Development Of MODBUS-PROFINET Protocol Conversion Gateway Based On ARM

Accompanying the popularization of intelligence,the application of microelectronics and integrated circuits,traditional industries have gradually begun to develop towards intelligence.At present,in the industrial process control system,the three systems of Distributed Control System(DCS),PLC control and Fieldbus Control System(FCS)are represented,and when the concept of Industry 4.0 is proposed,such as PROFINET Fieldbus control systems are gradually emerging,but traditional industrial communication is the most common and application of MODBUS bus.In order to protect the original assets and introduce new buses,the conversion between fieldbus protocols will become a focus of industrial intelligence.Based on the industrial environment,this paper analyzes the delay of gateway communication,and proposes a general calculation formula for delay in the system under real-time communication and isochronous real-time communication between controller-gateway-switch-IO equipment.According to the functional requirements of the gateway,the gateway design is divided into two aspects:software and hardware.The software design adopts the platform Keil5,whose main language is C language.It adopts the method of driver porting and user source code to design the accuracy,reliability and troubleshooting ability of the gateway protocol conversion.The platform used for hardware design is Altium Designer.The main control chip adopts ARM core processing chip STM32 series chip.On the basis of STM32 chip,the peripheral hardware circuit is designed.It is necessary to consider the component selection,arrangement and anti-electromagnetic.Interference and other issues.Finally,the gateway performance is tested under laboratory conditions.Through testing,it is found that when there is MODBUS error message in the serial port,the program will print and display the error message,discard the error frame data,wait for the parsing of the next frame data,and can store in the ring buffer when receiving more data.Waiting in the zone,it will not be lost.By comparing the data transmitted by the PROFINET with the miniUSB port,it can be seen that when the MODBUS error occurs,the PROFINET data will not be affected,and the welder's welding tongs operate normally,and the welder control cabinet does not appear.The alarm interrupts the welding process.Through analysis,the gateway is fault-tolerant and can eliminate the erroneous data without affecting the overall operation of the system.The gateway designed by this subject has practical application value and prospect,and can realize the conversion between MODBUS and PROFINET protocols.