Micro 70 Wire Guidance
PS S8.0 8200
F-code Section C-code
Version no T-code
001 OE35
© BT Products
305
Service Manual 1997-10-24
7. Component Function and
Relationship
The Micro 70 controller is the center of the guidance system.
The Micro 70 controller consists of a single printed circuit
board mounting an INTEL 80C196 Microprocessor. There are
no mechanical trim pots on the Micro 70 controller to be
adjusted. The logic board has a number of digital, analog,
and encoder inputs and outputs incorporated into the ten
plug-in connectors. All of the operating software and design
parameters come pre-loaded onto the CPU. A long life lithium
battery maintains the memory in the CPU.
The CRA 70 antenna is an active receive antenna. Two
antennas are used to send a signal back to the Micro 70
controller relating the position of the truck in relation to the
guide wire. One antenna is mounted on the frame skirt
directly in front of the drive unit and one is located in the area
between the outriggers, behind the mast columns and in front
of the load wheels. The two antennas are identical with the
exception of the cable connections into the antenna. Both
antennas should be mounted on the truck with the epoxy side
facing away from the center of the truck. One antenna is used
for guidance in the steer wheel direction of travel and both
antennas are used for guidance in the load wheel direction of
travel.
The steering feedback potentiometer sends a signal to the
Micro 70 controller to indicate the position of the drive unit
relative to a centered position of the drive unit.
The tachometer is used to determine the travel speed of the
truck and the travel direction. It is mounted to drive directly off
the drive motor. It outputs a signal of 7 volts DC per 1000
RPM. Any change of tachometer polarity will result in a
change of the connection of the CRA 70 antennae within the
Micro 70 system.
The signals from the steering feedback potentiometer and the
travel tachometer are fed to the Micro 70 controller through a
feedback/tachometer interface (FTI 7). Mounted on the FTI 7
is a mechanical zero potentiometer that is used to fine tune
the steering feedback potentiometer signal as it goes into the
Micro 70 controller. The FTI 7 also selects the multiplier for
the feedback signal to the controller. When the system is in
the acquisition mode the feedback signal is amplified to the
To Next Page
Loading...
