Section 8. Theory of Operation
Model 5200 High-Level Orderpicker
Steering •
These square waves are read by the CM. The CM sends this information over the transmit line to the STM.
•
The STM sends voltages to the steer power head to activate the steer motor. STEER DIR 1 and STEER DIR 1 PWM turn on the transistors required to turn in one direction. The STEER DIR 2 inputs turn it the other direction.
•
The BOOST + and BOOST - inputs are required for both steering directions. BOOST + is used to power one set of transistors for steering and Boost - is used for the reference by Boost +.
•
While the steering is activated, the Steer Power Head sends a voltage to the STM that indicates the current draw of the motor over the STEER CURRENT FB. There is also a voltage that is sent over the STEER CURRENT LIMIT whenever the motor is in current limit.
•
The position of the drive wheel is indicated by the three LEDs on the operator display. These are based on the input from the Steer Feedback Encoder. See Table 8-1.
Table 8-1.
Steering Indicator Display Messages Display
Lift Truck Condition
All LEDs scroll in side-to-side pattern
Drive unit position is unknown
Left LED on steady
Drive unit in left, end-of-travel zone (more than 65° counterclockwise)
Mid-Left LED on steady
Drive unit in left zone (10-65° counterclockwise)
Center LED on steady
Drive unit in center zone (within 10° of center)
Mid-Right LED on steady
Drive unit in right zone (10-65° clockwise)
Right LED on steady
Drive unit in right end-of-travel zone (more than 65° clockwise)
All LEDs blink in unison as the horn chirps
In Maintenance Mode
8-8
Publication Number: 1043922B, Revised: 2 Sept 2015
