Theory of Operation T400 Ozone Analyzer Operator’s Manual
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13.4. FRONT PANEL TOUCHSCREEN/DISPLAY INTERFACE
Users can input data and receive information directly through the front panel
touchscreen display. The LCD display is controlled directly by the CPU board. The
touchscreen is interfaced to the CPU by means of a touchscreen controller that connects
to the CPU via the internal USB bus and emulates a computer mouse.
Figure 13-20: Front Panel and Display Interface Block Diagram
13.4.1. FRONT PANEL INTERFACE PCA
The front panel interface PCA controls the various functions of the display and
touchscreen. For driving the display it provides connection between the CPU video
controller and the LCD display module. This PCA also contains:
power supply circuitry for the LCD display module
a USB hub that is used for communications with the touchscreen controller and the
two front panel USB peripheral device ports
the circuitry for powering the display backlight
06870C DCN6332