CNC carving and milling machine tool of the origin and limit position control module

Every step motor shaft must run within a certain range of security, so at each support guide are installed on both ends of a limit sensor. Limit sensor is composed of photoelectric sensor and auxiliary circuit, its basic principle is that when the CNC carving and milling machine tool in one shaft moves, installed on the shaft of light barrier will glow in photoelectric sensor to move between the client and the receiving end. According to CNC carving and milling machine table moving distance set limit position at the ends of the shaft, when the light barrier with the workbench moves to limit position, photoelectric sensor output level will change, DSP detected level after the change, stop sending stepper motor pulse signal and a limit alarm signals. Below is of a limit sensor signal processing circuit, sensor signal by the comparator LM339, compared with the reference voltage Verf, higher Vref output high level, whereas output low level ( For the limit point location) Output, low power sensors work lights light up D1 at ordinary times. After 6 n137 isolation step-down switch signal send F24O7A I/O port detection, exceeds the limit range, the motor stalling, alarm indication signal at the same time. For moving coordinates calibration, and has set up a on each axis's origin, and here a position sensor installation, each axis motion coordinates based on this point, principle and limit sensor is the same. CNC carving and milling machine tool limit control module circuit diagram