I'm new user. I like to acquire, save and process the dynamic signal data

[Ahmed Khwaja]

My signal is from 5-10KHz and I'm using NI4551. I would like to acuire data for 5-10 sec, save it on the file and then perform frequency spectrum analysis. I realy appreciate if somebody refers me a vi, that I can modify to perform this particular task.
Also I know there are good examples in Labview 6.1 but I don't know which would be appropriate for my application, and how to integrate separate vi's and achive my task.

Thanks for the help

[Gerald Albertini]

If you're using a 4551 board, you should be using NIDSA 1.2 instrument driver in order to program your application.
NIDSA 1.2 installs its own palette in the instrument driver palette and I would recommend you open the example called "NIDSA Getting started with Capture Mode"
This example will allow you to set you baseband span (10kHz in your case), and will ask you to enter a file where to save your data.
It could easily be modifed to precisely fit your needs.
Since you're a new user, I would recommend you to look at the NI-DSA software manual :
http://digital.ni.com/manuals.nsf/websearch/032430F78301D4A986256AC7004DFC52?OpenDocument&node=132100_US
More specifically, page 3-14 is entitled : "Using Capture Mode to Acquire Time Domain data"
The captu
re mode is not the only way to save data to disk - You could use "traditionnal" file I/O vi's in order to save spectra or other information that may have been processed by the onboard DSP.
I hope this helps.
Please just let me know if you need more info.

Gerald

[Ahmed Khwaja]

Hi Gerald,
Actually I'm using 4451, instead of 4551. Do I have still NIDSA 1.2 instrument Driver.
Sorry for key mistake

[Gerald Albertini]

In this case, you will not be able to use NIDSA.
In order to program the 4451, you need to use the NIDAQ functions that are available in LabVIEW.
I attach an example that shows how to save data acquired on a single channel to disk.
Things you may want to add are :
- Gain (input limits) depending on your sensor
- AC/DC coupling

I also compute a power spectrum on the whole waveform.
You probably want to analyze your data in smaller blocks or analyze transients and modifying this example should be very easy.
Please note I've been using the "waveform data type" to save data to a file in binary format.
If you want your data to be "readable" by humans (ie save in XLS file format), you will have to use the "Export waveform to
spreadsheet file" available in the waveforms manipulation palette

I also would like to point you to the "Sound and Vibration 2.0 toolset" user manual :
http://digital.ni.com/manuals.nsf/websearch/AC7BC19618C720BD86256BB2005AB842?OpenDocument&node=132100_US
You may find useful information about signal processing in this manual.

Hope this helps !

Gerald