relay automatic test bench

[Berkley]

I'm writing to ask some help about automatization of relay/switch based testbench.

The main idea is to command pass/not to pass signals (150 Vac @400 Hz for three-phase power,
about 30 Vdc and 2 A) according to an established tests order.

The system dialogues via GPIO (or other types of communication) in order to set correct voltage supply and other settings.

The outputs to verify tests are:

- voltage readings

- current  readings (max 6Adc)

- oscilloscope (frequency (max1200 Hz) and amplitude (10-20V); activation time between imposing input and getting output)

- PC screen readings (sent from device under test to RS-422)

Test implementation is led to pursue a step-by-step view.

Is it possible to implement this system via NI software?

I've seen NI Switch, but I don't understand if it is possible to implement this kind of system .

I look forward to your answer and if you need other specs.

Thank you.

Barkley

[Logan_081]

Hello Barkley,

Thank you for sharing your questions on this forum. In my opinion you need to evaluate a system design with a Sales Engineer in order to identify SW/HW components that best fit your requirements. I can suggest you some Getting Started manual so that you can get more informations about NI solutions:

Getting Started with Instrument Control

Getting Started with Instrument Control

Let me know if you want to go ahead and need further informations.

Best regards

[Berkley]

Hello Matteo,

thank for your advise. I'll check out this documentation. As soon as I finish, I'll give you a feedback.

Best regards

Barkley

[EricS.]

Hi Berkley,

I wanted to comment that your system is almost defintely possible with NI Hardware and Software.

I can comment most about the Switches you would need.  You first mentioned 150V, 400Hz, then 30VDC and 2A, and a maximum current reading of 6A. How much AC current does your three phase need to supply?  Would the 6A maximum current be just a quick current spike or steady state current?

There are a few modules that I would look at for your system:

PXI-2586 - 10 channel SPST, 300VDC CAT II, 12A max current

PXI-2568 - 31 channel SPST, 150VDC, 2A max current

PXI-2567 - 64x1 channel multiplexer, 300 V CAT I, 2A max current

How many devices will you need to be testing at once?  We also have the PXI-2585, a 10 channel 12A multiplexer (rather than SPST) so you can route power to one of 10 different DUTs.

We also have high speed digitizers that could function as your oscilloscope.  I would contact your local sales engineer who can help spec out the whole system for you.  You can find your sales engineer by going to ni.com and clicking 'contact us' in the upper right.

[Berkley]

Hi Eric,

I answer point by point.

"I can comment most about the Switches you would need. You first mentioned 150V, 400Hz, then 30VDC and 2A, and a maximum current reading of 6A. How much AC current does your three phase need to supply? Would the 6A maximum current be just a quick current spike or steady state current?" 

I have one three-phase 115Vac and 2mA (AC) supply, one three-phase 55 Vac and 6,5A @ 1585 Hz (max value) supply and one DC supply 28Vdc and 2 A max. Another supply can be derived from the previous ones to feed lower voltage (1Vac 120mA @ about 500 Hz) loads."

There are a few modules that I would look at for your system:

PXI-2586 - 10 channel SPST, 300VDC CAT II, 12A max current

PXI-2568 - 31 channel SPST, 150VDC, 2A max current

PXI-2567 - 64x1 channel multiplexer, 300 V CAT I, 2A max current

"How many devices will you need to be testing at once? We also have the PXI-2585, a 10 channel 12A multiplexer (rather than SPST) so you can route power to one of 10 different DUTs."

Ten DUTs are a good number for my test bench, if security requirements and test correctness are fullfilled (i.e. time parallel test procedure). The minimum number is 1  or 2 at once.

"We also have high speed digitizers that could function as your oscilloscope."

My idea is to attach several equipments to a "NI relay card" (i.e oscilloscope, amperometer, voltmeter, multimeter ecc. ecc.), piloted by PC via bus in order to setup meters and record data about th test.

" I would contact your local sales engineer who can help spec out the whole system for you. You can find your sales engineer by going to ni.com and clicking 'contact us' in the upper right."

Thanks for your attention and time. I write down a document with main specification to get  a better system view of test bench .

[EricS.]

Hi Barkley (I just notieced your username is Berkley and you sign your name as Barkley),

Thanks for the updates.  The modules I listed previously would best be used to switch the high power and high current signals to your devices under test.  When using a multiplexer (like the PXI-2585), you can only power one device at a time.  You mentioned needing 1 or 2 devices powered at the same time, so perhaps using a SPST switch module would be better.

As far as the voltmeter oscilliscope are concerned, those will be much lower current and we have several switch module that may be able to switch those instruments to your devices under test.  The ammeter, because such high currents will be measured, will still need to be switched using the modules I mentioned earlier.   You could also use a small shunt resistor and measure the voltage across it to derrive the current.  This would now reduce the current so you could use the same switch module for it as the digitizer and voltmeter.

Your sales repesentative will be able to help you spec out your entire system, using some of these switch recommendations as well as adding in the appropriate multimeter and digitizer.

Having a system diagram and specifications will greatly help when selecting the test instrumentation.