Optical Fiber Communication Rate Research Base On SERCOS Bus In CNC System

Bus technology is an important direction of computer numerical control system. Purposeof this paper is to combine SERCOS fieldbus technology and DSP embedded technology，toachieve the communication between computer numerical controller CNC and servo drive inCNC machine tool.In this paper, after brief comments on the basis of the development trend of open CNCsystem and the application of field bus technology in numerical control system, a serialreal-time communication structure of CNC system based on SERCOS was introduced: themotion controller as the master station and feed servo drive for slave station for themaster-slave ring network. The motion controller sent command data to the servo slave stationthrough the fiber loop, achieving the synchronous control of servo; servo slave station fedback the state date to the SERCOS synchronous controller periodically.Make a profound analysis of the SERCOS bus protocol and features of thecommunication interface device-SERCON816. Then design the communication interfacecircuit of master station basis on DSP6713and program its software. Design the servo drivebased on DSP2812as the main control chip，then design the communication interface circuitand program its software. Finally, achieve the design on the motion controller and servo drivedeveloped in the laboratory, build a three-axis CNC system and do the simulated experimentson the system. Experimental and processing operation suggests that based on SERCOS buscommunication rate for4MHz is able to complete the requirements of the machine tool CNCcommunication.