get EDVR(0) error every now and then

[gchan]

This happens rather infreqenctly. But every now and then, SendIFC and ibfind will return a EDVR(0) code. I can recover by unplugging and replugging the usb and it will work again. I am using GPIB-USB-HS, driver rev 2.4. I did not notice this problem when GPIB-USB-B was used. Also, once this happens, the NI-488.2 troubleshooting wizard also is reporting an error when run.

Here is an NI spy output fragment:
> 32660. SendIFC(0)
> Process ID: 0x00000F10 Thread ID: 0x00000DE8
> Start Time: 14:03:29.892 Call Duration: 00:00:00.047
> ibsta: 0x8000 iberr: 0 ibcntl: -534904741(0xe01e005b)
> 32661. ibfind(GPIB0)
> Process ID: 0x00000F10 Thread ID: 0x00000DE8
> Start Time: 14:03:29.892 Call Duration: 00:00:00.047
> ibsta: 0x8000 iberr: 0 ibcntl: -534904741(0xe01e005b)
> 32662. ThreadIbsta()
> Process ID: 0x00000F10 Thread ID: 0x00000DE8
> Start Time: 14:03:29.939 Call Duration: 00:00:00.000
> ibsta: 0x8000 iberr: 0 ibcntl: -534904741(0xe01e005b)
> 32663. ThreadIbsta()
> Process ID: 0x00000F10 Thread ID: 0x00000DE8
> Start Time: 14:03:29.939 Call Duration: 00:00:00.000
> ibsta: 0x8000 iberr: 0 ibcntl: -534904741(0xe01e005b)
> 32664. ibonl(0, 0)
> Process ID: 0x00000F10 Thread ID: 0x00000DE8


Also, I brought up the Event Viewer and it was saying that there is a warning from the plug&play manager at round 14:02pm. I do not know if the EDVR error and this warning are related, even though the time stamp are close to each other.

For that is worth, the content of the event properties read:
Source : PlugPlayManager
Type : Warning
EventID : 256
Description : Timed out sending notification of device interface change to window.

[gchan]

I guess I did not ask a question in my previous posting. The questions are what causes the EDVR error? And what changed in GPIB-USB-HS that this would occur and not when GPIB-USB-B was used?

Thanks in advance.

[Matt_S.]

Hi Gchan,

The EDVR error is caused when either

A) Your computer can't find the GPIB controller or
B) Your computer can't load the driver for the GPIB controller

In this case it sounds like you're suffering from case A. It sounds as though at some point during the execution where you're opening and closing the access to the GPIB card your computer has a problem with the plug-n-play engine and loses track of the GPIB-USB-HS. Then when you try to do the GPIB open again it fails. You may want to try just opening the reference to the GPIB card once and then doing reads and writes using that VISA resource. This may prevent your system from losing the controller.

As far as why this is happening more with the HS than the B, I'm not sure. I'm betting, though, that if you avoid doing opens and closes often in your application and stick to having one open resource that you access throughout the application the problem won't occur any more.

Hope this helps!
Matt S.

[Matt G]

I've been having the same error (EDVR 0xe01e005b) except it's been recurring very frequently all of today (have yet to successfully connect to the instrument despite reboots).  I ran into it a few weeks ago with a different instrumental setup (USB instrument-USB/GPIB hub-GPIBUSB hub-computer), but the current setup (GPIB instr-GPIBUSB hub-computer) has begun having problems again.  Did you find a good resolution to that problem or a way to reset the communication between the computer and the instrument?

[gchan]

Hi Matt,

Here was a response I received from NI apps:

Basically from our understanding, the PC you are using may not be providing enough current to drive the device and throw an occasional EDVR error. What we would like you to try is using an external pluggable USB hub or an alternate machine to further attempt to isolate and resolve the issue (please note that if you do attempt to use it on another machine with the same motherboard, this may yield the same results because it may be using the same motherboard revision/components etc. Therefore we would suggest to use a different model of PC).


We implemented the suggestion of adding a USB hub and that helped.

Gerald

[Matt G]

Hi Gerald,

Thank you for sending that my way.  We have 3-4 devices interfaced with a laptop, so that analysis makes sense.  Thankfully, unplugging everything and reconnecting "fixed" the problem for today, but we will be implementing usb hub solution.  That probably will explain the problems encountered with the TEK-USB-488 converter as well.

Thanks again,
Matt

[sowji]

Hi,

I see similar problem when I provide supply to TEK-USB-488 with external power supply. Somehow after running for sometime, I get LV error of Invalid Object reference for GPIB Communication object.

Can someone help me why I do see this error frequently? When I power off & on the TEK-USB-488 Adaptor, it works fine but again after running for sometime, it somehow looses connection.

Is TEK-USB-488 Adapter provide reliable communication?

Thanks

Sowjanya

[Matt G]

Basically, my understanding was that the sudden loss of functionality stemmed from loss of communication.
Utilization of an externally powered usb hub failed to solve the problem.

[chris_amadasun]

Hello,
What Operating System and driver versions are you using?

Concerning the specific error  EDVR, have you look up this KnowledgeBase on common GPIB errors?

You might want to find out exactly when and why this could be happening by taking a NI-Spy log and looking at this article.

[JasonSmith]

---

@Matt G wrote:
Basically, my understanding was that the sudden loss of functionality stemmed from loss of communication.
Utilization of an externally powered usb hub failed to solve the problem.

---

Matt, was this referring to the problems you were having with GPIB-USB-HS controllers, or TEK-USB-488 adapters?

-Jason S.