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34401A sampling rate frequency

Hello,

 

I have the Agilent 34401 Read Multiple Measurements.vi example

it appears to read as fast as possible

does anyone have any examples where you can set the sampling frequency?

google AI says maximum is 1kHz / 1 sample per millisecond

so if I set it to 10kHz, I assume I would get an error or maybe it would default to the maximum it could do

but if I want to sample every 100ms for example, how could I do that?

I supposed I could put a 100ms delay in the while loop but this doesnt seem efficient. 

 

Thank you

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Message 1 of 10
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Hi cwhw,

 


@cwhw112 wrote:

if I want to sample every 100ms for example, how could I do that?


I guess you could read the manual for your device to find the answer.

Did you?

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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Message 2 of 10
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It looks like it can be set with remote interface operation

cwhw112_0-1732929175515.png

 

I dont know how to do this

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I have been searching online and not finding much of anything.

I made the code:

cwhw112_0-1732935166930.png

and ran it and didnt get an error

but when I ran the example program

cwhw112_1-1732935213722.png

with 10 samples, it only took a few seconds, not 100

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has anyone ever came across this or have any ideas?

I am willing to try any suggestions.

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Message 5 of 10
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Hi cwhw,

 


@cwhw112 wrote:

has anyone ever came across this or have any ideas?

I am willing to try any suggestions.


The command in your code image is different to the command in the manual image in the message before.

And it seems you don't send an EndOfLine char with the command…

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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yes, i am sure I didnt implement it correctly. I am just guessing and hoping my guessing will add something that will spark an idea in someone who is more familiar with this type of thing.

 

I would think this is a fundamental feature commonly used

but Maybe there is a simpler answer that the sampling rate can not be set or determined with labview/34401A DMM.

Does it just take the specified number of samples at a rate that we can not set or verify?

 

The manual references remote interface operation in several locations but nowhere shows how to use/implement it and my internet searches have not yielded any labview examples.

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I put the feedback node in from this post

https://forums.ni.com/t5/LabVIEW/Timing-a-while-loop/td-p/3922638

 

into the read multiple points from the instr.lib

 

cwhw112_0-1733710987585.png

for 10 samples it is zero, for 100 it is 1.7, so shouldnt it be 0.17 for 10

50 is also 1.7, so is 2.1???

 

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I tried a flat sequence:

cwhw112_0-1733711515660.png

1 sample 673

2 samples 842

3 samples 1014

5 samples 1350

10 samples 2194

20 samples: 3881

50 samples 8945

100 samples 17383

200 samples 34262

cwhw112_1-1733711837559.png

 

it appears to have a setup time of 500ms and then sampling frequency of around 6Hz (1/0.16878)

 

this method seems to be somewhat accurate at checking the frequency

 

but 6Hz is quite a ways from the claimed 1000Hz

cwhw112_2-1733712119258.png

which can be configured, so they question would be - how do you configure the reading rate

 

 

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Message 9 of 10
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Hi cwhw,

 


@cwhw112 wrote:

so they question would be - how do you configure the reading rate


By reading the manual and implement ALL the recommendations to achieve this high sampling rate.

(I will not do the reading for you…)

 

From my experience:

  • such DMMs offer higher sample rates only on limited resolutions
  • sometimes they only offer highest supported sample rates only when reading into their internal buffer

All this will be mentioned in the manual. And the programming manual will show all the needed commands to set those pre-requisites…

Best regards,
GerdW


using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019
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