hello, I am using ignition 8.05, there is a Modbus RTU Over TCP Communication Timeout error occured frequently.
Site device protocol is modbus RTU, 10+ devices connected to Serial Device Servers, ignition communicate with these devices with Modbus RTU Over TCP driver, read ever 5 minutes. Some config as follows:
At first, all is OK, tag read good, but after some time later, tag quality turns bad, device Log Activity display message Request failed. FailureType==TIMEOUT . Then I watch TCP message with Wireshark, as I see, every query has answer from site device, some screenshots as follows:
When I reconnect the TCP scoket, the problem disapper and tag turns good.
Now I don’t konw where the problem is, I hope to find the real reason but I don’t know why ignition report the error, can anyone help me?
After observing the packet, maybe I have found the reason, every time ignition receive disturbed packet not normal Modbus Packet, the regular communication will become disorder.
I think modbus driver have kept the disturbed packet and judge with the following packet, I am not sure, can you give me some advice?
That stray packet probably has something to do with it. Can you upload the Wireshark capture for us to look at?
You might be able to get the driver to recover on its own by enabling that “Reconnect After Consecutive Timeouts” option for now.
I will upload the capture next time the stray packet appear as I have fixed it by reconnect the communication wire, I also have simulated this phenomenon on my computer, response abnormal packet twice , then normal, but tag will never become good.
Enabling the “Reconnect After Consecutive Timeouts” option will work, but if I have many devices, if some device turn off, it will always reconnect and never read other devices. if I can change the number of " consecutive timeouts ", it will be better.
Thank you!
