What is Modbus TCP/IP?

EtherNet/IP is a networking protocol that is used in industrial automation and control systems.

It is based on the Common Industrial Protocol (CIP) and runs over Ethernet. EtherNet/IP is used to connect industrial devices such as PLCs, HMIs, and sensors to allow them to communicate with each other and exchange data.

It is designed to be reliable, fast, and easy to use, and is widely used in a variety of industries, including manufacturing, oil and gas, and water and wastewater treatment.

Modbus TCP/IP is a variant of the Modbus protocol that uses TCP/IP as the transport layer instead of a serial link.

Modbus is a simple and widely used industrial communication protocol that is used to send data between industrial devices.

Modbus TCP/IP allows Modbus devices to communicate over Ethernet, making it easier to connect devices over longer distances or to connect to devices over a network.

Modbus TCP/IP is commonly used in industrial automation and control systems to connect devices such as PLCs, HMIs, and sensors.

See the new expandable and field configurable Modbus TCP/IP modules.

The Modbus messaging structure is the application protocol that defines the rules for organizing and interpreting the data independent of the datatransmission medium.

TCP/IP refers to the Transmission Control Protocol and Internet Protocol, which provides the transmission medium for Modbus TCP/IP messaging.

Simply stated, TCP/IP allows blocks of binary data to be exchanged between computers. It is also a world-wide standard that serves as the foundation for the World Wide Web. The primary function of TCP is to ensure that all packets of data are received correctly, while IP makes sure that messages are correctly addressed and routed.

Note that the TCP/IP combination is merely a transport protocol, and does not define what the data means or how the data is to be interpreted (this is the job of the application protocol, Modbus in this case).

So in summary, Modbus TCP/IP uses TCP/IP and Ethernet to carry the data of the Modbus message structure between compatible devices. That is, Modbus TCP/IP combines a physical network (Ethernet), with a networking standard (TCP/IP), and a standard method of representing data (Modbus as the application protocol).

Essentially, the Modbus TCP/IP message is simply a Modbus communication encapsulated in an Ethernet TCP/IP wrapper.

Acromag manufactures a full line of Ethernet I/O modules with Modbus TCP/IP communication.

For more information, download our Introduction to Modbus TCP/IP White Paper.

Acromag also offers Ethernet/IP I/O modules.