Issue with VISA device

[SeppR]

Hi,

in a program that works many years i have a agilent 34461a connect over usb. Program works fine last 12. may. Yesterday i have run program and now it have a error with communicate 34461 over VISA. In the MAX i can see the device correct. I think no change in usb setup from 34461, no change in connection to pc. i don't know the reason.

[santo_13]

Just the word "error" could mean a lot of things, please provide more information about the error and your application.

[JÞB]

Did you try the VISA interactive control panel from MAX?  If that worked, did you remember to close the panel to release the VISA Resource?

Another uncommon problem may be that a calibration facility has changed the device language.   That supply supports both SCPI and HPPSL (HP power supply language) 

 Send "SYSTem:LANGuage?" and read the response.

[SeppR]

Hi,

below the error message. This time i am not be able to VISA interactive control from MAX (not visible).

[RTSLVU]

BFFF0011h = Insufficient location information or the device or resource is not present in the system.

Make sure NI-VISA and NI-488.2 are both properly installed.

Also make sure the instrument can be "seen" in NI-MAX and that NI-Max can open a VISA session to it.

Another good tool that gets installed with the full version of NI-VISA is the VISA Test Panel. 

I find this invaluable for troubleshooting instrument connectivity issues.

[SeppR · Accepted solution]

Now it work correct.

The link from resource name in lv code to visa (alias) was lost, for whatever reason.

--> edit in MAX.

Thanks

[JÞB]

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@SeppR wrote:

Now it work correct.

The link from resource name in lv code to visa (alias) was lost, for whatever reason.

--> edit in MAX.

Thanks

---

You most likely moved the USB connection to another USB Port.  The serial enumerator (in Windows Registry HKEYs) reserved the alias for that device on the original port and hence, when it connected through a new port, it registered as a new device because of the new location.

Now that you know that, you can work within the Plug-n-Pray framework with fewer problems.

[RTSLVU]

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@SeppR wrote:

Now it work correct.

The link from resource name in lv code to visa (alias) was lost, for whatever reason.

--> edit in MAX.

Thanks

---

Probably the number one reason not to hardcode VISA alias or anything VISA related. (GPIB address, IP address, com port, etc.)

Write a routine that searches all the available VISA resources for your instrument on startup. 

Here's an example I wrote to find a Ci5001iX AC power source:

[JÞB]

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@RTSLVU wrote:

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@SeppR wrote:

Now it work correct.

The link from resource name in lv code to visa (alias) was lost, for whatever reason.

--> edit in MAX.

Thanks

---

Probably the number one reason not to hardcode VISA alias or anything VISA related. (GPIB address, IP address, com port, etc.)

Write a routine that searches all the available VISA resources for your instrument on startup. 

Here's an example I wrote to find a Ci5001iX AC power source:

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Better yet Rename the Alias programmatically.  Very useful for USB devices when they move or even when devices are swapped out for calibration.

[Brzhou]

Hi Sir,

I am also working with 34461A, could you share your sample code ?

Or say, where you get the sample code.

Thanks.