SLC 500 Faults

Hello,
I was wondering if there is a way to view all the previous faults
from a SLC 5/05 controller?

Are there faults stored somewhere?

I was wanting to go back & look at all the faults that the controller
had faulted on if possible?


thanks,

No, there is no history of faults.

You might be able to send a message (MSG) to another PLC or other device on the network. You would have to write the code to do this in a "Fault Routine".

There's little point in storing faults internally, since quite a few of the major faults will clear the processor memory anyway, to protect itself.

I dont think so I once took an advanced class from RA and we did it with another node... the last scan of the faulted CPU sent the error code to a healthy CPU, if you are having a issue with one CPU that is losing everything (including comms) then you can set up another node to capture the error code

geniusintraining said:

I dont think so I once took an advanced class from RA and we did it with another node... the last scan of the faulted CPU sent the error code to a healthy CPU, if you are having a issue with one CPU that is losing everything (including comms) then you can set up another node to capture the error code

Click to expand...

I don't think that will be reliable - you would have to read it very rapidly, even then there'd be a chance you can miss it before the memory is cleared.

I'm convinced the only way is to try and send the error code in a fault routine, which will get executed before the processor shuts down. Even then, some major faults, the non-recoverable ones, don't execute the fault routine at all

There is no "last scan" of a faulted CPU - it will exit wherever it is, execute the fault routine if one exists and it's a recoverable fault, the the processor will "fault".

daba said:

There is no "last scan" of a faulted CPU - it will exit wherever it is, execute the fault routine if one exists and it's a recoverable fault, the the processor will "fault".

Click to expand...

We are talking about the same thing... just different terminology, a fault routine is what I was referring to, I dont teach Allen Bradley so my wording is not the same as your

The advanced class that I took was about 15 years ago...

"last scan" = fault routine

geniusintraining said:

We are talking about the same thing... just different terminology, a fault routine is what I was referring to, I dont teach Allen Bradley so my wording is not the same as your

The advanced class that I took was about 15 years ago...

"last scan" = fault routine

Click to expand...

It's good we got that cleared up.

But I don't think the OP has any chance of capturing the worst type of faults, i.e. those that don't execute the fault routine, and clear the memory.

I can't see justification in trying to capture just some of the faults, my efforts would be in ensuring the faults don't happen in the first place.

If a processor can be reloaded/restarted, then it unlikely to be a hardware fault, it's probably a software fault, and I would hunt them down...

Yes it does seem like a lot of work to capture faults... I dont think I have had that many to ever justify it, I did have a power supply that was giving me issues on a 5/04 a long time ago at that time I did the WAG and got lucky when I change the power supply it never came back