MODULE 1684672 - Caterpillar

Lighting Switch
The lighting switch for the machine turns on the internal back lighting of the MPP for operation at night. Whenever the switch is moved from the OFF position to any other position, voltage is supplied to the circuit breaker for the tail lamp. Then, the voltage goes to connector B contact 11 of the MPP. This turns on the back lighting within the MPP.Machine Monitor
Whenever the operator selects a different function to be shown on the readout of the MPP, the MPP momentarily sends a signal to the machine monitor. This signal briefly activates the action alarm. The sounding of the action alarm notifies the operator that a different function is being shown on the readout. When you press keys (6) in the proper manner, the function that is being shown on the readout will change. The MPP will momentarily ground the output from the alarm signal. This causes the machine monitor to sound the action alarm briefly with a "chirp" sound.During normal operation, the MPP maintains the action alarm output (floating signal) to the machine monitor and the action alarm is not activated. (This occurs when the operator is not changing functions.)The alarm signal comes from connector A contact 7 of the MPP. See the Topic "Modes of Operation" for additional information.Note: The action alarm also warns the operator of abnormal conditions that exist on the machine. See the Operation and Maintenance Manual.