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Agilent N9320B IP3

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My goal is to obtain IP3 data from an N9320B spectrum analyzer. I figure the closest way to get there is through the VI that provides Third Order Intermodulation. I tried to modify the example for acquiring a measurement to measure the Third Order Intermodulation rather than Channel Power....but it doesn't work. I am getting Error -420 Query UNTERMINATED. Also I get Error -113 sometimes, "Missing header."

 

I have attached the picture of the diagram to this message. If I simply take out the part that says "Read Measurement (Third Order Intermodulation)" then it runs perfectly fine...although doing nothing. Does anyone have any advice? 

 

 

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I wanted to add more information about this problem. I began to trace through to find when the UNTERMINATED Query error begins. It looks as if the "Read Measure (Third Order Intermodulation)" VI calls upon another VI called "Fetch measurement (Third Order Intermodulation)." I have attached this "Fetch measurement" VI. 

 

When tracing through, "Undefined Header" error appears on my spectrum analyzer at the first arrow (on the picture) and "Query Unterminated" appears at the second and third arrows. The error code that I am given for this "Fetch measurement" VI is: 

 

"Code -1073807339"

"VISA Read in Agilent N9320.lvlib:Fetch Measurement (Third Order Intermodulation).vi"

 

These VIs should work...they came with the driver package. The only thing I changed on the example "Acquire Measurement" VI was change the type of measurement on the drop down box from Channel Power to Third Order Intermodulation. I would assume they wouldn't include options on a drop down box that don't work? 

 

 

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Solution
Accepted by topic author SlipStreams

I figured it out. The drivers claimed to be the most recent version, but they were using VISA commands that were not correct. I found the programmer manual for the N9320B and found I needed to change:

 

:FETC:TOI:IP3?;

:FETC:TOI?;

 

to

 

:FETCh:TOIntercept:IP3?;

:FETCh:TOIntercept:IP3?;

 

 

While it's great that it's working now...it was like spending hours trying to fit a LEGO house together and then you find out that a few of your LEGOs were a millimeter shorter than the others. You didn't do anything wrong, someone gave you the wrong parts. Are Labview instrument drivers open source? Who is responsible for making sure they are working correctly? 

 

I really do like the Labview software. It's neat...but very time consuming as I learned today.

 

This feels like the first time I tried Linux when it took me 3 hours to install GNUradio.

 

 

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Hi SlipStreams,


I’m glad to hear you were able to resolve the issue!

 

The instrument drivers at ni.com/ident, such as the Agilent N9320B driver you are using, are open source. Anyone can submit a driver for listing on IDNet, making IDNet somewhat analogous to a database of examples for communicating with specific instruments and devices.

 

We test some of the drivers that are listed, so appreciate feedback when a driver does not work with a device it is listed as supporting. The best way to give feedback on the driver is to use the form and/or email address listed on the download page for the driver (linked below):

http://sine.ni.com/apps/utf8/niid_web_display.download_page?p_id_guid=60ED9B6E489D2045E0440003BA7CCD...

 

 

Catherine B.
Applications Engineer
National Instruments
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The SCPI standard says you do not need the entire command so TOI should work exactly the same as TOIintercept. Might be a bug in the instrument's firmware.
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