Modbus is a serial communication protocol developed by Modicon in 1979 for use with its programmable logic controllers (PLCs). It is a simple and robust protocol that is widely used in industrial automation applications.
Modbus works by using a master-slave architecture. The master device is responsible for initiating all communications and the slave devices are responsible for responding to the master's requests. Modbus messages can be used to read or write data from the slave devices.
Modbus is a request-response protocol. This means that the master device sends a request to the slave device and then waits for the slave device to respond. The slave device then responds to the master device with the requested data or with an error message if the request was not valid.
Modbus is a very versatile protocol and can be used to communicate with a wide variety of devices, including PLCs, sensors, actuators, and other industrial devices. It is also relatively easy to implement and use, which makes it a popular choice for industrial automation applications.
Modbus is used in a variety of industrial applications, including:
- Manufacturing
- Process control
- Building automation
- Energy
- Transportation
- Infrastructure
Here are some specific examples of where Modbus is used:
- In a manufacturing plant, Modbus can be used to connect PLCs to sensors and actuators to control the manufacturing process.
- In a power plant, Modbus can be used to connect PLCs to sensors and actuators to control the power generation and distribution process.
- In a building, Modbus can be used to connect PLCs to sensors and actuators to control the heating, ventilation, and air conditioning (HVAC) system.
Modbus is a powerful and versatile communication protocol that is widely used in industrial automation applications. It is simple to implement and use, and it can be used to communicate with a wide variety of devices.
