Pulse counter over a MSG instruction

Hi to all!

I would like to know if it's a good idea to send a photoeye sensor signal from a PLC-5/40E to a SLC 5/05 over ethernet. This signal will increase a counter on the SLC (i.e. the signal I want to use to trigger a counter in a SLC program is wired to a PLC5).

I'm adding a timer on the PLC5 side to hold the signal for 1 sec. but I don't know the frequency of the signal during normal operation, so I think it's not a good idea (however, if that signal is ON for more than 250 msec, a "Jam" is reported).

Anyway, what I don't want is to loose any counts on the SLC side.

Thanx in advance!

You would be better to do the counting in the PLC 5 and then send the count value as an integer to the SLC, that way you will be sure not to loose pulses.

The MSG instruction unsuitable for sending a pulse or counting input between controllers, because the completion speed of a MSG depends on network traffic, network connectivity, and scan times of both controllers.

Definitely do the counting and timing in the PLC-5 controller to which the sensor is wired.

Thanks to both for the help.