Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers - Manual (Page 356)

Publication 1785-UM012D-EN-P - July 2005
F-8 Troubleshooting
Troubleshooting Guide for the 1771-ASB Series C and D
Adapter Module (continued)
Indicators Description Probable Cause Recommended Action
Active Adapter
Fault I/O
Rack
Off Off On
I/O chassis fault.
(1)
No communication
on link.
Problem exists between:
• adapter and module in chassis; the
module will stay in fault mode until
fault is corrected
• shorted printed circuit board runs on
backplane or I/O module
Cycle power to the chassis to clear a
problem resulting from high noise.
(2)
• Remove and replace all I/O modules one at a
time
• If problem does not clear, something is
wrong in chassis or I/O module
Blink Off On Communication
on link.
Possible shorted
backplane • Noise on backplane
• Shorted circuit board runs
• Faulty card in chassis • Eliminate noise
• Isolate noise
• Add surge suppression
• Replace chassis
• Replace defective card in chassis
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
See 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) The I/O chassis is in faulted mode as selected by the last state switch on the chassis backplane.
(2) Cycling power clears block-transfer request queue. All pending block transfers are lost. Your program must repeat the request for block transfers.