USB GPIB-HS conflicts with USB hub

[RTSLVU]

I have a USB GPIB-HS and recenly have been running short on USB ports so our IS department gave me a generic USB hub.

If I plug in the hub to any USB port the NI USB GPIB-HS stops responding.

Unplugging and replugging the USB GPIB-HS causes Windows to detect it but Windows can not identify it. (Unknown USB Device)

I have to reboot with the hub plugged in then plug in the USB GPIB-HS to get Windows to recognise it.

When I have it working and try to remove a flash drive from the hub while the USB GPIB-HS is in use Windows gives me a warning that the flash drive can not be stopped. If I then just remove the flash drive anyway the USB GPIB-HS stops responding and any program (like Labview) that is using the USB GPIB-HS will crash stating the GPIB interface can not be found.

Is this a Windows issue?
Is Labview or VISA sonehow grabbing 100% of the USB resources?
Why would removing a flasdrive from a USB hub that is plugged into a diferent USB port (the USB GPIB-HS is not plugged into the hub) cause issues with the USB GPIB-HS?

Also the USB GPIB-HS will not work at all when plugged into the USB hub, even if the USB hub is powered from an exteranal 5V/1A power supply.

[fivestar]

It sounds to me as though your hub isn't really operating properly.  The GPIB driver doesn't have anything to do with the flash drive, so it couldn't prevent it from being stopped and ejected.

If the power supply is 5V/1A, does the hub have only 2 ports, or 4?  USB allows an individual device to draw up to 500mA, and that's how much the GPIB-USB-HS uses.  If your hub has 4 ports and a 1A power supply, then it could be restricting current draw to 250mA per port (or should be).

I've had good luck with D-Link and Adaptec hubs, and I know they come with a 5V/2A power supply.

[RTSLVU]

More information on this.

I have taken the hub out of the system and still I can not safely remove a USB flash drive while the USB GPIB-HS is in use.

Windows gives me a warning that the flash drive is currently busy and can not be stopped.

If I then just remove the flash drive anyway the USB GPIB-HS stops responding and any program (like Labview) that is using the USB GPIB-HS will crash stating the GPIB interface can not be found.

THis seems to have started recently with the latest upgrade

LV8.5

NI-488.2 v2.52

NI-VISA 4.2

Message Edited by RTSLVU on 11-14-2007 01:32 PM

[pBerg]

Howdy,

Sorry to hear you're still having difficulty with your flash drive. Do you have your flash drive and USB GPIB-HS plugged into the front or rear USB ports on your computer? Changing which USB ports you use to connect either device should allow you to get better results with your devices. It sounds like both devices are connected to the same onboard USB controller, and that controller doesn't want to release both devices.

I've connected a USB flash drive and a USB GPIB-HS device to my PC here in the office in different configurations in an attempt to duplicate your issue. So far I haven't been successful in seeing the behavior you experience.

Another thing I might suggest would be to stop the USB GPIB-HS device before removing the flash drive if you must connect the flash drive to a USB port using the same controller.

[RTSLVU]

I did a little trouble shooting this morning.

It does not matter if I use the USB ports on the back or front of the computer for the flash drive.

While stopping the running Labview app first allows safe removal of the flash drive. The intent here is to be able to use the flash drive to transfer data files without stopping the test.

I noticed this morning while switching things around that if I move the USB GPIB-HS to any other USB port I get this error.

VISA: (Hex 0xBFFF00A5) The interface type is valid, but the specified interface number is not configured. (see VISAerr1.jpg)

But I can go into Measurement and Automation explorer and see the interface, all my instruments, and communicate with them. (see max.jpg)

I have to reboot the computer for VISA to see the USB GPIB-HS every time I move it to a different USB port.

This and the fact that this problem just started recently leads me to believe it is a problem in NI-VISA 4.2

If I can find the time I will try rolling back to an older version of NI-VISA

On a side note the latest MAX really leaves a lot to be desired.



Message Edited by RTSLVU on 11-16-2007 10:12 AM

[pBerg]

Hello,

I spent some more time trying different configurations and have still been unsuccessful in duplicating your issue, but hopefully some of the questions I present here will help us narrow down the cause of your problem.

That error (pictured in VISAerr1.jpg) is a VISA error that usually means you are incorrectly addressing the VISA resource. This can occur when the specified address of a GPIB device no longer exists. What appears to be happening is your LabVIEW application is configured to communicate with a GPIB device at a specific location, and the location of the device changes, causing that error.

Going back to your previous post--I have a few questions about your LabVIEW application. You mention using a flash drive to transfer data without stopping the test. Does your application write to a flash drive as it's communicating with the GPIB device? If you eject your flash drive in the middle of the program execution (while it's writing to a file) without properly releasing the USB flash drive's resources, then that would cause an error. Maybe the error you see is a red herring that's actually caused by removing the flash drive prematurely as data is being written to or read from it, which would also explain why Windows will let you not eject your flash drive until the application stops.

In looking at other issues dealing with that error 1073807195, customers seem to have narrowed that error down to either a improperly selected GPIB address or an NI-488.2/NI-VISA installation gone awry. For the first case, simply make sure you have selected the proper GPIB address on the VISA task. For the former case, a reinstallation of NI-488.2 and/or NI-VISA seemed to have fixed the issue.

In your MAX screenshot, I see that you have several GPIB devices connected via the GPIB-USB-HS interface. Do you have all four GPIB devices chained to one GPIB-USB-HS cable? If it's possible, let's try using just one GPIB device connected to the cable to see if the problem still occurs. Also, do you Scan for Instruments in MAX each time you connect a GPIB device?

Lastly, let's try running a few tests using the NI-488.2 Troubleshooting Utility. Access this tool by right clicking on the GPIB-USB-HS device under Devices and Interfaces in MAX and seleting NI-488.2 Troubleshooting Utility. Make sure to check all the boxes in this utility and run it. Each item should pass the test. If an item doesn't, then that that's a good indication of a configuration error.

Again I'm sorry to hear that you're still having a bit of trouble with the device. If I were able to easily duplicate the problems you're experiencing, then it would make troubleshooting easier. Regrettably, I have been unable to do so, which makes causes of problems like this especially difficult to pinpoint. Any additional information from you is welcomed, and I'm anxious to hear back from you so that we can work together to get this issue resolved as efficiently as possible.

Regards,


Message Edited by Patrick_B on 11-19-2007 07:25 PM