Is there a way to increase the amount of memory available to tasks run on 4461 from its max value of 2^24?

[theman10]

I am creating taks using MAX to run on 4461 for data acquisition.  I need to acquire more data than the 16M memory limit for the task allows.  It there a way to increse this memory limit?

[dgriffin91]

I don't quite understand what you mean when you say, " I need to acquire more data than the 16M memory limit for the task allows." Could you please elaborate more on the task you are trying to create? For example, are you trying to set the "Samples to Read" to 16M?

Additionally, I assume you got the 2^24 from the fact that the ADC on this card is 24 bit. This affects the resolution of the card and can not be changed.

Finally, the onboard FIFO buffer size is 2,047 samples. Thus the max samples you can read at one time is 2,047. Otherwise, the buffer will overflow and you will lose data. 

[theman10]

Thank you for your interest in this problem.

When I create a task, I can set a number of samples.  This has a max possible of 16M.  This is the number I like to be able to increase.

[dgriffin91]

What is your acquisition mode set as?

[Chantastic!]

Is there a reason why you want to acquire that many at once? 

When you set that "Number of Samples Per Channel" you are only defining how many samples you are going to pull from your onboard hardware buffer onto the software. Can you acquire continuously, and then store the incoming data in the software?

For example, if you're trying to obtain 64M of data, you can acquire 4 chunks of 16M, or 16 chunks of 4M, or 64 chunks of 1M. 

[theman10]

Acquisition Mode is set to "N Samples".

[dgriffin91]

As Chantastic! said you should acquire continuously and make sure that you are pulling enough samples at a fastest enough rate so the on board buffer doesn't overflow. 

[theman10]

I need to acquire the data with no time gaps. If I can acquire the chunks you are talking about continuously, then please tell me how. I am doing an FFT on this data and need very fine frequency resolution so continuity is the important thing.

[theman10]

My problem is that the task won't let me set the number of samples more than 16M even in continuous mode. So when I run the task in Labview it runs for 16M samples and stops.

[dgriffin91]

You will set the Acquisition Mode as continous samples. Then set a value for "Samples to Read" and the "Rate (Hz)". This way the specified samples to read will be acquired at the given rate. Also, your card has a max sample rate of 204.8 kS/s.

Again, your card has an on board buffer of 2,047 samples. Thus the max samples you can grab at one time without losing data is 2,047.