ELECTRO-HYDRAULIC CONTROLS CONTINUED
Hydrostatic Joystick Control
The hydrostatic joystick control (Figure 6, Item 5) is located just to the left of the operator's seat. The joystick
contains the recall speed switch (Figure 6, Item 3), horn switch (Figure 6, Item 2) and acceleration/deceleration
thumb roller (Figure 6, Item 4). The control base contains the steering sensor (Figure 6, Item 1).
1. Recall Speed Switch
The recall speed switch (Figure 6, Item 3) has a normally open contact and a normally closed contact. These
contacts provide switch ground inputs to the machine ECM to indicate switch position. When the operator presses
the recall speed switch for three seconds, forward and reverse speeds write to memory in the machine ECM. The
operator can recall the set speeds by pressing the speed recall switch for less than three seconds.
2. Acceleration/Deceleration Thumbroller
The machine ECM decreases machine speed when the operator rolls the thumb roller (Figure 6, Item 4) to the left
and increases machine speed when the operator rolls the thumb roller to the right.
3. Steering Sensor
The steering sensor (Figure 6, Item 1) provides input to the machine ECM as the operator moves the control
handle in either the forward, neutral, reverse, forward right, forward left, reverse right, or reverse left direction.
The control has a two-axis joystick. The longitudinal displacement (fore/aft) controls forward and reverse direction.
The lateral displacement (side to side) provides steering control. The steering sensor (Figure 6, Item 1) provides a
500 Hz pulse width modulated (PWM) signal to the machine ECM. The signal is proportional to the sensor position
for each axis. The range of the sensor in the longitudinal (fore/aft) axis is nominal at 27% at the full forward position
to 3% at the full reverse position. The range of the sensor in the lateral (side to side) axis is nominal at 3% in the full
left position to 7% at the full right position. Refer to Neutral, Forward Travel, Reverse Travel, Left Pivot Turn, Left
Counterrotate Turn, Right Pivot Turn, and Right Counterrotate Turn in this work package for additional information.
Figure 6. Hydrostatic Joystick Control.