Jmeadows7676
Member
I am having an issue with my Modbus Communications. I have a PLC 5 running a Prosoft 3100-MCM as Master. It is polling a total of 3 Devices. 2 Airtek Air Dryer Control Centers (Old Air Dryers) and a Micrologix 1400 (New Air Dryer). The issue is slow communication about 4 secs for round trip. If i pull up the Channel Status 0 on Micrologix i see there is about 10 Message Received to 1 Message Send. I have double checked all settings and everything seems to be right. It's a Daisy Chained Network with proper resistors on both ends of the line. During troubleshooting i noticed if i took the 2 Airtek Control Centers out to the Modbus scan the Message Received and Message Sent on the Micrologix match with no blinking error light on the Prosoft 3100-MCM card and speed was good. If i took the Micrologix out of the scan and just had the Airtek controllers it was the same, no error light and speed good. I can't wrap my head around the issue. Any help or insight will be greatly appreciated.
See Attachment for Channel 0 Status
Thanks,
See Attachment for Channel 0 Status
Thanks,
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