Point to Point Internet Tunneling communication

I have a IAP set up on a point to point tunnel, but if we have a power fail the tunnel goes down. To reestablish communications the IAP needs to initiate communications. Is there any way to do this in the configuration. It is a modbus slave device attached so I don’t have a master on the serial end to initiate the communications. Can anyone help

How is the DOIAP setup?

If it is really just a point-point serial tunnel, then under the TCP Sockets serial profile you’ll find a check-box and settings to automatically establish an outgoing TCP connection.

If you need MB/TCP to RTU bridging then there’s no standard way to have such ‘slave-phone-home’ connections for Modbus/TCP, however it’s something we could consider.

Thanks for responding. I guess I wasn’t clear since you can have a tunnel on either end. My tunnel is on the ethernet side using the internet on a DSL line. I originally had a static IP then our IT people said we could use a dynamic IP. It works, but if the router looses power then something has to initiate communications from the remote site to the main HMI to reestablish communication. It could be as simple as a ping command.

Then the TCP Sockets Auto-Connect should work - you’d need to put the fixed central IP (as destination) into the DOIAP with dynamic IP. Thus the DOIAP would attempt to always reconnect back home. Then the DOIAP just moves raw serial data as normal … as you say, in a true tunnel either end can open or close it.

There’s no way to force the DOIAP to “ping” a remote.