基于负逻辑控制的数控机床限位保护装置及方法研究

现有数控机床的限位保护装置普遍采用的控制方式是正逻辑控制，这种控制方式可能因线路开路而产生限位失灵现象。为解决现有数控机床的限位控制电路的缺陷，研制出一种新的限位控制方式，即负逻辑控制。其特点是限位行程开关的工作触点采用常闭触点，数控系统的PLC输入端口设置为负逻辑，负逻辑的实现可以通过编写机床的PLC程序和通过设定机床参数实现。这种方法提高了限位电路的可靠性。经过实际使用达到了很好的效果，解决了现有数控机床限位控制电路的缺陷。

Study on CNC Machine Tool's Position Limitation Protection Equipments and Control Method Based on Negative Logic Control

Currently CNC machines are provided with positive control limitation protection equipment so that it is likely to have malfunction due to its circuit opening to a new road. A new posilion protection method, negative logic control, was developed to solve the shortcoming. Characteristic of negative logic control position limitation protection equipment lies that its working touching point usually is shut up and it sets its PLC program inpul as negative logy, which can be come into reality through writing PLC program and setting its machine parameters. The position limitation protection equipment improves its reliability for position limitation and successfully solves the shortcomings of current equipments.