PLC例子.主要是工业控制系统.梯形图的设计代码.内容很丰富

工业控制，西门子S7-200PLC的恒压变频供水系统控制程序-Industrial Controls, Siemens S7-200PLC constant pressure frequency conversion water supply system control program

基于西门子S7-200PLC的保压系统源代码，采集、自动控制、界面、打印等功能，是了解除工控软件外，用VB设计工控软件的好实例。-Based on Siemens S7-200PLC pressure maintaining system source code, data acquisition, automatic control, interface, print and other functions, is lifting the industrial control software