VXI MXI data move problems in linux

[xorn]

I am experiencing problems with  viMoveIn16 function with PCI-MXI-2 on Linux.

I was trun off DMA.

I used viMoveIn16 function for read directly local memory.

So, I try to read  more then 16 points. but the data was wrong.

ex)

signed short readVal13[16], readVal24[16];

 err = viMoveIn16(id, VI_A16_SPACE, VXI_FIFO_HIGH, 16, readVal13);

 err = viMoveIn16(id, VI_A16_SPACE, VXI_FIFO_LOW, 16, readVal24);

And,I got error message "ERROR = Invalid length specified." when  I try to read more then 20 points.

and then I got wrong data.

What's the problem ?

What can I read maximum counts of  viMoveIn16 function?

Do I need another setting for VXI ?