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Smart Instruments Increase LED Production Test Throughput

In the past, a PC often controlled all aspects of the test in many LED production test systems. In other words, in each element of a test sequence, the sources and instruments had to be configured for each test, perform the desired action, and then return the data to the controlling PC. The controlling PC then had to evaluate the pass/fail criteria and perform the appropriate action for binning the DUT. Each command sent and executed consumed precious test time and lowered throughput. Obviously, in this type of PC-centered test configuration, a large percentage of the test sequence time was consumed by communicating information to and from the PC.

过去，在很多LED生产测试系统中人们常常采用PC机控制测试[1]的各个方面。换句话说，在测试序列的每个组成部分中，每个测试必须对信号源和测试仪器分别配置，执行所需的操作，然后将数据返回给控制PC。控制PC然后进行pass/fail判断并执行相应的操作对DUT进行分拣。发送和执行的每条命令都浪费了宝贵的测试时间，降低了产能。显然，在这类以PC为中心的测试结构中，大部分测试序列时间都被PC和测试仪器之间的通信所消耗了。

In contrast, many of today’s smart instruments, such as Series 2600A System SourceMeter® instruments, make it possible to increase the throughput of complicated test sequences dramatically by decreasing the amount of traffic over the communications bus. In these instruments, the majority of the test sequence is embedded in the instrument. A Test Script Processor (TSP®) is a full-featured test sequence engine that allows control of the test sequence, with internal pass/fail criteria, math, calculations, and control of digital I/O. The TSP can store a user-defined test sequence in memory and execute it on command. This limits the set-up and configuration time for each step in the test sequence and increases throughput by minimizing communications to and from the instrument and PC. The process for programming an instrument of this type is relatively simple: 1) create the script; 2) download the script to the instrument; and 3) call the script to run. For Series 2600A instruments, scripts can be written and downloaded to the instrument using the Test Script Builder software provided with the instrument or downloaded to the instrument from custom applications written in languages such as Visual Basic or LabVIEW.

相反，当前很多智能仪器，例如2600A系列数字源表[2]，通过减少通信总线上的通信量，使得大幅提高复杂测试序列的产能成为可能。在这些仪器中，测试序列的主要部分嵌入在仪器内部。测试脚本处理器（TSP®）[3]是一种全能的测试序列引擎，能够利用内置的pass/fail判据、数学和计算公式控制测试序列和数字I/O端口[4]。TSP能够将用户自定义的测试序列保存在存储器中然后根据命令执行它。这样就限制了测试序列中每一步的设置和配置时间，通过最大限度减少与PC和仪器的通信而提高了测试产能。这类仪器的编程过程相对简单：1）创建脚本[5]；2）将脚本下载到仪器中；3）调用脚本执行。对于2600A系列仪器[6]，用户可以利用仪器本身提供的Test Script Builder软件编写或者下载脚本，或者从用Visual Basic或LabVIEW等语言编写的用户应用程序中下载到仪器中。

LED Test System for a Single Device
Figure 2 is a simplified block diagram of a system for testing a single LED. For automation purposes, a PC and a component handler—a probe station for on-wafer measurements—are typically included.

[1] PC机控制测试：http://docs.google.com/viewer?a=v&q=cache:fakLf_4zCNQJ:www.keithley.com.cn/data%3Fasset%3D50234+PC%E6%9C%BA%E6%8E%A7%E5%88%B6%E6%B5%8B%E8%AF%95&hl=zh-CN&pid=bl&srcid=ADGEESjFvBbm2V98qQdPWz54fHPFoHD7rbywml1-hLNKNueCR_IElK98Puwl6UEd8cy7zZAVs0DmbF6RJ9RnHxRyIn0NUP20j6fAwUZJKprcfq_0iqFnBpkfbNZ83UfqRksXeP-nCczG&sig=AHIEtbRSXDd0X-58Ja2nLIa5QoSQyA_yDg

[2] 2600A演示视频http://keithley.adobeconnect.com/p81871518

[3] 脚本处理器：http://www.keithley.com.cn/products/tsbscripts/tsprocessor

[4] I/O端口：http://www.keithley.com.cn/products/localizedproducts/dataacqmodules/kusb3160

[5] TSP: http://www.keithley.com.cn/products/dcac/voltagesource/header_table

[6] 2651A仪器：http://www.keithley.com.cn/news/prod110414