Modbus was invented by Modicon (now a brand of Schneider Electric) in 1979 and is the world's first bus protocol to be truly used in industrial fields.

The Modbus network is an industrial communication system consisting of a programmable controller with a smart terminal and a computer connected by a public line or a local private line. Its system structure includes both hardware and software. It can be used for a variety of data acquisition and process monitoring.

Modbus network has only one host and all communications are sent by it. The network can support up to 247 remote slave controllers, but the actual number of slaves supported depends on the communication device used. With this system, each PC can exchange information with the central host without affecting the PC's own control tasks.

1. Modbus Protocol:

For the better popularize and promote Modbus on distributed Ethernet-based applications, Schneider Electric now owns the ownership of the Modbus protocol to the IDA (Interface for Distributed Automation) and has formed the Modbus-IDA organization, for the future development of Modbus, laid the foundation. In China, Modbus has become the national standard GB / T19582-2008. According to incomplete statistics, as of 2007, the number of node installations of Modbus has exceeded 10 million.

The Modbus protocol is a common language used on electronic controllers. With this protocol, the controllers communicate with each other and with the controller over the network (such as Ethernet) and other devices. It has become a common industry standard. With it, different manufacturers control equipment can be connected to an industrial network for centralized monitoring. This protocol defines a message structure that a controller knows to use, regardless of the type of network over which it communicates. It describes how a controller request access to other devices, how to respond to requests from other devices, and how to detect and record errors. It defines the common format for message structure and content.

When communicating over the same Modbus network, this protocol determines that each controller needs to know their device address, recognize messages sent by address, and decide what action to take. If a response is required, the controller generates a feedback message and sends it using the Modbus protocol. On other networks, messages that include the Modbus protocol are translated into frames or packet structures for use on this network. This conversion also extends the method of resolving section addresses, routing paths, and error detection based on a specific network.

This protocol supports legacy RS-232, RS-422, RS-485 and Ethernet devices. Many industrial devices, including PLCs, DCSs, and smart meters, are using the Modbus protocol as a communication standard between them.

2. Modbus Data Acquisition:

Taichen VMS platform complete realizes the Modbus data acquisition standards, and supports national environmental HJ-212 communication standards, reports real-time acquisition data.

Taichen VMS platform, in the same data acquisition program, you can also support hundreds of Modbus data acquisition module to achieve data acquisition and processing.

Taichen VMS platform collects Modbus data information in the monitoring center, to achieve a summary of the data inquiries, to provide decision makers with very meaningful statistical information.