10BASE-T & AUI.........Pinout and cable information This document contains 10BASE-T cabling information, troubleshooting, and the pinouts for 10BASE-T and AUI ports. NOTE: This document or an updated version (if the procedure changed since this was written) is available on FaxBACK. Document # 6202. If you would like additional information on the 10BASE-T specification, you can call the IEEE at 800-678-IEEE. INTRODUCTION: ------------- A 10BASE-T cable from the network card to the hub should be a straight through unshielded twisted pair cable. A typical problem with 10BASE-T is a crossed wire in the cable or wiring closet. If you experience problems where a hub cannot "see" a workstation, check to make sure the wiring is correct. To allow for a straight through cable, the hub provides an internal transmit/receive crossover function. This means the transmit circuit of the network card is connected to the receive circuit of the hub and vise versa. Function Pin# Pin# ------------------------------------- TX+ 1 <---------> 1 TX- 2 <---------> 2 RX+ 3 <---------> 3 RX- 6 <---------> 6 ------------------------------------- STRAIGHT THOUGH CABLE Even though there are eight pins on a 10BASE-T connector, only four are used (pins: 1 and 2 should be a pair, 3 and 6 should be a pair). The RJ-45 connector can support unshielded twisted pair (UTP) cable of 22, 24, or 26 gauge. The cable must comply with the IEEE 802.3 10BASE-T standard with the maximum distance between the computer and the hub being 100 meters. Silver satin is not within the 10BASE-T specification and cannot be used. If used, it may not work at all, or may give intermittent results. PRE 10BASE-T: ------------- If you're in a Pre10BASE-T environment, you'll need to use the AUI connector on the EtherExpress card with a transceiver. The transceiver must be setup for Pre10BASE-T (link integrity off). LINK INTEGRITY: --------------- For 10BASE-T networks, Link integrity (LI) needs to be on. Some transceivers, ethernet cards, or other network devices allow you to turn it off, but Link Integrity is always on with the EtherExpress cards. If you're using a transceiver to go to a thick/thin ethernet segment, Link Integrity must be set to on for the transceiver. POLARITY PROBLEMS: ------------------ Another problem in 10BASE-T wiring is crossing the positive and negative phases of the transmit or receive signals. For example, a problem would occur if pins 1 and 2 were crossed. (TX+ connected to TX-). Some 10BASE-T network adapters can automatically detect this problem an adjust for it internally. Early EtherExpress 16 TPs did not have this feature, but the current EtherExpress 16 TP and EtherExpress MCA TP do. Even though the current EtherExpress adapters can take care of this crossover for you, it is best to check your wiring and correct this problem if you find it. If your workstations are having problems connecting, reset or power off/on your concentrator or hub. CONNECTING TWO WORKSTATIONS WITHOUT A HUB: ------------------------------------------ 10BASE-T uses a star topology. This means there is a hub or concentrator is in the center of a star and each workstation or server is connected to this hub. For test purposes, you can connect directly connect two workstations or a workstation and a server without using a hub. This requires a special cable that incorporates the crossover function talked about at the being of this document. Function Pin# Pin# Function -------------------------------------------------- TX+ 1 <---------> 3 RX+ TX- 2 <---------> 6 RX- RX+ 3 <---------> 1 TX+ RX- 6 <---------> 2 TX- -------------------------------------------------- CROSSOVER CABLE PINOUT FOR RJ-45 CABLE CONNECTOR: --------------------------------- ---------- -------------------------- 1 |-- | 1 |------------ | 2 |-- | 2 |------------ | 3 |-- --- 3 |------------ | 4 |-- | 4 |------------ | 5 |-- | 5 |------------ | 6 |-- --- 6 |------------ | 7 |-- | 7 |------------ | 8 |-- | 8 |------------ | ---------- -------------------------- END TOP PIN NAME AND FUNCTION 1 Transmit Data Plus. The positive signal for the TD differential pair. This signal contains the serial output data stream transmitted onto the network. 2 Transmit Data Minus. The negative signal for the TD differential pair. This contains the same output as pin 1. 3 Receive Data Plus. The positive signal for the RD differential pair. This signal contains the serial input data stream received from the network. 4 not connected 5 not connected 6 Receive data minus. The negative signal for the RD differential pair. This signal contains the same input as pin 3. 7 not connected 8 not connected PINOUT FOR AUI PORT: -------------------- shell = protective ground | --------------------------------------------- | o o o o o o o o | \ 1 2 3 4 5 6 7 8 / \ / \ o o o o o o o / \ 9 10 11 12 13 14 15 / --------------------------------- PIN NAME AND FUNCTION 1 Control-in Shield. The shield for the CI twisted pair on the AUI cable. 2 Control-in Circuit A. The positive signal for the CI circuit. This circuit is used to send the mau_available and signal_quality_error messages to the equipment. 3 Data-out circuit A. The positive signal for the DO circuit. 4 Data-in Shield. The shield for the DI twisted pair in the AUI cable. 5 Data-in Circuit A. The positive signal for the DI circuit. 6 Voltage Common. The ground return for the VP circuit. 7 not connected 8 not connected 9 Control-in Circuit B. The negative signal for the CI circuit. This circuit sends the same signals as listed under pin 2. 10 Data-out Circuit B. The negative signal for the DO circuit. 11 Data-out Shield. The shield for the DO twisted pair in the AUI cable. 12 Data-in Circuit B. The negative signal for the DI circuit. 13 Voltage Plus. The power supply to the transceiver. The supply must remain in the range of 12V - 6% to 15V + 5%. 14 Voltage Shield. The shield for the VC and VP (pins 6 and 13) twisted pair. 15 not connected