How to use twain?

I use scanner type is kodak 800.

I start to scan when scanner is sleep.

In this case,scanner will hung up.

So I  will call a method to stop scanner like follow source.

But the follow source is C.

I want to use leadtool interface(vb.net version)  to do the same thing.

But I don't kown how to do.

long CTwscanCtrl::TwFuncStopScanner()
{
TW_UINT16   twRC = TWRC_FAILURE;
int         nRet=0;
TW_PENDINGXFERS  twPendingXfer; 

  twRC = glpfnDSM_Entry(&gAppId,
                         &gSourceId,
                         DG_CONTROL,
                         DAT_PENDINGXFERS,
                         MSG_RESET,
                         (TW_MEMREF)&twPendingXfer);
   if (twRC != TWRC_SUCCESS) { 
   nRet = -1;
      //sTwFuncDspErrDetail("DAT_PENDINGXFERS-MSG_RESET", twRC);
      CTwscanCtrl::sTwFuncLogMessage("TwFuncResetScanner - MSG_RESET(中止)エラー");
   }
   return nRet;
}