测试西门子S7-200系列PLC自由口用的例程，时常简洁。正常通信情况下，串口调试助手会不断返回16进制的25 26 27 28 29这几个数据。-Test Siemens S7-200 series PLC free port with routines, often simple. Under normal traffic conditions, serial debugging assistant will continue to return 16 of the 229 25262728

plc 例程 必学的几个程序 西门子plc s7-200(s7-200 Several programs that PLC routines must learn from SIEMENS PLC S7-200)