How do I disable the "automatic search for new devices" function when LabView 7 finds a VISA Resource Name Control on the front panel in edit mode

[William]

I work with GPIB control in LabView in LV version 5.1, LV 6i and in LV 7 Express. In LV 7 National developed a new feature: When LV finds a "VISA Resource Name" control in the front panel in edit mode, it automaticaly starts searching for all hardware devices conected to the system to display an updated list of devices and their adress. When working in slower computers this function last more than 10 minutes to acmoplish, and only then I can work at the vi again, during the execution of this function LabView becomes almost as if it has crashed. Does somebody knows how to turn this feature off?

Thanks!

William Robert Heinrich

[LuI]

Bill,

AFAIR this scan does happen when at least one of those controls/displays is _visibel_. In case of constants, I am not sure about their behaviour. One of NIs support people once suggested to use a string cnstant instead of VISA constants.
It  might as well be helpfull to select the VISA class for those controls to limit the search and the scan duration.
Just my Euro 0.02...

Greetings from Germany!<br>-- <br>Uwe

[William]

Thanks Lul, that is exactly what I´m doing to escape from the scan, I just though it would be great if this was an option that we could change.

William

[JoshuaP]

I know in 7.1 they made some changes to make this faster and I think they may do some caching now. However, I'm not sure of the speed comparison of LabVIEW 8. Do you have a copy of 7.1 you could try with the latest VISA. Each VISA release we are always trying to find little tweaks to make the scan faster.

-Josh

[William]

I don´t have LabView 7.1 to test it, but I will upgrade my LabView to version 8 soon, than I will compare the scan speed, if I discover something new I´ll post here for everyone who wants to know. I will try to sugest this modification in the VISA driver as well, I think it is very usefull if sometimes you could disable this function.

I don´t know about you guys, but I use LabView in a very old laptop sometimes, a toshiba, TECRA 8000, pentium II with 128MB of RAM, and the performance of labview is very good in most applications and vi´s, except when apears a VISA control at front panel, sometimes it freezes the screen for more than 15 minutes.

[LuI]

William,

my machines are quite new and state_of_the_art, but with a PXI chassis and more than 35 devices (including lots of serial ports) this had taken up to two minutes as well...Greetings from Germany!<br>-- <br>Uwe