VISA resources not selectable in runtime on Mac OSX

[Jeff Gee]

I have built an application that I'd like to distribute that requires the user to select the VISA resources to which the instruments are connected. The instruments being controlled all have an RS232 interface and so we are using a 4 port Keyspan USB to serial converter. On the development machine (OS 10.3.5, with LV 7.0 and VISA 3.2) the VISA resource control works just fine for this. The standalone application, however, intermittently will not allow selection of certain VISA resources. The application is being run on a second Mac with the same system, v.3.2 VISA Run-time Engine and v7 of the LV Run-time Engine.

For example, all four ports will show up in the pull down menu for the VISA resource control, but one or m
ore of these resources simply may not be selectable. In this case the control simply remains blank when you select and "unselectable" resource. Any ideas why this might be happening or how to get around it?

thanks,

jeff

[SVences]

Hello �

When running a VISA Executable, you need to use the assigned aliases to the computer�s resources instead of the standard port names. Please take a look at the following Knowledge bases:

My VISA Executable Does Not Run on a Non-Development Machine
VISA Program Does Not Run as a Distributed Application

Hope this helps!

S Vences
Applications Engineer
National Instruments

[Jeff Gee]

Thanks for the comment but that isn't exactly the problem. I'll try to be more specific. I have a VISA resource control on the standalone application and a 4 port Keyspan plugged into USB1. I can view the list of available resources (e.g. ASRL1,ASRL11,ASRL12,ASRL13,ASRL14 where the latter 4 are the Keyspan ports) but you simply cannot select one or more of the ports. So I am using the VISA resource names and not the aliases. It's not clear what the alias for a serial port on a USB<->RS232 expander would be - the Measurement and Automation Explorer doesn't exist on the Mac and the VISAconfig application does not provide alias information.

Hope this is clearer.

jeff