
Troubleshooting
Remote I/O
5-24
troubleshooting – remote I/O system, 1771-ASB series B continued...
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 1772-SD and 1772-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.
Indicator
(on I/O rack)
Response
Description
Probable Cause
Recommended Action
Active
Adapter Fault
I/O Rack Fault
On
Blinking
Off
module placement
error in remote I/O
chassis
incorrect placement of
high-density modules
Verify addressing modes and
switch settings
Active
Adapter Fault
I/O Rack Fault
Both flash in
unison
Off
incorrect starting I/O
group number for
chassis size
error in starting I/O group
number or I/O rack address
Refer to processor manual to verify
acceptable beginning I/O group number; set
switches correctly
ACTIVE
ADAPTER
FAULT
I/O RACK
FAULT