Connecting to an RT target running an older version of RT from Labview 2024 Q3 project set to 21.0

[toddy]

I have an application running in LV2021 SP1 which is running on several RT PXI controllers (most are Pharlap, some are Linux RT).

I have just upgraded to LV 2024Q3, thinking that if I save the project as "Save Version 21.0" which I have done, I'd be still able to connect and run with the Pharlap controllers. It now appears that this was a bad assumption.

Is someone able to confirm that there's no way I can make this work? I'm stuck with only being able to go up to LV2022 programming environment if I want to be able to run the code on my Pharlap controllers?

Perhaps I could make code changes from the LV2024Q3 environment, but only be able to build and deploy from an earlier environment?

Thanks!

[Bob_Schor]

The Good News is you should be able to run it on a computer that has (only) LabVIEW 2021 (and older) versions.  You can always remove all versions of LabVIEW from the one with LabVIEW 2024 and reinstall LabVIEW 2021.  Is it only PharLap that is the problem?  Are the PXI systems upgradable?

Bob Schor

[toddy]

Hi Bob,

Thanks for the reply.

Unfortunately most of our PXI controllers are PXIe-8133 or PXIe-8135, neither of which NI have provided a Linux RT image for, and it doesn't seem like they're interested in doing so. I'm not sure if there's a technical reason for this, or if it's a commercial decision. It's disappointing though for sure!

Luckily it seems to work from my existing LV21 environment, even with LV2024Q3 installed on the same computer. We try and avoid having multiple versions of Labview as it just gets confusing, but hardware compatibility seems to be becoming more and more of an issue.

[softball]

Hi

Controllers like PXIe-8133 were introduced before 2012 so they are dead by now. NI does wisely not upgrade such systems to Linux. Where should the money to do so come from ..

LabVIEW 2024 Q3 is able to load and save projects in most older LabVIEW versions. It is not able to run 2021 code emulating that version of LabVIEW. It will run the code in its native 2024 Q3 identity.

Support for Phar Lap based controllers has been removed in NI software since 2022. See the attachment. So the last LabVIEW environment supporting Phar Lap was the 2021 version you have.

LabVIEW and Real-Time hardware requires the same version of code used by both parties. No exceptions. So, LabVIEW 2021 must be running on the host. And the LabVIEW 2021 Real-Time target must be installed on the controller. LabVIEW 2024 Q3 will not work.

I agree that it is wise to install only one LabVIEW version on a disk partition if you need to also install complex hardware support like the Real-Time development environment. Confusing is a good word for what results when installing multiple LabVIEW versions.

Regards

[rolfk]

You are a bit unclear with your naming of running code.

Yes LabVIEW 2021 and newer has no support for developing code for Pharlap ETS targets. There is not way to install that as only PXI Platform Services 20.7 and older supports that.

For Pharlap ETS based cRIOs this is even CompactRIO 19.6 and accordingly LabVIEW 2019 SP1 for the 908x, for the 900x support was already discontinued with LabVIEW 2016.

So developing code in a newer LabVIEW version is not an option as is deploying code to the controller. On the other hand you can deploy existing build executables to that target that have been compiled in earlier LabVIEW versions and communicate with them in whatever way (most probably TCP/IP, network streams or similar) you have implemented in them even from a newer LabVIEW application on your Windows development system.