Teledyne GFC-7000T - Trace CO2 Analyzer - manual - Manual (Page 230)

Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer
Teledyne Analytical Instruments 212
9.4. 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 9-17: Front Panel and Display Interface Block Diagram
9.4.1. LVDS Transmitter Board
The LVDS (low voltage differential signaling) transmitter board converts the parallel display bus to a
serialized, low voltage, differential signal bus in order to transmit the video signal to the LCD interface
PCA.
9.4.2. Front Panel Touchscreen/Display Interface PCA
The front panel touchscreen/display 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 device ports
 the circuitry for powering the display backlight