Using both Specific and Generic IVI Drivers in LabVIEW

[gopinath]

In LabWindows/CVI, I am aware that you can use the Get Specific Driver Handle function to use specific IVI driver functions along with the generic class driver functions. How can this be done in LabVIEW?

[Glenn Burnside]

It's actually even simpler in LabVIEW - you can wire the class driver session directly to the specific driver vi's you want to use, and LabVIEW internally manages retrieving and using the specific driver handle for those calls.

[gopinath]

That does not seem to work for me. I get a bad wire when I try to connect the instrument handle output of the Generic IVI driver Initialize VI to a specific driver VI. The error message says "Wire:Class Conflict".

[Glenn Burnside]

The class information that LabVIEW uses is inside the .rc file, which is part of the instrument driver's fileset. So, it's possible that the specific driver's rc file is not presenting the appropriate class information, so LabVIEW doesn't recognize it as belonging to the instrument driver class of the class driver you are using. What specific driver and class driver are you using?

[gopinath]

I am using the IVI Scope class driver and the specific driver for the HP54645 scope. The specific driver was downloaded from the NI Website.

[gagi1]

I am not seeing this issue in either LabVIEW 6.1 or 7.0 with the IVI Compliance Package 2.0 and the latest hp54645 driver. I am able to wire IviScope Initialize.vi with any hp54645 VI. Are you using property nodes as well? There is one thing to point out:
Downcasting from a class driver to a specific driver using property nodes may return an error in the following cases:

* when using a combination of specific driver VIs and specific driver property nodes
* when using a specific driver property node with inherent properties

The suggested workaround is to either
* not use specific driver property nodes, or
* use specific driver property nodes but without any inherent properties and not in the conjunction with specific
driver VIs.

If you are not using property nodes, then try the following:

- right-click on the logical name control in the IviScope Initialize.vi and go to "Select IVI Class" to check if the correct IVI class is selected.
- do the same thing in the specific driver VI - check that the hp54645 is selected under the IviScope Class.

I hope this helps!

Regards,

Vesna Jadric
Instrument Drivers/IVI

[gopinath]

This seems to be a problem with the installation of the specific driver on my PC. I tried it out on other PC's and it worked as expected.

Thanks,
Geeth