Front Panel Interface; Stepper Motor Driver; Carriage Processor Interface; Sensors - HP DesignJet 200 Service Manual

Front Panel Interface

The front panel consists of nine LEDs and eight switches. The servo processor interface to
the front panel consists of nine control signals and two sense signals.

Stepper Motor Driver

The servo processor controls a stepper motor used for print cartridge servicing and
alignment.

Carriage Processor Interface

The servo processor serial port is used to communicate with the carriage processor.

Sensors

Four sensors provide input to the servo processor:
D The is a mechanical switch that detects if the window has been raised.
window sensor
This serves the purpose of a safety interlock. While the window is raised, the servo
processor halts any carriage movement.
D The detects the presence of media in the media path. It is also used to
media sensor
determine media size.
D The
pinch arm sensor
processor uses the sensor to determine the pinch arm position during the initialization
sequence.
D The detects whether the bail has been raised. The servo processor uses the
bail sensor
sensor to determine the bail position during the initialization sequence.

EEROM

A serial EEROM is used as nonvolatile storage for calibration and configuration data. This
data is typically unique for the plotter. It includes the following information:
D RS 232 configurations
D Certain front panel selections
D Pen pallet information
D Constants created during the various plotter calibrations
The EEROM is soldered to the Main PCA (both new and rebuilt). Should the EEROM be
cleared or the Main PCA replaced, perform all calibrations. (Details ' chapter 7.)
The servo processor drives the EEROM control signals, chip select and shift clock. A reset
signal disables the chip select during power transitions to reduce loss of data.
C3187 90000
detects whether the pinch arms have been raised. The servo
Functional Overview 5 27