Hello Fullist,
If you take a look here,
it has more details on the format that the Scan_to_disk function uses. In
addition, the Scan_to_disk function performs both the data measurement and
saves to disk all in one task. This
means that you will have to read the data from the file to display it to a
graph. If you want to display the data
to a graph, I would suggest using another function to read in the data. If you are using Traditional NI-DAQ, I would
take a look at the AI_Read or AI_Read_Scan functions to acquire the data into the form of an
array. This would allow you to graph the
array and save the array to file using one of the file I/O functions provided
by your programming environment. I’m not
familiar with wxDevC++ and I would recommend contacting
them to determine the fastest and most appropriate function to write to file.
In regards to whether or not it is impossible to measure data, save to file,
and display the data on a graph in one second, there are many factors that
affect the speed you can do these three functions. The rate that you can
complete these functions will depend on your operating system, hard drive
speed, CPU speed, Data Acquisition card, programming environment, what device
driver you're using, etc. I would recommend running each thread seperately to determine it's individual speed. This might help you determine which task is slowing down your execution. You might also look at methods of storing the array in PC memory until the total acquisition is done until you write it to disk. This would depend on the rate you are acquiring and the total time you will be acquiring at that rate as to whether you can store this information in memory. However, this would increase the loop rate you're using to read in the data from the DAQ card and display to graph.
Regards,
Paul C.
