SCREEN ASSEM. 8B1580 - Caterpillar

Hystat Features
Parking Brake Control
This feature is used in order to determine when the parking brake solenoid will be turned ON or OFF. The parking brake is applied when the solenoid is de-energized. The parking brakes are released when the solenoid is energized. The ECM will disengage the parking brake once the the lever is placed into forward or reverse and after the following conditions have been met:
The engine is running.
The neutral interlock is not active.
The operator is present.
Diagnostics that prevent movement of the machine do not exist.The ECM will engage the parking brake if any of the following conditions are true:
The parking brake switch is set.
The brake/decel pedal is depressed enough that the limit switch is triggered.
The neutral interlock is active.
A warning of level 3 is detected.
The transmission stall test is performed.
The status of the lockout for the parking brake is set to "Lockout".
The transmission pressure override calibration is active.Neutral Interlock
The ECM does not allow movement of the machine when the neutral interlock is active. The following conditions must be met in order to release the neutral interlock:
The parking brake switch is in the Park position.
The engine is running.
The joystick for the transmission is in Neutral.
The presence of the operator is recognized.
Diagnostics that prevent movement of the machine are not active.Joystick Speed and Steering Control
The ECM controls the speed of each track independently in order to achieve the desired speed and steering. The advantages of the feature for the desired speed and steering are listed.
Precise motor speed control
Repeatable speed and steering control
Improved straight tracking
Consistent tracking and steering control in all speed rangesThe feature for the desired speed and steering assists in compensating for changes in the machine such as the oil temperature and component wear. The ECM uses the input from the operator from the following items in order to determine the desired speed and steering:
The transmission joystick
The joystick steering
The thumbwheel for acceleration and for deceleration
The brake/deceleration pedal
The speed recall button
The parking brake switchThe desired speed is controlled based on feedback from the hydrostatic components. The ECM modulates the current to the pump and motor solenoids. The modulation is used in order to achieve the desired speed on each track.Pilot Transmission Control
This feature provides hydraulic pilot oil to the hydrostatic pumps and the motors as well as the park brake solenoid. This feature is controlled by the neutral interlock. The transmission pilot supply solenoid is energized once the neutral interlock is released.Brake and Deceleration Pedal
The brake/decel pedal controls the speed of the transmission based on the position of the pedal. This feature can be configured as a brake or decel pedal. See Systems Operation Section, "Configuration Parameters" for more information.Hystat Speed Recall
The feature allows a desired forward and reverse speed to be saved. The operator can recall the saved speeds.Straight Tracking Control
This feature is used in order to provide straight travel to the machine. The ECM monitors the speeds of the motors and the ECM compares the speeds with the desired speed. The ECM determines the solenoid current