1、通过DLL与PLC通信，基于ppi协议。



2、DLL文件名：S7_200_PPI.dll



3、串口，连接线为西门子PC-PPI电缆或自己焊接



4、S7-200 PLC 默认参数即可



5、默认一次最多读取100个VB字节或50个VW字，通过DLL函数修改，可以读取更多



6、为了简化程序，仅提供V区操作，实际应用中足够了



7、操作VW字时，地址应为偶数-1, through the DLL communicates with PLC, based ppi agreement. 2, DLL file name: S7_200_PPI.dll 3, serial cable for the Siemens PC-PPI cable or own welding 4, S7-200 PLC default parameters to 5, the default read a maximum of 100 bytes or 50 VW VB words, by modifying the DLL function, you can read more 6, in order to simplify procedures, only V zone operations, practical application is sufficient to 7, the operation VW words, the address should be an even