Instrument Control (GPIB, Serial, VISA, IVI)

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I can't configure the resolution on my 34460A DMM with IVI

I'm trying to acquire data from my 34460A using IVI. When I use Configure Measurement, the DMM doesn't seem to be taking the resolution properly. It seems to be setting full range (slow) measurements no matter what I set there. I set the range to 3A and the resolution to 0.0001 but I'm getting measurements in the 4±2µA range

 

http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=21588

 

 

FYI, the non IVI (LabVIEW) driver works fine.

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Hello Oligarlicky,

So devices that are IVI compliant are usually advertised as such. Unfortunately, I was unable to find any information or verbiage from the manufacturer's website that indicated the 34460A is in fact IVI compliant. Here's the link for the product page: http://www.keysight.com/en/pd-2269458-pn-34460A/digital-multimeter-6-digit-basic-truevolt-dmm?cc=US&...

 

Additionally, it seems on the link you provided for the drivers, under the IVI drivers, it lists the models that have been tested with the IVI drivers. It turns out that the model in question, 34460A, has its tested status listed as "Blank". See attached photo:

models supported.png

 

From what I've gathered, it seems that the 34460A is most likely not compatible with IVI drivers. At least the LabVIEW Plug and Play drivers work. Was there any reason you wanted to use the IVI drivers over the LabVIEW Plug and Play drivers?

 

Regards,

 

Jae

 

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Yes, I wanted to use the IVI drivers so I could drop this instrument into an existing software deployment that uses IVI or at least drop it in with as few changes as possible. The two intruments (34460A and 34461A) are so similiar that I suspect you'd find the same issue with the 34461A though I don't have one available for testing.

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It makes no sense to say that an instrument is IVI compliant. I have never heard of such a thing. IVI is software and the software is written by NI. The download page says the driver supports the instrument though the particular model was never tested. If it wasn't tested, NI should not be listing it.

To determine where the problem is, I would recommend that you use I/O Trace to capture the commands and compare to what is in the manual. If you find the problem, use the feedback on the download page to report the issue. Quite frankly, if you are going to use IVI, you should have a copy of LabWindows/CVI on hand do you can fix any bugs.
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Would you please use I/O Trace to record the commands sent to 34460A by LabVIEW PnP and IVI-C respectively? We’ll probably find the cause of the issue by comparing the command logs.


I noticed that in LabVIEW PnP, it will send ***:RANG:AUTO OFF before setting the range and resolution. However, in IVI-C, it sets the range and resolution directly without sending ***:RANGE:AUTO OFF.
Generally, range auto feature will be automatically turned off after setting the range and this is why IVI-C skips sending ***:RANGE:AUTO OFF. However, you can try to add code to IVI-C driver to send ***:RANGE:AUTO OFF command explicitly and see if this solves the problem.
Take DC_VOLTS_RATIO measurement function for example, in function ag3446xAttrRange_WriteCallback, add one line before setting the range (see the attached snapshot).

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Where is that file located?

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If you install the IVI-C driver by it's default location, you can find the source files at:

C:\Program Files (x86)\IVI Foundation\IVI\Drivers\ag3446x,  C:\Program Files (x86)\IVI Foundation\IVI\Include\ag3446x.h for x86;

and C:\Program Files\IVI Foundation\IVI\Drivers\ag3446x, C:\Program Files\IVI Foundation\IVI\Include\ag3446x.h for x64.

 

By the way, after modifying the source code, you need to replace the ag3446x_32.dll/ag3446x_64.dll to make it work.

 

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