Loss of input USB input devices

[lmd2]

for a while now we have noticed an occasional loss of communication from our input devices (mouse/keyboard) using the PXI-8196 controller (running Win XP). Unplugging and re-seating the USB connector solves the problem.
On at least 2 occasions we have lost communication with a programmable DC supply (BK Precision 1786B). I don't think that this is a factor of the power supply but rather a problem with the USB on these controllers.
If you loose the mouse, you are by definition at the system and can effect a re-initialization. But if the power supply stops talking during an automated 4 day test you are hosed.
Any one have some good news about the USB connectivity of these controllers and a fix for this issue??

thanx
lmd2

Lawrence M. David Jr.
Certified LabVIEW Developer
ALE Consultants, LLC

[MissyS]

Hi Lawrence,

I apologize in advance if this sounds obvious. Do you know if the USB connections were bumped or dislodged during the testing?

Or were the USB devices already properly connected, and you had to disconnect and reconnect them to get connection?

Regards,

[lmd2]

Hi
thanx for the reply.
The input device problem has happened numerous times. It is possible that maybe using the mouse 'jiggled' the leads but nothing really out of the ordinary. We did notice that the problem seemed to happen more often when we were running some EMI testing so I wondered if noise on the bus  maybe affected the USB (I was hoping that maybe this was a known issue?).
Any way this wasn't too much of a problem because we were sitting at the system and just pulled, and reinserted the USB connector.
When the power supply seemed to loose communication it was an overnight run (of a 4 day test) I don't believe anyone was in the building.
There may have been minor vibrations in the PXI chassis from the fans running or whatever but it shouldn't have adversely affected the USB connection.
I could be wrong but I wasn't thinking a physical issue as much as an electrical or driver issue.
I guess this isn't a "known issue"? Too bad
Hope you have some insight.
Thanx for your time
(if it works better for you, would it help if I called and we spoke?)

lmd2

[lmd2]

not sure if this is a factor or not, but one of the modules in our PXI chassis is an hsDIO PXI-6542 card. This module occasionally returns an error (trigger error mostly, but not exclusively)  -   we could get 12 hours of running fine and then a glitch out of nowhere.
Could this heavy traffic on the backplane cause any bus issues for the other hardware (i.e. the USB devices).