串行通信在压铸机控制中的应用

压铸机生产的压铸件广泛应用于汽车、仪表、航空等领域，现代化的生产要求多台PLC与计算机构成多级分布控制系统。以松下FP系列PLC为例，介绍了用VB6．0串行通信控件实现计算机与松下FP系列PLC之间的通信，说明了FP系列PLC的通信协议、硬件连接、通信格式以及开发的VB程序。在系统中，松下FP系列PLC作为下位控制机实现整个压铸过程动作的控制，工控机作为上位机实现压射力和压射速度曲线的实时采集和显示，以及PLC控制参数的修改和设定。实践表明，该方法简单易行，实用可靠。

The Application of Serial Communication in Controlling Die-casting Machine

Die-castings are popularly used in the areas of automobile, instrumentation and aviation, etc. Multi-level control systems composed of computer and programmable control systems are requested in modern production. With Panasonic FP Series PLCs as example, communication between computer and Panasonic FP Series PLCs by adopting VB 6.0 serial communication control is introduced. PLC communication protocol of FP Series, hardware connection, communication format, and VB program developed are described. In this system, FP PLCs are used for controlling the whole procedures of Die-castings, while the industrial PC is operated as host computer for real time data acquisition and display for extrusion force and speed curves, adjustment and setting of control parameters of PLCs. The practice shows that the method is simple, easy and reliable.