12-14-2010 06:29 PM
I have 4 SCXI-1127 cards plugged into an SCXI-100 chassis with a USB interface.
I am using VBA in Excel.
On our old XP PC, the niSwitch_init command would execute in 1-2 seconds per card.
On the new windows 7 PC, this command takes about 8-10 seconds per card. Or, about 30-40 seconds for the 4 cards.
the exact commands I'm using are:
status = niSwitch_init("SC1MOD1", VI_TRUE, VI_TRUE, card1)
status = niSwitch_init("SC1MOD2", VI_TRUE, VI_TRUE, card2)
status = niSwitch_init("SC1MOD3", VI_TRUE, VI_TRUE, card3)
status = niSwitch_init("SC1MOD4", VI_TRUE, VI_TRUE, card4)
Has anything changed in the Windows 7 version of niSwitch?
What could be causing it?
Subsequent commands to the switch execute in the same time as before. It's onlt the niSwitch_init command that's slow.
Solved! Go to Solution.
12-15-2010 04:28 PM
Several factors can affect the run-time performance of your application; however, there's a similar issue addressed in the following KnowledgeBase, where NI-Switch applications have shown to run slower on Windows 7 machines. If this is the case, National Instruments recommends either upgrading to NI-Switch 4.2 or enabling the HPET on your Windows 7 system.
12-15-2010 06:06 PM
This appears to address my issue. But, it says the solution is to upgrade to niSwitch 4.2.
I can only find niSwitch 4.1 here: http://joule.ni.com/nidu/cds/view/p/id/2225/lang/e
Where can I get the 4.2 update?
12-16-2010 01:25 PM
Thank you for your response. The KB indicates NI-Switch 4.2 (and later) because the problem will be fixed with the release of these drivers. However, the official release date of NI-Switch 4.2 has not been announced yet. At this juncture, the best work around workaround would be to enable the HPET on your Windows 7 system.
12-16-2010 02:33 PM
The increased time is due to a low level change in Windows 7. If the wait time is not tolerable and you are not able to enable HPET, I recommend using Windows XP for now.