Hello Randall,
Thanks for the answer.
I try to generate signals continously and at high rate (1 Msamples/s on 4 channels). The signals (format int16) a computed in a Matlab node because it is faster. But to write the data to Labview buffer, I have to convert the datas in double format (to export in Labview) and then convert them to int16 (I use the writeInt16 VI from Labview). This way of doing slows down much the process of gneneration. It's why I tries to export directly the datas in int16 format from Matlab.
Félix