflicts (e.g., COM ports 1 and 3 share IRQ 4, and COM
ports 2 and 4 share IRQ 3). To change a COM port IRQ, use
the Edit Card Configuration option of the Configure menu in
section 2.3, Configuration Utilities for DOS and Windows.
The "ATA Socket" screen appears with "Yes" highlighted.
20. If you plan to use ATA-type cards, press ENTER. If you do
not plan to use an ATA card with this computer, highlight
"No" with the down arrow key and press ENTER.
If your computer has more than one PCMCIA socket, a second
"ATA Socket" screen appears, asking which socket contains
the ATA hard disk card. Press ENTER to specify Socket 0 or
use the down arrow to highlight another socket then press
ENTER to confirm your socket choice.
The PCMCIA Network Card Selection screen appears.
21. You don't need to specify any network type at this time since
you can dynamically configure your system for a network card
when you add the card using either the PCM or PCMWIN
utilities. Simply press ENTER to exit this screen.
If you want to specify either Token Ring or Ethernet network
for a PCMCIA network card, follow these instructions:
a. Use the up or down arrow to highlight one of the network
types.
b. Press the spacebar to select the option. An arrow appears to
the right of your selection. To deselect that option, press the
spacebar again and the arrow disappears.
c. Press ENTER to confirm your choices.
22. At this point, a power management warning may display if you
do not have APM or POWER.EXE loaded. Press ENTER to
move on to the final screen. Refer to Appendix H,
Troubleshooting, for information on this warning.
The "Setup complete" screen appears with "Yes" highlighted.
23. Press ENTER to complete the installation. PCMSETUP
updates the PCM.INI file, PROGMAN.INI, CONFIG.SYS,
WIN.INI, and SYSTEM.INI files as appropriate. It also adds
the PCM Plus directory to your PATH statement in
AUTOEXEC.BAT.
Type N and hit ENTER to abort the installation.
The program exits to the DOS prompt. For additional
information, type README and hit ENTER. Several pages of
enhancements, additions, and corrections to the software and
manual are provided.
Note: Since Quick and Advanced Install change your CONFIG.SYS,
SYSTEM.INI, and AUTOEXEC.BAT files, you must reboot
your system before these changes become active. Use your
system reset button, press CTRL-ALT-DEL, or turn your
system off and then on again.
24. After rebooting, you are ready to install the MultiModemLT
according to the instructions in Chapter 3. If you want to
change the card configurations, go to the next section.
2.3 Configuration Utilities for DOS and Windows
After PCM Plus is installed, it should recognize a majority of the
PCMCIA cards when you insert them and dynamically configure them,
including the MultiModemLT. However, there may be instances when
PCM Plus either does not recognize the inserted card or has trouble
assigning configuration values that do not conflict with other programs
in your system.
To solve this problem, this configuration program provides fast and
easy configuration for any PCMCIA I/O card you install. This
configuration utility provides information about the current card(s)
inserted, and lets you edit the configuration of the card(s) to define and
use the most appropriate configuration for your system. You can also
configure new cards and modify their configurations, but this requires a
basic knowledge of system resource allocation.
A version of PCM is available for both the DOS (PCM) and Windows
(PCMWin) environments. Both programs are explained in this chapter.
Note: This PCM Plus configuration program can only configure I/O
cards although it can display information about all card types. If you try
to configure another type of card, for example an ATA or flash memory
card, PCM Plus cannot do it. If PCM Plus reports a non-I/O card as
unconfigured, PCM Plus will be unable to configure it.
2.3.1 PCM_DOS Configuration Utility
PCM is a menu-based DOS configuration utility that lets you view and
configure PCMCIA cards. The menus include view, information,
configure, and option. (Press the F1 key for help information related to
each menu item.) Each menu is described in greater detail in the
following sections.
Note: Do not try to execute this utility in a Windows environment.
Instead, use the Windows information utility described in the next
section.
Table 2-1
Opening, Viewing, and Exiting PCM
1. To open the PCM Plus configuration program, go to the PCM
Plus directory (C:\PCM3) at the DOS prompt.
2. Type PCM and hit ENTER. The General Information Per
Socket screen appears with information on the card presently
inserted in the designated socket.
Here you can check the status of your MultiModemLT or other
PCMCIA card. The status line displays the card's current
configuration status. If PCM Plus configured the card
automatically, the line reads "Card configured successfully".
If the program did not recognize the card or the card has no
CIS, this line reads "Unconfigured". In this case, you must
configure the card manually using this program.
If you insert or remove a card while PCM is running, a
message will appear which reflects the card's insterted or
removed status.
If you have more than one socket and card installed in this
computer, use the PgUp/PgDn keys to view them.
To view any of the menu options, press the ALT key and type
the highlighted letter of the menu option.
3. To exit, press the ALT key and select the Exit option by either
highlighting "Exit" and pressing ENTER, or simply by typing
X.
2.3.2 PCMWin_Windows Configuration Utiltiy
This PCM Plus configuration process is handled almost the same in
Windows. PCMWIN is installed automatically by PCMSETUP if it
finds your computer has Windows installed. The installation program
inserts a PhoenixCardManager group in Program Manager and places
the PCMWin icon inside that window.
Note: PCMWin does not work in Windows standard mode. To run
PCMWIN, use 386 Enhanced mode.
To run and configure cards using PCMWin (which is very similar to the
DOS program PCM), follow the steps below.
Table 2-2
Opening, Viewing, and Exiting PCMWin
1. Bring up Windows and double-click the PCMWin icon. A
screen displays information on the card presently inserted.
Here you can check the status of your MultiModemLT or other
PCMCIA card. The status line displays the card's current
configuration status. If PCM Plus configured the card
automatically, the line reads "Card configured successfully".
If the program did not recognize the card or the card has no
CIS, this line reads "Unconfigured". In this case, you must
configure the card manually using this program.
If you insert or remove a card while PCM is running, a
message will appear which reflects the card's insterted or
removed status.
To check other sockets, either use the up/down arrow keys or
press the Previous/Next buttons. To view any of the menu
options, click on the menu option.
2. To exit, click the View menu option and then click on "Exit".
2.3.3 PCM and PCMWin Menu Options
The PCM and PCMWin menus include four options: view, information,
configure, and option. To view any of the menu options, either press the
ALT key and type the highlighted letter of the menu option or click on
the menu option. Each menu is described in greater detail in the
following sections.
2.3.3.1 View
The View menu lets you display advanced information about your
PCMCIA card (such as resource and register information), and also lets
you exit PCM.
2.3.3.2 Information
The Information menu lets you access a list of all card configurations
and client drivers already recorded. You can then quickly review
configuration information on all I/O cards previously configured by this
computer under PCM Plus, as well as a list of client program
information.
2.3.3.3 Configure
The Configure menu lets you add a card and edit configuration
information for an inserted card. The following tables give instructions
on both of these processes.
Table 2-3
Adding a Card to the List
1. At the main menu, press the ALT key and type C or use your
mouse to select the Configure option.
2. Select "Add Card to List" (after you have inserted the card).
3. Each installed card can have several card configurations
defining specific memory, I/O, or IRQ settings. Press the
up/down arrow keys or select the Previous/Next buttons to
display configuration settings already defined for this card.
Select the configuration you want by pressing ENTER.
4. You are prompted on whether or not to validate this
configuration.
Select "Yes" to test the configuration values you've just
entered. If the PCM configuration utility finds any conflicts, it
reports them and provides you with an opportunity to change
the conflicting value. If there are no conflicting values, the
program reports a successful configuration.
Select "No" to bypass the validation and testing process.
5. You are prompted on whether or not to save this configuration.
Select "Yes" to save the new values. These parameters take
effect immediately. The configuration information you added
is automatically written to the PCM Plus initialization file,
PCM.INI.
Select "No" to return to the main configuration menu without
saving the new values.
Table 2-4
Editing a Card's Configuration
1. At the main menu, press the ALT key and type C or use your
mouse to select the Configure option.
2. Select "Edit Config Parameters". You can only edit some of
the lines which appear in this window; the rest are provided for
your information. The values that you can edit appear below
the Compliance field, including Configuration Loaded,
Memory Window, I/O Window, IRQ, and Configuration
Registers.
Press the up/down arrow keys or select the Previous/Next
buttons to display configuration settings already defined for
this card.
Press the TAB key to move from field to field, and press the
Shift + TAB keys to move backward through the fields. Or use
your mouse to highlight a field to edit.
3. Change a field by typing in new values. When you have
changed all the values required for this card, confirm this
configuration and exit to the main menu by hitting ENTER or
selecting the OK button.
4. You are prompted on whether or not to validate this
configuration.
Select "Yes" to test the configuration values you've just
entered. If the PCM configuration utility finds any conflicts, it
reports them and provides you with an opportunity to change
the conflicting value. If there are no conflicting values, the
program reports the configuration was successful.
Select "No" to bypass the validation and testing process.
5. You are prompted on whether or not to save this configuration.
Select "Yes" to save the new values. These parameters take
effect immediately.
Select "No" to return to the main configuration menu without
saving the new values.
2.3.3.4 Option
The Option menu lets you select whether or not to enable a message
whenever a PCMCIA card is inserted or removed from the computer.
Note: PCMWin includes two additional Option menu selections: Run
Minimized (allowing PCMWin to come up as a symbol whenever it is
selected) and Associations (which lets you automatically launch a
particular application when a specific PCMCIA card is inserted, such a
MultiExpress data communication software).
3.1 Introduction
This chapter tells you how to install, connect, and remove your
MultiModemLT.
Note: It is easier to tell if you have properly connected your
MultiModemLT to your computer and the telephone line if you first
install the device drivers (and enable beeps) according to Chapter 2.
Note: Do not insert or remove the MultiModemLT PCMCIA card
with data communications software in operation (refer to Section 3.4,
Removal). Also refer to Section 3.4 for specific PC operating
instructions.
3.2 Modem Installation
Your MultiModemLT's "hot insertion" feature lets you install the
modem without rebooting or cycling power to the computer.
Note: Some older laptop PCs do not support hot insertion. Contact
your PC's manufacturer if you are having problems with the
MultiModemLT's hot insertion feature.
Note: Carefully follow the instructions in your PC and modem
manuals while installing and using your MultiModemLT to ensure that
you safely install and use it in applications for which it was intended.
Follow these steps to install your MultiModemLT (see Figure 3-1).
Table 3-1
Installing the MultiModemLT
1. Gather this manual, your PC's manual (for reference), your
modem, and go to your PC which has at least one 3.5" floppy
disk drive and a PCMCIA Type II slot.
2. Follow the instructions in your PC's manual to
prepare your PC for MultiModemLT insertion.
3. Unpack the MultiModemLT, saving the packaging and
antistatic bag.
4. Align the MultiModemLT with the Multi-Tech logo facing up,
and the arrow pointing toward the PCMCIA card modem slot.
5. Slide the MultiModemLT into the PCMCIA card modem slot
until the 68-pin connector is seated firmly. Do not force the
MultiModemLT.
6. If your PC is turned on, you will hear a multi-toned beep. If
you have loaded the PCM Plus software, and you have
selected the beeps option in the Super Client Driver (default),
you will hear two beeps and, shortly afterward, a multi-toned
beep. (Refer to Table 4-3, Beep Result Codes for more beep
information.)
7. If you are reinstalling the MultiModemLT after removing it
during data communications software operation, check your
com port configuration to ensure that the MultiModemLT is
set for the correct COM port setting.
8. Connect the modem to the phone line as described in
Table 3-2, Connecting Your Modem to the Phone Line.
3.3 Phone Line Connection
The MultiModemLT is designed to communicate over public switched
telephone network lines.
3.3.1 MT2834LT Connection
Connect your MT2834LT to the telephone system with the supplied 9-
pin to dual RJ11 CoolJax connector and a 7-foot phone cord (RJ11 plug
to RJ11 plug). See Appendix C for more information about cables and
connectors.
Note: Any cables connected to the computer should be shielded to
reduce interference.
3.3.2 MT2834LTI Connection
Connect your MT2834LTI to the telephone system with the supplied 8"
Line Adapter Module (LAM) and a phone cord. See Appendix C for
more information about cables and connectors.
Note: Any cables connected to the computer should be shielded to
reduce interference.
Note: Make sure you are using the appropriate country-specific LAM
for your MT2834LTI.
3.3.3 Connecting Your Modem to the Phone Line
To connect your MultiModemLT to the phone line, perform the
following steps. The MultiModemLT should be installed in the
computer (see section 3.2, Modem Installation). If you are installing an
MT2834LTI, follow the instructions for the MultiModemLT except
where indicated.
Table 3-2
Connecting Your Modem to the Phone Line
1. Gather this manual, your PC's manual (for reference), your
cables, and go the PC into which you installed your modem.
2.a. For the MT2834LT, align and connect the CoolJax's 9-pin
connector to the MT2834LT's 9-pin receptacle.
2.b. For the MT2834LTI, align and connect the LAM's 15-pin
connector to the MT2834LTI's 15-pin receptacle.
Note: The 15-pin connector from the LAM interface should only be
connected to Secondary Extra Low Voltage (SELV) according
to EN60950.
3.a. If you are using an MT2834LT, plug one end of the phone
cord into either RJ11 jack of the CoolJax connector. You may
also choose to plug a telephone into the CoolJax's other RJ11
jack. This allows you to use your telephone any time you are
not using your MT2834LT modem without the inconvenience
of swapping plugs.
3.b. If you are using an MT2834LTI, plug one end of the phone
cord into the LAM's modular jack.
4. Connect the other end of the phone cord to a working wall
jack.
5. Turn on the PC's power.
6. Install data communications software (such as the supplied
MultiExpress for Windows software), and fax software (such
as the supplied MultiExpressFax for Windows software).
Refer to the MultiModemLT Quick Reference Guide for
installation instructions.
7. To learn about "hot removal" of your MultiModemLT, go to
the next section. Otherwise, once all MultiModemLT software
is installed and running, proceed to Chapter 4, Manual Dial
and Automatic Answer.
3.4 Removal
The MultiModemLT provides a "hot removal" feature that lets you
remove the modem from the computer without first having to power
down the computer.
Follow these steps to remove your MultiModemLT from the computer.
1. Exit from your MultiExpress for Windows (or other) data
communications software application.
2. Slide the MultiModemLT out of the card modem slot.
If you remove and then reinsert the MultiModemLT from the computer
with MultiExpress for Windows (or other) data communications
software running, the software program needs to reconfigure the COM
port setting for your modem to work since it sees the MultiModemLT
as a 16550 UART device. If you are using MultiExpress for Windows,
enter ALT-G; with other data communications software, exit and
reenter the software package to reset the UART.
4.1 Introduction
A common application of the MultiModemLT is to dial a remote
computer. The MultiModemLT is factory preset to originate a call to
another 28,800 bps modem set for V.34 operation, hardware flow
control, V.42 error correction, V.42bis data compression, and
CTS/RTS operation. If the answering modem is not set up similarly, the
MultiModemLT automatically adjusts to the appropriate protocol.
4.2 Keyboard Dialing/On-line/Answering
After loading data communications software, such as the supplied
MultiExpress for Windows software, perform the following basic steps
to originate and answer in data communication mode.
1. Dial.
2. Establish an on-line connection.
3. Terminate the call.
Use the keyboard of your computer to easily enter a command, telling
the MultiModemLT to dial.
If you use one of the more sophisticated communication software
packages (e.g., MultiExpress for Windows), the software lets you enter
phone numbers and other information. If this is the case, the software
gives the dialing commands to the modem. Refer to the MultiModemLT
Quick Reference Guide to install MultiExpress for Windows data
communications software.
If you are giving commands directly to your modem (and not through
your communication software), each command must begin with the
letters AT (ATtention) characters. AT characters may be entered in
upper or lower case.
Typing AT automatically sets the modem's speed to match the speed of
the computer and also sets the modem's parity. The AT characters alert
the modem that a command follows. The AT command can also clear
the command buffer, simply by typing AT and hitting ENTER.
The MultiModemLT commands and S-Register operations are handled
by the data communication software.
The letter D in a command causes the modem to dial the numbers
immediately following it (e.g., ATD6127853500). You have a choice of
either pulse (ATDP) or tone (ATDT) dialing methods.
The MultiModemLT responds with CONNECT on your monitor after
the number is dialed and a connection signal is detected (since the
MultiModemLT defaults to V.34/V.42/V.42bis, the actual response is
CONNECT 28800 LAPM COMPRESSED) if the MultiModemLT
"connects" with a similar modem (see Section 4.2.3, Result Codes). The
modem is now in On-line mode and is ready to communicate with a
host site.
If no connection signal is detected within the specified time period
(adjusted with S-Register S7), the MultiModemLT goes on hook (hangs
up) and returns to Command mode. At this point, your monitor displays
NO CARRIER.
Type ATH to hang up and terminate the modem's On-line mode. At this
point your monitor displays OK.
In addition to its call originating capabilities, the MultiModemLT can
also automatically answer incoming calls. Since you need not be
present, you control the situation by configuring the modem to either
answer or not, or to answer after a specified number of rings (set with
S-Register S0). Refer to Chapter 5 for modem commands, and Chapter
6 for S-Register specifics.
4.2.1 Handshaking
This section briefly explains what happens between two modems before
transferring data. We are assuming that MultiModemLTs are at both the
originating and the answering ends of the telephone line. (If other
brands of modems are used with our modems, you may need to
accommodate slightly different delay timings and sequences.)
When a phone call is made from the originating modem, the called
modem responds to the ringing by switching to answer mode and by
turning on the Ring Indicator (RI) bit of the modem status register as
each ring is detected. (Refer to Appendix E, Programming Reference,
for more Modem Status Register information.)
Note that for the called modem to answer the incoming call, it must
have a high DTR (Data Terminal Ready) signal. This signal comes from
the computer to which the modem is inserted, on the DTR bit of the
modem control register. (Refer to Appendix E, Programming
Reference, for more Modem Control Register information.)
When the called modem answers the call, it goes off hook and the
ringing stops. About two seconds after the call is answered, the called
modem begins transmitting its answerback tone, which includes
information about what speeds and other capabilities it has.
The originating modem, which has been off hook and waiting for the
answerback tone, turns on its transmitter when it hears the tone. Then
each modem probes the communication line to find the fastest speed
that both modems and the communication line will allow. Once this is
established, the CD (Carrier Detect) bit of the Modem Status Register
signal turns on.
The called modem then responds to the originating modem and
handshaking is complete. Both modems turn on their CD signals.
Note: If you are using Reliable or Auto-Reliable mode, some
additional handshaking takes place.
4.2.2 Call Termination
The following are methods by which you terminate a call (hang up):
1. Command Mode Control. To terminate a call by Command
mode, type +++ATH then hit ENTER; or send a break signal
followed by ATH and hit ENTER.
2. DTR Control. If DTR (Data Terminal Ready) is turned off for
50 milliseconds or more, a disconnect occurs. (For information
about DTR dialing, see the $D command in Chapter 5.) This is
probably the most common method used by computer systems
at the automatic-answer end of the line to cause the answering
modem to disconnect after log-off procedures.
3. Loss of Carrier. After a data connection is established, the
modem disconnects if a loss of carrier occurs for a specified
time period adjusted by S-Register S10 (see Chapter 6). S10
can only be set at speeds of 2400 bps or less. Note that one
cause of carrier loss is if one of the modems disconnects
normally.
4. Abort Timer. Answer mode: When the modem goes off hook,
the called modem starts a timer and waits for a carrier signal
from the originating modem. If a carrier is not detected within
this period, the modem disconnects (hangs up) and is ready for
another call.
Originate mode: The abort timer functions the same as in
answer mode, except that the timer begins after the modem has
completed dialing instead of when it first goes off hook (see S-
Register S7 in Chapter 6).
5. Inactivity Timer. Causes the modem to disconnect if no data is
transmitted or received for a specified time. The timer is
restored any time a character is passed through the serial port
in either a send or receive state. This timer runs in both normal
and reliable connections and is controlled by S-Register S30
(refer to Chapter 6). The Inactivity Timer is disabled by setting
S30 to 0, which is the factory default setting.
4.2.3 Result Codes
The MultiModemLT Command mode provides you with several
responses, or "Result Codes", that keep you informed about the results
of the commands you issue to your modem. These Result Codes are
displayed on your monitor.
You can choose to have these Result Codes displayed in either a
"verbose" (full word) or "terse" (digit) format by typing the ATV0
(terse) or ATV1 (verbose) command. The terse Result Code for
CONNECT 28800 is 28. The MultiModemLT defaults to the verbose
format.
You can also choose Result Codes that closely match those of the
standard AT command set, or choose our enhanced-function Result
Codes (Multi-Tech responses). Use the &Q command to select the type
of Result Codes you prefer.
&Q0 selects Multi-Tech responses with Reliable/Compression
modifiers, giving you more information. With error correction and data
compression enabled, an example of the verbose Multi-Tech Result
Code at 28,800 bps is CONNECT 28800 LAPM COMPRESSED. With
&Q1 (selecting the standard AT command set responses), the verbose
Result Code for 28,800 bps is CONNECT 28800.
The following two tables define which Result Codes are generated by
the &Q command:
Table 4-1
&Q0 Multi-Tech Result Codes
TERSE VERBOSE
0 OK
1 CONNECT
2 RING
3 NO CARRIER
4 ERROR
5 * CONNECT 1200
6 NO DIAL TONE
7 BUSY
8 NO ANSWER
9 * CONNECT 2400
11 * CONNECT 4800
12 * CONNECT 9600
13 * CONNECT 14400
19 * CONNECT 19200
21 * CONNECT 21600
24 * CONNECT 24000
26 * CONNECT 26400
28 * CONNECT 28800
* When error correction is enabled, the word RELIABLE
(verbose) or the letter R (terse) is added to these responses. When data
compression is enabled, the word COMPRESSED (verbose) or the
letter C (terse) is added to these responses, along with Reliable
modifiers (e.g., CONNECT 28800 LAPM COMPRESSED).
Table 4-2
&Q1 Standard AT Result Codes
TERSE VERBOSE
0 OK
1 CONNECT
2 RING
3 NO CARRIER
4 ERROR
5 CONNECT 1200
6 NO DIAL TONE
7 BUSY
8 NO ANSWER
10 CONNECT 2400
11 CONNECT 4800
12 CONNECT 9600
13 CONNECT 14400
19 CONNECT 19200
21 CONNECT 21600
24 CONNECT 24000
26 CONNECT 26400
28 CONNECT 28800
No Reliable/Compression modifiers are displayed with these standard
AT Result Codes.
Table 4-3 documents the MultiModemLT Beep Result Codes.
Table 4-3
Beep Result Codes
# OF BEEPS DESCRIPTION
1 MultiModemLT removed
2 MultiModemLT inserted, recognized, and
configured
Multi-toned Automatic Self Test successful
Windows note: Hot insertion/removal within
Windows may cause
intermittent beeping or discontinued beeping. If this is the case, exit and
reenter Windows.
5.1 Introduction
The MultiModemLT has a microprocessor-based Command mode
which recognizes instructions you enter either with your data
communications software or from your keyboard. This chapter
describes commands you type to access the full set of AT commands
for entering phone numbers for automatic dialing without a telephone
set, configuring various modem options, and monitoring phone activity.
You can also access advanced features such as error correction, data
compression, speed conversion, and more.
The MultiModemLT AT commands and responses are compatible with
all systems and software programmed for automatic, software-
controlled auto-dialing using the AT command set.
The MultiModemLT has a Help command which provides short, on-
screen explanations on the use of the AT commands. The Help
command (AT$H) is explained in detail in Section 5.4.12, Immediate
Action Commands.
5.2 AT Command Editing
The BACKSPACE key on your keyboard edits characters in the AT
command line. An AT command is not executed until the ENTER key
is pressed. The BACKSPACE key erases the previous character for
reentering. (It does not erase the AT characters once they are entered.)
If your keyboard has no BACKSPACE key, CTRL-H does the same
thing. The character recognized by the modem as BACKSPACE may
be changed to any other ASCII character with S-Register S5.
To cancel an entire command that is entered but not yet executed, enter
CTRL-X. This also clears the command buffer. The effect is the same
as backspacing to cancel the entire command, only quicker.
Characters entered in a command are stored in the MultiModemLT's
command buffer (memory) until executed by hitting ENTER. The
command buffer's capacity is sixty characters. The Attention (AT)
characters do not count in the sixty allowed command characters.
Spaces, used for increased display readability, may be used when
entering a command but are not stored in the command buffer and are
not counted in the sixty allowed characters. Hyphens, parentheses, etc.
are not allowed.
If the sixty character limit is exceeded or if invalid characters are
entered, the command buffer automatically erases and an ERROR
message appears. You then reenter the command within the sixty-
character limit, using only the allowed characters.
5.3 Functional Modes
The MultiModemLT operates in one of two functional modes (see
figure 5-1), Command mode and On-line mode (the exception is an in-
between state, "Wait-for-Carrier", where the modem is out of Command
mode but not yet on-line.) When the modem is initially powered up, it is
in Command mode and accepts and responds to commands from your
keyboard or software.
The MultiModemLT enters On-line mode after dialing and making a
connection with another modem, and then detecting a valid carrier
signal. If no carrier signal is detected within a certain timeframe
(controlled by S-Register S7), the modem abandons the call and
reenters Command mode.
Once on-line, the modem exits On-line mode if the carrier signal is lost
or intentionally dropped. When this happens, the modem hangs up and
reenters Command mode. The MultiModemLT can enter Command
mode from On-line mode without losing the carrier signal. Entering
certain "escape" characters while on-line brings the modem back to
Command mode without terminating the connection.
The MultiModemLT can also enter On-line mode without the dialing
process by typing the ATD or ATA (the D or A command).
5.4 AT Commands
A wide variety of auto-dial operations and modem options are
controlled when the MultiModemLT is in Command mode. The more
common commands are toggle commands in which a "0" after the
command disables the feature and a "1" after the command enables it.
Type AT before the command for all commands except A/, A:, and the
two escape sequences. These commands are organized into several
functional groups. A brief summary of the AT commands follows
below.
Table 5-1
AT Commands by Function (with reference to section)
Dialing (Section 5.4.1)
D Dial
A: Continuous Redial
$D DTR Dialing
H Off Hook
Dial Modifer (Section 5.4.2)
P Pulse Dialing
T Tone Dialing
&P Set Pulse Dial Ratios
R Reverse the Mode of Operation
W Wait for New Dial Tone
Y Long Space Disconnect
, Automatic Pause in Dialing
; Return to Command Mode after Dialing
! Flash On Hook
$ "Calling Card" Detect Tones
@ Quiet Answer
Memorize Phone Number (Section 5.4.3)
D...N Store a Phone Number
L List Numbers Stored in Memory
N Dial a Stored Number
NN Number Linking
Store Modem Configurations and Defaults (Section 5.4.4)
&F Load Factory Defaults
&W Store AT Command Settings and S-Register Values
Z Reset Modem
Configure Command Responses (Section 5.4.5)
E Echo Command Mode Characters
Q Result Codes and No Response Answer Mode Select
&Q Result Codes (Multi-Tech/Standard AT)
V Result Codes (Terse/Verbose)
X Result Codes (Basic/Extended) and Call Progress
Select
Condition Phone Lines (Section 5.4.6)
#A Automatic Speed Detect
B Bell or CCITT Tone
#F Fallback when On-line
&G Guard Tones
M Monitor Phone Line
&T Remote Digital Loopback Signal
#T Trellis Coded Modulation
$T Calling Tones
Control RS232C/V.24 Interface (Section 5.4.7)
&C Carrier Detect (CD) Control
&D Data Terminal Ready (DTR) Control
&R Clear to Send (CTS) Control
&S Data Set Ready (DSR) Control
&RF CTS/RTS Control
&SF DSR/CD Control
Error Correction (Section 5.4.8)
&E0 Normal Mode
&E1 Auto-Reliable Mode
&E2 Reliable Mode
#L0 Negotiate V.42 Mode During Handshake
#L1 MNP On/LAPM Off
#L2 LAPM On/MNP Off
#L3 Direct LAPM/Phase Out Handshake
$A Auto-Reliable Buffering
$E V.42 Error Correction at 300 bps
$F Auto-Reliable Fallback Character
$R Retransmit Count
Data Flow Regulation (Section 5.4.9)
&E3 Flow Control Disabled
&E4 Hardware Flow Control
&E5 Xon/Xoff Flow Control
&E6 Xon/Xoff Flow Control No Pass-Through
&E7 Xon/Xoff Flow Control Pass-Through
&E8 Enq/Ack Off
&E9 Enq/Ack On
&E10 Normal Mode Flow Control Off
&E11 Normal Mode Flow Control On
&E12 Computer-Initiated Pacing Off
&E13 Computer-Initiated Pacing On
&BS Maximum Block Size
#P Parity Select
#X Send Single/Multiple Xoff Characters
Data Compression (Section 5.4.10)
&E14 Data Compression Disabled
&E15 Data Compression Enabled
Speed Conversion (Section 5.4.11)
$BA Baud Adjust
$MB Modem Baud Rate Select
$SB Serial Port Baud Rate Select
Immediate Action (Section 5.4.12)
+++AT<CR> In-Band Escape Sequence
BREAK AT<CR> Out-of-Band Escape Sequence
A Force Answer Mode
%E Select Recognized Escape Sequence
$H Help
I Inquiry for Product Code
L5, L7 List Current Operating Parameters
L6 List S-Register Values
L8 List On-line Diagnostics
O Exit Command Mode and Go Back On-line
Read/Assign S-Register Values (Chapter 6)
Sr? Read Current S-Register Value
Sr= Assign S-Register Value
Perform Diagnostic Tests (Chapter 7)
U Self-Test Modem
&T Remote Digital Loopback Signal
Perform Remote Configurations (Chapter 8)
#I Set LOGIN Password
#S Set SETUP Password
5.4.1 Dialing Commands
D Dial
The letter D in a command causes the modem to dial the telephone
number immediately following it. For example, if you type
ATD5551212 and hit ENTER, the MultiModemLT dials the phone
number 555-1212.
The D command is also used with a telephone set for manual dialing.
Dial the desired number on your telephone set; after hearing the answer
tone on your handset, type ATD and hit ENTER, then hang up the
handset. The number is dialed. We recommend using your keyboard to
enter the telephone number in the command string after the D
command, unless you have a specific need to use manual dialing.
The MultiModemLT supports several dialing methods. With the ATD
command, you can specify either pulse (ATDP) or tone (ATDT)
dialing. (Refer to the P and T Dial Modifier commands.)
You can also modify the dialing command with several characters
which are explained in Section 5.4.2.
The MultiModemLT lets you select either smart (wait-for-dial-tone)
dialing or blind dialing. With smart dialing, the modem waits for and
detects dial tones and busy signals. With blind dialing, the modem
works with timed pauses (determined by the value of S-Register S6),
not dial tone and busy signal detection. Refer to the X command for
smart/blind dialing information.
Another method of dialing, called DTR dialing, causes the modem to
automatically dial a number stored in modem memory. Refer to the $D
command for DTR dialing information.
A: Continuous Redial (not used with the MT2834LTI)
If you select the wait-for-dial-tone method of dialing (see X3 or X4
command), the A: command lets you continuously redial a busy number
until your call is answered (a maximum of 10 redials for DOC units).
This command is used only after reaching a busy number when
executing a normal dial command; type A: (you need not enter AT, nor
do you need to hit ENTER), and the modem redials the number. If you
again reach a busy signal, the modem continues to redial until it gets
through. You can stop the MultiModemLT from redialing by pressing
any key.
To save a step when redialing a phone number, enter a colon (:) at the
end of the phone number. The result is the same as if you entered A:.
$D DTR Dialing
$D is an alternate way to cause the modem to automatically dial a
telephone number. Data Terminal Ready (DTR) is a signal that comes
into the modem from the computer to which it is connected via the DTR
bit in the Modem Control Register (see Appendix E, Programming
Reference). With DTR dialing, the modem automatically dials a stored
phone number when it receives a high DTR signal.
$D0 disables DTR dialing, and is the factory default.
$D1 enables DTR dialing. The modem dials the phone number
stored in RAM memory location N0 when it receives a high DTR signal
(see the D...N command for information about storing phone numbers).
The DTR signal must remain high for the duration of the call, or the
connection is dropped.
Note: When the &D command is set to zero, the modem cannot DTR
dial.
H Off Hook
You can make the MultiModemLT hang up (go on hook) or go off hook
using the H command.
H0 (or ATH) hangs up the modem.
H1 brings the line off hook, just as if you picked up the telephone
headset.
It is not necessary to use the H1 command to bring the line off hook
when using the D command. The modem automatically goes off hook
when you hit ENTER at the end of the dial command.
5.4.2 Dial Modifier Commands
You can include Dial Modifier command characters within a dialing
command (following the letter D) to select pulse or tone dialing, pauses
in the dial sequence, automatic redials if a number is busy, and to revert
to Command mode and switch to answer mode after dialing.
P or T Pulse or Tone Dial
The MultiModemLT dials numbers using either pulse or tone dialing,
or a combination of both methods. Pulse dialing, used by rotary-dial
telephones, involves the timed opening and closing of line relay.
Tone dialing, used by push-button (touch tone) telephones, uses Dual-
Tone Multi-Frequency (DTMF) dialing.
P selects pulse dialing.
T selects tone dialing.
Insert the P or D in the dialing command, right before the digits you
wish to have dialed in that manner.
For example, you can pulse-dial the number 555-1212 by typing
ATDP5551212 and hitting ENTER. You can tone-dial the same
number by typing ATDT5551212 and hitting ENTER. If neither pulse
nor tone dialing is specified in the dial command, the MultiModemLT
uses whatever method was used last. If the modem has been reset or has
just powered up, it uses pulse dialing, even if the letter P is not included
in your dial command.
An example of combining pulse and tone dialing can involve a PBX
system that requires a pulse-dialed 9 to reach an outside line. After
pausing for a second dial tone, the rest of the number is tone-dialed.
This example is dialed by typing ATDP9, T5551212 and hitting
ENTER. (The comma causes a pause, which is explained later.)
&P Set Pulse Dial Ratios (not used with the MT2834LTI UK
version)
&P sets the time ratios between the open and closed positions of the
pulse-dialing frequencies.
&P0 (the factory default) to set a pulse dial of 40 to 60 mSec.
&P1 to set a pulse dial of 67 to 33 mSec.
R Reverse the Mode of Operation
The R command lets you reverse the modem's mode of operation from
originate to answer, or from answer to originate.
R0 disables mode reversing, and is the factory default setting.
R1 enables mode reversing.
If you want to reverse from originate mode, use R (with no number) in
the dialing string.
W Wait for New Dial Tone
A W inserted in the dialing command causes the MultiModemLT to
wait for another dial tone before resuming dialing.
It is not necessary to enter a W at the beginning of the dialing command
to wait for a modem dial tone because the modem pauses automatically.
For this command to work, select smart dialing (the X2 or X4
command) so your modem detects the dial tone.
Y Long Space Disconnect
When two modems are connected in Normal mode (i.e. without error
correction), there is no "polite" way to request a disconnect. A link
disconnect request packet is sent under reliable connections. As a result,
some "garbage" may be received when a hang-up command is issued.
Y0 disables the modem's use of the break signal, and is the factory
default setting.
Y1 enables the modem's use of the break signal, which shuts off
the modem's receiver and disconnects (both modems must have Y1
enabled).
, Automatic Pause in Dialing
You can make the MultiModemLT pause while dialing by entering a
comma character where the pause is desired. This pause lasts two
seconds by default. Longer pauses can be forced by entering multiple
commas, or you can change the length of the pause by setting S-
Register S8 (refer to Chapter 6). Each comma in a dialing command
counts as one of the sixty allowed characters in the command buffer.
For the MT2834LTI UK version, the pause caused by a comma lasts
four seconds by default.
; Return to Command Mode after Dialing
A semicolon, entered as the last character of a dialing command, causes
the MultiModemLT to return to Command mode immediately after
executing the command instead of waiting for a carrier signal and going
on-line.
For example, typing ATDT5551212; and hitting ENTER tone-dials the
number and immediately goes back into Command mode. This is useful
in dialing applications where modem data transfer is not desired, such
as voice communications, or in applications using touch tones as a data
entry method, such as bank-by-phone.
! Flash On Hook
Some switchboard systems react to a momentary on hook. An
exclamation mark inserted in the dialing command causes the modem to
"flash" on hook for half a second, just as if you held the telephone
headset down for half a second. (For the MT2834LTI UK version, an
exclamation mark causes the modem to flash on hook for 90 mSec.)
For example, to flash on hook after dialing the phone number 555-1234
to transfer to extension #5678, you might type ATDT5551234,!5678.
(The comma causes a pause; see Automatic Pause in Dialing, above.)
$ "Calling Card" Detect Tones
The MultiModemLT can detect AT&T calling card tones to access the
user's calling card number for originating an on-line connection. A $
symbol placed in the dialing string causes the modem to pause and wait
for an AT&T "calling card" or a 1600 Hz tone (prevalent in the United
Kingdom). You would first type the access codes and telephone
number, followed by a $ and your calling card number. For example,
you might type ATDT1028806127853500$123456789.
Once the tone is detected, the rest of the dialing string is processed. If
no tones are detected within the time period set by S-Register S7, the
modem aborts and indicates a NO CARRIER message. Hitting any key
also aborts the $ command.
@ Quiet Answer
The @ command is used for accessing a system that does not provide a
dial tone. The @ command causes the MultiModemLT to wait before
processing the next symbol in the dialing string. The wait is one or
more rings back followed by five seconds of silence.
For example, ATDT5551212@6313550 causes the MultiModemLT to
dial the first number (555-1212) and wait for the time specified in S-
Register S7 for at least one ring back and five seconds of silence. If a
busy signal is detected, the MultiModemLT hangs up and generates a
BUSY Result Code. If it does not detect five seconds of silence, a NO
ANSWER Result Code is generated after hanging up. If five seconds of
silence are detected, the second number (631-3550) is then dialed.
5.4.3 Phone Number Memory Commands
D...N Storing a Phone Number
The MultiModemLT stores up to ten telephone numbers in memory,
each containing up to sixty characters. As many as ten of these numbers
may be stored. The memory locations are labeled N0 through N9.
You store a command line by typing it as you would any other
command, appending the appropriate Nx memory location.
For example, the tone-dialed phone number 1-612-631-3550 is stored at
memory location N3 by typing ATDT16126313550N3 and hitting
ENTER. The number is not dialed with this command.
After storing a number, check to see that it has been stored correctly by
typing ATL and hitting ENTER.
When phone numbers are stored, the entire command line is also stored
so that you can effectively create a macro for each number. For
example, if you know a particular number needs extended Result
Codes, detect busy or dial tone, error correction, Xon/Xoff flow
control, pacing, and data compression enabled, the command line is
ATX4&E1&E5&E13&E15DT16126313550N3. This stores the entire
command at memory location N3.
L Listing Phone Numbers Stored in Memory
Use the L command to display telephone numbers (or full dialing
commands) stored in the MultiModemLT's nonvolatile memory. The
number's memory location (N0 through N9, see the D...N command) is
shown first, followed by the complete dialing command and telephone
number as originally entered.
Type ATL and hit ENTER to display the settings for all ten memory
locations, as shown below.
0 T14082345678
1 T16125551212;
2 P9,T14089876543
3 T3738315,12101,16126313550
4 T6313551R
5
6 P9,4258513
7
8
X4&E1&E5&E13&E15DT16126313550
9 T12138880123
N Dialing a Stored Number
A dialing command including a telephone number that is stored in the
MultiModemLT's phone number memory is automatically dialed by
typing ATNn, where n=0-9. For example, a dialing command stored at
memory location N3 is dialed by typing ATN3 and hitting ENTER.
Note: Do not include the letter D in this command or the stored
command is erased.
NN Number Linking
Number Linking establishes an alternate phone number for the
MultiModemLT to dial if the first number is busy using the stored
phone number memory locations; see the D...N command. This is
useful when a computer can be accessed through more than one phone
number.
To link the number in memory location N1 to the number in N2, type
ATN1N2 and hit ENTER. Several numbers can be linked in the same
command. For example, to link N1 to N2 to N3 to N4, type
ATN1N2N3N4 and hit ENTER. To link N1 to N2, back to N1 and then
back to N2, type ATN1N2N1N2 and hit ENTER.
The only limitation on the number of strings you can link is the 60
character maximum allowed in a command line. Number linking cannot
be used with blind dialing, since busy signals are not detected.
5.4.4 Store Modem Configuration and Default Commands
&W Store AT Command Settings and S-Register Values
The &W command stores AT command settings and S-Register values
in memory, so your settings aren't lost if the MultiModemLT is
powered down or is reset with the Z command.
&W0 (or AT&W) causes the MultiModemLT to store your
customized AT command settings and S-Register values in its
nonvolatile Random Access Memory (RAM). &W0 also sets the
modem so that it reads your customized settings stored in nonvolatile
RAM when powered down or reset. (The &W0 command only changes
the settings stored in nonvolatile RAM that you specifically intend to
alter. All other default parameters are applicable.)
&W1 causes the MultiModemLT not to store your customized
settings to nonvolatile RAM so that, after powering down or resetting
the modem, it reads the factory default settings stored in ROM.
&F Recalling Factory or &W0 Default Parameters
The MultiModemLT is shipped from the factory with a pre-configured
set of AT command and S-Register default settings. This set of "factory
defaults" is recalled by issuing the &F command.
In addition to recalling the factory defaults, the &F command can also
recall defaults stored under &W0 using the &F9 command. To set your
&W0 stored parameters as your defaults, type &F9&W0.
To return the &F command to reading the factory defaults, type
&F8&W0.
Many datacomm programs (including MultiExpress and MultiExpress
for Windows) issue the &F command automatically. Note that both
&F8 and &F9 commands are used with &W0.
Z Reset Modem
The Z command resets all configurations to their default values and
clears the entire Command mode buffer. The result is the same as if you
disconnect and then reconnect power to the modem. When ATZ is
typed, the state of the &W command defines the source of the default
values: &W0 defaults come from RAM and &W1 defaults come from
ROM.
Note that the Z command cannot be used in a dialing string; use the
&F8 and &F9 commands previously discussed.
5.4.5 Configure Command Response Commands
E Echo Command Mode Characters
The MultiModemLT may need to echo back characters entered while in
Command mode for them to be displayed. The E command is used to
configure Command mode echo.
E0 disables the echo.
E1 enables the echo, and is the factory default setting.
Q Result Codes and No Response Answer Mode Select
The Q command enables or disables Result Codes and the No Response
answer mode of operation.
Q0 (or ATQ) enables Result Codes, and is the default setting.
Q1 disables Result Codes, for applications such as computer-
controlled auto-dialing.
Q2 enables No Response answer mode, which leaves originate
mode intelligent while turning off answer mode responses and echo.
&Q Result Codes (Multi-Tech/Standard AT)
The MultiModemLT gives you a choice between the Multi-Tech Result
Codes and Result Codes that more closely match the standard AT
command set responses.
&Q0 selects Multi-Tech responses with Reliable/Compression
modifiers. With this command, the verbose Result Code for 28,800 bps
is CONNECT 28800 LAPM COMPRESSED.
&Q1 selects AT responses with no
Reliable/Compression modifiers. With this command, the verbose
Result Code for 28,800 bps is CONNECT 28800.
V Result Codes (Terse/Verbose)
The V command controls whether the MultiModemLT's Result Codes
display as word ("verbose") or single digit ("terse") messages. For
example, if after dialing no carrier signal is detected, the resulting
message displays as either NO CARRIER or as the digit 3.
V0 (or ATV) displays the MultiModemLT's Result Codes as
digits.
V1 displays Result Codes as words, and is the factory default
setting.
X Result Codes (Basic/Extended) and Call Progress Select
The X command selects the format in which the Result Codes are
displayed and the level of call-progress monitoring employed.
The MultiModemLT provides "basic" and "extended" Result Code sets.
The difference between the two is that the basic set provides one
response (CONNECT) to indicate a connection, while the extended set
provides a different response for different speeds (e.g., CONNECT
28800).
You can choose "blind" dialing, or to have the MultiModemLT monitor
call progress with "smart" dialing. With blind dialing, the modem waits
a fixed amount of time (determined by S-Register S6) after ENTER and
begins dialing without checking for a dial tone.
With smart dialing, the modem performs a certain level of call-progress
monitoring before and/or after dialing. Smart dialing may consist of
checking for a dial tone before dialing, or monitoring for a ring back or
a busy signal after dialing.
The MultiModemLT gives you a choice between the smart and blind
dialing. The X command selects the display of Result Codes, as shown
below.
X0 selects basic Result Codes (e.g., CONNECT) and blind dialing
(factory default).
X1 selects extended Result Codes (e.g., CONNECT 28800) and
blind dialing.
X2 selects extended Result Codes and smart dialing.
MultiModemLT checks for dial tone before dialing.
X3 selects extended Result Codes and smart dialing.
MultiModemLT checks for a ring back or a busy signal after dialing.
X4 selects extended Result Codes and smart dialing.
MultiModemLT checks for dial tone, dials, then checks for a ring back
or a busy signal after dialing.
5.4.6 Condition Phone Line Commands
#A Automatic Speed Detect
The MultiModemLT can operate at any speed between 300 and 28,800
bps. The #A command determines which speeds the MultiModemLT
uses for initial handshake and speed selection.
Remember, this command does not control the originating data rate of
the modem, that is done by the modem baud rate command $MB. This
command only determines the answer mode fallback speeds.
#A0 (or AT#A) lets the MultiModemLT use its entire range of
fallback speeds. It is also the factory default.
#A1 restricts the modem to 28,800 bps only.
#A2 causes the modem to operate at 28,800 bps, with incremental
fallback to 19,200 to 14,400 to 9600 and to 4800 bps.
#A3 lets it operate at 2400 bps, with fallback to 1200 to 300 bps.
B Bell or CCITT Tone (not used with the MT2834LTI)
The B command selects the frequency that the modem uses for its
answer tone. (The answer tone is the tone transmitted by a modem
receiving a call to the modem that called it, initiating the handshaking
between the two modems.) At higher speeds (2400 to 28.8K bps) there
is no conflict because high speed modems use ITU-T/CCITT
frequencies. At lower speeds (0-1200 bps), in the U.S., some modems
use the Bell frequency of 2225 Hz. The CCITT V.22 specification has
an answer tone frequency of 2100 Hz.
B0 enables CCITT frequencies including V.21 (300 bps) and
V.23 (1200/75 bps), and is the factory default setting.
B1 enables Bell frequencies including Bell 103 (300 bps).
#F Fallback when On-line
If line conditions deteriorate, the MultiModemLT automatically drops
its transmission speed (called "fallback"). The #F command controls the
way the MultiModemLT falls back.
#F0 (or AT#F) disables on-line fallback.
#F1 enables incremental fallback (based on the error rate or if three
retrains occur within a two-minute period) from 28.8K to 26.4K to 24K
to 21.6K to 19.2K to 16.8K to 14.4K to 12K to 9.6K to 4.8K bps.
#F2 enables incremental fallback from 28.8K to 4.8K, but also
enables fall forward in the same increments (from 4.8K to 28.8K bps) if
the phone line improves. It is the factory default setting.
&G Guard Tones (not used with the MT2834LTI UK version)
The &G command controls the presence or absence of guard tones from
the transmitter when in answer mode, at either 1200 or 2400 bps. Guard
tones are used in Europe and other areas to let the modem function in
certain telephone systems; they are not used in the United States.
&G0 disables CCITT guard tones (factory default).
&G1 enables 550 Hz guard tones.
&G2 enables 1800 Hz guard tones.
M Phone Line Monitoring via the PC's Speaker
The MultiModemLT sends a signal to the PC's speaker that functions
like the speaker in a telephone handset, enabling you to monitor modem
card and phone line activity. The M command determines when the
speaker is operational.
M0 disables the signal to the PC's speaker completely. This is the
default setting, and should be used in most applications.
M1 causes the signal to the PC's speaker to be on only until a
carrier signal is detected.
M2 causes the signal to the PC's speaker to remain on at all times.
M3 causes the signal to the PC's speaker to be on during dialing
and off during handshake.
Note: The M command also controls the self-test multi-toned beep.
M0 disables the self-test beep, while M1-3 enable the self-test beep.
(See Chapter 7, Testing Your Modem.)
&T Remote Digital Loopback Signal
The MultiModemLT has several self-test features (covered in Chapter
7). The tests are activated with different U commands, such as ATU1.
The &T command is a phone line conditioning command that enables
or disables the modem's ability to recognize the Remote Digital
Loopback (RDL) test signal.
&T4 enables the MultiModemLT's response to an RDL signal,
placing it in digital loop mode.
&T5 disables the modem's response to the RDL signal, and is the
factory default.
#T Trellis Coded Modulation
The #T command enables or disables the Trellis Coded Modulation
(TCM) for the MultiModemLT. There is usually no need to disable
(turn off) TCM except under an unusual line condition called impulse
noise.
#T0 disables TCM.
#T1 enables TCM, and is the factory default setting.
$T Calling Tones
The $T command enables or suppresses calling tones for the
MultiModemLT. If enabled, your modem emits a calling tone when
originating a call. Your modem sends out a pattern of an 1300 Hz tone
for half a second followed by 3 seconds of silence, until it detects an
answer tone. After the originating modem detects the answer tone,
calling tones emission ends and handshaking begins. For example, an
automated voice/data/fax switch hears the calling tones and switches
over to the data line; the modem is then able to answer.
$T0 enables calling tones.
$T1 disables calling tones, and is the factory default setting.
5.4.7 RS232C/V.24 Interface Control Commands
&C Carrier Detect (CD) Control
The &C command lets you control the status of the Carrier Detect
signal (CD bit of the Modem Status Register) on the RS232C/V.24 line
(refer to Appendix E, Programming Reference). You have four choices.
You can force the signal high, let it act normally, force the modem to
reset when CD drops, or set the signal to stay high until the modem
disconnects, go low momentarily, and then go high again. The last
option is useful with some CBX phone systems and mainframe front
ends which require CD to act in this manner.
&C0 forces CD on.
&C1 lets CD act normally, and is the factory default setting.
&C2 sets CD so that it drops for one second on disconnect and then
comes up again. (To change the S-Register S24 drop time, see Chapter
6, S-Registers.)
&C4 resets the modem to its current parameters when CD drops.
&D Data Terminal Ready (DTR) Control
Data Terminal Ready, the DTR signal of the RS232C/V.24 interface, is
required for the MultiModemLT to operate. A high DTR signal tells the
modem that the device to which it is connected is active, or ready to
communicate through the modem.
DTR has some other MultiModemLT functions. DTR can be used to
trigger a dialing sequence, called DTR dialing.
&D0 (or AT&D) causes the MultiModemLT to ignore DTR.
&D1 causes the modem to go on hook (hang up) with loss of DTR.
The modem enters Command mode when DTR goes high again. Auto-
answer is disabled while DTR is low.
&D2 causes the modem to go on hook with loss of DTR. The
modem enters Command mode when DTR goes high again.
&D3 causes the modem to reset to its default parameters, just as if
you had given the modem an ATZ command. The modem now resets
itself whenever DTR is dropped from on to off, and also goes on-hook
(hang up) if it is on-line.
&R Clear to Send (CTS) Control
&R lets you control the Clear to Send signal (CTS bit of the Modem
Status Register; see Appendix E, Programming Reference) on the
RS232C/V.24 interface. You have three choices. You can force the
CTS signal high, let it act normally, or set it to stay high until the
modem disconnects, go low momentarily, and then go high again. The
last option is useful with some CBX phone systems and mainframe
front ends that require CTS to act in this manner.
&R0 lets CTS act normally.
&R1 forces CTS on, and is the factory default setting. When the
modem goes on-line, CTS still provides flow control.
&R2 sets CTS so that it drops for one second on disconnect and
then comes up again. (To change the S-Register S24 drop time, refer to
Chapter 6, S-Registers.)
&RF CTS/RTS Interaction Control
In typical operation, Clear to Send (CTS) follows Request to Send
(RTS) when the modem is on-line. In other words, if RTS goes off,
CTS goes off in response.
&RF0 lets CTS follow RTS.
&RF1 lets CTS operate independently, regardless of the state of RTS.
This is the factory default setting. Refer to the &R command for control
of the Clear to Send signal.
&S Data Set Ready (DSR) Control
The &S command lets you control the status of the Data Set Ready
signal (DSR bit of the Modem Status Register; see Appendix E,
Programming Reference) on the RS232C/V.24 interface. You have
three choices. You can force the signal high, allow it to act normally, or
set it to stay high until the modem disconnects, go low momentarily,
and then go high again. The last option is useful with some CBX phone
systems and mainframe front ends, which require DSR to act in this
manner.
&S0 forces DSR on.
&S1 lets DSR act normally, and is the default setting.
&S2 sets DSR so that it drops for one second on disconnect and
then comes up again. (To change the S-Register S24 drop time, refer to
Chapter 6, S-Registers.)
&SF DSR/CD Interaction Control
In typical applications, Data Set Ready (DSR) follows Carrier Detect
(CD).
&SF0 lets DSR follow CD, and is the factory default.
&SF1 lets DSR operate independent of CD. Refer to the &S
command for control of the Data Set Ready signal.
5.4.8 Error Correction Commands
You can configure your MultiModemLT in one of three V.42 (error
correction) operating modes including Normal, Auto-Reliable, and
Reliable modes.
&E0 Normal Mode
In Normal mode, the MultiModemLT's V.42 error-correction
capabilities are disabled, and the modem functions as a normal (non-
error correcting) modem.
&E1 Auto-Reliable Mode
In Auto-Reliable mode, the MultiModemLT automatically determines
whether or not the modem with which it is communicating can use V.42
error correction (this negotiation occurs during the modems'
handshaking sequence). If V.42 is available on both modems, the
MultiModemLT switches itself into Reliable (V.42) mode and its error-
correction capability is enabled. If V.42 is not available, the
MultiModemLT remains in Normal mode without error correction. The
MultiModemLT's default setting is Auto-Reliable mode (&E1).
When operating in V.42 Reliable mode, the MultiModemLT uses its
memory, or buffer, to store data as it is received. During periods of
error-caused retransmissions or compression slowdowns, this buffer
may fill up. To prevent buffer overflow and subsequent loss of data, the
modem uses "flow control" to signal the computer attached to its
RS232C/V.24 port that the modem buffer is almost full. This causes the
computer to pause its data transmission until the modem is able to
empty its buffer sufficiently to accept more data, at which time the
modem signals the computer that it may resume transmission (see data
flow regulation, Section 5.4.9).
&E2 Reliable Mode
In Reliable mode, the MultiModemLT uses its V.42 error-correction
capabilities during all transmissions, and must be connected to another
modem with a similar protocol enabled (MNP or LAPM).
The V.42 standard implements both MNP Class 3 & 4 and LAPM error
correction methods. The V.42 Mode Select command (#L) selects the
type of error correction (MNP or LAPM) your MultiModemLT uses for
transmissions. The various #L command options are as follows.
#L0 Negotiate V.42 Mode in Handshake
The #L0 command lets a pair of modems negotiate which V.42 mode
(MNP or LAPM) to use in their transmissions.
Originate mode
a. If both modems have LAPM capability, the modems use
LAPM mode.
b. If one or both modems do not have LAPM capability and both
have MNP, the modems use the MNP mode.
Answer mode
The answering modem responds to either an MNP Link Request or
LAPM Originator Detection Pattern (ODP) signal, depending on which
the originating modem issues.
#L1 MNP On/LAPM Off
The #L1 command sets your modem to MNP error correction and
disables LAPM. This command is for originate mode only. In answer
mode, the modem still accepts MNP or LAPM.
#L2 LAPM On/Off
The #L2 command sets your modem to LAPM error correction, and
disables MNP. This command is for originate mode only. Answer mode
still accepts MNP or LAPM.
#L3 LAPM Directly/Phase Out Handshaking
In the prior commands, the modems use a two-phase process to
establish a V.42 connection (detection to establish whether the remote
modem is also error correcting, and then protocol establishment to
determine parameters and to establish the error correction connection).
If you know that the other modem is a V.42 error-correcting modem
and wish to use LAPM, the #L3 command disables the detection phase
and goes directly to protocol establishment. Both modems must have
#L3 in effect.
$A Auto-Reliable Buffering
In Auto-Reliable mode, the modem has four seconds to establish a
Reliable connection. After this four-second period, the modem drops to
Normal mode. Any data received during this period is typically
discarded. The $A command can cause the modem to buffer (save) data
that is received during this Auto-Reliable time-out period. This data is
then output by the modem after the CONNECT message.
$A0 discards data received during auto-reliable time period, and is
the factory default.
$A1 buffers data received during auto-reliable time period.
$E V.42 Error Correction at 300 bps
At 300 bps, error correction is not typically used.
$E0 disables error correction at 300 bps, and is the factory default
setting.
$E1 enables error correction at 300 bps. The modem is in either
Normal (&E0), Auto-Reliable (&E1), or Reliable (&E2) mode.
$F Auto-Reliable Fallback Character
In Auto-Reliable mode, the modem is given four seconds to establish a
Reliable connection. If a single ENTER is received from the remote
modem during this four-second period, the Auto-Reliable modem
assumes that the remote modem is not in Reliable mode and drops to
Normal mode. The ENTER is the only character that causes the modem
to drop to Normal mode. Any other character is either buffered or
discarded.
The $F command can be used to disable this fall-back-to-Normal-due-
to-ENTER feature.
The Auto-Reliable fallback character ($F) and Auto-Reliable buffering
($A) commands can be used together to cause the modem to buffer all
data received up until the ENTER and then drop to Normal mode. All
data received is then output following the CONNECT message.
$F0 restricts the modem from falling back to Normal mode if a
ENTER is received.
$F1 lets the modem fall back to Normal mode if a ENTER is
received. This is the factory default.
$R Retransmit Count
If errors are received during a Reliable connection, the modem re-sends
the block of data which contained an error. The modem counts the
number of times that a data block is resent. If the same block of data is
resent 12 times and still has not been accurately received, the modem
assumes that the line is unsuitable for transmission and aborts the
connection.
The modem keeps trying to send data and does not abort when the
retransmit counter is disabled (by the $R1 command), no matter how
many times the same block is resent.
$R0 aborts the connection if retransmit count is exceeded. This is
the factory default setting.
$R1 disables the retransmit counter.
5.4.9 Data Flow Regulation Commands
Data flow regulation is used between computer devices to stop and
restart the flow of data. It ensures that a device does not receive more
data than it can handle. The MultiModemLT regulates data flow in both
directions. As illustrated below, regulating the flow of data passing
from your computer to the modem is called modem-initiated flow
control, commonly referred to as simply "flow control"; whereas
regulating the data flow passing from the modem to your computer is
called computer- or terminal-initiated pacing, or simply "pacing".
The MultiModemLT supports both hardware and software flow
regulation, and also a special version used by Hewlett-Packard
compatible systems called ENQ/ACK pacing. The MultiModemLT also
lets hardware and software pacing pass through the modem to the other
end of the link so that your computer or terminal can control data
start/stop activity through your modem, called Xon/Xoff pass-through.
In review, the modem does flow control to the computer, while the
computer does pacing to the modem.
&E3 Flow Control Disabled
The &E3 command disables all data flow regulated by the modem. If
neither the hardware or Xon/Xoff flow control method is selected, the
modem defaults to no flow control.
&E4 Hardware Flow Control
The &E4 command enables the modem's use of the Clear to Send
(CTS) output signal of the RS232C/V.24 interface to regulate the flow
of data. The CTS signal is brought low to stop the flow of data, and is
brought high to restart it. This method of flow control works in
conjunction with pacing (i.e., computer-initiated flow regulation),
which uses the Request to Send (RTS) input signal.
You cannot enable hardware flow control unless an active error-
correction protocol is selected.
&E5 Xon/Xoff Flow Control
Xon/Xoff is the most commonly used method of flow control. Under
this method, control characters known as "Xon" and "Xoff" are inserted
by the modem into the data to start and stop the flow of data from the
computer or terminal to which the modem is attached. Xoff, which is a
Control-S, stops the flow of data. Xon, which is a Control-Q, restarts it.
Xon/Xoff flow control is not recommended for binary data because an
Xoff character could be part of the data, halting data flow.
&E6,&E7 Xon/Xoff Pass-Through
The local modem responds to the Xon/Xoff characters when Xon/Xoff
pacing is active. After responding to these characters, it can either
discard them or pass them through the data communications link.
&E6 discards the Xon/Xoff characters once the modem responds to
them (default setting).
&E7 passes the Xon/Xoff characters through the data
communications link once the modem responds to them.
&E8,&E9 Hewlett-Packard ENQ/ACK Pacing
If the MultiModemLT is used with Hewlett Packard (or similar)
equipment that employs ENQ/ACK pacing, the modem can be
configured to respond to ENQ/ACK commands. This does not affect
any other flow control or pacing method already configured in the
modem.
&E8 disables ENQ/ACK pacing, and is the default setting.
&E9 enables ENQ/ACK pacing. The modem accepts and responds
to the ENQ (Control-E) and ACK (Control-F) signals from HP
equipment according to Hewlett-Packard protocol.
&E10,&E11 Normal Mode Flow Control
When two modems are connected in Normal mode (not using error
correction), Xon/Xoff can control the flow of data between the
modems. Flow control is turned on or off with the Normal mode flow
control commands.
&E10 disables Normal mode flow control, and is the default setting.
&E11 enables Normal mode flow control.
When the modems are connected in Reliable mode, a different method
of flow control is used, and the commands for Normal mode flow
control are ignored.
To use speed conversion in Normal mode, first activate the modem's
Normal mode modem flow control. (Speed conversion is explained in
Section 5.4.11.)
&E12,&E13 Computer- or Terminal-Initiated
Pacing
As mentioned earlier, the MultiModemLT initiates flow control by
issuing Xon/Xoff commands or toggling the CTS signal on the
RS232C/V.24 interface.
The modem can also react to similar commands and signals from the
computer or terminal to which it is attached via the RS232C/V.24
interface; this is called pacing. Pacing is only enabled when you have
some other form of flow control active (i.e., hardware or Xon/Xoff).
&E12 lets the modem ignore pacing.
&E13 lets the modem respond to the terminal or computer pacing,
and is the factory default setting.
&BS Maximum Block Size
The maximum size of Reliable mode data blocks is controlled with the
&BS command. MNP Class 3 sends blocks of 1 to 64 characters. MNP
Classes 4 and 5 normally send blocks of 1 to 256 characters. For MNP
Classes 4 and 5, reducing the block size to 64 characters may give a
smoother flow of data and better throughput on noisy phone lines.
However, using smaller block sizes over good phone lines may cause a
slight loss in throughput (speed).
&BS0 transmits a maximum block size of 64 characters.
&BS1 transmits a maximum block size of 256 characters, and is the
factory default setting.
#P Parity Select
The #P command sets parity. Parity is a low-level form of error
detection used between asynchronous devices. It detects a single-bit
error in any 10-bit or 11-bit transmission. However, if two (or any even
number of) errors occur in the same character, they go unnoticed.
#P0 selects no parity, and is the factory default setting.
#P1 selects odd parity.
#P2 selects even parity.
#X Send Single/Multiple Xoffs Characters
The #X phone interface command sends either single or multiple Xoff
characters at the modem's buffer-full level. When the MultiModemLT's
buffer reaches its buffer-full level, the next character received causes an
Xoff to be sent for every character subsequently received by the
MultiModemLT.
#X0 causes one Xoff to be sent until the buffer reaches the Xon
level. This is the factory default setting.
#X1 causes one Xoff to be sent for every character received after
the modem reaches its buffer-full level.
5.4.10 Data Compression Commands
&E14, &E15 Data Compression
Data compression encodes data to take up less storage space.
Compressed files transferred over the phone line result in a higher
throughput.
&E14 disables data compression.
&E15 enables data compression.
Note: The default setting is &E15, but the modem will not compress
data unless the &E1 (Auto-Reliable mode) or &E2 (Reliable mode)
command is also issued.
The MultiModemLT has a variety of commands controlling its error
correction and data compression options, as listed below. (Remember to
precede each command with the AT characters.)
Table 5-2
Data Compression, Error Correction,
Flow Control, Pass-Through, and Pacing Commands
Normal/Auto-Reliable/Reliable Mode Commands:
&E0 = Normal mode
&E1 = Auto-Reliable mode*
&E2 = Reliable mode
Modem-Initiated Flow Control Commands:
&E3 = Disables flow control (no flow
control)
&E4 = Hardware flow control (CTS on/off
and RTS on/off)*
&E5 = Xon/Xoff flow control
Xon/Xoff Pass-Through Commands:
&E6 = Modem responds to Xon/Xoff
characters, but does
not let Xon/Xoff characters pass
through to remote
site.*
&E7 = Modem responds to Xon/Xoff
characters, and lets
them pass through to remote site
Enq/Ack Pacing Commands:
&E8 = Enq/Ack method of pacing off*
&E9 = Enq/Ack method of pacing on
Normal Mode Modem Flow Control Commands:
&E10 = Normal mode modem flow control
off*
&E11 = Normal mode modem flow control
(Xon/Xoff) on
Computer- or Terminal-Initiated Flow Control (Pacing) Commands:
&E12 = Pacing off
&E13 = Pacing on (either RTS on/off or
Xon/Xoff depending
on the setting of &E4 or &E5)*
Data Compression Commands:
&E14 = Data Compression disabled
&E15 = Data Compression enabled*
5.4.11 Speed Conversion Commands
Speed conversion is a necessary part of data compression since data
must be presented to the modem faster than it can send it over the
phone line.
Speed conversion lets the modem communicate at one speed over the
phone line and at another over its serial port (via its RS232C/V.24
interface), establishing one speed for data entering the modem and
another for the data leaving the modem.
In addition to data compression, speed conversion is important because
it lets the modem dynamically negotiate a speed with the other modem
while keeping the computer-to-modem speed constant.
$BA Baud Adjust
The $BA command lets the modem dynamically change the serial port
speed when the phone line speed changes. When using speed
conversion, set the modem so that it does not adjust its serial port speed
by disabling baud adjust.
Note: Do not be misled by the meaning of disabling baud adjust; it
conversely affects speed conversion:
Turning baud adjust off turns speed conversion on.
Turning baud adjust on turns speed conversion off.
$BA0 disables baud adjust.
$BA1 enables baud adjust (disables speed conversion). With baud
adjust enabled, the speed at which the modem communicates via phone
line is always the same as the speed at which it communicates via its
serial port (RS232C/V.24 interface).
$MB Modem Baud Rate Select
The $MB command establishes the speed at which the modem should
transmit data over the phone line when originating a call. When the
MultiModemLT receives (answers) a call from another modem, it
automatically switches its phone line transmission speed to match the
calling modem.
With baud adjust disabled, this transmission speed can differ from the
serial baud rate. To set the modem baud rate, type one of the following
commands:
AT$MB75 = CCITT V.23
AT$MB300 = 300 bps
AT$MB1200 = 1200 bps
AT$MB2400 = 2400 bps
AT$MB4800 = 4800 bps
AT$MB9600 = 9600 bps
AT$MB14400 = 14,400 bps
AT$MB19200 = 19,200 bps
AT$MB28800 = 28,800 bps (factory
default setting)
When speed conversion is disabled because baud adjust is enabled (via
$BA1), the modem baud rate command is ignored.
$SB Serial Port Baud Rate Select
The $SB command establishes the speed at which the modem should
transmit data through the serial port, in both originate and answer
modes. With baud adjust disabled, this serial port speed can differ from
the modem baud rate.
The MultiModemLT accepts AT commands at any speed, regardless of
the speed set by the $SB command. If the modem receives a command
at a speed different from the speed designated, the modem switches to
the speed it detects on the serial port. The value set by the $SB
command remains unchanged, so the serial port baud rate takes on that
value when the MultiModemLT is powered up or reset.
To set the serial port baud rate, type one of the following commands:
AT$SB300 = 300 bps
AT$SB1200 = 1200 bps
AT$SB2400 = 2400 bps
AT$SB4800 = 4800 bps
AT$SB9600 = 9600 bps
AT$SB19200 = 19,200 bps
AT$SB38400 = 38,400 bps
AT$SB57600 = 57,600 bps
AT$SB115200 = 115,200 bps (factory
default setting)
5.4.12 Immediate Action Commands
+++AT<CR> In-Band Escape Sequence
<BREAK>AT<CR> Out-of-Band Escape Sequence
Entering Command Mode while On-line
These commands let you enter Command mode and execute a command
after the modem goes on-line with a remote modem, without
disconnecting the call. Typically the older (in-band) escape sequence is
used to escape from On-line mode and hang up, because it lets you
append only four characters after the AT. The newer (out-of-band)
escape sequence lets you execute a command (of up to sixty characters)
and remain on-line; that is, unless the AT is followed by an H to hang
up or a Z to reset.
The number of command characters allowed after an escape sequence is
defined by S-Register S34; see Chapter 6 for S-Registers. See Appendix
D, Escape Methods, for more information about these escape
sequences.
A Force Answer Mode
You can force the MultiModemLT into answer mode with the A
command. Type ATA while in Command mode to bring your modem
off hook, out of Command mode and into on-line answer mode, and
cause the modem to transmit its carrier signal over the phone line. If no
responding carrier tone is detected by your modem within the specified
time determined by S-Register S7, your modem stops transmitting its
tone, hangs up, and returns to Command mode.
%E Select Recognized Escape Sequence
The %E command selects the following options for the escape sequence
your modem recognizes, if any.
%E0 makes the modem ignore any escape sequence.
%E1 selects the +++AT<CR> method as the escape sequence
recognized (factory default setting).
%E2 selects the <BREAK>AT<CR> method as the escape
sequence recognized.
%E3 lets the modem recognize both escape sequences.
%E4 disables the modem's OK response to an escape sequence.
%E5 enables the modem's OK response to an escape sequence
(factory default setting).
%E4 and %E5 enable/disable the modem's OK response, as is required
by some software packages during an escape sequence.
$H Help
The $H command briefly explains how to use each MultiModemLT
command available when you don't have access to a manual. You can
call up any one of the three screens of help information by typing
AT$Hn (where n = 1, 2, or 3).
$H1 reveals help screen #1
$H2 reveals help screen #2
$H3 reveals help screen #3
I Inquiry for Product Code
Some systems or software packages automatically check the
identification of the modem with which they are communicating by
using the I command. This "read" command lets the software identify
the type of modem with which it is communicating.
I0 reveals a modem ID number.
I1 reveals the firmware version.
I2 reveals the product name (e.g., MT2834LT).
L5, L7 List Current Operating Parameters
The L5 and L7 commands list the current operating parameters of your
modem. This information is useful when changing communications
software or when changing modem default settings.
L5 lists the MultiModemLT's current basic operating parameters.
L7 lists additional parameters on the MultiModemLT.
L6 List S-Register Values
The L6 command lists the current values stored in the modem's S-
Register. This information is useful when changing S-Register values.
(Refer to Chapter 6 for more information on S-Registers.)
L8 List On-line Diagnostics
The L8 command lists the current on-line CONNECT status of the
MultiModemLT. This display can be printed for use as a modem status
report, or as an informational tool about diagnostics when getting
technical support. The on-line diagnostics include the link type, line and
serial speeds, the type of error correction and data compression used,
and so on. The L8 command only works when the MultiModemLT is
on-line.
To use this command, first type +++AT<CR> or <BREAK>AT<CR>
(to enter command mode while staying on-line), the type ATL8. Your
monitor will display on-line diagnostic information about your current
on-line call or the last call made.
O Exit Command Mode and Go Back On-line
Type ATO (where O is the letter O, not the number 0) to undo the
effect of an escape sequence, bringing the MultiModemLT out of
Command mode and back into On-line mode. The O command brings
the modem into the same On-line mode (originate or answer) that it was
in prior to entering Command mode. (Refer to Chapter 6 for more
information on S-Registers.)
5.5 AT Command Summary
V.42 error correction is built into the MultiModemLT's hardware,
detecting and correcting virtually 100% of transmission errors (usually
caused by noisy phone lines). When errors are detected, the V.42
protocol causes the modem to retransmit the data block in which the
error was found.
V.42bis and MNP 5 data compression features are built into the
MultiModemLT's hardware, providing a higher data throughput than
the modem's modulation speed. The throughput increase depends on the
type of data transmitted.
The MultiModemLT also supports CCITT Group 3/EIA TR-29 Class 2
fax operation. This enables the modem to send and receive text,
graphics, and images to and from any Group 3 fax machine.
The MultiModemLT is set for one of three different modes of
operation, along with activating data compression in Reliable mode.
Normal mode (&E0) disables error correction, Reliable mode (&E2)
turns it on, and Auto-Reliable mode (&E1) lets the modem
automatically turn V.42 on when it detects its use in another modem.
Flow control methods are used by the MultiModemLT to prevent data
loss from buffer overflow. The modem both initiates flow control and
responds to pacing, using either Xon/Xoff commands or RS232C/V.24
signaling via CTS (from the modem) or RTS (from the
computer/terminal). Hewlett-Packard ENQ/ACK is also supported. If
needed, Xon/Xoff commands are passed through the modem to a
remote computer or terminal.
The MultiModemLT's speed conversion feature lets the modem operate
at one speed over the telephone line and another speed over the
RS232C/V.24 serial port. This lets the computer communicate with the
modem at a fixed speed of up to 115,200 bps, while the modem
operates at various rates of up to 28,800 bps (V.34 enabled). This
ability is vital for data compression, since your computer must send
data to the modem at a higher speed than the rate at which the modem is
sending data over the phone line.
6.1 Introduction
This chapter covers MultiModemLT software registers called S-
Registers, where certain MultiModemLT and Command mode
configurations are stored. Each S-Register is assigned a number (S0,
S1, S2, etc.). Values listed are valid for all MultiModemLT models
unless otherwise specified.
Use the S command to read and/or change the value stored in an S-
Register (ATSr? to read and ATSr= to change S-Register values). Refer
to Section 6.2, Reading and Assigning S-Register Values.
S0
Number of Rings until Modem Answers
Unit: 1 ring
Range: 0-255
Default: 1
Description: S0 defines the number of rings the
modem waits
before answering an incoming call. The default value is one ring
(Decimal 1), which means that the modem answers the call immediately
after the first ring. Setting the value to zero (0) disables auto-answer
completely.
S1
Rings which have Occurred
Unit: 1 ring
Range: 0-255
Default: 0
Description: S1 counts the number of rings that
have occurred. It is
a "read" type of register and is seldom, if ever, used in typical
operation. Each time an incoming ring signal is detected, S1 increases
its value by one, up to a maximum of 255. If you set S1 to a value other
than its default value of zero, or if the value is increasing with rings,
this new value remains stored in S1 for eight seconds after the last ring
is counted, after which time the value reverts back to zero.
S2
Escape Code Character
Unit: ASCII
Range: 0-127
Default: 43 (+ sign)
Description: S2 defines the escape code
character. The
default character is the plus (+) sign (Decimal 43). It may be set for any
ASCII character. Setting an S2 value greater than 127 results in no
escape character, and therefore no means of entering Command mode
from On-line mode without breaking the on-line connection.
S3
Return Character
Unit: ASCII
Range: 0-127
Default: 13
Description: S3 defines the character recognized
as Carriage
Return (ENTER) or Return. The default setting is CTRL-M (Decimal
13), which is the ASCII code for the ENTER key on most keyboards.
S3 may be set for any ASCII character.
S4
Line Feed Character
Unit: ASCII
Range: 0-127
Default: 10
Description: S4 defines the character recognized
as Line Feed. The
default setting is CTRL-J (Decimal 10), which is the ASCII code for the
Line Feed key on most keyboards. S3 may be set for any ASCII
character.
S5
Backspace Character
Unit: ASCII
Range: 0-127
Default: 8
Description: S5 defines the character
recognized as
BACKSPACE. The default setting is CTRL-H (Decimal 8), which is
the BACKSPACE key on most keyboards. S5 may be set for any ASCII
character.
S6
Wait Time for Dial Tone
Unit: 1 sec.
Range: 2-255, 4-255**, 4-7***
Default: 2, 4**
Description: S6 sets the time the modem waits
after the ENTER
key is pressed before executing a dial command. The default setting is
two seconds (Decimal 2) or four** seconds.
S7
Time for Carrier (Abort Timer)
Unit: 1 sec.
Range: 1-255, 1-55*
Default: 55
Description: S7 defines the Abort Timer (lack of
carrier) delay
time. The default value is 55 seconds (Decimal 55). This means that,
after dialing, the modem waits for a carrier signal for up to 55 seconds
and, if none is detected, aborts the call. The maximum S7 value is 255
(or 55*) seconds.
S8
Pause Time for Comma
Unit: 1 sec.
Range: 0-255, 4-255**, 4-7***
Default: 2, 4**
Description: S8 sets the length of the pause
caused by a comma
inserted in a dialing command. The default setting is two seconds, (or
two units Decimal 2) or four** seconds, where each unit is one second.
S8 may be set for up to 255 seconds.
S8 also sets the time the modem
waits before retrying
a call after detecting a busy signal. Some computer systems need more
than two seconds to reset (in which case you should increase the value
of S8).
S9
Carrier Detect Response Time
Unit: 100 mSec.
Range: 1-255
Default: 6
Description: S9 sets the time delay between
when the modem first
detects a valid incoming carrier signal and when the modem turns on its
Carrier Detect circuit. The default setting is 600 milliseconds, or six
units of 100 mSec each (Decimal 6). S9 may be set for up to 25.5
seconds.
S10
Carrier Loss Disconnect Delay Time
Unit: 100 mSec.
Range: 0-255
Default: 7
Description: S10 sets the time a carrier signal
must be lost before
the modem disconnects. S10 can only be set for speeds of 2400 bps or
less. The default setting is 700 mSec, or seven units (Decimal 7) of 100
mSec. Maximum delay is 25.4 seconds (Decimal 254). Setting the S10
value to 255 causes the modem to not disconnect with loss of carrier.
S11
Tone Dialing: Tone Spacing and Duration
Unit: 1 mSec.
Range: 1-255, 80-255*
Default: 70, 80*
Description: S11 sets the speed of tone dialing
(spacing and tone
duration times). The default value is 70 units (Decimal 70) or 80* units,
where each unit is one mSec, meaning that each tone is on for 70 mSec
with a 70 mSec pause between each.
The minimum S11 value allowed
by most telephone
systems is 50 mSec (50 units). Very few telephone systems can handle
anything faster than that. The maximum S11 value is 255 mSec (255
units).
S13
Remote Configuration Escape Character
Unit: ASCII
Range: 0-127
Default: 37 (% sign)
Description: S13 defines the remote
configuration escape character
(which becomes your modem's remote configuration character). The
default is three percent symbols (%%%). When the S13 character is
entered three consecutive times from a remotely connected site, your
modem responds with its Remote Configuration procedure.
S17
Changing Break Time
Unit: 10 mSec.
Range: 0-2500
Default: 250
Description: S17 defines the break time (space)
to the PC. Break
duration is adjustable. The break time is changed in 10 mSec
increments by increasing or decreasing the value of S17.
S24
PBX/CBX Disconnect Drop Time for DSR/CTS/CD
Unit: 50 mSec.
Range: 0-255
Default: 20
Description: Some PBX and CBX phone
systems require the
modem's DSR, CTS, and/or CD signals to behave in a certain manner
when calls are disconnected. The MultiModemLT's &R, &S, and &C
commands cause the modem to drop these signals for a specified time
period upon disconnect, and then bring the signal(s) up again.
S24 defines the length of time that
the signals drop.
The default setting of 20 results in a one second drop time, which is
what most PBX/CBX systems with this requirement need.
S25
DTR Dropout Time
Unit: 100 mSec.
Range: 0, 1 through 255
Default: 0
Description: S25 defines the amount of time that
DTR must be
dropped before the modem disconnects. Normally, a disconnect occurs
when DTR is dropped for 50 milliseconds or more.
The S25 unit value for zero is the
default value of 50
mSec. For values from 1 through 255, the unit value is 100 mSec.
S30
Inactivity Timer
Unit: 1 min.
Range: 0-255
Default: 0
Description: S30 causes the modem to
disconnect if no data is
transmitted or received for a specified time. This timer runs during both
Reliable and Normal connections. The timer restarts any time a data
character is passed through the serial port (either sent or received). If
noise on the phone line causes an error to be received during Normal
mode, this also restarts the timer. The inactivity timer is disabled by
setting S30 to 0, which is the factory default setting.
S32
Time Elapse for Escape Sequence
Unit: 1 sec.
Range: 0-255
Default: 20
Description: S32 sets the time period to validate
the escape
sequence. If the time interval expires before the escape sequence is
employed (by hitting ENTER), the escape sequence is aborted. The
default is 20 units (one second).
S34
Buffer Length of Command Mode after On-line Escape Sequence
Unit: ASCII
Range: 0-60
Default: 10
Description: If the number of characters after
AT exceeds the S34
buffer length value, the buffer is cleared and the escape sequence is
aborted.
S35
Low Power Mode Select
Unit: ASCII
Range: 0, 2
Default: 2
Description: S35 controls power management
for the
MultiModemLT. This power management feature is independent of any
PC-based power management. It is not necessary to change the default
setting of this S-Register.
When S35 is set to 2, the
MultiModemLT consumes
the minimum amount of power in idle mode.
When S35 is set to 0, the
MultiModemLT has no
power management. The amount of power consumed while idling is
about the same as when the MultiModemLT is on-line. This setting is
not recommended because the modem tends to drain your PC's battery.
6.2 Reading and Assigning S-Register Values
The S command reads and assigns S-Register values. To read an S-
Register value, type the letter S followed by the S-register number and a
question mark (?), then hit ENTER. For example, typing ATS7? and
hitting ENTER displays the value of S-Register S7 in a 3-digit decimal
form. The number 8 appears as 008, the number 30 appears as 030, and
the number 255 appears as 255.
To assign a value to an S-Register, enter the letter S followed by the S-
Register number and an equals sign (=), and then a decimal response to
the message ENTER THE NEW VALUE IN DECIMAL FORMAT.
Convert all ASCII characters to their decimal equivalents before
entering them. S-Register decimal values range from 0-127 for ASCII
characters, or 0-255 for numeric values. A complete ASCII conversion
chart is located in Appendix A of this manual.
6.2.1 Examples of Assigning Values
1. Let's say you wish to have longer pauses caused by the comma
in a dial command; five seconds instead of two. Typing ATS8=5
assigns 5 as the value for S-Register S8 (meaning the modem pauses
five seconds for a comma in a dial command).
2. In a second example, let's say that you wish to configure the
MultiModemLT to answer incoming calls after the 30th ring instead of
after the first ring. To configure S-Register S0 with a value of 30, type
ATS0=30 and hit ENTER.
6.2.2 Examples of Reading Values
To verify that you entered the value correctly in the above examples,
type ATS8? and hit ENTER in the first example and ATS0? in the
second example. You should receive the response 005 in the first
example and 030 in the second example.
When configuring the S-Registers, it is a good practice to include the
verification read-entry in the same command line as the configuration
assignment-entry. In the preceding examples, type ATS8=5S8? and
ATS0=30S3?.
6.3 AT Command and S-Register Summary
Your MultiModemLT's default configuration is originating a call to
another 28,800 bps modem that supports error correction, data
compression, and flow control ("maximum throughput"). If the
receiving modem is not compatible, the MultiModemLT can match any
CCITT or Bell standard modem (but not proprietary protocols).
You may, however, have applications where you do not want this kind
of maximum throughput (e.g., service not supporting error correction,
or the V.42 handshake interferes with logon sequence). If so, configure
the MultiModemLT as strictly an auto-answering device.
The &W command, used in conjunction with specific other AT
commands and S-Registers, reconfigures the MultiModemLT to
conform to a specific application. An example of the &W command:
AT&E2$SP1#L3$R0$MB28800$SB115200$EB1S0=10&W0<CR>
The MultiModemLT stores its configuration parameters and S-Register
values in its nonvolatile memory. The &W0 command stores current
parameters and values in its nonvolatile RAM. This command also sets
the modem so that on power up, or when reset with an ATZ command,
the modem reads all its configuration and S-Register parameters from
RAM, and not from the factory settings in ROM. The &W command
changes the configuration parameters stored in RAM that you
specifically intend to alter. All other default parameters remain
unchanged.
The &W1 command sets the modem so that it does not store parameters
to RAM and, on power up or when an ATZ command is entered,
parameters are read from the factory default settings in ROM.
Before using the &W command, view the modem's current operating
parameters. Use the L5, L6, and L7 commands to display the current
modem configuration.
7.1 Introduction
Each time you power up your computer or insert the MultiModemLT, it
performs an automatic self test to ensure proper operation. The
MultiModemLT also has three diagnostic test features: Local Analog
Loopback, Digital Loopback (local/manual), and Digital Loopback
(remote/automatic).
A loopback test involves entering data from your PC and looping that
data through the circuits of your modem and/or a remote modem. When
the loop is complete, the original data entered should match the data
received back which displays on your PCs monitor after the test.
The Local Analog Loopback test lets you verify that the modem's
transmitter and receiver circuits are functioning properly.
The Digital Loopback test (local/manual) lets you verify that the remote
computer , remote modem, serial ports, telephone line, and local
modem are functioning properly.
The Digital Loopback test (remote/automatic) lets you verify that the
local computer , the two modems, and the transmission line between
them are functioning properly.
Upon completion of testing, enter either escape sequence: +++AT<CR>
or <BREAK>AT<CR>.
Note: All loopback tests operate at all speeds except 300 bps.
7.2 Automatic Self Test
Each time you power-up the computer or insert the MultiModemLT, the
modem performs an automatic self-test to insure proper operation. At
the successful end of the test, you hear a multi-toned beep. If you do not
hear a multi-toned beep, it may be because your PCMCIA slot does not
support speaker input or that M0 is stored to nonvolatile memory. (See
the M command in Condition Phone Line Commands, Chapter 5.) If
you are not hearing beeps, you may want to verify that your card is
working by using PCM or PCMWin (see Configuration Utilities for
DOS and Windows in Chapter 2, Software Installation).
7.3 Local Analog Loopback Test/V.54 Loop 3
In this test, data from your computer is sent to your modem's
transmitter, converted into analog form, looped back to the receiver,
converted into digital form, and then received back at your monitor for
verification. No connection to the phone line is required.
The test procedure is as follows:
1. Connect the modem to your computer. With your
communication software, set the desired baud rate.
2. Type ATU0 (or ATU) and hit ENTER. This places your
modem in Analog Loopback mode, in originate mode. The modem is
now out of Command mode and in a pseudo On-line mode.
3. Once you receive a connect message (if responses are
enabled), enter data from your keyboard. For this test, typing multiple
upper case "U" characters is a good way to send an alternating test
pattern of ones and zeros.
4. For a more complete test, you should also test the modem in
answer mode. To do this, you must "escape" from originate mode by
entering an Escape Sequence (+++AT<CR> or <BREAK>AT<CR>).
Then type ATU1 and hit ENTER to place the modem in Analog
Loopback mode, in answer mode. Then repeat step 3.
5. When testing is completed, you may exit answer mode by
entering an Escape Sequence (+++AT<CR> or <BREAK>AT<CR>),
returning the modem to Command mode.
6. Your modem passes this test if the data entered from your
keyboard is the same as the data received which displays on your
monitor. If different data appears on your monitor, your modem is
probably causing the problem (although it could also be your
computer). If your modem passes this test but you are receiving errors
while on-line, the remote modem or the phone line is probably at fault.
7.4 Digital Loopback Test/V.54 Loop 2 (Local/Manual)
In this test, your modem must be on-line with another modem that can
respond to a request for Digital Loopback, such as another
MultiModemLT. The Digital Loopback test is an on-line test that loops
data sent from one modem across the phone line to another modem,
then back to the first modem.
There are two ways to put a modem into Digital Loopback mode.
1. Locally or Manually, described in this section.
2. Remotely or Automatically (see Section 7.5).
Note: The Digital Loopback tests can only be used with the modem
in Normal mode (error correction off).
In this test the local modem is placed in Digital Loopback mode. Data
is entered and transmitted from the remote modem (which is not in
Digital Loopback mode), sent across the phone line to the local modem,
and looped back to the remote modem.
The test procedure is as follows:
1. Go into Terminal mode. Type AT and hit ENTER; you should
get an OK message.
2. Dial the remote modem by entering the Dial command and the
phone number, establishing On-line mode.
3. Type the Escape Sequence (+++AT<CR> or
<BREAK>AT<CR>), bringing your modem into Command mode
while still maintaining the pseudo On-line mode with the remote
modem.
4. Type ATU3 from the local PC and hit ENTER. Once you
receive an OK message from your modem (if responses are enabled),
the local modem is placed in Digital Loopback mode.
5. Data is typed from the remote keyboard. For this test, typing
multiple upper case "U" characters is a good way to send an alternating
test pattern of ones and zeros. The data received by the local modem
enters its analog receiver, converts to digital data, reconverts into
analog, and then loops through its transmitter back to the remote
modem. Your modem passes this test if the data entered from the
remote keyboard is the same as the data received which displays on the
remote monitor.
6. When testing is complete, you may end the test by typing an
Escape Sequence (+++AT<CR> or <BREAK>AT<CR>), bringing
your modem into Command mode. The modem should respond with an
OK message. To stay on-line with the remote modem for normal data
transmission, type AT0 and hit ENTER. To terminate the call, type
ATH and hit ENTER to hang up.
7.5 Digital Loopback Test/V.54 Loop 2 (Remote/Automatic)
In this test, your modem must be on-line with another modem set up to
respond to a request for Digital Loopback, such as another
MultiModemLT. With the MultiModemLT, this ability to respond is
controlled by the &T command. &T4 enables the response to Digital
Loopback test (remote/automatic). &T5 disables the response. The
modem defaults to disable on power up, so this must be changed on the
remote modem before the modem responds to a request for the Digital
Loopback test (remote/automatic).
Initiate the Digital Loopback test (remote/automatic) with the ATU2
command which automatically places the remote modem in Digital
Loopback mode. Data from your computer is transmitted through your
modem and over the phone line to the remote modem, where it is then
looped back to your modem.
The test procedure is as follows:
1. Go into Terminal mode. Type AT and hit ENTER; you should
get an OK message.
2. Dial the remote modem by entering the Dial command and the
phone number, establishing On-line mode.
Note: The &T4 command must be set on the remote modem to run this
test.
3. Type the Escape Sequence (+++AT<CR> or
<BREAK>AT<CR>), bringing your modem into Command mode
while still maintaining the connection with the remote modem.
4. Type ATU2 and hit ENTER. The local modem responds to
this command by transmitting an unscrambled marking signal, which
causes the remote modem to place itself in Digital Loopback mode.
Then the local modem exits Command mode and enters a pseudo On-
line mode.
5. Type data from your keyboard. For this test, typing multiple
upper case "U" characters is a good way to send an alternating test
pattern of ones and zeros. The data received by the remote modem
enters its analog receiver, converts to digital data, reconverts into
analog, and then loops through its transmitter back to the local modem.
Your modem passes this test if the data entered from the local keyboard
is the same as the data received which displays on your monitor.
8.1 Introduction
This chapter describes how the MultiModemLT Remote Configuration
feature operates. This feature uses a multilevel security system that
involves the use of LOGIN passwords, SETUP passwords, and remote
escape characters.
The primary level security code is the modem's LOGIN password. Once
this password is entered, other passwords can be used. For instance,
entering the LOGIN password lets you enter the SETUP password.
The remote escape character is the key to using the Remote
Configuration feature. The remote escape character lets you enter
Command mode via a remote call, so that you can enter AT commands
just as if you were locally connected. You must also enter your
modem's SETUP password. The remote escape character is contained
in S-Register S13.
8.2 Remote Configuration Description
The Remote Configuration feature is a network management tool that
lets you configure modems remotely. This means you can configure
modems anywhere in your network from one location, without having
to visit the sites or rely on remote users to follow your instructions.
With Remote Configuration, which is protected by two-level security,
you can downline load new parameters, program new V.42 capabilities,
and implement new features. Remote Configuration also makes
troubleshooting remote locations a lot easier.
S-Register S13 contains the special remote configuration escape code.
When calling a Remote Configuration equipped modem, you enter the
proper remote escape code and SETUP password. After entering both
correctly, you can then execute AT commands as if you were connected
locally. If you set S-Register S13 to zero, Remote Configuration is
disabled.
8.3 Initial SETUP Procedures for Remote Configuration
Your modem is shipped with default LOGIN and SETUP passwords
(LOGIN=MULTI-TECH and SETUP=MODEMSETUP) so you can
configure the modem. Because the defaults are in the owner's manual,
anyone can find out what they are. You should change the codes as the
first step of your initialization procedure.
To change your modem's LOGIN and SETUP passwords, follow the
steps below.
Note: Passwords are upper/lower case sensitive. The case you enter
here is the case that must be used at log-in.
Table 8-1
Modem LOGIN, SETUP, and Remote Escape Codes
1. Type AT#IMULTI-TECH and hit Return. Your modem
responds with:
OK (if the LOGIN password is wrong, the modem's
response is ERROR)
2. Type AT#SMODEMSETUP and hit Return. Your modem
responds with the following:
OK (or ERROR if the wrong SETUP password is entered)
Note: At this point you can change the LOGIN password
and SETUP passwords.
3. Type AT#I=xxxxxxxxxx (with any keyboard characters used:
minimum = 6, maximum = 10) and hit Return. Your modem
responds with:
OK
4. Type AT#S=yyyyyyyyyy (with keyboard characters
used: minimum = 6, maximum = 10) and hit Return. Your
modem responds with:
OK
To change the status of your Remote Configuration feature:
5. To disable Remote Configuration, set S-Register S13 to 0
(zero). See Chapter 6 for details on how to set S-Register
values.
6. To enable Remote Configuration and change the remote
escape character, type in a new S-Register S13 value.
8.4 Remote Configuration AT Commands
The following AT commands are used with the Remote Configuration
feature.
#I Modem LOGIN Password
The #I command lets you select a unique LOGIN password for your
modem. Once you have selected a LOGIN password for your modem, it
only responds to that code. Your modem is shipped with MULTI-
TECH as its default password so that you can gain access to the
command initially. See Table 8-1 for instructions on changing the
LOGIN password.
#S Modem SETUP Password
The #S command lets you select a unique SETUP password for your
modem. Once you have selected a SETUP password for your modem, it
only responds to that code. Your modem is shipped with
MODEMSETUP as its default password, so that you can gain access to
the command initially. See Table 8-1 for instructions on changing the
LOGIN password.
8.5 Remote Configuration S-Register
S-Register S13 is used with Remote Configuration. It defines the
MultiModemLT remote configuration escape character. When the S13
character is entered three consecutive times from a remotely connected
site, your modem responds to it with its Remote Configuration
procedure. The default remote configuration escape character is the
"%" sign. See Chapter 6 for more information about this S-Register.
8.6 Remote Configuration Procedures
The following table explains how to use the Remote Configuration
feature; they are the same whether or not a call originates from the
remote modem.
Table 8-2
Remote Configuration Operation
1. Enter a break signal, then type the S13 remote configuation
escape character three times (the default S13 value is the "%"
sign).
The modem responds with:
1. - DATA Mode
2. - COMMAND Mode
2. Select 1 or 2. With option 1, the modem goes back into Data
mode and with option 2, the modem responds with Password>.
3. Enter your SETUP password and, if the code is correct, the
modem responds with OK.
You can now use any AT commands remotely as if they were
entered locally. You cannot change the LOGIN password until
you enter the proper LOGIN password.
4. When you are done entering AT commands and you wish to
exit, type AT0 and hit return. The modem responds with:
1. DATA Mode
2. COMMAND Mode
5. Enter a 1 to go back on-line with your computer, or enter 2 and
the correct password to talk to your modem.
Appendix B: Dial Pulse and Tone Dial Frequencies (not used with the
MT2834LTI UK version)
B
Closed
A
Open
Digit 2 Digit 1
In the example above, the digit 2 is pulse dialed, followed by the digit
1. Each pulse consists of an A mSec open and a B mSec close, where A
is either 60 or 67 mSec and B is either 40 or 33 mSec for a total of 100
mSec per pulse, or a rate of 10 pulses per second. The interdigital pause
time is 800 mSec. The pulse ratios are controlled by the &P command.
Hz Digits
697 1 2 3
770 4 5 6
852 7 8 9
941 * 0 #
Hz 1209 1336 1477
The tone-dialing method, referred to as Dual-Tone Multi-Frequency
(DTMF) dialing, combines two frequencies for each of the twelve digits
found on a Touch Tone dial pad.
The four horizontal rows on a Touch-Tone pad use the four low
frequencies (697, 770, 852, 941 Hz), while the three vertical columns
use the three high frequencies (1209, 1336, 1477 Hz). The generally
accepted tone frequency tolerance is +0.02%.
For example, the digit 4 is dialed by combining two tone frequencies. It
uses the frequency 770 Hz from the second row, and the frequency
1209 Hz from the first column. In another example, the digit 9 is dialed
with the tone frequencies of 852 Hz and 1477 Hz.
The extended DTMF characters (A, B, C, D) are the high-end
frequencies (1633 Hz) defined on some telephone sets with a fourth
vertical column of buttons. This fourth column provides for extended
PBX control functions; the actual functions provided are dependent on
the PBX manaufacturer's implementation and feature set.
Hz Digits
697 1 2 3 A
770 4 5 6 B
852 7 8 9 C
941 * 0 # D
Hz 1209 1336 1477 1633
Appendix D: Escape Methods
An escape method lets you issue AT commands to your modem while
on-line with a remote modem without disconnecting the call. You may
return on-line afterward; however, most users escape to hang up the
modem.
Our modems offer two escape methods: in-band and out-of-band. Both
incorporate Time Independent Escape Sequence (TIES) methodology.
An escape sequence is a pattern, or sequence, that the modem
recognizes as a signal to shift from On-line mode to Command mode.
"Time independent" means that the modem recognizes the escape
sequence without a prefixed and/or suffixed delay.
The modem recognizes the in-band escape sequence as a pattern sent to
it as part of the data stream or band (hence its name). Our in-band
escape sequence is +++AT<CR>.
The out-of-band escape sequence is a pattern that cannot and does not
occur in the data stream. Our out-of-band escape method is
<BREAK>AT<CR>. A break signal cannot be sent as part of a data
file; instead, the command is sent directly to the UART from the
keyboard.
Break is defined as the transmission of binary 0 for either a minimum of
10 bits or a minimum interval of 135 milliseconds as established in the
CCITT X.28 standard. Routines in high level languages and keys have
been established on most computers that send break for fixed intervals,
but you may control the break's duration by referring to your UART's
specifications.
D.1 Selecting an Escape Method
To escape and wait for a command before returning to On-line mode,
use +++AT<CR>. This escape sequence is helpful when you need to
review a help screen in the midst of a communications session.
To combine the escape with command(s) and immediately return to On-
line mode, use the <BREAK>AT<CR> method. The modem also waits
before returning on-line with this method.
Select one of the following escape methods that your modem
recognizes with the %E command.
%E0 makes the modem ignore any escape sequence.
%E1 selects the +++AT<CR> method as the escape sequence
recognized (factory default setting).
%E2 selects the <BREAK>AT<CR> method as the escape
sequence recognized.
%E3 lets the modem recognize both escape sequences.
%E4 disables the modem's OK response to an escape sequence.
%E5 enables the modem's OK response to an escape sequence
(factory default setting).
D.1.1 In-Band Escape Method: +++AT<CR>
The following is an example of using the in-band escape method to set
S-Register S0 to 1 while on-line.
1. Type +++AT<CR>. The modem transmits the +++, buffers the
AT, and starts the "Wait for <CR> timer". Upon receiving the
<CR> signal, the modem escapes to Command mode and
responds with "OK".
2. Type ATS0=1<CR>. The modem buffers ATS0=1<CR>,
identifies it as a valid command, then escapes to Command
mode to execute the command. S-Register S0 is set to 1.
3. Type ATO<CR> to return to On-line mode.
D.1.2 Out-of-Band Escape Method: <BREAK>AT<CR>
The following is an example of using the out-of-band escape
method toset S-Register S0 to 1 while on-line.
1. Type <BREAK>AT<CR>. The modem buffers the <BREAK>
signal, and starts the S32 "Wait for <CR> timer".
2. Type ATS0=1<CR>. The modem buffers ATS0=1<CR>,
identifies it as a valid command, then escapes to Command
mode to execute the command. S-Register S0 is set to 1, and
the modem returns
to On-line mode.
D.2 S-Registers and Escape Sequences
Two S-Registers settings can modify your escape sequences'
functions. The first, S-Register S32, establishes the amount of
time that elapses between receiving the beginning of either
escape sequence and the <CR> signal. This time interval is
known as "Wait for <CR> timer", or break pass-through.
With the +++AT<CR> method, the timer begins when the "A"
in +++AT is received by the modem. With the
<BREAK>AT<CR> method, the timer begins when the
modem receives the break signal.
Use S-Register S34 with the in-band escape sequence to allow
the maximum number of characters your modem can buffer
following an "AT" signal before the <CR> signal. (Do not
confuse this buffer size with the Command mode buffer, which
has a maximum of 60 characters.)
S-Register S34 does not affect the out-of-band escape
sequence's buffer length, which is fixed at 60 characters.
D.3 Aborting an Escape Sequence
The +++AT<CR> escape aborts if you do not issue a <CR>
before the "Wait for <CR> timer" interval expires.
The <BREAK>AT<CR> method also aborts if you do not
issue a <CR> before the "Wait for <CR> timer" interval
expires, and also if any of the following occurs:
* an illegal sequence is detected, including: a character other
than "A" following the <BREAK>, a character other than "T"
following the <BREAK>A, or two breaks received in
succession, or
* the command buffer overflows before a <CR> signal occurs.
Appendix E: Programming Reference
This appendix contains technical reference information for
programmers and systems engineers writing their own communications
software to control the MultiModemLT. It is not necessary to read or
understand the content of this appendix if you are not writing your own
software.
The MultiModemLT includes an on-board serial communications COM
port which can be configured as either COM1, COM2, COM3, or
COM4. You can also use the extended addressing feature as a COM
port with user-configured base address (100 hex to 3F8 hex) and IRQ
(2, 3, 4, 5, or 7). The on-board serial communications port is
functionally equivalent to the IBM Asynchronous Communications
Adapter. This port includes a 16550 UART (Universal Asynchronous
Receiver Transmitter). The registers associated with the UART are
detailed in this appendix, as well as an additional Modem Data Rate
Indicator Register. These registers are defined with respect to the
MultiModemLT.
E.1 Data Communications Device Address
The MultiModemLT may be assigned to either COM1, COM2, COM3,
or COM4, or when using the extended addressing feature, as a COM
port with a base address and IRQ that you assign. Only one device in
the system may be assigned one of these designations. Select the
MultiModemLT's COM port by rerunning the PCM Plus
software's"PCMSetup" or by changing the number x in the /COM=x
argument located in the PCMSCD command line of your
CONFIG.SYS.
COM Port I/O Addresses Interrupt
COM1: 3F8 to 3FF IRQ4
COM2: 2F8 to 2FF IRQ3
COM3: 3E8 to 3EF IRQ4
COM4: 2E8 to 2EF IRQ3
For example, COM1 occupies hex I/O addresses 3F8 to 3FF; it
generates an interrupt signal to the computer on Interrupt Request line
IRQ4.
E.2 UART Registers
This section describes and details each UART register. The description
for each register includes the register name and abbreviation, its base
address, and one of the following designations: R/W (Read/Write), R/O
(Read Only), or W/O (Write Only). The register addresses are given for
the COM1 selection. If you select another COM port, or use the
extended addressing feature to select a base address and IRQ different
than COM1, use the following procedure to identify the new address of
the register.
Example: When COM1 is selected, the base address is 3F8 hex and the
Line Control Register is at 3FB hex. If you select COM2, by either
reinstalling the PCM Plus software or by changing the number x in the
/COM=x argument located in your CONFIG.SYS file's PCMSCD
command line, the base address becomes 2F8 hex and the Line Control
Register address is at 2FB hex. Or, if you use the extended addressing
feature to select a base address (for example, 200 hex), the address of
the Line Control Register is 203 hex.
Note: The address of the register remains the same incremental
distance above the base address (3 hex). Therefore, by examining the
difference between the COM1 base address and the COM1 address of
the desired register, you can easily determine the register's address for
any base address.
Note: The MultiModemLT enables high speed data rates (115.2K
bps) with a 16-byte First In First Out (FIFO). The MultiModemLT
provides the standard 16550-compatible interface.
E.2.1 Line Control Register (LCR) 3FB R/W
Specifies character format and controls access to other registers.
Table E-1
Line Control Register
BIT NAME DESCRIPTION
0 Word Length Select Sets bit length for each character.
Bit 0 (WLS0) See table above.
1 Word Length Select Sets bit length for each character.
Bit 1 (WLS1) Bit 1 Bit 2 Word Length
0 0 5 bits
0 1 6 bits
1 0 7 bits
1 1 8 bits
2 Number of Stop Bits 1 2 stop bits per character
(STB) (1.5 for 5 bit words).
0 1 stop bit per character
3 Parity Enable (PEN) 1 Enables parity generation
or checking.
0 Disables parity generation
or
checking.
4 Parity Select (EPS) 1 Even Parity (bit 3 must be
1).
0 Odd Parity (bit 3 must be
1).
5 Stick Parity 1 If Stick Parity is set when
bit 4 is a
logical 0, parity bit is
always a 1;
when bit 4 is a logical 1,
parity bit
is always a 0.
0 Parity bit is unaffected.
6 Set Break 1 Causes the modem to
transmit a
continuous break signal
(all binary zeros).
0 Stops the break signal.
7 Divisor Latch 1 Enables access to the
Divisor
Address Bit Latches of the Baud Rate
(DLAB) Generator during a read or
write operation.
0 Enables access to the
Receiver Buffer,
Transmitter
Holding Register, and
Interrupt Enable Register.
E.2.2 Divisor Latch (DLL) 3F8 R/W
(least significant byte)
Contains the lower eight bits of the baud rate divisor used to set the
Baud Rate Generator. The most significant byte is contained at the next
address. Together, both addresses must contain the hexadecimal
equivalent of the divisor necessary to generate the desired baud rate. All
undefined values default to a baud rate of 9600 bps. The following table
indicates the proper hex value for each speed:
Baud Rate Hex Value
300 bps 80 hex
1200 bps 60 hex
2400 bps 30 hex
4800 bps 18 hex
9600 bps 0C hex
19,200 bps 06 hex
38,400 bps 03 hex
57,600 bps 02 hex
115,200 bps 01 hex
E.2.3 Divisor Latch (DLM) 3F9 R/W
(most significant byte)
Contains the upper eight bits of the baud rate divisor. All undefined
values default to a baud rate of 9600 bps.
Baud Rate Hex Value
300 bps 01 hex
1200 bps 00 hex
2400 bps 00 hex
4800 bps 00 hex
9600 bps 00 hex
19,200 bps 00 hex
38,400 bps 00 hex
57,600 bps 00 hex
115,200 bps 00 hex
The divisor table is reproduced in the IBM Technical Reference
manual. The divisor for selecting another baud rate (within the modem's
range) is calculated from the following formula:
To access this register, bit 7 (DLAB) of the Line Control Register must
be set equal to 1.
E.2.4 Line Status Register (LSR) 3FD R/O (bit 0, R/W)
Provides error indication and other information pertaining to data
transfer. Bits 0 through 5 produce an interrupt, provided that the
interrupt is enabled (see Interrupt Enable Register).
Table E-2
Line Status Register
BIT NAME DESCRIPTION
0 Data Ready (DR) 1 Indicates that a character
has been received and is
held in the Receiver
Buffer Register. This
bit is reset to 0 by the CPU
when data is read from it;
data may also be written to
it.
0 Indicates that the Receive
Buffer Register is empty.
1 Overrun Error (OE) 1 Indicates that a character
in the Receive Buffer
Register was lost before it
was read; reset to zero
whenever the Line Status
Register is read.
2 Parity Error (PE) 1 Indicates that the parity of
the received data character
does not match the parity
as selected by EPS of the
Line Control Register; set
to zero when the CPU
reads the contents of the
Line Status Register.
3 Framing Error (FE) 1 Indicates that the received
character did not have a
valid stop bit. Resets to 0
whenever the Line Status
Register is read.
4 Break Indicator (BI) 1 Indicates the presence of a
break signal. Occurs when
the received data is held in
spacing (logical 0)
condition for more than a
full character transmission
time (i.e., longer than the
total time of start bit +
data bits + parity + stop
bits). The BI bit is reset
to 0 whenever the Line
Status Register is read.
5 Transmitter Holding 1 Indicates that the
transmitter
Register Empty is ready
to accept the next
(THRE) character for transmission.
Reset to 0 with the loading
of the Transmitter Holding
Register.
6 Transmitter Shift 1 Indicates that no
characters
Register Empty remain in the Transmitter
(TSRE) Shift Register. Resets to 0
when data is transferred
from the Transmitter
Holding Register
to the Transmitter Shift
Register.
7 _ 0 Permanently set to logical
0.
E.2.5 Modem Control Register (MCR) 3FC R/W
Controls the MultiModemLT interface.
Table E-3
Modem Control Register
BIT NAME DESCRIPTION
0 Data Terminal Ready 1 Enables modem operation.
(DTR) 0 Disables modem: modem
will not accept commands
nor auto-answer; if on-
line, modem disconnects.
1 Request to Send 1 RTS is inactive and lets
data
(RTS) flow from the modem
when using RTS pacing.
0 RTS is inactive and halts
data flow from the modem
when using RTS pacing.
2 Output 1 (OUT1) 1 Resets the modem,
equivalent to a power
off/on reset. Must be held
high (logic 1) for at least
50 milliseconds then
brought low (logic 0)
again.
0 Setting for normal
operation.
3 Output 2 (OUT2) 1 Enables interrupts.
0 Disables interrupts.
4 Loopback (LOOP) 1 Activates a loopback
feature for diagnostic
testing of the UART.
0 Setting for normal
operation.
5-7 _ 0 Permanently set to logical
zero.
E.2.6 Modem Status Register (MSR) 3FE R/O
Provides the current state of the control signals from the modem to the
CPU. Whenever bit 2 or 3 is set to logic 1, a Modem Status Interrupt is
generated, provided that Modem Status Interrupts are enabled.
Table E-4
Modem Status Register
BIT NAME DESCRIPTION
0 Delta Clear to Send 0 Unused, always logic 0.
(DCTS)
1 Delta Data Set Ready 0 Unused, always logic 0.
(DDSR)
2 Trailing Edge Ring 1 Indicates that the RI input
to
Indicator the UART has changed
from
(TERI) an On (logic 1) to an Off
(logic 0) condition.
3 Delta Received Line 1 Indicates that the Received
Signal Detect (DRLSD) Line Signal Detect input to
the UART has changed
states.
4 Clear to Send (CTS) 1 Indicates CTS is active
and modem is ready to
transmit data.
0 Indicates CTS is inactive
and is not ready to
transmit data.
5 Data Set Ready 1 Indicates modem is in
Data
(DSR) mode and connected to the
communications channel.
0 Indicates modem is not in
Data mode.
6 Ring Indicator (RI) 1 Indicates that the
MultiModemLT
detects a ringing signal on
the telephone line.
7 Carrier Detect 1 Indicates that the
MultiModemLT
(CD) detects a valid data carrier
signal on the telephone
line.
0 Indicates an absence of a
valid data carrier signal.
E.2.7 Receiver Buffer Register (RBR) 3F8 R/O
This location contains the most recently received data character. The
character is received serially with the least significant bit received first.
To access this register, DLAB of the Line Control Register must equal
0.
E.2.8 Transmitter Holding Register (THR) 3F8 W/O
This location contains the next character to be transmitted serially
through the modem. The least significant bit (bit 0) is transmitted first.
To access this register, DLAB of the Line Control Register must equal
0.
E.2.9 Interrupt Enable Register (IER) 3F9 R/W
Enables the interrupt sources to the UART interrupt output signal.
Disabling all the interrupts inhibits the Interrupt Identification Register.
Note: Set OUT2 (Bit 3 of the Modem Control Register) to a logical 1
to let the interrupts reach the computer bus for processing (it enables
the interrupt line).
Table E-5
Interrupt Enable Register
BIT NAME DESCRIPTION
0 Enable Received Data 1 Lets the UART generate
Available Interrupt an interrupt whenever
Data
(ERBFI) Ready (DR) of the Line
Status
Register becomes a logical
1.
0 Disables Data Ready
interrupt.
1 Enable Transmitter 1 Allows the UART to
generate
Holding Register an interrupt whenever
THRE
Empty Interrupt of the Line Status Register
(ETBEI) becomes a logic 1.
0 Disables Transmitter
Holding
Register Empty interrupt.
2 Enable Receiver 1 Lets the UART generate
Line Status Register an interrupt upon
receiving an
Interrupt Overrun Error, Parity
Error,
(ELSI) Framing Error, or Break
signal.
0 Disables OE, PE, FE, or
BI
interrupts from the Line
Status Register.
3 Enable Modem 1 Allows the UART to
generate
Status Interrupt an interrupt whenever RI
or
(EDSSI) CD of the Modem Status
Register becomes a logical
1.
0 Disables interrupts
generated
by RI and CD of the
Modem Status Register.
4-7 _ 0 Always logical 0.
E.2.10 Interrupt Identification Register (IIR) 3FA R/O
Stores and indicates which prioritized interrupts are pending. The
information contained in this register is always available even if
interrupts have been turned off at the Interrupt Enable Register.
Table E-6
Interrupt Identification Register
BIT NAME DESCRIPTION
0 Interrupt Pending 1 No interrupts have
occurred.
(IP) 0 Indicates that an interrupt
occurred.
1-2 Interrupt ID Bit 1 in conjunction with
bit 2,
(IID1 & IID2) indicates the highest
priority
interrupt which has
occurred.
See the table below.
3-7 _ 0 Always logical 0.
Table E-7
Interrupt ID
IID2 IID1 PRIORITY INTERRUPT SOURCE
1 1 1 Overrun Error (OE), or
(highest) Parity Error (PE), or
Framing Error (FE), or
Break Indication (BI)
(see Line Status Register)
1 0 2 Data Ready (DR)
(see Line Status Register)
0 1 3 Transmitter Holding
Register Empty (THRE)
0 0 4 Ring Indicator, or
(lowest) Received Line
Signal Detect (CD)
(see Modem Status
Register)
Appendix F: PCMCIA Driver Deinstallation
Use this appendix to deinstall old PCMCIA drivers. The files affected
are your CONFIG.SYS, AUTOEXEC.BAT, SYSTEM.INI, and
WIN.INI. Complete the deinstallation process only if, during the
installation process, PCM Plus alerted you that other software was
already loaded on the computer, or you know you have other PCMCIA
support software on your computer.
You may use the Deinstallation utility included with PCM Plus
following the instructions in Table F-1, below, or you may manually
deinstall according to the instruction provided in section F.2.
F.1 Using the Deinstallation Utility
PCM Plus will not install with other versions of PCMCIA utilities
loaded on your PC. Use the instructions in the following table to
deinstall old PCMCIA drivers with the Deinstallation utility included
with your PCM Plus software.
Note: When using the Deinstallation utility, you may press the F1
function key at any time for context-sensitive Help. Also, you may exit
the installation at any time by pressing the F3 function key.
Table F-1
Deinstalling Old PCMCIA Drivers using the Deinstallation Utility
1. Create a bootable diskette containing your CONFIG.SYS,
AUTOEXEC.BAT, SYSTEM.INI, and WIN.INI files. For information
on creating a bootable diskette, refer to your DOS manual.
2. Copy the files from the PCM Plus diskette to your hard drive.
3. Type DEINSTALL and press ENTER in the directory where
you copied the files.
The deinstallation utility title screen appears. (You may exit
the installation at any time by pressing the F3 function key.)
4. Press any key to display an informational message about
creating a bootable diskette.
5. Press any key to display the Remove or Comment Out screen.
Here you may choose how to disable your old PCMCIA
utilities. You may choose to have a comment line placed in front of
each line by selecting the "Comment-out lines" option, or choose
"Remove lines" to delete these lines entirely.
Make your selection by using the up and down arrow keys and
press ENTER. The Deinstall from All Configurations screen appears.
6. If you are running DOS 6.0 or later with the multiple boot
option, the Deinstall from All Configurations screen appears.
Here you may choose to deinstall PCMCIA utilities from the
current configuration or from all configurations. If you choose to
deinstall from only the current configuration, all other configurations
will be left unchanged.
Note: If you are running Windows, you must choose to deinstall
from all configurations. Windows does not let you specify different
Windows drivers for different boot configurations, because the same
driver is used every time you boot.
Make your selection and press ENTER. The first Windows
Directory screen appears.
7. If you have Windows installed, select Yes and press ENTER.
Otherwise select No and press ENTER.
If you selected Yes, the second Windows Directory screen
appears.
Either enter the path where you have Windows installed, or
press ENTER to accept the default option. The View Changes screen
appears.
8. We recommend you select Yes to see what changes the
Deinstallation utility will make to your files. Then you can accept or
reject the changes.
9. The affected files are displayed. To accept the changes, press
ENTER; to reject the changes, press ESC. You may also exit the
Deinstallation utility by pressing the F3 function key.
10. Once you have viewed all the affected files, a screen appears
containing a summary of which changes have been made and what the
backup copies are named. Press ENTER to continue. The Reboot
System screen appears.
11. This screen reminds you to reboot you PC after returning to
the DOS prompt so that the changes can take effect. Press ENTER to
exit the Deinstallation utility.
12. Reboot you PC so that the changes can take effect.
Appendix G: PCM Plus Drivers & Memory Management
In addition to utilities and programs, PCM Plus also includes drivers
that provide necessary services for PCMCIA cards. Most of these
drivers are installed by PCM Plus during installation. Occasionally,
however, you may need to 'fine-tune' these drivers to provide maximum
performance.
The most important way to optimize driver performance is to increase
the efficiency of memory usage. This requires some knowledge of the
way in which the drivers use memory.
The appendix provides details on how to best use the drivers that PCM
Plus installs on your computer.
Note: In the normal course of operation, you should find that the
default settings for drivers are adequate to your needs. Only edit these
settings if you have some experience with memory optimization.
Your MultiModemLT requires you to install Socket Services
(PCMSS.EXE), Card Services (PCMCS.EXE), and the Super Client
Driver (PCMSCD.EXE). Refer to the information that follows to
determine how much memory each driver requires.
G.1 Memory Management
All drivers are mapped to specific memory sites in your computer's
RAM. Available sites are shown below.
Table G-1
Available Memory Ranges and Types
Memory Range Amount Memory Type
1FFFFFF - FFFFFF... up to 64MB Extended
Memory
0E0000 -0FFFFF 128KB
System BIOS
0C0000 - 0DFFFF 128KB Upper Memory (UMB)
I/O adapter ROM
0A0000 -0BFFFF 128KB
Video RAM
000000 - 09FFFF 640KB Conventional Memory
Conventional (base) memory
The first 640KB of RAM in your system is called "conventional"
memory. Most, but not all, of this 640KB is available for applications,
depending on the DOS version you are running and which device
drivers are loaded. The rest of the first megabyte (the upper 384KB) is
called "upper" memory, or UMB for upper memory block. It is reserved
for video and system BIOS, device drivers, and so on. The area above
the first 1MB is called "extended" memory, and is accessible through
memory managers which support the storage of data up to a theoretical
limit of 4 gigabytes (a 486 processor can physically handle 64MB).
Within this memory range, PCM Plus drivers normally use
conventional and upper memory. The table below shows the
MultiModemLT drivers and where they normally reside. The default
switches are also given below.
Table G-2
MultiModemLT Memory Requirements
Driver Conv. Memory UMB Memory Fixed/Var Default
Required Required
PCMSS.EXE 7K 0K
PCMCS.EXE 36K 4K Fixed /ADDR=C8
PCMSCD.EXE 20K 0K
Note: If PCMCS detects RAM or ROM at C800, it attempts to find
the next available memory. This CIS window address can be specified
in the "Advanced" menu of PCMSETUP or in the PCM.INI file using
the /ADDR option.
G.2 Minimizing Memory Usage
Use the following suggestions to reduce memory usage.
* Load only those drivers absolutely required for the cards you
plan to use. For example, if you are going to use your MultiModemLT
card exclusively, load only the PCMSS, PCMCS, and PCMSCD
drivers.
* Make all of your upper memory block addresses contiguous so
that you don't leave memory "holes."
* Use Microsoft's MSD program to maximize memory usage.
G.3 PCM Plus Drivers
When PCM Plus is installed, the program automatically installs those
drivers that you specify cards for. At that time, it also assigns
parameters to the driver, indicating such things as memory allocation,
slot assignment, and address size.
The drivers normally loaded for the MultiModemLT are as follows.
Driver Purpose
PCMSS.EXE Used to support Socket Services.
Works at the BIOS
level as an interface between the
PCMCIA card socket and PCMCS,
the Card Services program.
PCMCS.EXE Used to support Card Services.
Works at the operating system level
to manage all PCMCIA cards.
PCMSCD.EXE Used with the MultiModemLT and
LAN cards.
CNFIGNAM.EXE Used to specify which PCM Plus
configuration should be accessed
from the PCM.INI file.
Normally you won't need to change these original assignments.
However, occasionally, in order to optimize system performance or to
add a new driver for a newly-acquired PCMCIA card, you may need to
add one of these drivers to your CONFIG.SYS file. This section
provides specific information on all the PCM Plus drivers currently
available.
Note: Only the PCM Plus drivers provided are defined. Drivers
provided by third party suppliers are not defined here.
The way we represent certain commands and switches is
COMMAND /switch.
COMMAND is the necessary word to type or
invoke in order to run
the driver or program.
/switch is an option which can be omitted. Normally a default setting
already exists.
G.3.1 About the Installed Drivers
The PCM Plus software drivers work together to let your PC and your
MultiModemLT communicate. Socket Services provides the interface
between your PC and the socket in which your MultiModemLT is
installed. The Super Client Driver configures the MultiModemLT and
handles all card events such as insertion and extraction. Card Services
acts as a liaison between Socket Services and the Super Client Driver.
G.3.2 Socket Services (PCMSS.EXE)
The Socket Services (PCMSS.EXE) component of PCM Plus provides
the interface between your PC and the socket into which the
MultiModemLT is inserted.
PCMSS Options
When you install PCM Plus, the Socket Services device driver
PCMSS.EXE is loaded in your CONFIG.SYS file. You can modify the
device driver options for Socket Services with PCMSETUP Advanced
Mode or by editing the PCM.INI file directory. The PCMSS= argument
is found in the PCM.INI file.
Add or change options of PCMSS.EXE by typing a slash and then the
option, like in the following example.
PCMSS /RS=n /RW=n /APOFF /LOCK
Table G-3
PCMSS Options
RS=n Reserves socket n. Default=none.
RW=n Reserves socket-window controller n. Default=none.
/APOFF Disables hardware auto-power mode. Default=hardware auto
power mode enabled.
/LOCK Enables socket locking features. Default=socket locking off.
The following sections define each option in more detail.
For more information about Socket Services, you may order the
PCMCIA Socket Services 2.0 Interface Specification: write to the
PCMCIA Committee, 1030G East Duane Avenue, Sunnyvale, CA
94086 or call (408) 720-0107.
/RS
/RS=n1 n2 specifies the number of sockets to be reserved. When you
use the Reserve Socket option you prevent Socket Services from
colliding with other dedicated PCMCIA software that is accessing the
socket hardware directly. You can also use this option to limit access to
a socket that may not be accessible in the system. You can reserve a
maximum of two sockets.
/RW
/RW=n1 n2 reserves a socket controller window. Reserve either I/O and
memory windows to prevent conflicts with software that are not
allocating resources from Card Services. n specifies the window
number starting at zero on the first socket. There is no distinction
between I/O and memory windows since the number and type of
windows is controller-specific. You can reserve a maximum of two
windows.
/APOFF
/APOFF disables Auto-Power Mode. This option disables the "auto
power mode" on some socket controllers. Use this option for maximum
compatibility on MCA-bus machines or with controllers having
problems with auto-power mode.
/LOCK
/LOCK enables Socket Locking. This option supports socket-
locking/unlocking hardware. Use this option to specify that socket
locking is available. This switch only works if your PCMCIA hardware
has socket-locking capability.
G.3.3 Card Services (PCMCS.EXE)
The Card Services (PCMCS.EXE) component of PCM Plus interfaces
directly with Socket Services, coordinates access to the PCMCIA cards,
and allocates PC system resources among Card Services client drivers.
A client driver is a device driver (hardware-specific software) designed
to support one or more PCMCIA cards. Card Services is provided as a
DOS loadable driver.
Card Services manages:
* all resources available for PCMCIA Cards. When a PCMCIA
card is inserted into a socket, Card Services determines if the requested
resources can be provided for that card.
* client drivers that are written for specific PCMCIA cards.
These client drivers are registered with Card Services during
initialization (system boot-up). Card Services then provides the
registered client drivers with pertinent information when PC card events
occur, such as card insertion or extraction, as well as status changes,
such as battery low, card ready, and card locked.
PCMCS Options
When you install PCM Plus, the Card Services device driver
PCMCS.EXE is loaded in your CONFIG.SYS file. You can modify the
device driver options for Card Services with PCMSETUP Advanced
Mode or by editing the PCM.INI file directory. The PCMCS= argument
is found in the PCM.INI file, and is used to pass options to PCMCS.
The DEVICE=PCMCS.EXE line appears in the CONFIG.SYS file.
Add or change options of PCMCS.EXE by typing a slash and then the
option, like in the following example.
PCMCS.EXE /ADDR=nn /CLIENTS=nn /MCA /NOBEEP /NOPM
/PMOFF /POLL /REGIONS=n /WAIT=n /XIRQ=xxxx
Table G-4
PCMCS Options
/ADDR=nn Sets internal memory window to address xx00:0000
(first available)
/CLIENTS=n Allows n clients to register.
/IRQ=n Enables IRQn for status-change interrupts
/MCA Forces Micro Channel compatibility mode.
/NOPM Ignores all Power-Management events.
/NOBEEP Turns off the tone emitted when cards are inserted
and removed.
/PMOFF Disables sending Power Management events to Clients.
/POLL Uses polling instead of interrupts for card events
/REGIONS=n Uses up to n different memory regions at a time.
/WAIT=n Delays n 18.2 ms periods before configuring I/O card.
/XIRQ=xxxx Bitmask of unavailable interrupts.
See the following sections for more details on these options.
For more information on the additional responsibilities and services
performed by Card Services, you may order the PCMCIA Card
Services 2.0 Interface Specification: write to the PCMCIA Committee,
1030G East Duane Avenue, Sunnyvale, CA 94086 or call
(408) 720-0107.
/ADDR
/ADDR=nn specifies the PC Card Configuration Address. This option
defines the starting segment address for Card Services for PC Card
configuration. You must locate the segment nn within the first 1MB
address space and must specify the start address of a 2-digit hex
segment address. The granularity of nn is dependent on the socket
controller; however, the minimum address granularity allowed is 4K.
Leaving out the /ADDR argument defaults to an address beginning at
C000. However, if you follow normal setup operations, PCMSETUP
uses the /ADDR flag to anchor the CIS window to C800 (or another
address specified by the user).
Address Range: /ADDR= C0h-F0h.
/CLIENTS
/CLIENTS=n specifies the maximum supported Client Drivers. This
option controls the maximum number of client drivers that can register
with Card Services. Each client driver requires Card Services to
allocate 60 bytes of memory.
Default Value: /CLIENTS=10
/FLASH
/FLASH enables Flash File System Compatibility. /IRQ=n specifies the
Card Services IRQ level. This option defines the IRQ resource that
Card Services uses for PCMCIA card events such as insert and remove.
This IRQ is unrelated to the communication (COM:) ports.
Interrupt Range: /IRQ=8-15
Default Value: /IRQ=10
/PMOFF
/PMOFF disables the Power Management Option. This option controls
the power management provided with Card Services. If /PMOFF is
specified, then PCMCIA Cards are unilaterally powered-down on
SUSPEND messages; on RESUME messages the PC Cards are
powered-up and reconfigured (if there is an associated client driver) by
sending an artificial insertion message.
/MCA
/MCA enables Micro Channel Mode. This option handles interrupts and
card events as if it were working on a Micro Channel Bus. Use this
option if Card Services cannot automatically detect MCA.
/NOPM
/NOPM causes the program to ignore Power Management. This option
disables all CS power management, preventing CS from monitoring
power-management events. Use this option to prevent collisions with
non-APM-compliant power management schemes.
/POLL
/POLL enables Poll Card Events. This option enables sense-driven
rather than interrupt-driven card events. This switch is useful for noisy
hardware environments or when an IRQ is not available. This mode is
automatically enabled when an MCA is detected or the /MCA option is
used. Use this option when more than one adapter is present, avoiding
the need for multiple interrupts for monitoring card events.
/WAIT
/WAIT=n specifies the Card Settle Time. The Wait parameter is a value
specified in system timer ticks (18.2 per second) that determines the
delay time needed from the time you insert a PC card to the time at
which it becomes accessible. This option is useful for PC Cards that
have longer settle times.
Default value: /WAIT=1
Range: /WAIT= 1-100.
/XIRQ
/XIRQ=xxxx specifies system IRQs to exclude. On a bare IRQ system,
as shown in the table below, Card Services can use only IRQ10, IRQ11,
IRQ12, or IRQ15 for card events. Fully loaded systems, however, such
as multimedia systems, often require these same IRQ levels. In such
cases, use /XIRQ to exclude these IRQs from Card Service
consideration and avoid conflicts.
The variable xxxx decodes to the following IRQs.
\XIRQ=0400 Excludes Card Services from using
IRQ10
\XIRQ=0800 Excludes Card Services from using
IRQ11
\XIRQ=8A00 Excludes Card Services from using
IRQ10, IRQ11, and IRQ15 from
Card Services, leaving only IRQ12
available.
The following table shows what IRQ levels are typically dedicated to
certain devices.
IRQ0 Timer Output
IRQ1 Keyboard
IRQ2 Route to Interrupt Controller 2, IRQ8 to 15
IRQ3 Serial Port COM2
IRQ4 Serial Port COM1
IRQ5 Parallel Printer Port 2
IRQ6 Floppy-disk controller
IRQ7 Parallel Printer Port 2
IRQ8 Real-Time Clock
IRQ9 Software redirect to IRQ2 (INT 0AH)
IRQ10 Reserved (default PC Card events)
IRQ11 Reserved
IRQ12 Reserved
IRQ13 80x87 Math Coprocessor
IRQ14 Hard-Disk controller
IRQ15 Some Hard-Drive/SCSI controllers
G.3.4 Super Client Driver (PCMSCD.EXE)
The Phoenix Super Client Driver is a Card Services client that increases
the efficiency of resource acquisition by requesting system resources
from Card Services, such as memory, I/O, and IRQ. When requested in
this way, they appear to the system as resident for use by software.
PCMSCD must reside in the same directory as the active PCM.INI.
PCMSCD reads its boot options as well as configuration information
used to enable PCMCIA cards from PCM.INI.
When PCMSCD is booted, selected card configurations are loaded into
a list maintained by PCMSCD. When a PC Card is inserted, PCMSCD
identifies the card and looks for a possible configuration in this list. If a
configuration is found that matches the card, the configuration is
attempted. If a matching configuration is not found, PCMSCD
examines the CIS configurations on the card to see if the card is a
generic modem/fax/serial card and if it is, PCMSCD tries to enable the
card as such. If a configuration is successful, PCMSCD beeps once.
PCM Plus automatically loads PCMSCD.EXE into the CONFIG.SYS
file and writes the PCMSCD= argument to the PCM.INI file.
Note: Do not try to write the arguments listed below to
CONFIG.SYS. They belong in the PCM.INI file.
Add or change options of PCMSCD.EXE by typing a slash and then the
option, like in the following example.
PCMSCD /NOBEEP /NOMS /NODB /NW /LEVEL
Table G-5
PCMSCD Options
/NOBEEP Disables beeps when a LAN or
Fax/Modem PCMCIA
card, such as the MultiModemLT is configured. The default is beeps
enabled. (The program emits a high beep when a card is inserted or is
successfully configured and emits a lower beep when a card is
extracted.)
/NOMS Do not save modem state
information on power down.
/NODB Disables internal card information
database.
/NOMODEM Disables the generic configuration
for modems.
System no longer automatically
recognizes Fax/modem PC cards.
/NW Do not wait on error/warning
message.
G.3.5 Resource Manager (PCMRMAN.SYS)
When PCMCS loads, it has no way of knowing which system resources
have been allocated and to which addresses and IRQs they are now
assigned. PCMRMAN.SYS is the program that tells PCMCS what the
system resources are. PCMRMAN.SYS loads before PCMCS and scans
I/O and RAM memory space (in the UMB from A000-FFF), as well as
IRQ assignments. It then checks the PCM.INI file under
INSTALL.Resources to determine what the Manufacturer's overrides
are. Once these are established, PCMRMAN.SYS passes the
information along to PCMCS which then goes about the job of making
device allocations.
Normally, when you install PCM Plus, PCMRMAN.SYS is
automatically copied over to the appropriate directory and is written
into the CONFIG.SYS file. If this is not the case, PCM Plus will not run
properly, if at all.
Note: Never run PCM Plus without having PCMRMAN.SYS loaded
first.
PCMRMAN /NOSCAN
Disables the PCMRMAN.SYS scan which determines system
resources. If you use this resource, make very certain that every system
resource is documented as included or excluded to PCM Plus in the
[INSTALL.Resources] section. Otherwise, do not include this
parameter.
G.3.6 Configuration Name for Multiple Boot Option
(CNFIGNAM.EXE)
CNFIGNAM.EXE is a device driver that specifies which PCM Plus
configuration parameters to use based on the selected boot
configuration. CNFIGNAM is added to the CONFIG.SYS file by the
PCM Plus setup utility.
You have only one configuration option unless you are using DOS 6.0
in multiple boot mode. In this case, PCM.INI will have defined system
resource requirements for all boot configurations for which PCM Plus
is installed. After you specify a boot configuration at startup,
CNFIGNAM identifies your selection when CONFIG.SYS is loaded
and removes the relevant configuration information from the PCM.INI
file.
CNFIGNAM.EXE /config_name identifies the PCM Plus configuration
to use. For example, cnfigname.EXE /NEW identifies /NEW as the
name of the boot configuration selected at system startup.
The PCM.INI file may contain multiple setup configurations for PCM
Plus. Each of these sections is identified using square brackets, [ ].
If you type CNFIGNAM at the DOS prompt without argument, it
reports the current boot configuration name for PCM Plus.
Appendix H: Troubleshooting PCM Plus
PCM Plus provides you with a large number of help messages which
should smooth the way during the installation, setup, and configuration
process.
PCM Plus also provides a large number of error messages which should
help you understand not only what is wrong but, more importantly, how
to fix it.
H.1 PCM Plus Installation
You may see the following messages when running the PCM Plus
installation program. Follow the instructions provided below the
message.
APM and POWER.EXE are not loaded.
Copy APM over to your /DOS directory. POWER.EXE should already
be there. Define the location of both files in your CONFIG.SYS file.
Could not allocate memory!
Not enough memory space found. You probably have to reallocate
memory resources either by changing the CONFIG.SYS or by
rerunning your memory manager. See Appendix G for more details.
Directory does not exist!
PCMSETUP could not find the directory you specified. Create a new
directory.
Error! It has been determined that your system has another version of
PCMCIA utilities installed.
Remove all old version of PCMCIA utilities currently in your
CONFIG.SYS and AUTOEXEC.BAT files. See Appendix F for more
details.
PCM+ Drivers already installed!
You have already installed this version of PCM Plus, in which case you
don't have to reinstall it.
PCM+ Subsequent Installation!
Your old PCM Plus files are already loaded. REMark out all references
to previous versions of PCM Plus in your CONFIG.SYS and
AUTOEXEC.BAT files according to the instructions provided in
Appendix F.
Warning! It has been determined that your system is capable of multiple
boot configurations.
As previously mentioned in this manual, MS-DOS 6.0 allows multiple
boot configurations. If the PCM Plus installation program finds this
program, it queries you as to whether you want PCM Plus installed on
this particular boot configuration or another. If you prefer to have PCM
Plus loaded on a different boot configuration, exit the install program,
reboot the system, and specify the configuration you do want.
H.2 PCM Configuration
Most of the error messages you will encounter in PCM Plus are self-
explanatory. The following are error messages that might need a little
more explanation.
ERROR: Card Services is not installed !!!
The file PCMCS is not properly installed. Either run the PCM
installation program again or manually copy the PCMCS.EXE file from
the distribution diskette to the current PCM Plus directory (usually
/PCM31).
ERROR: PCM cannot run under MS-Windows. Use PCMWIN.EXE
instead.
You have tried to access PCM from Windows. This is a DOS program
and does not run under Windows. Install and use PCMWIN. See
Chapter 2 for details.
Requested configuration unavailable
One or more of the configuration changes you tried to make to this card
is not available. If possible, make another selection or leave the
configuration at its default values.
Requested I/O unavailable
The I/O setting you tried to assign this card is not available, probably
because it is being used by another device. Either select another I/O
setting, accept the default, or reallocate the I/O of the device that
currently controls it.
Requested IRQ unavailable
The IRQ level you tried to assign this card is not available, probably
because it is being used by another device. Either select another IRQ,
accept the default, or reallocate the IRQ of the device that currently
controls it.
Requested Memory unavailable
The memory range setting you tried to assign this card is not available
probably because it is being used by another device. Either select
another range setting, accept the default, or reallocate the memory of
the device that currently controls it .
Unavailable COM
The COM value you tried to assign is already being used by another
device. Either reassign this card port to another COM or reassign the
port that already has this value.
Unconfigured
The card you tried to install does not have a CIS. Use PCM to assign
parameters to the card.
If the card you inserted is a Flash Card and receives this message, it
does not mean that PCM Plus cannot run the card; try it and see. In
most cases, the card will run. If the card receiving this message is an
I/O card, it means PCM will not be able to run it.
H.3 PCM Windows Configuration
Most of the error messages you will encounter in PCMWIN are self-
explanatory. The following are error message that might need a little
more explanation.
PCMCS.EXE not loaded.
The card services driver is not loaded. Either rerun PCM installation or
manually copy PCMCS.EXE from the distribution diskette to the
appropriate PCM Plus directory (usually /PCM31). If problems persist,
check the path name designated in the CONFIG.SYS file and change it
if necessary.
PCMSCD.EXE not loaded.
The super client driver is not loaded. Either rerun PCM installation or
manually copy PCMSCD.EXE from the distribution diskette to the
appropriate PCM Plus directory (usually /PCM31).
Unable to locate PCM.INI.
The program cannot find PCM.INI. Rerun PCM installation.
Unable to allocate enough memory.
PCM Plus could not find sufficient memory to do its job. Run your
memory manager to optimize your memory use (see Appendix G) or
remove some of your TSRs from memory. If you have many
applications currently running in Windows, exit them and try again.
Requested configuration unavailable
One or more of the configuration changes you tried to make to this card
is not available. If possible, make another selection or leave the
configuration at its default values.
Requested I/O unavailable
The I/O setting you tried to assign this card is not available, probably
because it is being used by another device. Either select another I/O
setting, accept the default, or reallocate the I/O of the device that
currently controls it.
Requested IRQ unavailable
The IRQ level you tried to assign this card is not available, probably
because it is being used by another device. Either select another IRQ,
accept the default, or reallocate the IRQ of the device that currently
controls it.
Requested Memory unavailable
The memory range setting you tried to assign this card is not available
probably because it is being used by another device. Either select
another range setting, accept the default, or reallocate the memory of
the device that currently controls it .
PCMWIN can only add I/O cards (i.e., Fax/Modem, LAN, SCSI, Sound
Card).
PCMWIN automatically configures media cards such as Flash cards
and ATA disk cards so you won't have to configure these. You should
only have to configure I/O cards.
H.4 Additional Error Messages
The following are other error messages you might find.
Socket Services not loaded
The file PCMSS.EXE is not loaded. Either rerun PCM Plus installation
or copy PCMSS.EXE from the distribution diskette to the appropriate
directory. If problems persist, check the path name designated in the
CONFIG.SYS file and change it if necessary.
Socket Services version must be 2.0 or greater
The copy of PCMSS.EXE you have loaded on your machine is not up-
to-date. Copy PCMSS.EXE from your distribution diskette to the
directory where the old version of PCMSS currently resides.
Optionally, reinstall PCM Plus with an updated version.
Incorrect command-line parameter(s) detected
While loading one of the PCM Plus programs or drivers, an incorrect
parameter was detected. Check your CONFIG.SYS, PCM.INI, and
WIN.INI files for incorrect switch settings. See Appendix G for more
details.
ERROR: Syntax error in command line !
The program tried to load a driver that had the wrong syntax in its
CONFIG.SYS or PCM.INI line. Refer to driver descriptions in
Appendix G.
ERROR: PCMSCD requires 80386 processor or above.
PCMSCD and PCM Plus cannot be run on a computer possessing less
than an 80386 processor.
Appendix I: Regulatory Compliance
This appendix contains compliance information about the
MultiModemLT and the FCC, DOC, and BABT. See the following
sections for more information.
I.1 FCC Regulations for Telephone Line
Interconnection
1. This equipment complies with Part 68 of the Federal
Communications Commission (FCC) rules. On the outside surface of
this equipment is a label that contains, among other information, the
FCC registration number and ringer equivalence number (REN). If
requested, this information must be provided to the telephone company.
2. As indicated below, the suitable jack (Universal Service Order
Code connecting arrangement) for this equipment is shown. If
applicable, the facility interface codes (FIC) and service order codes
(SOC) are shown.
An FCC-compliant telephone cord and modular plug is
provided with this equipment. This equipment is designed to be
connected to the telephone network or premises wiring using a
compatible modular jack which is Part 68 compliant. See installation
instructions for details.
3. The ringer equivalence number (REN) is used to determine the
quantity of devices which may be connected to the telephone line.
Excessive REN's on the telephone line may result in the devices not
ringing in response to an incoming call. In most, but not all areas, the
sum of the REN's should not exceed five (5.0). To be certain of the
number of devices that may be connected to the line, as determined by
the total REN's, contact the telephone company to determine the
maximum REN for the calling area.
4. If this equipment causes harm to the telephone network, the
telephone company will notify you in advance that temporary
discontinuance of service may be required. But if advance notice isn't
practical, the telephone company will notify the customer as soon as
possible. Also, you will be advised of your right to file a complaint with
the FCC if you believe it is necessary.
5. The telephone company may make changes in its facilities,
equipment, operations, or procedures that could affect the operation of
the equipment. If this happens, the telephone company will provide
advance notice in order for you to make necessary modifications in
order to maintain uninterrupted service.
6. If trouble is experienced with this equipment (the model of
which is indicated below) please contact Multi-Tech Systems, Inc. at
the address shown below for details of how to have repairs made. If the
equipment is causing harm to the telephone network, the telephone
company may request you remove the equipment from the network until
the problem is resolved.
7. No repairs are to be made by you. Repairs are to be made only
by Multi-Tech Systems or its licensees. Unauthorized repairs void
registration and warranty.
8. This equipment cannot be used on public coin service
provided by the telephone company. Connection to Party Line Service
is subject to state tariffs. (Contact the state public utility commission,
public service commission or corporation commission for information.)
9. If so required, this equipment is hearing-aid compatible.
Manufacturer: Multi-Tech Systems, Inc.
Trade name: MultiModemLT
Model Number: MT2834LT
FCC Registration Number: AU7USA-21724-MM-E
Ringer Equivalence: 0.2B
Modular Jack (USOC): RJ11C or RJ11W (single line)
Service Center in U.S.A.: Multi-Tech Systems Inc.
2205 Woodale Drive
Mounds View, MN 55112
(800) 328-9717
(612) 785-3500
(612) 785-9874 FAX
I.2 Canadian Limitations Notice
Notice: The Canadian Department of Communications label identifies
certificated equipment. This certification means that the equipment
meets certain telecommunications network protective, operational and
safety requirements. The Department does not guarantee the equipment
will operate to the user's satisfaction.
Before installing this equipment, users should ensure that it is
permissible to be connected to the facilities of the local
telecommunications company. The equipment must also be installed
using an acceptable method of connection. In some cases, the
company's inside wiring associated with a single line individual service
may be extended by means of a certified connector assembly (telephone
extension cord). The customer should be aware that compliance with
the above conditions may not prevent degradation of service in some
situations.
Repairs to certified equipment should be made by an authorized
Canadian maintenance facility designated by the supplier. Any repairs
or alterations made by the user to this equipment; or equipment
malfunctions, may give the telecommunications company cause to
request the user to disconnect the equipment.
Users should ensure for their own protection that the electrical ground
connections of the power utility, telephone lines and internal metallic
water pipe system, if present, are connected together. This precaution
may be particularly important in rural areas.
Caution: Users should not attempt to make such connections
themselves, but should contact the appropriate electric inspection
authority, or electrician, as appropriate.
The Load Number (LN) assigned to each terminal device denotes the
percentage of the total load to be connected to a telephone loop which
is used by the device, to prevent overloading. The termination on a loop
may consist of any combination of devices subject only to the
requirement that the total of the Load Numbers of all the devices does
not exceed 100. The Load Number for this product is 2.
This digital apparatus does not exceed the Class B limits for radio noise
emissions from digital apparatus set out in the Radio Interference
Regulation of the Canadian Department of Communications.
Le présent appareil numérique n'émet pas de bruits radioélectriques
dépassant les limites applicables aux appareils numériques de la classe
B prescrites dans le Règlement sur le brouillage radioélectrique édicté
par le ministère des Communications du Canada.
I.3 Compliance with BABT Requirements
Approved for connection to telecommunications system specified in the
instructions for use subject to the conditions set out in them.
Warning: Interconnection directly, or by way of other apparatus, of
ports marked "SAFETY WARNING see instructions for use" with ports
marked or not so marked may produce hazardous conditions on the
network. Advice should be obtained from a competent engineer before
such a connection is made.
I.3.1 European Low Voltage Directive
When correctly installed and maintained, the modem will present no
hazard to the user. When correctly installed the modem will be
connected to the PSTN and to a Data Terminal Equipment (DTE).
I.3.2 Compliance with BS6305 Clause 6.2, BS6320 Clause 7.2, and
BABT/SITS/82/005S/D
a. The modem is suitable for connection to the Public Switched
Telephone Network (PSTN) provided by British Telecommunications
pic or Kingston Communications (Hull) pic. Circuit supply by British
Communications, Mercury Communication, or Hull City Council. Only
direct exchange lines may be used, not shared service.
b. The modem is suitable for household, office, and similar
general indoor use. It is not suitable for use as an extension to a
payphone.
c. BT lines supplied must support either loop disconnect or
multifrequency tone signalling.
d. REN (Ringer Equivalence Number).
The REN value of a unit is calculated from 3/n where n is the total
number of units which can be connected in parallel which will still
cause the standard bell (as defined in BS6305 Appendix D) to ring.
REN values of less than 0.3 cannot be assigned.
REN = 1
If a telephone or other device is connected in parallel with the modem,
the combined REN must not exceed 4. A BT supplied telephone may be
assumed to have REN of 1.0 unless otherwise noted.
The approval of this modem for connection to the British Telecom
public switched telephone network is INVALIDATED if the apparatus
is subject to any modification in any material way not authorized by
BABT or if it is used with or connected to:
i. internal software that has not been formally accepted by
BABT.
ii. external control software or external control apparatus which
cause the operation of the modem associated call set-up equipment to
contravene the requirements of the standard set out in
BABT/SITS/82/005S/D.
All apparatus connected to this modem and thereby connected directly
or indirectly to the British Telecom public switched telephone network
must be approved apparatus as defined in Section 22 of the British
Telecommunications Act 1984.
I.3.3 Compliance with BS6789: Section 3.1 and Part 2
a. The modem is not capable of allowing Auto Call using '999' or
other PABX emergency numbers.
b. Modes other than modes 1, 2, or 3 should not be used on the
BT PSTN. This modem is a mode 1 device.
c. Users are advised to check the numbers entered during the
Auto Call set up phase prior to dialing.
d. The user should not issue any sequence of commands to the
modem which would cause the modem to exceed the maximum
allowable pause of 8 seconds from the time the modem goes off hook
until dialing begins.
e. For correct operation of the call progress monitor, the power
has to be properly connected and switched on.
I.3.4 Compliance with DTI 83/009
a. The apparatus is only approved for compatible PBXs. Consult
the supplier for an up-to-date list of compatible PBXs.
b. There is no guarantee of correct working in all circumstances.
Any difficulties should be referred to Multi-Tech Systems.
c. If sockets are required for connection to the PBX, use the BT
post card only if BT owns the wiring to the PBX.
This apparatus has been approved for the use of the following facilities:
* Auto-calling
* Loop disconnect and MF dialing
* Phone number storage and retrieval by a predetermined code
* Operation in the absence of proceed indication
* Automatic storage of last number dialed
* Tone detection-busy
* Auto clear from the originating end
* DTR dialing
* Modem
* PBX timed break register recall
Any other usage will invalidate the approval of the appartus if, as a
result, it then ceases to comply with the standards against which
approval was granted.
