Shared variable version on host and RT target

[tom_z]

Hi, Is it possible to use different shared variable engine on host computer and RT target? We use shared variable to communicate between RT target and host computer. Once the products shipped to customers we will keep the software on RT target unchanged but we would like to keep updating the program on the host computer with newest LabVIEW version. Is it possible to just update the host computer without updating the RT target?Thanks for help! Tao

[Justin_P]

Hi Tom,

You can have different shared variable engines on your host and target.  So what you want to do should work.

[tom_z]

Hi Justin,

    The shared variable engine has to be the same version on host and target. This is my problem. I only want to update the version on host computer.

    Tom

[Justin_P]

"The shared variable engine has to be the same version on host and target."

How exactly have you determined this/ what issues are you running into?

If you would like to prove this to yourself, you could create an RT app that runs in LabVIEW 8.6 or older.  Then in LabVIEW 2009 use the Read Variable.vi or DataSockets to access the variable running on target (in an older version of LabVIEW).  This will work.

If you are having any specific issues please let me know.

[tom_z]

Hi Justin,

    I have tried. I installed shared varaible engine 8.6 on RT target and LabVIEW 2009 on host and it doesn't work. 

    Tom

[Justin_P]

Hi Tom,

Are you getting an error code or some thing else?

Attached are two zip files.   The 8_5.zip is a LabVIEW project that was written in 8.5 and deployed to a cFP.  The 9_0.zip is a LabVIEW project written in LabVIEW 2009 (9.0), that reads the shared variable off of the cFP running the 8.5 code.

This works for me, so if you could give a little more detail, hopefully I can help you out.

[tom_z]

Hi Justin,

    Your example works great. But for each shared variables the shared variable refnum has to hardwired with a fixed IP. After deploying the host program we want to have the flexiblity to change the IP address. I know if it is possible?

    Thanks for help!

    Regards,

    Tom

[Justin_P]

Sure Tom, I can't see why not.  This could be done by entering URL of the Shared Variable into a string control.  Or you could have your program read an array of Shared Variable URLs from a text file, and then index through the array in a for loop to read all of the variables.  But its definitely possible.

[tom_z]

I don't know it can take string input as url. Thanks a lot!