基于GPIB的数字电路自动测试系统研究

Research of an automatic digital circuit test system based on GPIB

结合虚拟仪器技术、GPIB(General Purpose Interface Bus)技术设计了一种数字电路自动测试系统.测试系统由硬件和软件两部分组成.硬件包含主控计算机,GPIB转接卡,USB(Universal Serial Bus)集线器,USB数字量I/O模块,具有GPIB接口的测试仪器.主控计算机通过USB接口控制数字量I/O模块和GPIB接口的测试仪器,并处理测试数据、显示测试结果.测试系统软件基于LabVIEW平台,采用图形化编程的形式开发.软件由应用程序和数据库管理程序两部分组成,应用程序为"主模块+功能插件"的形式,数据库管理程序采用Microsoft Access软件.本文阐述了数字电路的通用测试流程,并描述了测试系统在测试矢量生成环节的实际工作过程.该系统已用于雷达接收机数字电路的自动测试,性能稳定.

The application of digital circuits has gone deep into various aspects of daily lives and productions. Nowadays,digital systems are becoming more and more complex,which increase the complexity and difficulty of testing the digital circuits.As an important and effective method,automatic test of digital circuits has been extensively studied for testing complex digital circuits.Therefore,we propose an automatic digital circuit test system based on the Universal Serial Bus（USB）and the General Purpose Interface Bus（GPIB）in this paper.The design of the automatic test system can be divided into two parts：the hardware and the software.The hardware of the system includes computer,GPIB converter,USB digital I/O modules and test machines with GPIB interface.Buses are the medium of information transmission between the computer and other equipment.Owing to the widely use of USB and GPIB,we select USB and GPIB to connect all the modules of the hardware.The computer is the core of the hard-ware,which controls the I/O module and the test machines with GPIB interface via the USB interface.The computer also plays the role of processing the current test data and displaying the result of the test.Software of the system is based on LabVIEW and developed in the form of graphic program.With LabVIEW,we can quickly create the＆amp;nbsp;software front panel and call the hardware modules in need.The software consists of applications and database. Structure of the applications can be described as “major module＋functional plugs”.Content of the major module is fixed while content of the function plugs is flexible.The applications contain the major part of the automatic test system,not j ust functional test module of the digital circuits,but also the fault isolation module and etc.The applications rely on the database.Microsoft Access is selected to work as the database software.The actual working process of the system is also introduced in this paper besides the hardware and software.Generation of the testing vectors is essential for the process.As a result,two common generation test algorithms are emphasized.The automatic test system has been applied to debug digital circuits of the radar receiver system.