Best Test Flow for Automated OScope Capture

[gbusletta]

I am wondering what the best test flow might be for automated testing with oscope waveform capture for power supply testing.

I currently have a setup an a vi that allows the operator to setup the test equipment etc. and then manually adjust the oscope trigger and waveform properties to yield the best possible waveform image.

After the user manually captures all of this data nd waveforms for a particular test ( such as over current, startup/shutdwon etc.), the data file itself can be re-loaded so that additional units can be tested without having to configure the scope and the rest of the equipment again.

The problem is that even though the setting of the scope worked fine for the first unit, the second unit might just be different enough where manual intervention is needed to clean up the trigger and waveform. This means that an operator has to sit there and "watch" the process as it is occurring.

Does anyone have experience with this type of setup and how I can make it hands free?

I was thinking of using some type of external trigger that could trigger the oscope and all other equipment in a certain sequence. This would provide consistency between all duts so that it is not relying on a signal from the dut which might be different than the original.

Has anyone ever written a vi that judges the quality of the waveform capture to ensure it meets a certain criteria?

Here is a list of some equipment we are using:

TDS3054B Oscilloscope

Agilent E3633A Power Supply

Agilent N6705B Power Anlayzer ( not used on every test bench)

Chroma 6312 DC Electronic Load

Agilent 33220A Arb

Agilent 34972A Data Mux

Here is just one example waveform that I am interested in capturing

[jdubs]

gbusletta,

If you wanted to automate the process, you would probably need to bring in the data and compare it to some kind of benchmark, and loop that process until it was within tolerance.  Unfortunately, there doesn't seem to be anything pre-written that will do that part for you.  However, your specific requirements are probably unique enough that writing your own VI would provide the best fit for your application.  You could compare the data to some expected value and then compute a percent difference.  A pass/ fail designation could rely on an average tolerance that you require.  There would likely be complications with matching phases between your base and what you capture, which you might be able to minimize by still having some user interaction for that.

Hope this helps,

Jen W

Applications Engineer

National Instruments