Hello Francesco,
The DAQCard-6062E actually has an internal FIFO of 8,192 Samples. You can check this out in the specifications manual below.
NI DAQCard-6062E Specifications
http://digital.ni.com/manuals.nsf/webAdvsearch/DDB7B2BFAE6B11B786256DA20072C425?OpenDocument&vid=niwc&node=132100_US
I hope this helps.
Regards,
Todd D.
NI Applications Engineer