一个西门子与plc通讯的实例，很好理解的一个东西，希望对你有帮助。-Two pilots have been suspended after a plane carrying 280 passengers plunged suddenly in the airspace over Turkey. Air regulators in India have set up an investigation into the “serious...suddenly in the airspace ove

西门子PLC的PPI通讯协议上位机读写。PLC端无需编程直接读取。