Help for data acquistionusing 6024e

Question

   The platform using is labVIEW 7.1.The daqsing is 6024E. I had acquired data of a calibration system (valve calibration) both the static as well as dynamic calibration.
Normally the system is uses the signal as small incremental steps withsome holding time (upto 1sec) as input it is fe d through A0 .The response from the valve is taken through A1.
From the i/p and response I have to calculate the dead time settling time as 63%. 86%,..........,deadband ,hystersis....
Moreover I have to take the data from particular step to some time .
Normally it is as the form of logging the continous data  
The problem I here facing is how I can reterive the data from the acqiured (stored one) from a particular time to another particular time without going through the whole stored file (while on request)
Here I tnk the problem is due to my lack in knowledge in data logging.
Is any tool which can help .
Another problem i been facing is the lack of knowledge in sampling rate ,sampling time for a the frequency being used
I here send the acquired date
Can anynone help me for these fundamental knowledges
With Hopefully
Rathesh
Attachments:
Data Ip Vs Response.txt ‏90 KB

Answer 1

Rathesh,
From the explanation given, I'm not entirely sure how your
setup is working.  However, I think I understand your problem.  The
file you posted online is a LabVIEW measurement file.  You can use the
LabVIEW Read from Measurement File express VI to read this file.  This
express VI does not allow you to specify which line you want to read in
programmatically.  Once you have configured the LabVIEW Read Measurement File
express VI, you can modify the express VI by right clicking on it and selecting
Open Front Panel.  The code behind the front panel (Window >> Show
block diagram), allows you to select the starting row.  By
programmatically entering the starting row, and samples to read, you can
specify a window of time you want to read from the file.
You can calculate which row is your starting row and how
many samples to read by knowing the starting time (t0) and the sampling rate. 
You can retrieve the t0 (starting time) and dt (sampling period) by reading in
the first row of data.  The signal returned will contain this
information.  To calculate which row to start your read from (starting
row) you only need is t0 and dt.
Finally, sampling rate means the number of samples you are
acquiring per second per channel.  For example if you specify the sampling
rate to be 1000, you will read 1000 samples per second per channel you
specify in your channel list.  The period, or sampling period, is the
inverse of this.  A 1000 Hz sampling rate means 1/1000 (or 0.001)
milliseconds sampling period.
If you still have questions about sampling theory please
read through the complete data acquistion tutorial available here:
http://zone.ni.com/devzone/conceptd.nsf/webmain/48B4C2DC01295874862570D7007915DA?opendocument&Submitted&node=201181_US#1
Regards,
Jesse O
Application Engineering
National Instruments
Jesse O. | National Instruments R&D