The usb-6008 is shutting off while is running

[jcasillas]

I have an application in Labview 7.1 that is been working for a couple of years with no problems.

I am measuring data using the two com ports (default com1 and the other is using a serial-usb converter) and also I am using a usb-6008 daq.

Last week I needed to run the same application in a different computer (I'm actually running this application in 4 computers with no issues at all) and I started having problems with the usb ports. The usb-6008 is like getting disconnected and then Labview reports a problem obviously because there are no more daq installed. this is also happening with the usb port used to get some readings from the device using the serial-to-usb converter.

I thougth the problem was with the DAQ version so I used the same drivers I am using in another computer taht is working with no problems.

I installed Labview 7.1 and DAQmx 8.3 (this combination is working just fine in another computer with the same program) but the problem persists.

My application is continuously checking the DAQ for a trigger so it can start the whole test and when I got the error I just disconnect the Usb-6008 and then connect it again and then the connection got restored! and the program continues working for a while but the problem keep happening.

What could be the problem?

My computer has Windows XP SP3 and the only difference is that when I deploy the application in the first computer I was using also Windows XP but with SP2, I don't know if this might be a problem but I am thinking that some how Windows might be affecting the usb ports disconnecting my devices!

[EEsRULEtheWORLD]

Hi jcasilla2,

What specific error are you receiving?  You are correct about the version of LabVIEW and DAQmx being compatible, and there are no compatibility issues with your versions of LabVIEW and DAQmx with SP3.  From your description, it sounds as if your USB ports are the issue.  Here is a guide that may be helpful in restoring functionality to your USB port.  Let me know if this works.

Happy Holidays!

[JÞB]

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jcasilla2 wrote:

My application is continuously checking the DAQ for a trigger so it can start the whole test and when I got the error I just disconnect the Usb-6008 and then connect it again and then the connection got restored! and the program continues working for a while but the problem keep happening.

What could be the problem?

My computer has Windows XP SP3 and the only difference is that when I deploy the application in the first computer I was using also Windows XP but with SP2, I don't know if this might be a problem but I am thinking that some how Windows might be affecting the usb ports disconnecting my devices!

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You are right on the issue!  Great description of your problem.

I have seen similar issues and resolved found some potential sources for this behavior related to USB disconnects.  First, since, the 6008 is powered from the USB hub, a hardware problem in the 6008 could require more power than the hub manager can supply.  If the Windows power manager detects an overload it shuts of the port, disconnecting the devices attached to it for good reason.  (Just wait till the first time you find a solidly shorted USB cable- As Windows boots it turns on the hub power and the CPU sees its 5V supply driven to ground- The uP reboots over and over until the offending cable is disconnected).

Second the HUB may be poor quality.  PC manufactures assume that you are connecting a camera, memory device, or something you aren't using often to the USB ports.  So in 95% of all cases if your USB connection hangs its no big deal and you never even complain.  A USB Data Acquisition application is a different paradigm, for this type of use, you need a high reliability USB connectio.  This may not be built in to the convienience ports on the machine.  

Lastly, its that darn U in USB, Universal.  This means you never know what devices have been stuck in that port before - or what problems they had that damaged the port or its hub.  A very close analog is a social disease.  One broken flash drive can degrade the performance of any number of USB hubs.

The solution- Always use a high quality externally powered USB hub and protect it from being used for temporary device connections.

[jcasillas]

Thanks Jeff, I think the problem is related with something like that. But, I have tried 3 different CPUs and I have the same issue with all of them.The weird thing is that I am using a model of CPU similar to another one that is currently working with no issues. I am also using another usb port to receive data from another device, but this has a RS232-to-usb converter and seems to me that it was not working properly because I was getting conflicts with the com port selected for that device. So, I changed that converter and I thought the problem got fixed but it wasn't, the problems is still there but now is happening like twice per day. This machine is running 24X7 and since I have this PC running a Production machine, Production is complaining about this.I can definitely add an usb hub with its own power supply just to try this theory but the fact that a different CPU (same model type) is working make all this confusing.

[Jiggly1234]

Did you try updating your BIOS?

[jcasillas]

Unfortunatelly Bios, Windows OP is controlled by the IT department and every CPU is configured according to theirs image discs. I don't think that would be the case because every machine is exactly the same, drivers, softwares installed, etc.

[JÞB]

Make sure you get a high quality hub that can source at least the current you need to drive the 6008.  I've had some luck with Belkin and fond the D-link products somewhat problematic.