The threshold adjustment is available if an alarm output is required. This is the adjustment used to get a simple output signal change when the ultrasonic input has either exceeded or gone below a setpoint.There is a Alarm Threshold Sense output at pin 8 on the DB9 connector or on the Blue colored I/OCable wire. This can be detected as a voltage from 0-10 VDC which is where the threshold or set point is currently adjusted to. To raise the level, turn the potentiometer clockwise and to lower the level turn the potentiometer counterclockwise.