Revers connection RTU over TCP

[goranach]

Is there way to poll such system: PLC (slave) <-> 3G modem <-> PC (master)? But modem hasn't external ip, so modem init TCP connection to PC. And than start poll RTU. http://www.irz.net/en/products/terminals/atm-series/atm3-485

[morkai]

PC w/ external IP:

• has a server that listens on port 3000, anything it receives should be forwarded to the client of the 502 server
• has a local server that listens on port 502, anything it receives should be forwarded to the client of the 3000 server
• has a Modbus Master that connects to the local server on port 502

PC w/ 3G modem:

• connects to PC w/ external IP on port 3000, anything it receives should be forwarded to the PLC
• connects to the PLC, anything it receives should be forwarded to the PC w/ external IP on port 3000

Something like this.

[goranach]

Thank you very much. Thought so.