Matrix Switch Integration

[TrumpBite]

                            I am looking to test 2 40 pin connectors. (2 rows by 20 columns each)  This is a quality project, and for each pin I need to measure any adjacent pin for a short through a connector cauesd by poor soldering.  (Adjacent is defined as one step away from the pin I am currently referencing - up down left right diagonal up down left right)  The max connections is 5 and the min is 3.  I will use a DMM card and a matrix card connected through a PXI backplane.  The PXI will have an embedded computer which will be programmed with Labview 8.0 and Switch Executive (Hopefully) to measure resistances within a tolerance range.  My question pertains to the matrix card.  What kind should I use?  What do I look for? How will it interact with a breakout board with the 2 40 pin ribbon cables that are attached to the pins that I am measuring? For the matrix card itself, there are 2 wire, 4 wire, and many m x n combinations for the cards, which should I use?.  Also, how does the DMM interact with the matrix card. (does the excitation current go throught the two testing nodes or do I need another 2 nodes to send the current and 2 to measure the resistance?)  Finally, could someone give me an overview of Switch Executive? Any assistance from persons experienced with the NI Switching Matrix Cards, Switch Executive, or a project similar to this would be much appreciated.

Thanks.

[Guy Ferraro]

TrumpBite,

First I need to tell you that you will not be able to route any analog signals to the PXI back plane. As per PXI specifications, only triggers and timing signals can be routed to the back plane. The analog signals during resistance measurements will be routed through the switch but not to the back plane. The input and output will be on the front connector.

For your application I will use a PXI-2530 in dual 64x1 1 wire mux. You can connect each pin of your connector to a channel of both 64x1 (on the front of the PXI-2530) and the DMM to com1 and com4 (also on the front of the PXI-2530).   

The DMM will provide the current excitation needed for resistance measurements.

The terminal block TB-2630 has ribbon cable connectors and ships with connectors that you can use to connect your ribbon cables from your DUT connectors. The pith of the connectors is 0.1 in. so the cable has to be 0.05 in. You can order more connectors is needed. (Part #762120-01)

For an overview of NISE please visit http://www.ni.com/switchexecutive/ where you will find a online demo video.

Guy Ferraro

Switch product Support Engineer

NI - USA

Message Edited by Guy Ferraro on 01-17-2006 04:09 PM

Message Edited by Guy Ferraro on 01-17-2006 04:09 PM

[TrumpBite]

Guy,

   Thanks a lot for your help.  I have more questions regarding multiplexer vs. matrix switching.  Is there an email that I could reach you at?  I can send you a little more information regarding this project by uploading some files and diagrams.  This will also help me in determining what terminal blocks I will need to breakout the board.  There is also a little confusion on my part regarding what exactly dual 64 x 1 dual wire is vs. 128x1, 32 x 4, etc.  I have never used a matrix switch before and would like to be confident that what I am buying will work for this application. Thanks again for your help.

Dave Kenin

Xerox Corporation

David.Kenin@xerox.com

[Guy Ferraro]

Dave,

I set up a Service Request for you to reach an application engineer that will answer all your questions. The AE will consult with me if needed.

Phone Number # (866) 265 - 6964

SR# 762841

Guy Ferraro

Switch product Support Engineer

NI - USA

[Guy Ferraro]

Phone Number should be # (866) 275 - 6964.  Sorry for the inconvenience