简单的TwinCAT PLC示例，包含TwinCAT3.1的PLC端程序，VB.NET写的两个连接PLC并读写数据的客户端程序。平台为VS2015(A simple TwinCAT PLC sample with a PLC program using TwinCAT 3.1 and 2 VB.NET sample client program to communicate with PLC. Platform is VS 2015.)