public static extern short SetTrigger(short handle,
                                       ushort enabled,
                                       ushort autoTrigger,
                                       ushort autoMS,
                                       enPL1000Inputs channel,
                                       ushort dir,
                                       ushort threshold,
                                       ushort hysteresis,
                                       float delay);
 public static extern short Enumerate(short handle,
                                      enPL1000Inputs channel,
                                      out ushort value);