Design And Implementation Of CANopen Protocol And ICAN Protocol Gateway Module Based On RTOS

With the development of the Internet of Things,fieldbus technology is gradually applied to the field of automatic control.And CAN bus is widely used in various industries due to its excellent performance and low cost.However,CAN bus only defines the physical layer and data link layer,it cannot meet the interconnection requirements of equipment in industrial automation applications.Application protocol is needed to define the use of identifiers and data fields in messages.The CANopen protocol was formulated by the CIA and has been widely recognized in Europe once it was launched.It is now the world's most popular CAN bus-based application layer protocol and has a wide range of applications.The iCAN protocol is an application layer protocol based on CAN bus developed by Guangzhou Zhiyuan Electronics Co.,Ltd.,with independent intellectual property rights.It is a real-time,reliable,and easy-to-develop protocol that provides a low-cost solution for the construction of small and medium-sized CAN bus application networks.Due to the late start of China's fieldbus technology,and the inability of iCAN devices to communicate with devices using other CAN Application layer protocols,its application is limited.The gateway module designed in this paper can realize the data conversion between CANopen protocol and iCAN protocol,make iCAN devices compatible with the widely used CANopen network,greatly enhance its openness,and help promote the further application of domestic bus technology iCAN and the development of China's independent intellectual property products.Firstly,this artical explains the characteristics and application status of CANopen protocol and iCAN protocol,as well as the research significance of the gateway module in detail.Then the artical briefly describes the technology applied in the gateway design process,focuses on the analysis of the communication mechanism of the two protocols and the working principle of the FreeRTOS operating system used in this article,and proposes the communication scheme and the overall software and hardware design scheme of the gateway module through demand analysis.Then according to the overall hardware design of the gateway module,the artical proposes the hardware architecture of the gateway module,chose STM32F107VCT6 as the control chip to build the hardware platform,and designs the CAN communication interface circuit,power supply circuit,and USB to serial port circuit.Afterwards,relying on the hardware platform of the gateway module,the artical ports the FreeRTOS operating system as a software platform to design the program,and uses its task management function as well as queue and semaphore mechanism to develop the function of the gateway module.This article implements the communication function and protocol conversion function of the gateway module by porting CANfestival protocol stack,implementing iCAN protocol communication function,developing driver,configuring object dictionary,and designing data forwarding process.Finally,the artical builds a hardware experiment platform,connects the gateway module to the CANopen network and the iCAN network at the same time,captures the communication messages between the CANopen device and the iCAN device through the CAN analyzer,analyzes the messages and verifies the protocol conversion function of the gateway module.The experiment proves that the gateway designed in this paper can realize the data conversion between CANopen protocol and iCAN protocol,and support communication between CANopen device and iCAN device.It has a good role in promoting the application of the iCAN protocol with China's independent intellectual property rights.