Communication can be split into seven layers, Layer 1 to Layer 7, in accordance with the ISO/OSI Model. The FPSC Ethernet TCP/IP gateway convert Layers 1 and 2 of the FPSC system (RS232/Modbus ASCII) to the corresponding fieldbus system. Layers 3 and 4 are covered by the TCP/IP-protocol, Layer 5 and 6 are blank, and Layer 7 is forwarded transparently on the standard gateways.

In the characteristic application in the TCP/IP-protocol, after switching on, the gateway is in the state "Passive Open" under an IP-address and port number that was determined in the configuration. A Client processor is in the position to open a TCP/IP connection with the gateway under the port determined in the configuration. After a successful connecting, data can be exchanged.

At the protocol TCP/IP, a full duplex data connection is available after establishing a connection between the gateway and the attached Ethernet-Client. The data stream is protected by the TCPI/IP-protocol in both directions. When operating with UDP/IP-protocol, no connection is established before data is transferred. In this case the application is responsible for the control of the data flow as well as for the backup of the data.

With a socket-API (e. g. Winsock under Windows or Berkley sockets unser UNIX) it is possible to realize various application cases within your software. The API provides the complete functionality for the data transport across the network.