onelukec (Customer) asked a question.
Modbus devices do not reconnect
Hello,
I am running into an issue wherein when a network connection between the P2CDS-622 PLC and a Modbus server/slave drops out, the PLC does not reconnect.
So far, the only way I've found to reconnect is to perform a warm reset on the PLC.
This is consistently reproducible by connecting a PLC to a modbus slave via a network switch, and then disconnecting power to the network switch for a short period. Once powered on, the modbus connection never recovers.
For TCP...this should fix- Select "AutoReconnect" to TRUE. If Serial, same selection in it's settings.
Serial:
Thanks Bruce! Unfortunately I already have this option set to TRUE:
Hmmm...yeh that was too easy :)
Okay,so you have the "IsolationMeter" that goes offline, then comes back up and is never seen.
Not sure if its related to the ETH port settings in some way. To get a baseline, would you add the "P2CDS622_NetConfig" device and screen shot the settings during a good connection and then when device not reconnecting (fail mode).
In parallel, I will try to emulate here today. Will advise.
Also a screenshot of the "Log" may be helpful during fail mode.
Okay.... I have the RSIM PC Modbus Simulator running as the Slave and all is well.
I emulate a disconnect by changging the Port to 501 from 502 in the RSIM and it disconnects. I change back to 502 and automatically connects and data in Holdings. etc look good.
Will be back on Jan 2nd if need more looking into. Happy New Year!