DrewDarnell

Thought I would come back and provide what seems to have solved the issue. For reference I am using Socket 2... When a remote site would go into comm fail, I was able to go online with the V570 and set a value of 50 in SI105. From there I would manually reinitialize my ethernet card, plc name, socket init, and modbus configuration. On all sites that I have done this for I have had no further issues. Hope this helps someone else in the future.

Kratam I have my modbus config in the main routine right up at the top. But it is good to know for the future that it should be included in every scan. Ausman I like your ideas to write some traps and debugging tools. That is a great idea and I will certainly try that. Joe I increased my time in SI103 and I think that has helped. I have not had issues with any sites where I have changed that value. But if one comes up I will try your idea. Hoping not to have to pull wireshark out sniff the packets. Butttt, I suppose this is what makes us the experts. Thank you all!

Apologies, I forgot to thank y'all. This is my first time posting in the forum. Long time reader of the forum though haha. Thank you!

Thank you all for your help. Kratmel: I have sb168 = 1, I left that as is. Flex The PLC is being polled over a WAN Network about every 2 minutes. I recently found the keep alive settings SI103-106, and set a value of 50 in SI105 I believe for a couple sites to test with. ( I am using socket 2 as it is standard for modbus communications) Ausman Going through my WAN connection I can still get OPLC information and go online with the PLC (so I know the WAN connection is okay), but no modbus communications seem to make it to the PLC. I watch the corrosponding SDW and do not see the soclet 2 RXD total session increment ever. So my fix was to go online with the PLC and reinitialize the ethernet card, socket 2, and the modbus config block No other devices such as VFDs or anything that I would guess make a lot of noise.

Hello, I have a V570 that is being polled by VTScada via ethernet, and it works GREAT 80% of the time. Connection is great yet sometimes the PLC will just quite responding. You cant ping it. you cant poll it with a utility like MODSCAN. And the only fix i have found is reinitializing the ethernet card, socket 2 init, and modbus IP config block. This will bring the PLC back online the next time it is polled. Any ideas what could be the issue? Thank you!