To Next Page

To Previous Page

Troubleshooting

Chapter 4

4-3

Recommended ActionProbable CauseDescription

Indicators

Active Adapter I/O

Fault Rack

Blink On Off Module identification line fault Excessive noise on backplane Verify power supply and chassis

grounding

Off Off Off Module not communicating Power supply fault

Wiring from scanner to adapter module

disrupted

Scanner not configured properly

One faulted chassis within a rack group

address causing scanner/distribution

panel to fault all chassis in rack group

address (when in disable search mode)

Check power supply, cable

connections, and make sure adapter

module is fully seated in chassis.

Correct cable and wiring defects

Refer to publication 1772-2.18 for

scanner configuration

Check sequentially from the first

module to the last module to pinpoint

fault; correct any faults and proceed to

the next chassis

1. You must select the operating mode of the remote I/O adapter module as outlined in the publication furnished with the remote I/O scanner/distribution

panel, remote I/O scanner-program interface module, or I/O scanner-message handling module. Pay close attention to the disable search mode in

the 1771-SD, -SD2.

2. The I/O chassis is in faulted mode as selected by the last state switch on the chassis backplane.

3. Cycling power clears the block-transfer request queue. All pending block transfers are lost. Your program must repeat the request for block transfers

from the chassis.

4. If a fault occurs and the processor is in the run mode but is actually operating in the dependent mode, the chassis fault response mode is selected by

the last state switch on the chassis backplane.

5. The I/O chassis is in faulted mode as selected by the last state switch on the chassis backplane.

6. If excessive chassis faults occur, check switch SW2, position 6 for the OFF position.

In this chapter you learned how to use the indicators on the front of the

module to troubleshoot your module.

Summary