Error Msg? "current buffer overwritten by the acquistion"

[mgerceker]

I got a error msg while doing IMAQ 1394 acquisition, it is random.
Anyone had an idea on what the possible reason is?
Thanks


The message shows as following:

----
Error -1074364365 occurred at an unidentified location

Possible reason(s):

NI-IMAQ IEEE-1394:  (Hex 0xBFF68033) Requested buffer unavailable. Contents
of the current buffer overwritten by the acquistion.


NI Software :  LabVIEW  version 7.1.1
NI Hardware :  Image Acquisition (IMAQ) device NI IMAQ for 1394
Driver Version :  2.0.1
OS :  Windows XP
 

[shoneill]

I've never done 1394 Acquisition, but with respect to normal DAQ, there's a similar message which occurs when you're doing buffered I/O and you don't read out the buffer quickly enough.  Once the acquisition has filled the buffer, it overflows (or overwrites to be more exact) and then gets either very unstable or gives an error message.

If you're doing buffered I/O, check that your buffer is large enough, and that you're reading the data from the buffer quickly enough.  And of course, lowering the acquisition rate will often also help solve this particular problem (if this is the problem at all).

Again, I've never done 1394 acquisition, but the message kind of rings a bell.

Hope this helps

Shane.

Message Edited by shoneill on 11-22-2005 10:29 AM

[Lorne H.]

Mehmet,

Shoneill is on the right track.  I think it would be helpful if you posted your code to the forum. That should help narrow the problem down.

make sure you set the Continuous? input of the IMAQ1394 Configure Acquisition VI to continuous if you are doing a continuous grab.

Although, setting this incorrectly usually results in a different error code.  Like I said above, if you can attach your code to the forum, that would help a bunch.

Lorne Hengst
Application Engineer
National Instruments

[mgerceker]

Here is an oversimplified version of my software, only acquiresition and display.

Thanks

http://support.neuro-kinetics.com/files/TestBPC1.rar

[Lorne H.]

mehmetg,

I have narrowed your issue down to the IMAQ 1394 Occurances.  If you remove all of the 1394 occurance code from your VI, the errors will go away.  I am still in the process of determining whether or not this is expected behavior, a bug, or something else.  I will keep you updated.

Lorne Hengst
Application Engineer
National Instruments

[Lorne H.]

Mehmet,

You no longer need to use Occurances in your program as of the IMAQ 1394 driver version 2.x

You will not loose anything by removing all of occurance code in your VI.

"Does it make a difference in terms of real time and synchronization of images captured from two cameras." As of version 2.x, the code you are trying to implement with occurances in your VI is actually already implemented inside of the IMAQ 1394 Get Image VI, so there is no reason to use occurances with the IMAQ 1394 Driver version 2.0 and higher.

I hope this helps,

Lorne Hengst
Application Engineer
National Instruments