industrial//fieldbus//Modbus//Modbus TCP

Modbus carried over TCP/IP, normally on Ethernet. The register vocabulary is unchanged; what changes is the transport: devices are identified by IP address instead of a serial address and can sit behind ordinary switches with many other hosts.

Modbus carried over TCP/IP, normally on Ethernet. The register vocabulary is unchanged; what changes is the transport: devices are identified by IP address instead of a serial address and can sit behind ordinary switches with many other hosts.

It is the simplest member of the industrial Ethernet family, and its advantage is exactly that: simplicity and interoperability. Almost everything can speak it.

It offers none of the sophistication of the control-grade networks: no object model, no scheduled real-time traffic, no device diagnostics. For a drive or a remote I/O rack under a PLC, PROFINET or EtherNet/IP are the usual choice; for reading a meter, Modbus TCP is enough (industrial Ethernet).