Modbus is a communications protocol for data transfer. In the petrochemical industry, Modbus is widely used for connecting measuring and control devices to process control systems (PLCs). Most PLCs can be fitted with interfaces for Modbus communication. Modbus interfacing enables the reliable transmission of information over just one data line. It can be used both to read information from analyzers and to control certain functions. A distinction is drawn between Modbus RTU, Modbus ASCII (both based on serial field bus communication) and Modbus TCP (Ethernet-based).
Modbus is supported by MAXUM edition II, MicroSAM, SITRANS CV, SITRANS SL and SIPROCESS GA700