Good Morning,
I have two Schneider PLCs, M221s, communication over Modbus TCP/IP. They are linked together over an IPSec VPN tunnel between two cellular routers. Once we got the VPN setup correctly, we used standard Modbus TCP/IP programming for the communication. The problem is that if for some reason the VPN link drops out, like just a electronic glitch, the communication function block in my plc program does not error out on an error or timeout. It just acts like everything is fine even if it has no connection to the other PLC because the VPN tunnel shutdown. Programming done in SoMachine Basic v1.5. I was using the MSG3 function block for communication. Any inputs on how to better monitor the status of the communication would be greatly appreciated.
I have two Schneider PLCs, M221s, communication over Modbus TCP/IP. They are linked together over an IPSec VPN tunnel between two cellular routers. Once we got the VPN setup correctly, we used standard Modbus TCP/IP programming for the communication. The problem is that if for some reason the VPN link drops out, like just a electronic glitch, the communication function block in my plc program does not error out on an error or timeout. It just acts like everything is fine even if it has no connection to the other PLC because the VPN tunnel shutdown. Programming done in SoMachine Basic v1.5. I was using the MSG3 function block for communication. Any inputs on how to better monitor the status of the communication would be greatly appreciated.