Section 8.Theory of Operation

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 Table8-1.

Table 8-1.Steering Indicator Display Messages

All LEDs scroll in side-to-side pattern Drive unit position is unknown

Left LED on steadyDrive 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 steadyDrive unit in center zone (within 10° of center)

Mid-Right LED on steady Drive unit in right zone (10-65° clockwise)

Right LED on steadyDrive unit in right end-of-travel zone (more than 65° clockwise)

All LEDs blink in unison as the horn chirps

In Maintenance Mode

Model 5200 High-Level Orderpicker

Publication Number: 1043922B, Revised: 2 Sept 2015