TUBE AS 6N7550 - Caterpillar

Sensors provide information to the main display module about changing conditions. Two of the changing conditions are speed and temperature. The sensor signal changes in a proportional manner in order to reflect the condition. The main display module shows the sensor information on the gauges. The recognized sensor signals are listed below.Frequency - The sensor produces an AC signal with a frequency (Hz) that varies as the condition changes.Pulse Width Modulated - The sensor produces a digital signal with a duty cycle that varies as the condition changes. The frequency of this signal is constant.Pulse Width Modulated Sensors
Illustration 1 g00288430
Pulse Width Modulated Signal
Illustration 2 g00497140
Typical PWM Sensor CircuitPressure Sensor (Air Inlet)
The air inlet pressure sensor is an input of the Caterpillar Monitoring System. This sensor gives the Caterpillar Monitoring System a value for the air inlet pressure. A gauge displays the status of the pressure. This pressure sensor senses the turbo compressor outlet pressure. The air inlet pressure sensor is a pulse width modulated sensor. This sensor continuously generates a PWM signal. The duty cycle of the PWM signal varies from 10% to 90% in proportion to the air inlet pressure. The base frequency of the sensor is constant at 500 150 Hz. The signal wire of the air inlet pressure sensor connects to connector contact 27 of the Caterpillar Monitoring System. The sensor is supplied operating power through connector contact "A". Connector contact "A" comes from connector contact 24 of the Caterpillar Monitoring System.Pressure Sensor (Engine Oil)
The oil pressure is an input of the Caterpillar Monitoring System. The oil pressure sensor tells the Caterpillar Monitoring System the pressure of the engine oil. A gauge displays the the status of the engine oil pressure. This sensor continuously generates a PWM signal. The duty cycle of the PWM signal varies from 10% to 90% in proportion to the oil pressure. The base frequency is 500 150 Hz. The signal wire of the oil pressure sensor connects to connector contact 17 of the Caterpillar Monitoring System. The sensor is supplied operating power through connector contact "A". Connnector contact "A" comes from contact 24 of the Caterpillar Monitoring System.Pressure Sensor (Fuel)
The fuel pressure sensor is an input of the Caterpillar Monitoring System. The fuel pressure sensor tells the Caterpillar Monitoring System the pressure of the fuel. A gauge is used to display the status of the fuel. The pressure sensor senses the pressure of the fuel. The fuel pressure sensor is a pulse width modulated sensor. This sensor continuously generates a PWM signal. The duty cycle of the PWM signal continuously varies from 10 to 90% in proportion to the air inlet pressure. The base frequency of the sensor is constant at 500 150 Hz. The signal wire is contact "C". The signal wire of the fuel pressure sensor connects to connector contact 38 of the Caterpillar Monitoring System. The sensor is supplied operating power at connector contact "A" from the Caterpillar Monitoring Systemconnector contact 24.Temperature Sensor (Engine Oil)
Temperature sensor