Storing trending data

[MogaRaghu]

The application is for a data logger.

I am acquring 5 channels of Pressure data from connected chambers and plotting it. The acquisition is rather slow at about 30 sec sampling interval. This is a continuous process and I need to keep storing the data and also display . 

The data  is in this format : ( Date &Time Time Stamp followed by 5 Channel data )

DD:MM:YYYY:hh:mm - U16 - U16- U16 - U16 - U16 

Since the storing happens non stop I must find an elegant way to store it so that its easy to retrive . The retrieval criteria is :

Start [ Date &Time]  to End [ Date & Time ] of  any one Specified Channel.  Once the information is retrievd, the data needs to be plotted. Thats it. 

I am thinking of following options :

A. Use Active-X and use Excel in background. 

B. Use MS Access again with Active -X

C. Just use a Two Dimensional Array native to LV. One day will produce just 2880 rows of data which I think is not much. 

ANy other good options exist ? And since the acquistion is rather slow, I think I will write once every acqusition. The write may be slow but the read needs to be fast since the user might specifiy a large amount of data to retireve. Thats the main concern in choosing a particular method... 

Any help would help !

[Bob_Schor]

I assume that there are two independent tasks, a "Data Collection" task that involves writing a sample every 30 seconds in some "Friendly" File format (you suggested Excel, Access, and what I'm guessing is a Binary file format -- I've never used TDMS myself, but I suspect this would be something others would certainly suggest), and a separate "Read and Process the Data" task that takes place after the data have been collected.  Obviously, if you need to process the data during data collection, this is considerably more complicated.

I gather one consideration is for the data (you mention 2880 rows) to be easily "human-reviewable", which suggests something other than a Binary file format.  Excel isn't bad -- you can certainly open an Excel file, add a row to the end, and close the file within 30 seconds (you can also open the file, write a row every 30 seconds, and close it when you are all done, but you might consider it "safer" if the file is closed "most of the time").  If you take this approach, and if you have either LabVIEW 2014 or the Report Generation Toolkit, I strongly urge you to use the Report Generation tools instead of ActiveX -- it is so much easier (you can do the entire task with at most 5 or 6 function calls, all very straight-forward).

I'm now blocking on the NI product that works with TDMS files, but you should at least look at this to see if it better fits your needs.  Oh, yes, DIAdem.  This might be overkill, but it also might be Just What You Need/Want.

Bob Schor