PLC 5 Faulted / Not Faulted

I have a PLC5 rack that had a power supply go out. Changed power supply and unable to communicate with processor with the exception of seeing it in RsLinx. No fault light on processor but when trying to go online with it it shows faulted and gives me the error in the attached image. I am connecting to it through a ControlLogix ENBT and DHRIO module. Keyswitch is in Run position. What am I missing?

Going online with a faulted controller needs the same sort of resources as making an edit, so you can't do it with the keyswitch all the way in hard RUN mode.

The phrase "Check for keyswitch in RUN mode" means "it can't be in RUN mode" not "check to be sure it is in RUN mode".

Switch to PROG mode cycle power, and try again.

another point ...

since the RSLinx doesn't appear to be showing a NAME for the processor, then the processor MIGHT have completely lost its program ... "dead in the water" ... this usually occurs when the battery is dead - and the power is turned off ...

if that's the case, you'll need to download the program ...

after you cycle the keyswitch, recheck the PROC light (LED) on the front of the processor ... is it SOLID red - or FLASHING red? ...

You didn't specify in your post whether the PLC was the 5/30 or the 5/80. I think we are assuming it is the 5/80 since you said you can see it in RSLinx. If it is instead the PLC-5/30 you are trying to talk to, please let us know.

You mentioned there is no fault light on the CPU. I assume you are saying there are no red lights on the CPU. If the keyswitch is in Run, you should see a solid green PROC light. If it were faulted, it would be flashing or solid red. RSLinx seems to think it is faulted.

But as Ron pointed out, not seeing a name for that CPU would usually indicate a fault where the controller has dumped the program. That would show a solid red PROC light (non-recoverable fault) on the CPU. If that is the case then you cannot go online with the controller since there is no program loaded. It cannot recover from this, The program must be reloaded.

If the key is in the hard run position, the fault cannot be cleared and you can't reload the program. Move it to the REM position and the software will be allowed to clear the fault.

If the light is flashing red, then the program is still there but there is a recoverable fault. With those, the existing program is intact so you can recover from this. But, by all indications, this is not the case.

OG

I had something similar on a SLC that was running with RSLinx.


Had to close RSLinx, delete the harmony files, then reopen it. Somehow the fault locked the reading in RSLinx.


Here's how to do that - it does NOT delete your drivers or settings, only the WhoIs display information that is recreated when opened.


EDIT - I just use the manual method, delete 2 files in the Rockwell Software folder.

The PLC had lost it's program. Whenever Ron mentioned the name of the PLC missing I went back to RsLinx and noticed that only the default configured channel was communicating on the DH network and not the other which was also configured to communicate on the DH network. Went today switched it to REM and was able to download backup copy of program. All is good.

Thanks guys for the extra set of eyes and bits of troubleshooting hints.