RALRM Mode 2 not working

Hi all,

I'm having a strange problem with the call of RALRM in OB82 with TIA V18 and 6ES7 516-3AP03-0AB0 (FW V3.0).

Until yesterday it wasn't working correctly, so I tried to check the SW to fix it and after some tries it stopped working completely, even when I restored an old backup of the SW.

Initially the problem was that RALRM was giving "short circuit" error on an AI card even if there weren't errors going online on the Device configuration.

Long short story:

In my company we are using a modified version of the FB "1500Diag82" given in this example: 1500Diag82 (RALRM) Reference

We are calling a "1500Diag82" FB for each card of each ET200SP in another FB (just to have less DBs in the code) and each FB is called in a FC to group them. At the end, the FC is called in the OB82.

To be clearer, there is an example with 2 ET200SP respectively with 2 and 3 cards:

While I was searching for a solution, after many stop/run of the PLC, the SW diagnostic stopped working even I still see the errors from the Device configuration and i tried to remove "CardDiag_FC" form the OB82 and call directly there a RALRM FB with an fId of a card that is in error:

After a stop/run of the PLC, "OB82_AuxDB".callsCounter goes to 17, but "OB82_AuxDB".idCatched is never set and remains 0 even if there is an error on the card with the ID 307:

This is the reason I'm saying OB82 has a strange behavior, because it looks like RALRM FB isn't catching the ID of the card in error.

The card I'm trying to diagnostic is a "6ES7 134-6GD01-0BA1", but it doesn't work with any card, and actually more or less the half of my cards are in error.

Probably the only things I didn't tried is to power cycle and factory reset the CPU.

Any help would be appreciated, thanks in advance!

Hi eduard.lucaci,

Your code is inside OB82 or OB122 ?¿

Hi,

thanks for the suggestion, I will try it, but I don't think this is the solution as the diagnostic doesn't work even if "1500Diag82" FB is called only one time (like I showed in the screenshot in the first post).

One of my colleagues confirmed the problem is known on many of our plants and that sometimes he's able to fix it by power cycling the remote ET200SP (not the CPU like I did). I will try also this solution.

Thanks for your help