Control Logix faulting a 1771-ASB module

i seem to be having an issue with a Remote IO adapter part number 1771-ASB. We are communicating to it via a control logix PLC
using a 1756 RIO module.

So here is the issue. The dip switch settings on the backplane of the rack holding the 1771-ABS are set accordingly.

So at any instance when we do a full download to the Control logix PLC, the 1771-ASB module goes into a faulted state.

Their are 3 diagnostics LED's on the 1771-ASB module The first one is an Active, second being Adapter fault and third being I/O rack

So when we have the fault the Active and the Adapter fault Blink alternatively. So i looked at the Troubleshooting guide for a solution to this
and it mentions that either the Adapter module not actively controlling the I/O or adapter module in the processor restart lockout mode
(adapter to scanner link not normal)

As a solution the manual suggested that the IO chassis is in a faulted mode as selected by the last state switch on the chassis backplane
i looked at the state of the switch for the last state and its currently set to oFF which means the outputs of this IO chassis are denergized when
a fault is detected. which is fine in out application.

I just don't see why doing a full download to the control logix PLC the 1771-ASB faults with the LED description that i described. And the only way
the fault on the 1771-ASB adapter is cleared is if we turn off the rack and turn it back on.

I know we get an Input and output process image table for the 1771-ASb via the 1756 RIO module, maybe in their i can monitor the status of an error
bit then send a reset request

IF anyone knows why this is happening please let me know.

It is totally normal for a RIO adapter to fault when you do a download to the ControlLogix. At that point the 1756-DHRIO isn't just in an Idle state (like it would be in Program Mode) but has to completely stop scanning the network because it doesn't have a control connection from the CPU.

What's not normal is having to cycle power to get the RIO adapter to restart. That's usually because the Processor Restart Lockout DIP switch in the 1771 backplane chassis is set to enable PRL.

"Processor Restart Lockout" means the PLC scanner (PLC-2, 3, 5, or ControlLogix) cannot restart a faulted 1771 adapter over the RIO network, but rather the adapter needs to be manually reset. This is sometimes implemented with keyswitches (terminals 11 and 12 on the wiring swingarm) but typically is accomplished with a power cycle.

Ken thanks for your reply,, when I said we turn off the rack and turn it back on I meant using the key switch and toggling it off then on and that clears it. I was just hoping that every time we download to the control logix Plc we dont have to manually reset it if their is a way around let me know. The current switch setting for the processor restart lockout switch is ON meaning the processor can restart the io chassis

If the PRL switch on the backplane is ON, the 1771-ASB should go back into run mode when the PLC goes back into run mode.

PRL is the second switch from the top, and it should be pushed to the right to place it in the ON position. Cycle it back and forth a few times to be sure it's seating properly.

I haven't worked on 1771-ASB adapters in three or four years so my knowledge is a little stale. I don't have any to test or experiment with.