Detailed features:

Ethernet I/O Module
TCW122B-RR is an Ethernet based remote relay control module that has two digital inputs and two relay outputs, with normally open and normally closed contacts. To arrange remote relay control two devices should work opposite one another – one in “client” mode and other in “server” mode. The “client” sends periodically the status of its digital inputs to “server”. As answer the “Server” returns its digital inputs status. Client-server model allows following variants: both devices are connected to Internet, with public IP addresses; both devices are connected to one LAN, with private IP addresses; “Client” is connected to LAN (private IP address) and “Server” is connected to Internet (public IP address); “Client” is connected to LAN (private IP address) and “Server” is connected to different LAN but behind router with public IP address and port forwarding.