COUNTERWEIGHT 3560042 - Caterpillar

Frequency Sensors
Frequency sensors produce a signal. The signal is a sine wave signal or a square wave signal. The frequency varies as the condition changes.Oil Pressure Sensor for the Lift Cylinder
Illustration 1 g00582059
Oil Pressure sensor of the lift cylinder (1) Schematic Symbol. (2) Sensor.
Illustration 2 g01358940
Series H oil pressure sensor of the lift cylinderThe oil pressure sensor (2) reacts to the pressure that is in the lift cylinder. The sensor receives operating power from the electrical system of the machine. The sensor sends a square wave signal to the ECM. The signal varies in frequency as oil pressure that is in the lift cylinder changes. The ECM measures the frequency in order to determine the pressure that is in the lift cylinders. The sensor does not require calibration.Pulse Width Modulated PWM Sensors
Illustration 3 g00582060
Pulse Width Modulated Signal
Illustration 4 g00582064
Typical PWM Sensor SchematicPulse width modulated PWM sensors produce a digital signal. The duty cycle of the signal varies as the conditions change. The frequency remains constant.Lift Position Sensor
Illustration 5 g00582067
Lift Position Sensor (1) Schematic Symbol. (2) Sensor.
Illustration 6 g00983934
Lift Position Sensor (1) Schematic Symbol. (2) Sensor.The lift position sensor is an input of the ECM. The position sensor is mounted at the pivot of the lift arm. The sensor is a Pulse Width Modulated PWM sensor. This operates on the voltage of the machine. The frequency (Hz) of this signal is 500 Hz. This frequency will remain constant. This sensor continuously generates a PWM signal. The duty cycle of the sensor varies in proportion to the angle of the lift arm. The control receives the PWM signal and the control measures the duty cycle. This determines the angle of the lift arm.Note: The lift position sensor is the only sensor that must be calibrated.ReferenceRefer to Service Manual, SENR6614, "Position Sensor (Lift Linkage) - Adjust" for more information.