Design Of Versatile Industrial Controller Base On STM32 And FPGA

At present,programmable logic controllers(PLC)are playing an increasingly important role in industrial control systems.As the core equipment of the entire industrial system,PLC directly affects the function and performance of the system.The domestic PLC market is almost monopolized by foreign brands.China's self-developed brands only occupy a small market share,and PLCs on the market still have poor compatibility,difficult development,and high costs.Therefore,this paper designs a versatile industrial controller based on STM32+ FPGA,which integrates the features of complex functions,good real-time performance,strong versatility,and high reliability.The main content of this paper is as follows:In terms of hardware,it is divided into a main controller and remote modules.The main controller adopts an integral PLC structure,which connects a core board,an interface board and a switching power supply through connectors.The core board uses STM32 and FPGA as control chips,and combines their respective advantages(STM32 can perform complex tasks,and FPGA can process high-speed signals),and uses a 512 K SRAM chip IS62WV51216 as a memory.The interface board is designed with 16 digital input ports,16 relay output ports,and 8 transistor output ports.These inputs and outputs are galvanically isolated using optocouplers or relays.Communication interfaces include RS485 communication,USB communication,and Ethernet communication.The switching power supply adopts separate excitation type,PWM pulse width modulation,and transformer-coupled type.It can convert220 V AC voltage to the 24 V DC voltage required by the controller itself.This paper describes the circuit design steps in detail,especially the parameter calculation of high-frequency transformer.The remote module is mainly aimed at the shortcomings of the control port of the main controller.Remote digital and analog input and output modules are designed as expansion modules.At the same time,a remote communication module is designed to communicate between the main controller and remote modules.In terms of software,STM32 on the main controller is transplanted with Free RTOS embedded operating system,which can more reasonably call multi-tasking and make full use of system resources.In terms of software system,seven sets of STM32 and FPGA system programs are designed,and two user program editing methods are designed for the PC and human-computer interaction interface.In terms of software functions,this paper has designed some modular functions,such as stepper motor module,PWM module,SPWM module,SVPWM module,high-speed counter module and PID module.In terms of communication protocol,RS485 is used for communication between remote modules.The RM-COM protocol is designed referring to Panasonic's MEWTOCOL-COM protocol.The main controller and the remote modules communicate through Ethernet,and the protocol adopts Modbus protocol.Finally,the hardware and software of the versatile industrial controller designed in this paper are tested,and the industrial robotic arm experimental platform is shown as an application case.This paper introduces the wiring methods between a variety of common industrial equipments as controlled objects and the versatile industrial controller,which reflects the versatility and stability of the versatile industrial controller and has certain research and application value.