Continuity Test

[med.taarit]

Hello everyone ,

I'm an engineering student and i'm currently working on my end of studies project which concists of realizing a continuity tester  and developing a graphical user interface.

This continuity tester is for a product that contains diffrent types of connectors and it's going to be used to test 38 connectors (connector per connector)

these connectors are called destination connectors. one destination connector can be cabled to 1,2,3 or 4 connectors that are called departure connectors.

The solution that i'm working on:

To test a destination connector you must connect all of its departure connectors to a source of current and then inject current to one cable and see in the destination connector in which cable there's  current (if not, the cable is not wired) then compare it to the data base and repeat this operation for all of the cables of the connector. then display on the user interface if it's cabled correctly or not .

the maximum of cables to be tested per connector is 68. so that means 68 in the departure and 68 in the destination

Is there a more appropriate solution for this problem? and which hardware is best suited ?

Best regards.

[Call.Me.Wilbur]

Hi, welcome to the forums!

I have a couple questions about your project.

Are you trying to do this all programmatically? If that's the case were you planning on using relays or a mux to select which cable is connected to the current source and measurement device? 

Do you have a current supply you were planning to use or were you thinking of supplying current from the same NI device that you'd be measuring it with?

Were you really set on measuring current instead of voltage? You would have much wider selection of devices to choose from if you drove the line in question to a known voltage and then measured that voltage on the other end.

With a device like the myRIO you could have one analog voltage output and one analog voltage input. The real tricky part of this comes in with selecting the lines to connect. I would advice against using a bunch of relays to do this since it would be really tricky to wire all those and you would have to have a bunch of digital outputs to select each relay. Alternatively, you could get a multplexer chip which operates of I2C or SPI. The myRIO is capable of communicating with both of these protocols.

[med.taarit]

Hi Wilbur ,

Thank for replying to my post.

i was hesitating between using relays or mux but now after your post i'm going to take your advice and work with mux.

i was planing of supplying current from the same NI device,but if you are sure that using a voltage source can do the trick then i'll work with voltage.

[Call.Me.Wilbur]

As long as your cables aren’t so long that there will be a giant voltage drop across them I don’t think you’ll have much of a problem supplying and measuring voltage. Anyways, the myRIO can only provide a constant voltage output so you’d have to select an alternate, more expensive system.