NI 4472 multi-card driver problem

Hi all,

I am trying to develop a comedi driver for the NI PXI-4472. I would like to 
use five cards synchronized together (thanks to the PXI features) in order to 
acquire data (in DMA mode) from all them.
With three cards, everything seems ok but with five cards, the acquisition is 
stopped rather instantly after its launching. At least, one of the five cards 
sends an interruption to signal an error : "buffer overflow".

 It is not an overflow of the dma buffer then the system does not seem to be 
overwhelmed by the data rate (the total rate is about 16 Mo/s, not a lot at 
all) but it is an overflow of a fifo (of 1024 samples) in which the ADC sends 
the acquirred values.

It seems that the mite does not have enough time (or something else) to grab 
data from this fifo and to send them to the DMA buffer.

Does anyone have already experienced this kind of problem ? 

Many thanks.

Alexis.

Received on 2004-10-17Z12:37:10