I Want to aquire more than 1000000 (1 million) samples from one of the analog input. For finite length aquisition, When the length of array exceeds 1 million i get floating point error. So i have decided to go for continuous aquisition. I am finding it difficult to save the aquired data in array to file when aquisition is in progress. I am using ANSI C API for programming NIDAQ card.
The NI-DAQ driver installs ANSI C example programs that show how to perform a continuous acquisition in the default location of C:\Program Files\National Instruments\NI-DAQ\Examples. I would start by taking a look at the examples that illustrate how to program continuous acquisition, and alter these examples to add file I/O functionality. More examples can be found in the Example Code Library at www.ni.com. As far as file I/O, it really depends on what library of functions you are using to program saving the data to file. ANSI C has the stdio.h header file that declares a variety of functions that perform input and output to files. LabWindows/CVI has an ArrayToFile function that makes programming this task even easier, as shown in this example: