Saving "counter" reading from DSO7104 oscilloscope

[Daliboromir]

Hi guys!

I would like to ask if it would be possible to access and save oscilloscope measurement readings using LabVIEW. I have Agilent/Keysight DSO7104 and corresponding drivers installed. I can acquire measured waveform all right, using the example .vi's. However, I would need to save automatically the reading from the counter. The oscilloscope is equipped with an integrated hardware frequency counter (which uses the trigger comparator output) and its reading can be accessed via Measurement menu and displayed on the oscilloscope screen. I need to save the readings automatically but could not find the way to access the frequency value (or any other measurement - amplitude, duty cycle , etc.) in LabVIEW.

Saving waveforms and analyzing them would not help. I need to count short pulses during a longer time period and as the sampling period is much longer then the duration of the pulses, they cannot be resolved in the waveform, while the counter is limited only by the oscilloscope bandwidth.

Has anyone encountered similar problem?

Thanks in advance,

Daliboromir 🙂

[Gregory · Accepted solution]

You can find the programmer's manual for 7000 series scopes here: http://www.keysight.com/upload/cmc_upload/All/7000B_series_prog_guide.pdf

Once you have that, you just need to create a new VI (copy and modify an existing one) that will write the correct query to the instrument and read back. If you look for the counter measure query you will find info on page 322:

Now that you have the syntax, you just need to write it to the instrument and read back the response. You only need to include the capitalized parts of the commands, but usually you can use the full word too. I put digital channel 0 as the source, but you can use one of the 4 channels or the external input as well by changing the string in VISA write. You will have to parse whatever is read back if you just want to extract the number, which can be done with the "scan from string" VI.

[Daliboromir]

Hi gregoryj!

Thank you for your quick reply. It helped a lot! I had to figure out few things, being a newbie to LW, but I got what I wanted in the end. I needed jut to change to CHAN# instead of DIG# and also, VISA read required byte count:

Thanks again. Very quick, precise and helpful.

Daliboromir

[Gregory]

You're welcome, please mark as solution if your question has been answered.