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| Illustration 1 | g06354309 |
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(1) Machine ECM
(2) Operator monitor (3) Engine speed dial (4) Engine ECM | |
Machine ECM (1) receives the engine speed dial (3) signal from the right side control panel. The machine ECM then transmits the desired engine speed to the engine ECM. The machine ECM, engine ECM, and right side control panel communicates these signals using the CAN data link.
Engine speed dial (3) is a 7-position switch. The selected position is displayed on operator monitor (2).
Note: The actual engine rpm and torque output will vary, depending on the setting of the power mode that is selected. The smart mode and the economy mode will change to high hydraulic power mode during travel.
Machine ECM (4) is a self-diagnostic component. The machine ECM monitors the inputs and the outputs. The machine ECM monitors the system problems that can occur and system warnings that are generated during the operation of the machine. The machine ECM will display a system warning that is generated, or a problem that has been detected, via the self-diagnostic function on operator monitor (2).
Note: A log file is kept for the warnings. The log file contains the time and the number of occurrences of each warning.
Automatic Engine Speed Control (AEC)
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| Illustration 2 | g06354311 |
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(1) Machine ECM
(2) Operator monitor (4) Engine ECM (5) Travel levers/pedals (6) Left/ right joystick sensors | |
The Automatic Engine Speed Control (AEC) automatically reduces engine rpm when the machine is inactive. The AEC system is designed to reduce fuel consumption and noise. Lower engine speeds can also increase engine life.
The engine rpm will recover automatically to the setting of the engine speed dial when any hydraulic function is activated.
Hydraulic demand is detected by lever signals.
Note: Input components related to the tool control system can detect hydraulic demand as well.
Automatic Engine Speed Control is activated when the engine start switch is turned to the ON position. The AEC function can be turned from ON to OFF from the monitor.
Note: The position of the engine speed dial has no relevance on the actions described above.
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| Illustration 3 | g06356373 |
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(1) Machine ECM
(2) Operator monitor (4) Engine ECM (7) Engine start switch (8) Hydraulic lock solenoid | |
The Engine Idle Shutdown function stops the engine automatically when the machine has been idle for longer than the set time. Before the engine stops, a warning message will be displayed on the monitor.
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| Illustration 4 | g06356384 |
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(1) Machine ECM
(2) Operator monitor (9) Pump pressure sensor | |
The pump regulator is controlled by the machine ECM. The machine ECM continually monitors various inputs. The machine ECM sends a signal to control the output flow of the pump by changing the hydraulic signal pressure that flows to the pump regulator.
The machine ECM controls the PWM driver sent to the PRV and determines the required pump flow based off the following inputs.
Desired engine speed - Determined by the engine speed dial.
Actual engine speed - Determined by the engine speed pickup.
Pump delivery pressure - The pump delivery pressure is measured by the pump pressure sensor on the main control valve.
Integrated Engine and Pump Power Management Control
The integrated engine and pump power management control is a suite of software programs loaded into the engine ECM and machine ECM. This power management control performs the function of coordinating hydraulic power demands with engine power production. The machine ECM communicates with the engine ECM to control the flow of fuel to the injectors in coordination with changes in power demands from the various machine systems. The engine output power is matched to the sum of all power loads to provide zero engine speed acceleration or deceleration. The steady-state control output can be attained nearly instantaneously using the CAN Datalink connection between the machine ECM and engine ECM.
Automatic Travel Speed Change Function
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| Illustration 5 | g06356389 |
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(1) Machine ECM
(5) Travel levers/pedal sensor (9) Pump pressure sensor (10) Travel speed control (11) Travel speed solenoid (12) Hydraulic temperature sensor | |
The travel function is one of the highest heat load applications. Hydraulic Temperature Sensor (12) is part of the system to ensure that the machine hydraulics do not overheat. If the machine is tracked for a long time (more than 20 min), the hydraulic system may begin to overheat. The travel may be throttled back based on the temperature of the hydraulics.
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| Illustration 6 | g06356391 |
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Travel speed control switch (10) | |
There are two modes of travel speed for the machine. The modes are "Tortoise" and "Rabbit". The control for the travel speed is on the key pad that is located to the right of the operator. The panel includes an indicator to display the speed function that is active. When the travel speed is set to Tortoise, the travel speed is fixed at the low speed (no change). When the travel speed is set to Rabbit the travel speed changes in response to the pump outlet pressure. When the main pump pressure is low, the travel speed is automatically increased to high speed. When the main pump pressure is high and the selected travel speed is Rabbit, the travel speed is automatically switched to low speed.
Reference: Testing and Adjusting, "Automatic Travel Speed Control - Test" for automatic travel speed control pressure specifications.
Reference: Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine speed specifications.