NI-5680-01 device connection issue

[SunshineDesign]

I am using the NI-5680-01 USB Power Sensor in a number of test stations and I am having an issue with the devices dropping off the list of devices connected. So when the test program is run, it fails due to the system (MAX) not seeing the power sensor attached to the system. I have used other USB power sensors and have not seen them drop off like the NI. Has anyone else seen this issue and/or have a fix for this?

[KittF]

SunshineDesign

USB disconnection is often due to the OS power saving settings or the specific USB hardware into which the USB device is plugged.  Can you give more information including the controller/PC into which the USB power meter is connected, the OS version, how long it works before dropping, are there any other USB devices plugged into same PC, is there a USB hub in between, how frequently does it occur, is it fairly repeatable, does it happen on different PC/controllers, have you tried a USB hub (sometimes PC can't supply appropriate power), does it happen with more than one power meter, what version driver are you using, does the PC/controller ever sleep/hybernate etc. 

[Timothy_S]

As Nemo noted above, the most likely cause of this type of intermittent behavior is a loss of power being sourced to the 5680 from the computer. I've seen in the past where sleep setting or power conservation settings on the PCs or Laptops can cause this behavior if the USB ports go to sleep as well. Check through any settings in the OS for power settings associated with the USB ports as the questions from the above post. That should give us enough to get a better idea about what could be going on. Thanks.

[SunshineDesign]

Thanks guys, I'll check that soon and let you know. It's been a persistant issue.

[SunshineDesign]

Power Saver was set to never be enabled and the Sleep mode was turned off. So it should have maintained the connection to the power sensor.

[Timothy_S]

SunshineDesign,

Let's dig in to the details on this a bit more with that in mind. What Operating System are you running on the system? Where are the ports that the power meter is being connected in to? By that I mean is it connected through a hub (powered or unpowered), and if not, is it directly connected to the PC from the front or the back of the system? Does this behavior only happen if the system and device are idle for a period of time, or has it cut out while the system is under use as well?

It still sounds like the issue could be with USB Port Power Settings as I know that some versions of Windows can control different USB ports and hubs with power settings specifically for those ports, so we may need to look in to that directly. Let me know what details you can about the above questions and we can take it from there.

[SunshineDesign]

Hi Tim. Thanks for joining. It's Windows Xp latest SP and all updates. USB Power save is off, standby mode is off and the USB Power Sensor is direct connected to the PC. I do have a USB hub on the system for other USB devices. The issue is when the PC has been idle for a while. When I go to start things up and run test, the meter code times out with a hard error because it is unable to recognize the power sensor.

[Timothy_S]

Thank you for the information, there are a few other questions I want to run through for us to try so I can do my best to recreate this on my end if we need to.

Does the computer go to sleep when this happens, or is it simply in an idle state when the USB power meter goes unresponsive? It sounds like you've got all of the power settings turned off that would usually cause this, so we'll need to dig a bit further. Have you tried the device in the USB hub or on a different USB port to ensure the behavior is only following the power meter and not connected to a port or hub?

What happens in Device Manager and MAX when we can't run the program with the 5680? Does Windows still recognize that a device is plugged in to that USB port? Can Windows recognize any hardware at that location? We'd want to compare what the Windows Device Manager and what MAX see for the device before and after it goes idle so we can see exactly what is going on. How often does this occur, and do you have a ball-park estimate on how long it needs to be idle before cutting out?

Let me know what you can.

[SunshineDesign]

Tim,

When the issue occurs, I was unable to see the handle for the USB Power Meter in Max, it dropped out. The power meter handle is no longer seen by Max or Windows. I had to unplug and replug in the power sensor or re-boot for the system to see the device again. It did not see anything else in the hardware location. I have not tried it on a different USB post as I have no open ones left. The issue has not occured for a couple weeks now, but I haven't been doing much testing at the development station I have here. I am not sure how long it must be idle for the problem to show up.

[Timothy_S]

Would it be possible at some point for you to try recreating the problem so that we can get some working and non working images of MAX/Windows Device Manager before and after the idle non-working state occurs? Another thing to test if you can would be disconnecting some of the other USB devices or the Hub from the system when trying to recreate it as it still sounds like it could be a power control or power sourcing problem. Without being able to recreate the issue regularly, it's going to be hard to track down the exact cause, but I'll let you know if I can cause similar behavior on my end here.