Design And Development Of Wireless Transmission System About Multi-Protocol Field Bus Based On WIFI

Due to the complexity of the equipment used in the industrial field or the upgrading of the equipment,the coexistence of multi-protocol bus devices in the field is often caused.The information interaction between different protocol devices often needs to be converted by protocol.This dissertation mainly aims at some specific limited complex multi-protocol industrial field environment.The use of traditional wired data transmission methods often encounters problems such as on-site wiring difficulties,even inability to wire,and high maintenance and application costs.Therefore,a solution for reliable and efficient multi-protocol data transmission using wireless data transparent transmission is proposed.Firstly,by reading a lot of relevant literature,this dissertation makes a detailed analysis and discussion on the development and research status of Modbus protocol,CAN bus protocol,ETHERNET protocol and the protocol conversion technology between them,which are widely used in the actual industrial field.At the same time,the development status of transparent transmission technology,especially wireless transparent transmission technology,is studied and elaborated in detail.Then,combined with the technical requirements of multi-protocol bus data transmission in industrial field,the wireless transmission technology line based on WIFI technology is selected by comparing various wireless short-distance communication technologies.According to the analysis of the working principle of wireless transmission of multi-protocol bus data and the structure of the system,the hardware and software architecture of the system is designed and completed.The core protocols and key technologies involved are briefly introduced.In terms of hardware circuit design,according to the functional requirements of the system,the STM32F407VET6 microcontroller is selected as the main control chip of the system.The chip selection and detailed schematic design of the basic peripheral circuit of the main control chip,WIFI communication module interface,485 bus interface,CAN bus interface,Ethernet interface and system power supply circuit are carried out respectively.Based on the safety protection of the fieldbus interface,the photoelectric isolation protection circuit is specially designed.In terms of software design,the software platform of embedded development is mainly transplanted and built,and the transplantation of μC / OS-II and LwIP is introduced.Based on the software platform,the driver of RS485,CAN,Ethernet and WIFI modules and the software of data conversion between Modbus and Ethernet,CAN and Ethernet,Ethernet and WIFI protocols are designed in detail.Finally,in order to test the feasibility of the system scheme,according to the designed circuit diagram,the corresponding electronic components are selected and the system is welded.Firstly,the power supply module of the system is tested.The test results show that the output of the power supply module of the whole communication system is stable and reliable.Secondly,GCAN-211 Config and AT Setup software are used to configure the basic parameters of the system,such as working mode,working port and module IP.Finally,the CAN / WiFi communication function test is completed by the network debugging assistant.The 485 / WiFi communication function test was completed using the USR-TCP232-Test test software.The 485 / WiFi communication function test was completed using the USR-TCP232-Test test software.The test results show that the design in this dissertation can meet the functional requirements of multi-protocol fieldbus wireless transmission,and has certain engineering application value for solving the data transmission in the application scenarios of unable wiring,difficult wiring and temporary wiring in the industrial control field.