comm. status to indicate motor running

brian.butler · Jul 1, 2014

I have been tasked to put a communication status in series with the Motor Auxillary run from the PLC to the Honeywell DCS run status to indicate that the DCS and PLC are still "talking" in RSLogix 5000. How would I accomplish this?

Tom Jenkins · Jul 1, 2014

There are a couple of ways to do this. One is a "heartbeat" bit that toggles on/off status every second or so based on a timer. If the bit doesn't toggle the comm fail is set. My favorite is to read the time register on the slave PLC. If it doesn't change within a set time delay or stays the same for several comm cycles then the comm alarm is set.

Your heading was confusing, as this to me is a communications alarm and has nothing to do with a motor running.

brian.butler · Jul 1, 2014

Tom Jenkins said:
There are a couple of ways to do this. One is a "heartbeat" bit that toggles on/off status every second or so based on a timer. If the bit doesn't toggle the comm fail is set. My favorite is to read the time register on the slave PLC. If it doesn't change within a set time delay or stays the same for several comm cycles then the comm alarm is set.

Your heading was confusing, as this to me is a communications alarm and has nothing to do with a motor running.

Thanks, Tom! Sorry about the heading. I can see where that would be confusing. I will try your suggestion, sounds like that's what I am looking for.

comm. status to indicate motor running

brian.butler

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