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

ModBus network is an industrial communication system composed of programmable controllers with intelligent terminals and computers connected through public or local dedicated lines. Its system architecture includes both hardware and software. It can be applied to various data collection and process monitoring.

The ModBus network has only one host, and all communication is initiated by it. The network can support up to 247 remote slave controllers, but the actual number of supported slaves depends on the communication device used. By using this system, each PC can exchange information with the central host without affecting the execution of its own control tasks.

1. Modbus protocol:

In order to better promote and popularize Modbus in distributed applications based on Ethernet, Schneider Electric has transferred ownership of the Modbus protocol to the IDA (Interface for Distributed Automation) organization and established the Modbus IDA organization, laying the foundation for the future development of Modbus. In China, Modbus has become the national standard GB/T19582-2008. According to incomplete statistics, as of 2007, the number of Modbus nodes installed has exceeded 10 million.

Modbus protocol is a universal language applied to electronic controllers. Through this protocol, controllers can communicate with each other and with other devices via a network (such as Ethernet). It has become a universal industrial standard. With it, control devices produced by different manufacturers can be connected to an industrial network for centralized monitoring. This protocol defines a message structure that a controller can recognize and use, regardless of the network over which they communicate. It describes the process of a controller requesting access to other devices, how to respond to requests from other devices, and how to detect and record errors. It establishes a common format for message domain patterns and content.

When communicating on 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 will generate feedback information and send it out using the Modbus protocol. On other networks, messages containing Modbus protocol are converted into frame or packet structures used on this network. This conversion also extends the methods of solving node addresses, routing paths, and error detection based on specific networks.

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

2. Modbus data collection:

The Taichen video surveillance platform has fully implemented the Modbus data acquisition standard and supports the national environmental monitoring HJ-212 communication standard, achieving real-time synchronous reporting of data acquisition signals.

The Taichen video surveillance platform can support hundreds of Modbus data acquisition modules simultaneously within the same data acquisition program, achieving centralized data acquisition and processing.

The Taichen video monitoring platform centrally stores Modbus data collection information and implements data aggregation and query in the monitoring center, providing decision-makers with highly informative statistical information.