Research And Implementation Of Universal Remote I/O Module

Dry fog dust suppressing technology is applied to dust removal in thermal power plant coal conveying system,but its application site environment is generally more severe,the pollution is more serious,and the interference is relatively large.This will have a greater impact on the controller of the dry fog dust suppression system.In order to place the controller in a less polluted and relatively clean place,remote I/O modules are usually used to realize remote control of field device signals.But the general remote I/O is produced with the controller,the agreement is closed,it is not universal,and the price is relatively expensive.This is a general-purpose configurable remote I/O module based on the Modbus protocol based on this requirement.It is used as an integral part of the dry fog suppression system to realize the core of the controller.The equipment is placed far away from the industrial site,and a relatively clean place ensures the stability of the control system.This article describes a universal remote I/O module based on the Modbus communication protocol with the STC15W4K32S4 controller as the core.The module has AI,AO,DI,DO interfaces,RS-485/RS-232/USB/SPI serial communication,Modbus-RTU protocol,at the same time,the module is also equipped with a fixed set of software,and supports multi-module expansion capabilities,a very wide range of applications.The article first introduced the Modbus communication protocol in more detail.Then described the hardware circuit of the module and the corresponding anti-jamming design method;program design uses the front and back software architecture;based on the MFC development of the setup software.Finally,the simulation results and the switch quantity and the experimental results of the Modbus protocol were given.The design of the circuit schematic is completed in the environment of Altium Designer.The design,the design,debugging and downloading of the program were completed in the Keil u Vision4 and STC-isp-15xx-v6.86 software environment.The supporting software design of the remote I/O module was completed in Visual Studio 2013.Finally,the universal remote I/O module is tested,and the experimental result graph and the Modbus message parsing diagram are given.The experimental results show that the communication parameters of the module can be correctly configured using the supporting software.The module can implement the Modbus protocol.The communication and analysis can realize the collection and control of analog and digital signals according to the different function codes.