Refresher course for operating units with Modbus
HMI operating units with Modbus RTU/TCP: Brilliant solutions for modern applications - customised and cost-effectively tailored to the process and the requirements of the operator.
The Modbus
... was defined by Modicon in 1979 and is still extremely widespread in industrial control systems today. Almost all PLC controllers support the Modbus protocol via RS-485 or Ethernet. There are also thousands of sensors and actuators available on the market that can be connected directly to a PLC via Modbus. This fieldbus is written down in the IEC 61158 standard(Digital data communication for measurement and control).
In the Modbus protocol, which transmits the data packets secured by a checksum, there are basically 3 different data types: Coil or Discrete Input (1 bit), Input Register or Holding Register (16 bit), and Real or Float (32 bit).
Data is transmitted via a 2-wire or 3-wire interface (RS-485) for Modbus RTU and via LAN/Ethernet or wirelessly via WiFi for Modbus TCP. The operating units are integrated into the system as servers or slaves - the controllers in the system (Siemens, Beckhoff, Rockwell, Panasonic, Wago etc.) are "clients" or "masters"...
