User manual

Troubleshooting
Extended Local I/O 5-27
Troubleshooting
Extended Local I/O 5-27
troubleshooting – extended local I/O system, 1771-ALX continued...
1
The I/O chassis is in faulted mode as selected by the last state switch on the chassis backplane.
2
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.
3
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.
Indicator Response Description Probable Cause Recommended Action
Active
Adapter Fault
I/O Rack Fault
Off
Off
Off
no power or no
communication.
power supply fault Check power supply, cable
connections, and make
sure adapter module is
fully seated in chassis
Active
Adapter Fault
I/O Rack Fault
On
Blinking
Off
module placement error
in extended local I/O
chassis
incorrect placement
of high-density
modules
Verify addressing modes
and switch settings
ACTIVE
ADAPTER
FAULT
I/O RACK
FAULT