Msg instruction in compact logix

Is it possible to configure the MSG instruction in CompactLogix to communicate with another CompactLogix in online mode or should the PLC be in Program mode...?
Actually, it is a running plant and this 2 CompactLogix need to communicate with each other
I am using Studio 5000 V32...

sreeragrsis said:

Is it possible to configure the MSG instruction in CompactLogix to communicate with another CompactLogix in online mode or should the PLC be in Program mode...?
Actually, it is a running plant and this 2 CompactLogix need to communicate with each other
I am using Studio 5000 V32...

Click to expand...

MSG instructions can be added online and in run mode, unlike Produce and Consume.

You should be fine.

I do a MSG Read only, this way when a search is performed on the tags, the MSG instruction is found, rather than MSG writing.

Basically set up a MSG read in each PLC, and I pass an incrementing value as heart beat. This accomplishes two things...

1 - You don't have to worry about someone putting the PLC you are reading in program mode and reading stale information.
2 - Heart Beat bits can produce false comm loss errors due to scan times, msg time...turns into a coin flip

celichi said:

Basically set up a MSG read in each PLC, and I pass an incrementing value as heart beat.

Click to expand...

+1. Sometimes known as a transaction counter.