During instrument operation, the door lock and interior light illumination ensure that you cannot reach into the instrument interior while the robot arm is moving.
However, certain service operations, such as changing the needle or teaching the modules of the instrument, require that the robot arm move while the door is open. An acoustic warning signal, which sounds before the robot arm movement (only when the door is open), warns and protects you from injuries caused by the robot arm (pinching of fingers or piercing).
If the door lock fails, a constant beeping sound plays and stops once the door is closed shut. Normal robot arm movement is represented by a pulsating beep.