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USB Disconnect Reconnect while idle U6Pro

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#1 dale

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Posted 24 October 2012 - 08:33 AM

I have a U6Pro, fresh install of Windows 7 64bit, installed the LabJackUDSetupV325.exe software, updated the labjackud.dll file in systemWOW64 with the LabJackUDv327 update. When the U6Pro is idle, meaning no program causing it to do I/O, it constantly disconnects and reconnects from the system about every 8-10 seconds. If I watch the Device Manager I can see the Labjack USB Device, disappear and reappear, and the system beeps with normal USB connection sound, and the green status light on the U6Pro, flashes Off for abiout 1/2 second and then back on and then flashes indicating communication. When I start either the LJControlPanel and go to Test mode, or start my program, the disconnects stop happening. When I exit the program or LJControlPanel the disconnect cycle resumes. I tried this with 2 separate U6Pros, and I have seen this issue on one other computer. Any ideas why the disconnects. The device seems to work properly logging a couple of Analog inputs in my program and looks OK in LJControlPanel Test mode.

#2 LabJack Support

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Posted 24 October 2012 - 09:14 AM

Sounds like the watchdog has been enabled:


... the reset-to-default jumper can be used to turn off the watchdog. Power up the U6 with a short from FIO2 to SPC, then remove the jumper and power cycle the device again. This resets all power-up settings to factory default values.

#3 dale

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Posted 24 October 2012 - 11:21 AM

Yes - that was the problem. Both units were shipped from the factory that way. Thanks.

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