CLX L32E Weird Problem

I'm having a weird issue with a brand new CLX L32E processor and I/O modules. When I remove power from the CLX system and the system is in RUN mode, once I apply power back I get a major Fault telling me that there's a problem with the module in slot 1 (which is a 1769-IQ16).

The full description of the error is:
(Type 03) I/O Fault
(Code 16) I/O module failed on required module
Port: Backplane
Module: Slot_1
Error: Connection Timed Out
Info: <none>

When I reset the error, everything operates fine until I power down the system and then power it back up. I also swapped the IQ16 module with another one thinking that it's faulty, but I still get the same issue.

If I switch the processor to Program mode and cycle the power and then put it into run, everything is fine.

Anybody run into a similar situation that can give me some advice?

TIA
Jr.

Have you got the 1769-ECR end cap fitted on the end of your i/o?

Yes the ECR cap is on and all the modules are locked in together.

The difference between the behavior when power is cycled in RUN mode versus PROG mode is the second checkbox on the Connections tab for the module; CompactLogix I/O modules are configured by default to cause a fault of the controller if the connection fails in RUN mode.

You can experiment by un-checking that box; the controller should behave the same when power cycled in RUN mode or PROG mode.

But that's not ordinary behavior at all. I would say there is a bent pin or damage to the CompactLogix backplane bus controller.

Another thing to check; if there are any 1769 analog modules on the bus that are receiving external power, doublecheck to be sure the power selector is set for External.

Usually Slot 1 errors really mean Slot 1 but on very rare occasions the fault is elsewhere on the bus but is detected at the first slow.

Ken Roach said:

Another thing to check; if there are any 1769 analog modules on the bus that are receiving external power, doublecheck to be sure the power selector is set for External.

Usually Slot 1 errors really mean Slot 1 but on very rare occasions the fault is elsewhere on the bus but is detected at the first slow.

Click to expand...

Now there's a handy piece of information to have. Glad I read this.

Makes me wonder...I just bought a brand new ComapactLogix L32E as well...I should try it to see if I get the same thing.

Thanks for the info Ken, I have a feeling it's going to be something stupid like the external power switch. I do have IF4 and OF2 modules in the system. Plus, I have an identical CLX system for a second machine and it doesn't have this problem. I'll do some more troubleshooting tomorrow and let you know how I make out.

That was it. My IF-4 module had the switch on external when I was using the backplane power. Thanks for the help.