Introducing Modbus

Modbus was designed for use with PLCs by Schneider Electric, at that time the PLCs were manufactured by a company called Modicon. Modbus is commonly used for communications between industrial electronic devices, often transmitting data sensors, instrumentation, and control devices back to a main controller. It is royalty-free and published openly. Compared to other standards for industrial communication, Modbus is easy to deploy and maintain. It also places a few restrictions on the format of the data to be transmitted.

Modbus uses character serial communications, Ethernet, or Internet Protocol (IP) as a transport layer. It supports communication to and from multiple devices on the same cable or Ethernet network. Modbus is used in Supervisory Control and Data Acquisition (SCADA) to connect supervisory computers to Remote Terminal Units (RTUs). SCADA is a system of software and hardware that collects and monitors data from remote or field devices and uses that...