1TGE120021R0610 Modbus TCP / RTU Profibus DP

1TGE120021R0110

The Modbus protocol is a serial communication protocol developed by Modicon Corporation (now

Schneider Electric) in 1979 for communication using programmable logic controllers (PLCS). The

protocol has become the industry standard for communication protocols in the industrial sector and

is now a common way of connecting industrial electronic devices.

The features of Modbus include:

Simple and easy to use: Modbus protocol is simple to use, easy to implement and maintain, supports

a variety of physical layer interfaces, and is suitable for various types of devices.
High reliability: Modbus protocol has high reliability, it uses CRC check code to detect communication

errors, and can connect multiple slave devices at the same time through multiplexing technology.
Strong flexibility: Modbus protocol supports a variety of communication modes, including serial

communication and Ethernet communication, so that it has a high flexibility.
Modbus protocol adopts the master-slave structure, one node is the Master node, and other nodes

that use Modbus protocol to participate in communication are Slave nodes. Each slave device has

a unique address. In serial and MB+ networks, only the node designated as the master node can

start a command (on Ethernet, any device can send a Modbus command, but there is usually only

one master device start command). A Modbus command contains the Modbus address of the

device to be executed. All devices will receive the command, but only the device with the specified

address will respond and perform the appropriate action.

Modbus protocol is widely used in industrial automation, intelligent buildings, remote monitoring and

other fields, used to connect different devices, sensors and control systems, to achieve data acquisition, transmission and monitoring.