Tait TP9100 - Digital and Front-Panel Interface Circuitry

TP9100 Service Manual Circuit Descriptions 71
© Tait Electronics Limited May 2005
LCD Module
The LCD module is physically connected to the front-panel interface board
but is controlled by a serial link from the FPGA. The backlighting
incorporated in the LCD module is controlled by a data line from the FPGA
that switches transistor Q907. Power is supplied to the LCD module
through a +3V3 signal on the front-panel interface.
Keypad
Backlighting
The keypad backlighting is controlled by the same FPGA output to
transistor Q907 as the LCD backlighting.
Man-Down and
Tem pe rat ure
Sensors on the front-panel interface board provide analog levels to indicate
the status of X-axis tilt, Y-axis tilt and front-panel temperature. The tilt
signals from the man-down sensor are multiplexed onto one output from the
interface (
FPI CDC MANDOWN). Whether this signal has X or Y sense selected is
determined by
DIG MUX ADC.
3.8 Digital Circuitry
Introduction For a block diagram of the digital circuitry, refer to Figure 3.8.
The digital circuitry is not serviceable at level-2 and is not described in this
manual.
3.9 Front-Panel Interface Circuitry
Introduction For a block diagram of the front-panel interface circuitry, refer to Figure 3.9.
The front-panel interface circuitry is not serviceable at level-2 and is not
described in this manual.