Volume II: Troubleshooting - Communication

FDDI/DX

Normal mode selftests run at powerup when the DIAG/NORM switch is in the NORM position. Attach a terminal set for 9600 baud, 8 data bits, no parity, and 1 stop bit to the serial port to monitor normal mode selftest output.

Extended selftests are run with the DIAG/NORM switch in the DIAG position. Attach a terminal set for 9600 baud, 8 data bits, no parity, and 1 stop bit to the serial port, and attach loopback cables between ports FDDI-A and FDDI-B. Enter s to enable the extended selftests. Enter a to display the Diagnostic Engineering Monitor (DEMON) menu.

LEDs indicate the status of the FDDI PCB and the network during operation.

LEDs 4, 1, and 0 indicate connection status for port FDDI-A.

LEDs 4, 3, and 2 indicate connection status for port FDDI-B. LED 4, RINGOP, is ON when the ring is not operational.

LED 5, PACKETIO, changes state each time a packet is received or successfully transmitted. LEDs 6 and 7 blink alternately four times per second under normal conditions.

LEDs 6 and 7 blink together two times per second when a non-recoverable firmware problem occurs.