BOOM GP 3671486 - Caterpillar

Inputs
The machine has several different types of input devices. The ECM receives machine status information from the input devices and determines the correct output action that is needed in order to control machine operations based on memory and software parameters. The machine utilizes the following types of inputs: switch type and sensor type. Switches provide signals to the switch inputs of the ECM. The possible outputs of a switch are listed: an open signal, a grounded signal and + battery signal. Sensors provide an electrical signal to the ECM that constantly changes. The sensor input to the ECM can be one of several different types of electrical signals such as: pulse width modulated (PWM) signals, voltage signals and frequency input signals. Each possible input to the ECM is listed in the tables for the 70-pin connectors.Inputs provide information to the ECM in the form of sensors or switches.Sensors
Sensors provide information to the ECM about the intent of the operator or changing conditions. The sensor signal changes proportionally to the changing of operator input or changing conditions. The following types of sensor signals are used by the ECM.Frequency - The sensor produces a signal and the frequency (Hz) varies as the condition changes.Pulse width modulated - The sensor produces a signal. The duty cycle of the signal varies as the condition changes. The frequency of this signal is constant.Analog - The ECM measures the voltage that is associated to a specific condition of the control.Steering Control Handle
Illustration 3 g03452236The steering control handle has two active pulse width modulated position sensors inside of the base. The sensors determine the position of the steering handle. The ECM uses the pulse width modulated signals to determine operator steering requests. Based on the signals, the ECM controls the steering system.Steering Motor Speed Sensor
Illustration 4 g03376774The steering motor speed sensor is an active frequency sensor. There are two proportional frequency signals produced by the sensor. The sensor detects the passing of a timing gear, and converts the speed of the timing gear into a frequency signal. Based on the signals the ECM receives from the sensor, the ECM can determine the speed of the steering motor.Switches
Switches provide an open signal, a ground signal, or a +battery signal to the inputs of the ECM. Switches are open or closed.
When a switch is open, no signal is provided to the corresponding input of the ECM. This “no signal” condition is also called “floating”.
When a switch is closed, a ground signal or a +battery signal is provided to the corresponding input of the ECM.Steering Charge Filter Bypass Switch
Illustration 5 g03348326The steering charge filter bypass switch is a pressure switch. The switch alerts the ECM when the steering charge filter is being bypassed. The contact floats to a high voltage when the switch is not closed. When the switch closes, the contact is pulled to a low or ground voltage state by the return line.Outputs
The ECM responds to decisions by sending electrical signals to the outputs. The outputs can create an