Showing papers on "Test card published in 2002"

A method for determining packet error rate of wireless LAN stations

Abstract: A test system (100) is disclosed in which the packet error rate of a wireless card can be determined without having knowledge of the software interface to the card. The wireless card under test (106) is placed inside an anechoic chamber (102). Test equipment emulates an access point and the card under test "associates" itself with the emulated access point. The test equipment includes an arbitrary waveform generator (130), RF signal generator (132), and a controller (114) which emulates an access point. The controller (114) commands the arbitrary waveform generator (130) and RF signal generator (132) to transmit a test data packet to the card under test (106). If the test data packet is correctly received by the test card (106), the card transmits back an acknowledgment packet. The controller (114) computes the packet error rate based on the number of lost packets relative to the total number of test data packets sent.

Automatic calibration and built-in diagnostic procedures for line scan cameras

Abstract: A new and improved line scan camera achieves the proper framing of the image field of view by using a first test card to calibrate the true bottom and leading edge portions of the test card which simulate the true bottom and leading portions of an article being scanned or photographed. Still further, the architecture of the electronic chip incorporated within the charge coupled device (CCD) of the camera effectively divides the linear array of pixels into a plurality of channels, and amplifier gain and black offset adjustments are made with respect to exposure levels, characteristic of the pixels disposed at the channel boundaries, under different degrees of input whiteness signals applied to a test card of a predetermined color shade, so as to achieve channel-to-channel seam matching. Subsequently, correction factors are effectively superimposed upon substantially all of the exposure levels characteristic of substantially all of the pixels comprising the line scan of the line scan camera such that true uniform exposure levels are in fact achieved.

Calibration of test cards that form part of a test system for carrying out of wafer tests, using a device that is suitable for calibrating test cards with unsprung contact elements

Abstract: Device for calibrating test cards (100') with unsprung contact elements (50') that are used to test semiconductor wafers has: a probe arrangement (200') that has first (KSIG') and second (KSCH') signal contact surfaces; and a positioning device for positioning the probe device on the test card so that first and second signal contact surfaces connect to first and second test card contact elements (50'); whereby the first and second contact surfaces are attached in a sprung manner to the probe arrangement.