西门子S7-200PLC用ModBus协议归纳-Siemens S7-200PLC using ModBus protocol summarized in

这个是西门子s7-300系列的所有模块的资料，想学PLC的可以来看一下-This is Siemens s7-300 series of all modules, and want to learn the PLC can look

对simens可编程控制器S7-300, S7-400 PLC 编程过程中，所涉及的寻址方式，做了简单介绍及示例。,S7-300, S7-400 PLC programming process involved in addressing ways and means to do a brief and simple example.