首先介绍了在系统可编程技术及器件的特点。根据开放式数控系统中通用伺服控制模板对I/O的要求 ,由高密度在系统可编程逻辑器件设计了单片数字I/O电路。所设计的单片数字I/O电路已用于开放式多坐标联动数控系统 ,结果表明所设计的电路完全达到设计目标 ,运行效果良好 First introduced in the system programmable technology and device features. According to the requirement of I / O for the common servo control module in the open CNC system, the monolithic digital I / O circuit is designed by the high-density system programmable logic device. The design of single-chip digital I / O circuit has been used in open multi-coordinate CNC system, the results show that the circuit designed to fully meet the design goals, the operation of good results