BEARING REPL G 1H5742 - Caterpillar

Electronic circuits within the controller make decisions in order to change the engine speed and the output of the hydraulic pumps. Proportional reducing valves are used to change the output of the hydraulic pumps. The inputs and outputs of the controller are connected to the wiring harness of the machine through a single connector. Input/Output
The controller sends information and the controller receives information on the data link. The data link is bidirectional. The data link communicates with the 123-6471 Portable Diagnostic Tool (PDT) and the Portable Tech Station. The data link is not a visible component. It consists of internal control circuits and the connecting harness wiring. See Special Instruction, SEHS9825, "Use Of The 123-6471 Diagnostic Tool Group" for more information about the PDT. Inputs
The inputs describe the status of the machine systems. Two types of inputs exist. The inputs can be either a switch type or a sensor type. Switches provide an open or a ground to the switch inputs of the controller. Sensors (frequency, PWM or voltage) provide a changing signal to the sensor inputs of the controller. Digital Inputs - Operational
The operational switch inputs provide information about operator requests and machine systems. The switch inputs include the following connector contacts: 19, 35, 36, 37, 38 and 39. The status of the inputs (grounded, open and +battery) tell whether the system conditions are normal or abnormal. The inputs receive information from switches or relays that are located within the machine systems. The inputs also receive information from switches that are controlled directly by the operator: power mode switch and travel lock switch. The ungrounded pin voltage is 5 DCV.Sensor Input - Frequency
Connector contact 53 and 18 are sensor inputs (frequency). The engine speed sensor provides an AC signal to the controller between these two inputs. The controller measures the frequency (Hz) of the AC signals. The resulting speed measurement is used by the controller to make decisions and to monitor the main pump's output. Analog Inputs - Voltage
Connector contacts 45 and 46 are sensor inputs (voltage). The voltage that is present at the inputs for voltage represents the condition of the machine system or the position of the sensor. The position of the speed dial is monitored at pin 45. The position of the governor actuator is monitored at pin 46. Analog sensors or senders provide information. The controller measures the voltage, which represents the information. The controller uses this information to make decisions. The controller also monitors systems of the machine. Outputs
The controller responds to decisions by sending electrical signals through the various outputs. The outputs create an action or the outputs provide information to the systems of the machine. The ON/OFF outputs include the following connector contacts: 30, 31 and 32. The ON/OFF outputs allow the controller to cause action. This could be energizing a solenoid, sounding an alarm, activating a motor or turning ON an indicator.