数控系统的点动控制

点动控制是数控系统手工调节过程中不可缺少的一个重要功能，而点动过程则需要自动升降速，当点动时间短还未达到最高速度时，也要从此速度开始降速，同时还要实时检测是否到用户设置的软限位及机床硬限位。如果到达，禁止机床向超程方向运行。因此详细介绍点动控制的硬件结构和软件结构的原理，给出具体的点动控制调度算法和中断服务程序控制的框图。

A Study on the Pointing Control of a NC System

As an important function of a numerical control (NC) system,pointing control is indispensable during manual adjusting process. A pointing process needs to increase or to reduce speed automatically and needs to reduce speed from a submaximal speed when the maximal speed does not reached in a short time.Moreover,it needs a real time detection on whether or not the soft spacing setup by the users and the hard spacing of machine tool are reached ;and a prohibition on the operation of machine tool towards overrun if soft and have spacing hare been reached.In this paper,the principle of hardware structure and software structure of pointing control are described in detail;and the flowchart of specific algorithm for adjusting pointing control and that for interrupting program control of service are given.