S7-200自由口与上位机通讯读取温度值的程序-S7-200 free oral communications with the host computer to read the temperature value of the procedure

西门子S7-300和S7-400的梯形图编程手册,供需要的人参考-Siemens S7-300 and S7-400 of the ladder programming manual for those who need it for reference