CNC handwheel based on CANopen communication protocol
                                                                      LIU Zhengrui, HONG Zhanyong
                   (Institude of Industry & Equipment Technology, Hefei University of Technology, Hefei 230009, China)

Abstract: Aiming at hand wheel drive in the numerical control, the problems of signal acquisition, signal processing and signal transmission in hand wheel drive was studied, the problems such as pulse missing register, pulse meter wrong and the signal output is not uniform has carried on the induction. A kind of hand wheel driving scheme that take the STM32 ARM cortexM3 as the core and use CANopen protocol that is highlevel protocol of CAN bus to bus communication was proposed. The functions such as pulse reading, pulse counting, the choice of feed shaft, the choice of the step length ratio, feed direction judgment and output signal was implemented at the signal acquisition end. The results indicate that the scheme can realize realtime control signal output and homogenization, through comparing the calculation of the succession of the packet data, host computer can determine whether there is leakage, record the amount of feed signal leakage, and can be used according to the corresponding way to compensate, so as to improve the accuracy and reliability of the hand wheel drive.

Key words: handwheel; CANopen; CNC system