Question

I have set up two TRB245, together with 2 PLC, and connected the TRBs and my PC on a ZeroTier VPN.
For testing I first set up both PLCs as Modbus slaves, using TCP-port 502.
On the ZeroTier I have routed the PLCs IP to the LAN-IP of the TRBs.
Both PLCs are set up with their local TRB IP as the Gateway-IP.
On each TRBs Port Forwarding I have set up: "From any host in Zerotier - Via any router IP at port 502" to PLC-IP and port 502 on LAN.
Using a Modbus master on my PC I get answers from both PLCs.

But if I change one of the PLCs to Modbus master, I get a "Node is offline" error when it tries to communicate with the Slave.
I have changed the roles of the PLC, but it behaves in the same way.
Is there some additional routing I need to add?

Answer 1

Any tips here?
I tried using Wireshark to see if I could spot where the communication stops, but after going into the first TRB all the communication gets encrypted, so I can't see what the replies are...

Comments

Hello,

I am currently investigating your issue and thinking of the possible cause of your troubles. You have mentioned that everything worked when PLCs were configured as Modbus slaves, right? Could you send me a private message with your troubleshoot file? You could download troubleshoot by navigating WebUI > System > Administration > Troubleshoot.

Regards.