{"id":8765,"date":"2024-02-27T11:01:46","date_gmt":"2024-02-27T10:01:46","guid":{"rendered":"https:\/\/selfbits.de\/modbus\/"},"modified":"2024-04-24T14:06:02","modified_gmt":"2024-04-24T13:06:02","slug":"modbus","status":"publish","type":"page","link":"https:\/\/selfbits.de\/en\/modbus\/","title":{"rendered":"Modbus"},"content":{"rendered":"\t\t
Modbus is a communication protocol used for data transmission in industrial automation systems. It was developed in 1979 and is one of the oldest and most widely used protocols for industrial automation. Modbus enables devices to exchange and communicate data with each other.<\/p>\n
Modbus is used in various applications, including process control systems, temperature controllers, measuring instruments, and other devices used in industrial automation. It is easy to implement and provides good compatibility between different devices, regardless of their manufacturer.<\/p>\n
Modbus has been the de facto standard for open protocols in the automation industry. However, in recent years, OPC UA<\/a> has become the preferred choice.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t Due to the openness of the protocol, it has been adopted in various application scenarios in recent years. These include:<\/p>\n 1. Process control systems: MODBUS is often used to exchange data between process control systems and other devices. This can include data such as process parameters, alarms, and other important information.<\/p>\n 2. Measurement devices: MODBUS is frequently employed to exchange data between measurement devices and other equipment. This can involve data like voltage, current, power, and other electrical quantities.<\/p>\n 3. Drive systems: MODBUS is commonly used to exchange data between drive systems and other devices. This can include data such as speed, torque, and other important drive parameters.<\/p>\n 4. Sensors: MODBUS is often utilized to exchange data between sensors and other devices. This may encompass data such as pressure, acceleration, and other critical sensor parameters.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t MODBUS can be operated either with older serial interfaces like RS-232 and RS-485 or via Ethernet.<\/p>\n There are different operating modes available:<\/p>\n MODBUS\/RTU: binary data transmission More details on the implementation of the standard can be found in the documentation<\/a>.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\tDissemination<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
Interfaces and Operating Modes<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\nMODBUS\/ASCII: transmission in ASCII format, theoretically human-readable
\nMODBUS\/TCP: similar to RTU, but Transmission Control Protocol (TCP) is used for transmission. TCP port 502 is reserved for MODBUS. Modbus\/TCP can also utilize Transport Layer Security (TLS) for secure data transmission since 2018, using TCP port 802 for this purpose.<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t