Teledyne gfc 7000ta Front Panel Touchscreen/Display Interface, Lvds Transmitter Board

Theory of Operation Model GFC7000TA Carbon Dioxide Analyzer

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

Teledyne Analytical Instruments 212