Displaying PLC fault codes.

Hello all,
I'm thinking about how helpful could be adding a HMI screen to display the faults or errors that can happen to the PLC. I usually use the Micrologix or Compactlogix series.
Let's say that I have an Allen Bradley Micrologix 1500, and I want to see the PLC faults on the HMI. I read I have to look at file S2:6 to see which code is active.
I don't want to reinvent the wheel, could somebody share their experience implementing this?

Thank you!

Elcan,

First thing I do with Micrologix is set S:29 (Fault Routine) to a valid subroutine number (ie. 99). Then I add code to SUB99 to read the fault code from S:6 and store it in a table that includes the date & time. Without going to far into it, I create a FIFO so that I have a fault history. The last line of code changes the Remote Display Command for whatever type of HMI I am using so that the HMI can display the current fault information.

Now, to display Micrologix fault information appropriately, you need to strip the upper byte from S:6. Save the upper byte because that will tell you if the fault is related to a specific Compact IO module. Use the lower byte to show the fault info in a multistate indicator. The pain in the arse is setting up the indicator since there could be 255 values.

Hope this helps!

mark