Principles of Operation Teledyne API T703/T703U Calibrator Operation Manual
204
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.

9.3.1.1. 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 device ports
he circuitry for powering the display backlight

9.4. SOFTWARE OPERATION

The calibrator’s core module is a high performance, Vortex 86SX-based microcomputer
running Windows CE. Inside Windows CE, special software developed by Teledyne
API interprets user commands from the various interfaces, performs procedures and
tasks, stores data in the CPU’s various memory devices, and calculates the concentration
of the gas being sampled.
Windows CE
API FIRMWARE
C alib rat or Op era t io ns
Calib ration Procedures
Configuration Pr ocedures
Aut o nomic Systems
Diagnostic Routines
Memory Handli ng
Calib ration Data
System Status Data
I nter fa ce Handling
Sensor input Dat a
Touchscreen
Analog Output Data
RS 232 & RS485
Ex ternal Digit al I/O
Measurement
Algorithms for
photometer
CALIBRATOR
HARDWARE
PC/104 BUS
PC/104 BUS
Figure 9-12: Schematic of Basic Software Operation
07223C DCN6572