Based Control Interface Board Display Test System Design

The display measurement system, developed by Dongfei display technology R&D, is not only suitable for spot measurement of CRT and helpful to improve the design of the guns or DU, but also able to measure some other display devices. The PCL₇26 card, one important control part in the system, can't satisfy new requiements of the system. In order to make the display measurement system extended to more applied fields, we have to design a right control card by ourselves.This card includes three modules. The measurment system works at low speed, so RS-232 standard is adopted in the interface data transmit circuit design, and the serial communication program is writeen using MSComm control component. In the second module, the singlechip, AT89C51, is the most important control core. Under the control of the singlechip, the data from computer can be changed into 0 to 10V or -10 to 10V low voltage analog signal to control high voltage in the system. By this way,the number of analog signals can reach ten. In the digital signal control circuit, the intel 8255A, a programmable I/O device, makes the number of I/O pins increased to 24, so the pins are enough for the system requirement. Besides,the 8259 makes the number of external interrupt sources increased form 2 to 8.In this paper, the interface data transmit module, analog signial and digital signal control modules have been completed, and the number of signal control is larger than the PCL₇26's. These facts prove that it is feasible to implement signal control in the display measurement system using serial communication.