6534 continous pattern generation with over 4GByte of data output

[holgerh]

I encounter a problem with continuous pattern generation with the NI 6534 when reaching 4GByte of output data. I using LV 7.1 and traditional DAQ. I have approximately 12 GB of data to be generated, split into 500 MB files, from which I read chunks of the buffer size at a time and pass it to the DIO write. This works all pretty well, but when reaching 4 GB of generated data the DIO write seems to stall and to wait for the specified timeout, but I don't get a error message.

I used the same vi some time ago with LV 6.1 and think that the problem did not occur at that time, but I'm not so sure about that. The interesting part was in the first 4GB of data so I did not look at the remaining data very closely.

Thanks for any help,

Holger 

[Tom_W_[DE]]

Hi Holger-

I am suspicious that this problem may be related to the fact that Windows can not address more than 4GB of virtual memory per application at any one time.  This sticks out in my mind because 4GB is a "magic number" that comes up a lot and dooms many applications.

Is it possible to verify whether the problem occurred with the older LabVIEW 6.1 version?  Can you test using NI-DAQmx to see if the problem persists?  How exactly are you reading the information from the file and presenting it to the DIO Write VI?

Thanks-

[WM_John_Weeks]

Right- 4 GBytes is the limit of 32-bit addressing. But it should be possible to read in chunks of the data set from disk and write it to a continuous waveform generation.

Added in edit:

Oh, wait. That's the technique you described in the original post. Is there a leak somewhere?

Message Edited by WM John Weeks on 12-01-2005 08:49 AM

[holgerh]

I posted a example vi in the Digital I/O forum, since I guess that's the appropiate one. I only posted my original request in the multifunction DAQ by mistake. Let's continue the discussion there http://forums.ni.com/ni/board/message?board.id=70&message.id=4010.

Thanks for all comments so far,

Holger