Mini-Circuits LabVIEW HTTP client doesn't work but browser/CURL does

[jhoover]

I wish that I had found this post sooner! I have spent at least 10 hours looking into this issue (Claude had me looking into a lot of empty rabbit holes). I too am trying to communicate with a Mini-Circuits ZTM RF switch. A former co-worker wrote the driver for this instrument and it has been used for at least 6 years on 20+ PC's across multiple labview versions beginning with 2017 and now 2026 without issue. Before finding this post I too was able get those commands to work using the double ??.

This post is good confirmation that its not just my setup. I don't see a way to downgrade just NI-Curl so I guess i will need to update this driver to comply. Fortunately the double ?? also works with the older labview versions.

[avogadro5]

I reported this to mini-circuits so they could update their example VI but they have not taken it upon themselves to do so.

[thomas-allibe]

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@avogadro5 wrote:

Been at this a long time, some more info that might mean something to someone who understands HTTP:

• The vendor provides example code for both LabVIEW and python
• Both examples append a ':' after the / so 'http://192.168.1.60/:FIRMWARE?'
• Only the python example works
• Omitting the ':' in the python example does not affect the result so I think it's a red herring
• The python example uses "urllib" module when I tried python myself I used "requests" and got the same (bad) response as my LabVIEW attempt
• The LabVIEW example doesn't work and has the same issue as the one I wrote from scratch because it's doing the same thing
  
• The NI advanced HTTP toolkit and JKI toolkit both have the same issue as the built-in library

The fact the LabVIEW example doesn't work means it may be something to ask the vendor about...

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Are you sure it's not a semi-colon ";" instead of a colon ":"? In the reference manual you linked, page 9:

If it has one, you need to provide a password before the ";". If it doesn't, I guess both "COMMAND" and ";COMMAND" are valid.
But it seems the device is very forgiving if it also accepts ":". There's also the possibility that the doc is not up to date.

Also have you tried encoding the "?" character into "%3F" (and maybe ":" into "%3A" or ";" into "%3B" to be consistent)?

Something like "http://10.10.10.10/FIRMWARE%3F"

It should prevent sanitization from LabVIEW HTTP client, but the device may not support it...

HTML URL Encoding Reference