Communication via port forwarding not working

[quintelosky]

Hello

I have an installation that connects remotely to a PLC. We use port 5656, but on the installation, the router forwards everything coming in on port 5656 to port 4840 and to the PLC’s IP address.

The Prosys OPC UA Browser connects without any issues, but the SCADA returns an error.

If I set the PLC, a S7-1200 (OPC server), to use port 5656 and configure port forwarding from 5656 to 5656 on the PLC’s IP, the SCADA connects. However, if I revert to the original setup (PLC on port 4840, with port forwarding from 5656 to 4840 on the PLC’s IP), the SCADA does not connect. Meanwhile, the OPC UA Browser still connects successfully.

Something must be happening with the OPC driver; it doesn’t seem to handle the router’s port addressing well.

What can I do?

https://ibb.co/G3vjgmWT
https://ibb.co/20btbKvH
https://ibb.co/HLNJ9fq2

Thanks

• This topic was modified 1 month, 2 weeks ago by quintelosky.

[Mikhail]

Hello,

What is the error message in the screenshot?
For some reason, the screenshot is in bad quality.

[quintelosky]

https://i.postimg.cc/4xpKY7Db/test-opc-1.png
https://i.postimg.cc/nLZXBVx7/test-opc-2.png
https://i.postimg.cc/zGTLybsv/test-opc-3.png

Error connecting to opc server: BadConnectionClosed

[Mikhail]

It may be related to the certificate. Try to get information from the OPC server to understand how it sees the client trying to connect.

[Author]

Posts