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Continuous voltage data acquisition with Agilent 34972A

Hello everybody,

 

I want develloped a LabVIEW VI which should log 3 voltages. The programme works fine . But it seems as if LabVIEW records the channels step by step and there are always about 1s between two different voltages for each channel.And the machine will have the sound of switching channels. How can I make these sounds disappear and keep the machine collecting data? I want them to be parallelized and continuous.It might be possible that my LabVIEW VI is the problem because I actually had no idea how to create my VI and I was really surprised when it seemed to work.

I attached my VI and a text data to show you how it looks like.I want new voltages been logged every 100ms.

I use Agilent 34972A and LabVIEW2016.

 

Thank you very much and if anything isn't clear yet, just ask.

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Message 1 of 17
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Hello everybody,

 

I want develloped a LabVIEW VI which should log 3 voltages. The programme works fine . But it seems as if LabVIEW records the channels step by step and there are always about 1s between two different voltages for each channel.And the machine will have the sound of switching channels. How can I make these sounds disappear and keep the machine collecting data? I want them to be parallelized and continuous.It might be possible that my LabVIEW VI is the problem because I actually had no idea how to create my VI and I was really surprised when it seemed to work.

I attached my VI to show you how it looks like.I want new voltages been logged every 100ms.

I use Agilent 34972A and LabVIEW2016.

 

Thank you very much and if anything isn't clear yet, just ask.

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Message 2 of 17
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Can anyone answer this question?  I would appreciate it very much.

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Message 3 of 17
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Can anyone answer this question?  I would appreciate it very much.

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Message 4 of 17
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You can speed things up by moving the initialize and all configuration of the measurements outside the while loop.  Your while loop should just have the trigger event and the reading code inside the loop.  Once you do that your readings will be MUCH faster!

 

If you want to run calculations on the data and still read as fast as possible look at a producer consumer architecture.

 

There's a great example here of a state machine design for your instrument - https://forums.ni.com/t5/LabVIEW/Continuous-data-acquisition-with-Agilent-34972A/m-p/3188756/highlig...

 

Hope that helps.

Craig

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Message 5 of 17
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Read my reply to the same question you asked here

 

But in general you are doing it wrong, do this:

  1. Configure measurements (voltages, current, thermocouples, etc) 
  2. Build a "scan list"
  3. "Scan" the instrument (take readings)
  4. Save and display measurements
  5. Wait for some time duration
  6. Goto 3 (Scan) or exit 

BTW: There are several parameters that effect the speed this instrument takes measurements. Read the manual.

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=== Engineer Ambiguously ===
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Message 6 of 17
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Thank you very much for your reply. I want to implement a VI like this: measure three DC voltages through the Agilent 34972, continuously measure, then display the current measured value on the meter, and finally put the three in the three waveform charts. I started to measure a voltage and found that every time I measure a data, the meter will make a sound, and the speed of the measurement data is slow. How can I make the meter emit the sound only for the first time? I attached my VI and a text data to show you how it looks like
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Message 7 of 17
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Thank you for your reply. My question now is how to make continuous measurements. When I measure, the instrument will continuously sound, and the current value cannot be displayed on the instrument screen.

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Message 8 of 17
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Dear RTSLVU ,
     Thank you for replying , read the post you wrote, I reprogrammed and communicated with the 34972 instrument. There is a VI I have written in the attachment. Now I have the following questions:
1.Now  I can collect 3 voltages data, but every time I collect it, the 34972 instrument will trigger once, it will make a sound, I wonder if I can trigger it once, then continue to collect a lot of points. Because I see other models of the instrument are equipped with multi-point acquisition module, as for 34972 I have not found this module, does it mean that it needs to be triggered once every time it is collected?
2. Although I can collect data now, I can't control the frequency of data collection, and I can't set the time interval for collecting data.
3. Every time I start collecting data, the display screen of the 34972 instrument will be locked. I can't see the date by pressing the"monitor"button. And the display screen is flashing "OPEN" and "VDC" all the time.
4. Also, every time I use the right mouse button to store waveform chart data, I can only store more than 1000. Can I increase the storage amount?
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Message 9 of 17
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If the meter beeps when you are accessing is that means your are getting an error and the error indicator on the meter is probably lit up. Have you tried viewing the errors and seeing what they are?

 

Judging from your questions about both this instrument and your LabVIEW code you need to:

  1. Read the operation and the programming manual for the 3479xA and learn how to use this instrument manually. Because it's next to impossible to write a program to automate an instrument when you don't understand how to operate in manually.
  2. Take some basic LabVIEW tutorials.
    1. A flat sequence is NOT a proper program architecture  
    2. A simple State Machine is what you should be using in this case
  3. I have posted many examples on how to properly use this instrument 
    1. Search for 34972A and 34970A as they are the same instrument except for communication options

 

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=== Engineer Ambiguously ===
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