Tait TP9100 Service Manual

Also see for TP9100: User guide Product safety and compliance information User guide Service manual Manual

Contents

TP9100 Service Manual Circuit Descriptions 71© Tait Electronics Limited May 2005LCD Module The LCD module is physically connected to the front-panel interface boardbut is controlled by a serial link from the FPGA. The backlightingincorporated in the LCD module is controlled by a data line from the FPGAthat switches transistor Q907. Power is supplied to the LCD modulethrough a +3V3 signal on the front-panel interface.KeypadBacklighting The keypad backlighting is controlled by the same FPGA output totransistor Q907 as the LCD backlighting.Man-Down andTemperature Sensors on the front-panel interface board provide analog levels to indicatethe status of X-axis tilt, Y-axis tilt and front-panel temperature. The tiltsignals from the man-down sensor are multiplexed onto one output from theinterface (FPI CDC MANDOWN). Whether this signal has X or Y sense selected isdetermined by DIG MUX ADC.3.8 Digital CircuitryIntroduction 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 thismanual.3.9 Front-Panel Interface CircuitryIntroduction 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 notdescribed in this manual.