Research Of Permanent Magnet Synchronous Motor Servo System With Modbus Protocol

With the continuous development of modern industry, permanent magnet synchronous motor servo system is used more widely. Generally, the system is composed of the touch screen, PLC, driver and permanent magnet motor. PLC is used for data communications between the touch-screen the driver. The independent control system is used widely, due to fewer I/O ports are required, the functions of PLC can be transplanted to the driver, the PLC is not used. In this paper, the development of the permanent magnet synchronous motor servo systems, only including touch-screen, driver and the permanent magnet synchronous motor. The driver and the touch-screen can direct communicate with Modbus protocol. In addition to the permanent magnet synchronous motor servo control, the driver can also complete other functions control of the system.This paper firstly describes the general structure of the permanent magnet synchronous motor servo systems. For the structure of an independent control system, the development program of the drives with Modbus protocol is put forward in order to complete the direct communication between the driver and touch screen that with excellent man-machine interface. Modbus protocol is simple and intuitive, high reliability, as well as touch screen is used widely, the data format and validation code algorithm of Modbus protocol is detailed analyzed. The paper designs the communication interface circuits for industrial use touch-screen and the DSP. Then summarizes the generic servo-drive design requirements, designs the hardware and software modules of permanent magnet synchronous servo systems and by MATLAB/Simulink simulation the whole system is testified. The simulation and experiments show that the driver based on DSP and the touch-screen can directly communicate with Modbus protocol. The system's software and hardware of permanent magnet synchronous motor control and other functions control of the system is feasible.