SLC 5/03 Fault A50h

I have a PLC stopping and generating this major fault once a week, or so. Does the "A" represent slot 10 according to the I/O configuration? If that is the case, it is the RIO scanner. If it is the 10th slot (9 in the config) then it is a 1746sc-OAP8I. In either case...what should I be looking for? This is shutting down a small 24 hour/day plant at random intervals. Thanks!!

As far as I remember, when you look at the online CPU Status in RSLogix, there is a description of the major error in clear text.

You are right.

From RSLogix online help:

The characters xx in the following codes represent the slot number, in hex. If the exact slot cannot be determined, the characters xx become 1F.
[...]
Error xx50 means: A rack data error is detected. This error is recoverable.

Click to expand...

That the error is recoverable means you can set the error fault routine to handle it. In that way you can possibly avoid the CPU from faulting.

But you should probably exchange the rack, the module in the slot, or both.

Yes Jesper, there is a text message if you get there when the PLC is still faulted. Unfortunately, the system can't be left faulted until someone gets there. What I was really asking is if the "XX" (in my case it displays A (10 decimal)) in the code represents slot 10 according to the I/O configuration or the 10th physical slot which would be 9 in the config? Thanks!

Try an unconditional rung at the bottom of the ladder to OTU S:5/0 as a stop-gap measure.

bluenoser, I believe the slot numbering is as it is in the IO Configuration. Which means the CPU or comms adapter is in slot 0, and the i/o modules are in slots 1,2,3...
Only 90% sure though

rguimond said:

Try an unconditional rung at the bottom of the ladder to OTU S:5/0 as a stop-gap measure.

Click to expand...

rguimond, the error he gets is A50hex wich points to a hardware problem with the rack or a module. S:5/0 is the math overflow trap bit. They dont have anything directly to do with each other.

Maybe it is possible to clear the error in software. Set the S:29 to a program file number for the fault handling code. Then in that file clear S:1/13.
But if the module in question is important or critical, then it is not recommended.