BEARING 8N0706 - Caterpillar

This section will provide an overview of the operation of the control. Illustrations 1 and 2 will show the block diagram of the control for reference in the following descriptions.
Illustration 1 g00668088
Illustration 2 g00668625
The control will use a microprocessor with 32 bits for all functions of the control. All adjustments for the control are made with the Control View, the Watch Window, or a programmer that will communicate with the control via a serial port. The programmer is disconnected from the control when the programmer is not in service in order to provide security against tampering.The control will control the speed of the engine at the set point of the reference. The closed loop path is interrupted by a "Low Signal Selector" that will limit the demand for fuel to the lowest value of all the inputs. In addition to the "PID" function, the following function can limit the demand for fuel:
an actuator shutdown
a maximum fuel
a limit for starting
a torque fuel limit
an air manifold pressure fuel limit
a torsional limitAlso, the bump actuator function is applied for a very short duration and this will limit the demand for fuel. The demand for fuel is a value that is based on a percentage of fuel that is required. Zero percent will generally represent no fuel and 100 percent will represent the maximum fuel. The demand for fuel is supplied to the function of the actuator in order to produce a current for the actuator. The current is supplied to the actuator in order to control the delivery of fuel delivery to the system.The control has a filter for the speed sensors that minimize the effects of torsional vibration from the flexible coupling. This filter will provide control that is very smooth and the filter will also match the dynamics of the control with the engine, instead of adjusting the engine in order to compensate for torsional vibration from the coupling. The speed signal is usually provided by a magnetic pickup or by a proximity switch that will supply 1 to 60 Vrms to the control. The control has two red indicators which illuminate if a speed sensor signal is lost.The control has a switching power supply with the following characteristics: spike, ripple and EMI rejection. The discrete inputs are optically isolated. The discrete inputs are capable of rejecting electromagnetic interference and variable resistance in switch contacts and/or relay contacts. The Analog inputs are a differential type with extra filtering for noise rejection of common mode. This will protect the control from interference and noise, which can cause shifts in speed and load.The control also provides 4 to 20 mA for the outputs that are configured. These outputs may be used for any of the following items:
an analog meter
a recorder
an input to a computerSpeed Input
One or two speed sensors provide an engine speed signal to the control. The method that is used to detect speed is selected by the software for either a digital type of detection or an analog type of detection.