PLC Modbus over TRB140s

[JI_UKNS]

Hi All,
I am trying to get two Schneider PLCs to communication through TRB140s on the same VPN.
I can communicate with both from a PC connected to the same VPN (Modbus Scan and ping) but cant do the same through the physical gateways.
After monitoring the ports it seems the ARP broadcast cannot find the target when done through the gateway.
This is what our arrangement looks like currently.

After playing a lot with port forwarding, traffic rules and not getting anywhere I had set them to accept everything.

After a lot of trial and error I did stumbler on the wiki entry for VXlan

VXLAN Configuration Example - Teltonika Networks Wiki

and followed the setup for VXlan over tunnel in the hopes it would be the solution to our problems but again no luck.

Both PLC’s communicate perfectly when directly linked.
Both can be communicated perfectly with from a device connected to the same VPN hub.
But
PLC1-ethernet- TRB140 4g/VPN TRB140-ethernet-PLC2
Will not pass information from PLC1 to PLC 2.
Any information about settings that I might me missing or a method you know that works for this I would greatly appreciate.
Many thanks,

[Marcelo.Barros]

hi…
Maybe another colegue have another sugestion, but…
Using vpn… by standard… you cannot have the same network in both sides.
So…
one side will keep 192.168.2.x, but another side, need to be changed.

[JI_UKNS]

Hi Marcelo,
Thank you for the suggestion.
I haven’t encountered that requirement before but I’ll give it a a go and update if how it goes.