Hi Caner,
thank you for the answer.
You can find the topology attached (sorry for the quality buti t was the only way to send you a sketch).
I simply want the customer PCs to be able to communicate with our PLC (they may want to use an OPC-UA client as an example).
Consider that all the protocols/port and whatever you can imagine must be allowed.
So, my poor knowledge said I had to connect the customer side on the WAN port and the PLC side to the LAN but this is not mandatory, it was just an idea.
This is the first time I use this approach so feel free to suggest the best way.
Of course, we cannot ask customer to change their network and I cannot change my network. On PLC side I can only change the gateway address on the devices configuration.
Look forward for your reply.
Regards.
