Data Logging Elapsed Time

I have a program that monitors a pressure reading from a transducer. The initial readings are logged at 10 second intervals until the pressure is increased by a set value and the logging interval increases to 100 points per second. Currently, when I graph the data, the elapsed time on the x-axis is inaccurate because the computer doesn't know when the 10 second stopped and the 100 points per second began. Is there a way to keep track of the time the points are being logged? Some sort of method of having the elapsed time between points logged so this can be used to create the x-axis?
Thanks in Advance!!
LabVIEW 2012 - Windows 7
CLAD

Hello,
It sounds like you'd like to have two plots on the same graph, but the x-axis scale and values are different for your two plots. You can control how data is plotted to a waveform graph by bundling the array of data you are plotting with an x0 (initial value) and a delta-x (distance between samples). The order for the bundle (into a cluster of course) should be, x0 value, delta-x value, y-array of data.
I have attached an example to illustrate this by allowing you to change the x0 and delta-x for two plots dynamically (the Generate Sine Pattern.vi is used as a subVI, where the other is the top level VI); I think this is exactly what you are looking for!
I hope this helps!
Best Regards,
JLS
Best,
JLS
Sixclear
Attachments:
Example1.zip ‏28 KB

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You could export your data to a spreadsheet file and then actually write then again in a second database using this example program in the devzone
http://zone.ni.com/devzone/conceptd.nsf/webmain/5A921A403438390F86256B9700809A53?opendocument
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DAQ Hardware: Not Selected Yet
LabVIEW Version: 6.1 (Feel free to recommend a v7 solution because I need to soon get it anyway.)
Operating System: Win 2000
In summary:
How do I control a graphing (data log) session for both period and sample time?
How do I stop the session without having to wait for the period to end?
How do I automatically interrupt and control a session during alarm conditions?
Does it make a difference if there is more than one graph (or chart) involved where there are variable sample rates?
Thanks,
Dave

Hello Dave,
Sounds like you have quite the system to set up here. It doesn�t look like you are doing anything terribly complicated. You should be able to modify different examples for the different parts of your application. Examples are always the best place to start.
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Robert Mortensen
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Hello all,
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Attachments:
Sine Wave.vi ‏104 KB

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<Brian A | Applications Engineering | National Instruments>

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Attachments:
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Run your loggging program for that time. When your program terminates then it will write all the logged data so far in text file.
Kudos are always welcome if you got solution to some extent.
I need my difficulties because they are necessary to enjoy my success.
--Ranjeet

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Hi,
I have created 3 tables with one column only. As an example Table 1 below:
SQL> create table T1 ( x char(2000));
So 3 tables are created in this way i.e. T1,T2 and T3.
T1 = in the default database tablespace of 8k (11g v11.1.0.6.0 - Production) (O.S=Windows).
T2 = I created in a Tablespace with Blocksize 16k.
T3 = I created in a Tablespace with Blocksize 4k. In the same Instance.
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I'll highly appreciate the expert opinions.
Bundle of thanks in advance.
Best Regards,

Hi Chris,
No I'm not using separate databases, it's 8k database with non-standard blocksizes of 16k and 4k.
Actually I wanted to test the Elapsed time of these 3 tables, so for that I tried to create the same size
tables.
And how I equalize these is like I have created one column table with char(2000).
555 MB is the figure I wanted to use for these 3 tables ( no special figure, just to make it bigger than the
RAM used for my db at the db startup to be sure of not retrieving the records from cache).
so row size with overhead is 2006 * 290,000 rows = 581740000(bytes) / 1024 = 568105KB / 1024 = 555MB.
Through this math calculation I thought It will be the total table size. So I Created the same no. of rows in 3 blocksizes.
If it's wrong then what a mes because I was calculating tables sizes in the same way from the last few months.
Can you please explain a little how you found out the tables sizes in different block sizes.Though I understood how you
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T8K =97177 BLOCKS=759MB *( 97177*8 = 777416KB / 1024 = 759MB )*
T16K=41639 BLOCKS=650MB
BT4K=293656 BLOCKS=1147MB
For me it's new to calculate the size of a table. Can you please tell me then how many rows I can create in each of
these 3 tables to make them equal in MB to test for elapsed time.
Then I'll again run my test and put the results here. Because If I've wrongly calculated table sizes then there is no need to talk about elapsed time. First I must equalize the table sizes properly.
SQL> select sum(bytes)/1024/1024 "Size in MB" from dba_segments> 2 where segment_name = 'T16K';
Size in MB
655
Is above SQL is correct to calculate the size or is it the correct alternative way to your method of calculating the size??
I created the same table again with everything same and the result is :
SQL> select num_rows,blocks from user_tables where table_name = 'T16K';NUM_ROWS BLOCKS
290000 41703
64 more blocks are allocated this time so may be that's y it's showing total size of 655 instead of 650.
Thanks alot for your help.
Best Regards,
KAm
Edited by: kam555 on Nov 20, 2009 5:57 PM

Data Blocks and the Elapsed Time

Hi,
I have created 3 tables with one column only. As an example Table 1 below:
SQL> create table T8k( x char(2000));
So 3 tables are created in this way i.e. T8k,T16K and T4K
T8 = in the default database tablespace of 8k (11g v11.1.0.6.0 - Production) (O.S=Windows).
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Bundle of thanks.
Best Regards,

Because I was not completely satisfied with the things last time. It doesn't seem so simple to me as people said
I thought may some guru have a look today, not just to point out that i have created it again.
And I have compact my question to avoid confusion.

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This is the LabVIEW board. You need to post your question to the SignalExpress board.

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Attachments:
DateTime.PNG ‏12 KB

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Attachments:
FYP.vi ‏15 KB

PT-
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