1. Power up the unit while holding the REC button
2. Press the 2 button, the 2 light should turn on
3. Press REC button, the REC light should turn on
4. This step toggles the normally closed setting.  
    a) For input 1: Press the 1 button, turning the 1 light ON for normally closed, or OFF for normally open.
    b) For input 2: Press the 2 button, turning the 2 light ON for normally closed, or OFF for normally open.
5. Press REC twice.  The unit will resume normal operation.