procedure TVisDataThread.Execute;
const
  _SECOND = 10000000;
var
  qwDueTime: Int64;
  liDueTime: _LARGE_INTEGER;
  ErrMsg: string;
begin

  if VisTimer = 0 then
    Exit;

  // Create a negative 64-bit integer that will be used to
  // signal the timer 1/4 seconds from now.
  qwDueTime := -1 * (_SECOND div 4);

  // Copy the relative time into a LARGE_INTEGER.
  liDueTime.LowPart := DWORD(qwDueTime and $FFFFFFFF);
  liDueTime.HighPart := longint(qwDueTime shr 32);
  if MySetWaitableTimer(VisTimer, // handle to a timer object
                        TLargeInteger(liDueTime), // when timer will become signaled
                        FDelayMS, // periodic timer interval
                        nil, // pointer to the completion routine
                        nil, // data passed to the completion routine
                        False {flag for resume state}) then
    // Following sentences are repeated every FDelayMS interval all the time from initial
    // start up to program end.
    repeat
      // We need to re-adjust timer interval according to the parameter "DelayMS" of vis plug-in.
      // (in case we exchange vis plug-ins)
      if FDelayMSChanged then
      begin
        FDelayMSChanged := False;
        CancelWaitableTimer(VisTimer);
        MySetWaitableTimer(VisTimer, TLargeInteger(liDueTime), FDelayMS, nil,
          nil, False);
      end;

      if WaitForSingleObject(VisTimer, 1000 {1sec}) = WAIT_OBJECT_0 then
      begin
        DoOnVisTimer;
      end else
        Terminate;

      SuspendIfHalted;
    until Terminated
  else
  begin
    ErrMsg := SysErrorMessage(GetLastError);
    ShowErrorMsgBox(ErrMsg);
    Terminate;
  end;
end;