System synchronous sampling method based on rs485 network

Abstract

The invention discloses a system synchronous sampling method based on an RS485 network. The system comprises a host and a slave, the host and the slave are connected through an RS485 interface. the connecting line of the RS485 interface is not only used as a communication connecting line between the host computer and the slave computer, and meanwhile, used as a synchronous signal line between thehost and the slave to control the sampling starting time of the slave by the host to realize synchronous sampling, and the configuration of the communication baud rate as the RS485 communication connecting line does not influence the synchronous sampling control as the RS485 synchronous signal line. According to the RS485-based system synchronous sampling method disclosed by the invention, synchronous sampling of the host and each slave is realized through combination of hardware and software.

Description

technical field [0001] The present invention relates to the technical field of communication, and more specifically, relates to a system synchronous sampling method based on an RS485 distributed network. Background technique [0002] With the wide application of RS485 communication in measurement systems, especially in distributed measurement systems, the problem of clock synchronization for data sampling of each device in the network is extremely prominent. In the RS485 network system, it is generally composed of a host and multiple slaves. The master and all slaves sample synchronously, and the master reads the data of each slave for analysis and processing. The usual practice is to use two RS485 signals, one for communication and one for synchronous sampling. For such two-way signal lines, the number of communication cables increases, the amount of wiring construction is large, and the cost is high. The hardware requires that the MCU controllers of the host and slave h...

AI Technical Summary

Problems solved by technology

For such two-way signal lines, the number of communication cables increases, the amount of wiring construction is large, and the cost is high.

The hardware requires that the MCU controllers of the master and the slave have at least two UART communication interfaces. There are too many restrictions on the selection of the MCU, and the hardware cost will increase.

And when the communication command is used to control the synchronous sampling, the sampling is started after the sampling command is analyzed and processed, and the command analysis process will cause the time deviation of the synchronous sampling to be too large due to the different hardware and software running parts of each slave.

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