HP DESIGNJET 3D, Service Manual

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Controller Board
Overview
The controller board provides all of the low level hardware control and
sensing for the system. The firmware runs on the controller CPU and is flash
resident (rather than on the HDD and SBC).
Voltage Generation
• +/-15 VDC is used for PMD DACs
• 10 VDC is used for DAC reference
• 3.3 VDC is used for controller board logic
Dual Port Memory Interface
The dual port memory located on the controller board provides the
communication channel with the single board computer (SBC) through the
P104 connector. The SBC provides the coordinates, velocities, and flow rate
commands for modeling to the controller. The controller board provides the
status/error information about the hardware back to the SBC.
X, Y, Z Axis Control
The controller takes the flow rate information from the SBC and sends it to
the PMD processor. The PMD 2840 processor services the X and Y stepper
motors and the model and support head servo motors. The 3410 processor
services the Z axis stepper motor. There is no feedback from the stepper
motors to the system (they are open-loop controlled).
Material Motor Control
The controller takes the flow rate information from the SBC and sends it to
the PMD 2840 processors. The PMD uses this information along with the
encoder signals from the material motors to generate an output signal to
drive the servo motors in the head assembly. Since the encoders provide
feedback the material motors have a closed-loop control. Their position and
rotation are precisely known at all times.
Temperature Control
The controller board reads the three thermocouple (T/C) inputs/signals - 2
for the head, 1 for the chamber.