S7-1200PLC的MODBUS-RTU通信的实战应用和完整SCL源代码，请参看下面的文章链接

https://rxxw-control.blog.csdn.net/article/details/132845221https://rxxw-control.blog.csdn.net/article/details/132845221MODBUS-RTU协议和常用功能码解读

https://rxxw-control.blog.csdn.net/article/details/133755924