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Query USB Enumeration


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I am working on an RT app and hardware that uses more than 50 USB devices connected via USB hubs to an NI rackmount computer.  After a hard reboot of the rack mount computer, the USB devices and hubs take more than 5 minutes to enumerate.  

 

I am looking for a way to verify all the USB devices have enumerated.  Polling VISA Find Resources appears to cause the entire system to lockup if we start it immediately in RT app.  If we manually delay for 10 minutes or so in the application and then call VISA Find Resources, it appears to work OK as long as all of the devices have successfully enumerated.  A hard-coded 10 minute delay is not optimal because on soft reboots, the delay is unnecessary.  

 

Are there any other ways to get the state of system USB enumeration other than VISA Find Resource?

 

During reboots, the NI boot loader takes a minute or so to "Enumerate USB devices" but it appears it only enumerates each USB hub before it completes and moves on.

 

 

 

PS. I know there are latency issues using USB on an RT system.  We chose to use the RT platform for stability (no windows updates, etc) vs determinism.  This may or may not be a good reason, but its what we have now.

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