I have 2 PLC's (both 315-2DP) opperating in master slave opperation. They both share some configured peripheral addresses. This work well.

But my problem is, when the slave PLC shuts down (what ever reason) the master in turn goes to stop. This is desirable in the reverse. But I can't have this happening when the slave goes off.

Does anyone know what OB can stop this from happening or is there another way of doing it. Your help would be appreciated.
Thanks,
Paul Pierce

 

On the master side, program OB84 (it does not need to have any instructions). This will prevent the master go into Stop mode.

 

Hi Paul,

on control.com we have discussed around this problem.

The most simple solution is placing in your master plc OB86, also empty, this will save you to go in stop mode, if you read related help you can discover which module or which device has fault.

I hope this helps you.

Gabriele Corrieri

 

Correction: It must be OB86, not OB84.

 

Hi All,
I have found a solution to the problem and it turns out to be that I need to have compination of OB 85, 86 and 122.
These all work together in reading the process image.
Thanks for you help.
Regards,
Paul.