Multi Instrument 3.8 - questions about Device Test Plans

Multi Instrument 3.8 - questions about Device Test Plans

Postby RJA4000 » Sun Jul 28, 2019 2:46 am

Hi

I'm evaluating different softwares for audio device measurement.
I use an external soundcard with ASIO driver.

One of those tools is MI Pro 3.8. I downloaded a demo and I give it a serious try.

One of the interests of your tool is that it provides some automation.

I have quite a few questions about the Device Test Plans:

I try to measure SMPTE IMD according to level.
For that, I've build a DTP with several measruements at different levels.
But I have a few issues.

1. I created a Panel setting. I can use it in manual and it works well.
But when I call the same Panel setting from a DTP, trigger is switched back to "single" and inter frame average is set to none.
I'd like the Spectrum analyser trend to look better, just to improve readability, so some averaging helps. (Measurements are not much impacted)
Any idea why and what I could do to fix that ?

2. I selected X-Y plot on "OutputAmplitude B" for X and IMD_B (dB) for Y. Also selected X range for 100dB.
I saved my DTP with those settings, but for some reason it's always reset to Frequency A and Amplitude A, and range is also reset.
Any idea why and what I could do to fix that ?

3. In DTP, I'd like to automatically save the SA graphs in Bitmap and txt at each step.
How can I specify a filename with the date in it ?

4. I want also to automatically write my Derived Data Point values to a text file.
Here, I can have the filename automatically including the date and hour
Is it possible to also include the minutes in the filename ?

5. To fill test file, the only way I found was to repeat several LOG instructions after each level measurement.
One call for each DDP
Is there a way to record all or a set of DDP with just one line in the DTP for each measurement ?

6. When the DTP is open, sometimes, while moving some DDP viewer, I minimize it.
But then, no way to retrieve it anywhere.
And sometimes, it's even not possible to do anything. I could just close all windows and the app and restart.
Is there a way to get those windows back in place without closing everything ?

7. In Spectrum Analyzer view, I'd like to move the A channel down by 20dB, to avoid overlapping of A and B and improve readability.
I can do that manually by clicking on the left of the SA, and then arrow up.
Then I save the Pannel Settings.
But that's also reset when run automatically.
Any fix ?

Let's stop here with this first batch of questions.
More to come...

Could you please help me ?
RJA4000
 
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Joined: Sun Jul 28, 2019 2:28 am

Re: Multi Instrument 3.8 - questions about Device Test Plans

Postby VirtinsTech » Tue Jul 30, 2019 3:54 pm

Thank you for your questions.

1.Inter-frame average is not supported by Device Test Plan in Version 3.8. But it is possible to use intra-frame average instead to smoothen the spectrum graph in DTP. For example, you can set the oscilloscope frame width to 2097152 (not necessarily to be a power of 2) and FFT size to 32768, then you will get an intra-frame average of 2097152/32768=64. The only drawback is that it uses a lot more memory. We will make Device Test Plan to support inter-frame average in the future.

2.The X and Y selection boxes in the top of Device Test Plan does not reflect the actual selections in the X-Y Plots. They will be reset to the default selections "A-Frequency(Hz)" and "A-Amplitude(V)" after loading a DTP. The actual selections in the X-Y Plots including the X and Y range setting are reflected by their X and Y labels (DDP aliases) and ranges in the graph. We have not encountered the problem you mentioned in our tests so far.

3. SEB and SET instructions can be used in DTP to output bitmap and text results of the spectrum analyzer into files. The file name for each instruction can be specified explicitly. It is possible to put these instructions inside a repetition loop (RPT instruction) and automatically "increase" the file name by "1" in each execution. To do that, the base file name should contain at least one numerical digit at the end before the file extension, e.g. July-30-2019-0.xxx, and the "+1" option must be ticked. In this way, you can include the date manually in the file name.

4. LOG instruction can be used to write the DDP values into a text file. The file name can automatically include date and time in various formats. The time can be any combination of hour, minute and second. Please refer to Section 8.2.5.13 of the software manual.

5. For one LOG instruction, only one DDP can be specified. It is possible to concatenate multiple DDP values in one line of the text file using <Record Separator>. Please refer to Section 8.2.5.13 of the software manual.

6. When Device Test Plan is opened, it is not possible to manipulate oscilloscope, spectrum analyzer, signal generator, multimeter, spectrum 3D plot. This is to ensure that Device Test Plan takes the control. However, it is still possible to manipulate those "monitoring only" windows: DDP viewers, DDP array viewer and Data Logger. We have not encountered the "minimized windows missing" problem so far. But if it happens, you can right click the right part of the Windows taskbar at the bottom of the screen and select [Cascade windows] to bring back those minimized and "missing" windows.

7. We have just tested this scenario but did not encounter any problem. We have tested the "Auto" setting button at the upper right corner as well as the LDP instruction in DTP. Probably you can provide more detail on this to help us to diagnose.
VirtinsTech
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Re: Multi Instrument 3.8 - questions about Device Test Plans

Postby RJA4000 » Fri Aug 02, 2019 9:29 pm

VirtinsTech wrote:Thank you for your questions.

1.Inter-frame average is not supported by Device Test Plan in Version 3.8. We will make Device Test Plan to support inter-frame average in the future.

2.The X and Y selection boxes in the top of Device Test Plan does not reflect the actual selections in the X-Y Plots.

3. SEB and SET instructions can be used in DTP to output bitmap and text results of the spectrum analyzer into files. The file name for each instruction can be specified explicitly.

4. LOG instruction can be used to write the DDP values into a text file. The file name can automatically include date and time in various formats.

5. For one LOG instruction, only one DDP can be specified. It is possible to concatenate multiple DDP values in one line of the text file using <Record Separator>. Please refer to Section 8.2.5.13 of the software manual.

6. We have not encountered the "minimized windows missing" problem so far. But if it happens, you can right click the right part of the Windows taskbar at the bottom of the screen and select [Cascade windows] to bring back those minimized and "missing" windows.

7. We have just tested this scenario but did not encounter any problem.


Hi
Thanks fo your detailed answer.
I summarized them somehow above.
1. OK, thx
2. OK
3. So no solution. OK
4. I will give the "minutes" a try, thx
5. That's what I do. That gives very long DTP file, but OK. It works, indeed.
6. It's easy to replicate for me: it happens anytime I click on "minimize" button. I'll try the cascade, Thx.
7. That's probably saved with the panel settings ? I'll try that too

8. I have logged an issue: The app hangs with a dtp at 192kHz.
Looks like it sometimes hangs when I use 192kHz manually too...
I still have 5 days trial period and I'm a bit stuck...

I'm also trying your API interface, which looks like the way to go for me.
RJA4000
 
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Joined: Sun Jul 28, 2019 2:28 am

Re: Multi Instrument 3.8 - questions about Device Test Plans

Postby VirtinsTech » Sun Aug 04, 2019 11:39 pm

The crash issue will be discussed at: viewtopic.php?f=7&t=1311

Yes, whatever can be done within Device Test Plan, can be done using the Automation API.
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Re: Multi Instrument 3.8 - questions about Device Test Plans

Postby RJA4000 » Tue Aug 13, 2019 12:36 am

Thanks
I started trying that and it looks like it works, indeed.
Actually, it works pretty well.

There is no way to create a XY plot inside VI through API calls, I guess ?
RJA4000
 
Posts: 6
Joined: Sun Jul 28, 2019 2:28 am

Re: Multi Instrument 3.8 - questions about Device Test Plans

Postby VirtinsTech » Tue Aug 13, 2019 9:30 pm

There is no Automation API to create a XY plot. You will have to use your own code to do it after obtaining DDP values through the Automation API.
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