C++通过R3IO与倍福Twincat交互的几个主要接口函数

C++通过R3IO与Twincat交互的几个主要接口函数

1，The TCatIoOpen function opens a connection to the TwinCAT I/O Server. Before any I/O processing TCatIoOpen should be called.

LRESULT TCatIoOpen();

2，The TCatIoInputUpdate function initiates the input mapping of the specified task.

LRESULT TCatIoInputUpdate( 
  USHORT nPort
);

Return Values 
If the function fails, the return value is non zero. Possible error codes: 

-1: I/O connection is not initialized 

IOERR_IOSTATEBUSY [0x2075]: I/O device is not ready

3，The TCatIoOutputUpdate function initiates the output mapping of the specified task.

LRESULT TCatIoOutputUpdate( 
  USHORT nPort
);

4，The TCatIoGetInputPtr function allocates an input buffer for the incoming process image.

LRESULT TCatIoGetInputPtr ( 
  USHORT nPort, 
  VOID** ppInp, 
  int nSize
);

5，The TCatIoGetOutputPtr function allocates an output buffer for the outgoing process image.

LRESULT TCatIoGetOutputPtr ( 
  USHORT nPort, 
  VOID** ppOutp,
  int nSize 
);