Extract automatically a portion of a signal

Hi, i'm trying to extract a portion of a signal automatically. I've extract it manualy using 2 cursors. I'm interested how can i point the cursor using an indicator. Basically, i have a signal and i want to find the index (index 1) when the signal grows above 0.01, and also when the signal goes below 0.01(index 2). and cut the part before index 1, and also cut the part after index 2. I will attach a photo to be more clear.
Thanks.
Attachments:
manually extraction.JPG ‏50 KB

Hi Fana,
at first you could use a simple "greater or equal" function to find all parts of the waveform that exceed your limit. Then splitting the array should be easy...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

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Extraction of a portion from graph

I have to extract a portion from Graph .
I know the starting and ending point in x-axis and i have to know the y-axis values.
I have used "extract a portion of signal " express VI but am not getting the values correctly.
There is a picture with this, in which the portion in red box is the part i have to extract.
@nk
Solved!
Go to Solution.
Attachments:
Untitled.jpg ‏57 KB

Hi uday ,
Thank you for a fast response .
The VI in the above link shows how to extract a portion of graph with use of cursors. In my VI the user won't do anything . Everything should happen automatically.
First of all.
1.I have detected the peaks in my graph using a peak detector VI. This process have given me the position of peaks in terms of time (i.e x-axis units).
2. I have added a constant offset time like 0.005 sec to each time value and then I provided that value as the starting point of extraction .
3.The length till which the extraction should be done is also kept constant.
4. I just need the amplitude vales of that particular part so that I can use them for my further calculations.
For clear information I am adding a picture of my graph in which the areas I have to extract is perfectly marked inside red box.
@nk
Attachments:
Untitled.jpg ‏57 KB

Report writer - create extracts automatically

Hello together,
as I heard it is possible to create extracts from reports automatically (e. g. over night on a daily basis). Unfortunately I don't find the way how to do this. I have looked up the t-code GRE0 etc., tried the SM37 but still I don't have a clue.
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Best regards,
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Please go through the enclosed document. This will give you step-by-step approach for Report painter:
http://www.virtuosollc.com/PDF/Get_Reporter.pdf
Check url
http://help.sap.com/saphelp_47x200/helpdata/en/da/6ada3889432f48e10000000a114084/frameset.htm
Check Report Painter Step-by-Step example under Tools->Report Painter / Report Writer->Report Painter->Creating a Report Painter Report.
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http://help.sap.com/saphelp_erp2005/helpdata/en/66/bc7d2543c211d182b30000e829fbfe/frameset.htm
http://help.sap.com/saphelp_erp2005/helpdata/en/5b/d22cee43c611d182b30000e829fbfe/frameset.htm
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REGARDS
VINOD

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Hi,
Thankyou for posting to the National Instruments Forums.
The feature you are looking for is the Subset and Resample step which may not be the exact thing you are looking for. If indeed this does not fulfil your needs we would love to hear about what features you would like implemented at the Product Suggestion Center.
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Data extraction automatically

Hi,
I have a requirement where user requests data from database table once using an interface. Process needs to run continuously until data gets updated in DB table. DB table can get updated any time. Actually can I keep a process timingly check the DB automatically without user action?
Thanks In Advance.
Yaseen.

Hi again,
1. Ya, sample code is there
   (but if u copy-paste directly in ur
   program, it won't work bcos
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2. However, The LOGIC will be clear to you
   once u see this program.
3.
REPORT abc.
TYPE-POOLS : icon.
INCLUDE yhri_inclfor_alv.
DATA : ctr TYPE i,
       nummax TYPE i.
DATA : BEGIN OF itab OCCURS 0.
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DATA: END OF itab..
CLASS my DEFINITION.
PUBLIC SECTION.
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ENDCLASS.                    "my DEFINITION
DATA timer TYPE REF TO cl_gui_timer.
DATA myh TYPE REF TO my.
      CLASS my IMPLEMENTATION
CLASS my IMPLEMENTATION.
METHOD run_handler.
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      EXIT.
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Init
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*AB WRITE /: 'abc'.
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IF sy-ucomm = 'TMR'.
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PERFORM alv_customize USING sy-repid 'ITAB'.
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Regards,
amit m.

Extract random portion of signal

If I am loading a signal from an LVM file, is there a way to extract a random portion of the signal? Just some background, I will be loading multiple files in through a for loop/case structure, and each of the files may be of different lengths, so I won't know ahead of time how long the signal is.
thanks,
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Solved!
Go to Solution.

LVM includes the number of points in each segment header. You can get this by reading and parsing the header yourself. The spec is located here. The Express VIs presume that, being an ASCII file, LVM files are relatively small. As such, the entire file is read into memory by the Express VI. You can use the array or waveform VIs to easily extract a portion of this.
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This account is no longer active. Contact ShadesOfGray for current posts and information.

Extract a signal portion

Hi,
I am new to Labview and trying to extract a portion of a signal. I can display the analog signal catured by an A-D card (Signal A)connected to PCI slot. I can capture another signal from the parallel port (Signal B) which I want to use for timing. Its a digital signal with two levels. I want to capture a portions from Signal A based on the time duration from Signal B and store them in a 2-D array or a matrix, so that I can use it as an image for further processing.
1. how to implement a counter to count number of pulses from signal A? I can convert it for boolian output if necessary.
2.how can I use that counter to extract portions from Signal B?
eg; extract signal from pulse 1 to 10 and store them in a first row of 2-D array
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Or is there any other way to cordinate these two signals so that I can save the reqiured samples from signal A to a 2-d array?
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Hi Fana,
at first you could use a simple "greater or equal" function to find all parts of the waveform that exceed your limit. Then splitting the array should be easy...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Most efficient way to extract the amplitude of a signal and display on an intensity graph

Hi All,
I am having difficulty to display the amplitude of an voltage signal (voltage picked up by NI DAQ card).
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I have difficulty to convert the dynamic 2D array to scalar 2D arry.
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Hi Hillary,
Thanks for your reply.
Yes, I did tried to use Amplitude and Levels Express vi, it should be the one I am looking for, but I found it not work in my case, I need to put the value of amplitudes into a 2D array.
If I use Amplitude and Levels Express vi, it will give me a 3D array, I have found the solution, just convert the dynamic data to single scalar. (see pic attached)
Anybody can help me to solve the following 2 problems:
1. The speed of this program is too low, i think ii due to the DAQ assistant in the 2 for loops (for creating 2D array), it should be able to re-write using DAQmx (as "centerbolt" told me), I am working on this now, if anybody can help, I will appreciate that.
2. Is there any other way to creat the 2D array (for purpose of increasing speed also).
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Extracting portions of the timeline from iMovie to create a 'Sound File'

Hello
I recently used my Cannon GL2 as a field recorder to record 16 bit audio sound effects.
I'd like to extract certain portions of the timeline to create various 'Sound Files' which will be used later (as sound effects), in either iMovie, or FCE HD.
In iMovie HD, the only method I'm familiar with to extract a portion of the timeline to a 'Sound File', is to FIRST export that portion to a Quicktime File. Then I use 'Sound Studio 2.2.4' to import the Quicktime File. In Sound Studio, I can then create either an AIFF File, or Wav File.
From there, I open iTunes, and import the Wav File. Now I convert that Wav File to an MP3 (if I need to compress the size of the file).
I know I can import Raw DV Video Files (Captures), into Garage Band, but then I can't export that edited project into a Sound File.
But I do know I can use Garage Band to edit (EQ), a portion of the timeline, then Export that portion (as I explained above). But I'm still going through some extra steps .....
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Hey Piero
Comestah?
I'm an Italiano too My Granparents are from Bari
Well yes thank you - that certainly answered part of my question
Now I wonder if I can extract just a 'PORTION' of the timeline? I tried to insert division points without actually cutting out all the unwanted stuff, and highlighted just that portion, but the Audio Extract process reverts back to extracting the ENITIRE timeline. So I guess I'd have to actually cut and delete all the unwanted parts, then 'save as' to that NEW iMovie project reflecting just that edit in order to extract JUST that audio piece?
I wonder if the process is more precise in FCE?
Gracias
Mike

Is there a way to have your iPad automatically switch wifi connection based on signal strength?

I have multiple wifi access points in my house as it is very large. The SSID's are different, and signal is fine coming from one of the two access points. The problem is that when I move about my house, I will stay connected to the access point that is far away, and so I have to go into settings and switch wifi networks each time. Is there a way to set up your iPad so that it automatically switches connections based on signal strength?

Probably not, or .. maybe. I can't think of any reason why that would be added into the OS as the number of situations where it would come into play is really quite small.
If they're all entered as wifi accounts and all show as accessible, walk around the house and sign in to each one in turn. They should all be remembered after that; now, walk around while staying logged into one and see what happens when you get a big spread in received signal strengths.
I really don't think it will change on its own, but it might. Who knows? Even if not, it'd be a matter of not more than 10-15 seconds to make the switch manually.

Does FCP automatically encode a copyright signal in videos?

Hello Everyone,
I am experiencing a weird problem that even has the Sony tech support stumped.
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Hi,
Thanks for you advice. We tried that. Here's the wierd thing. When we first hooked up the dsr45 to the dvd combo unit, using the back inputs, we used RCA patchcords. It gave us the message of "cannot copy copyrighted movies". I then switched to the front inputs, used S-video, and the left audio channel only. It worked.
Now its the next day and it won't work with any combination.
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Signal numeric integration

hello
i was having problem getting the area under the curve.to eliminate the
noise, i set threshold level by using basic level trigger. then extract
portion of the signal.
from the initial threshold level, i will get the t1 and t2
corresponding to the threshold value. but it does not represent exactly
the area. i still left out the hatched area. so i need to define t3.
(pls refer to diagram attached)
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thanks
here attached with the diagram and offline data
Attachments:
graph(dt).png ‏4 KB
1_06-12-14_1324.zip ‏50 KB

Integrating a noisy signal gets rid of a lot of noise automatically. Why don't you do a numeric integration of the signal, then pick the start and end point for the area? If the baseline is zero on the average, you can easily pick locations that are clearly outside and the area will still be correct.
LabVIEW Champion . Do more with less code and in less time .

Measure amplitude of a continuous signal within a given window of time

I'm working on an acqusition system that acquires a continuous 250kHz signal. My goal is to measure the peak-peak amplitude of the first signal response, the probelm with my setup is that the inital part of the signal is always larger than the part of the signal I'm intersted in. If I try to use the signal max pk-pk measurement VI it will repond with the pk-pk measurement of the initial part of the signal. See the attachment for a better understanding, I would still like to display the raw signal as is but I would like to measure the pk-pk voltage of the signal between the yellow cursors.
Thanks in advance...
Solved!
Go to Solution.
Attachments:
Capture.PNG ‏43 KB

If the initial transient always occurs in the first 12 microseconds, you can just use Array Subset or the similar Waveform function to extract the latter portion of the waveform. Then use the peak to peak measurement on that subset.
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Issue with MacBook Pro (mid 2009) wifi multiple AP signal 'confusion'

I'll try to explain this as best I can, not being an expert in networking!
I recently upgraded my router from a Linksys WRT160N to an Airport Extreme, in the hope that it would do a better job of broadcasting a stronger wifi signal throughout my house. Whilst it is improved, it's still no good enough for streaming to my iPad 2 where I want in the house. Reading around on the web I discovered that I should be able to use the Linksys as an AP to extend the effective range of my wifi network, as long as it is hardwired into the base station via Ethernet (no WDS support on the Linksys model).
So, I managed to get this all up and running, disabling the dchp on the Linksys, fixed ip allocation etc and using the same SSID and passwords etc. All is well with the iPhone and iPad2 access - they just automatically switch to the strongest signal no problem when I move around the house. Cool.
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I do have a workaround - if I name the SSID on the Linksys something different, the problem goes away. However, i effecktively now have 2 wireless networks & I then have to manually switch between the two SSID's to get the strongest signal depending where I am in the house. It's suffices for now but not ideal.
What I don't get is why is it only the MBP affected & the iPhone & iPad 2 are fine? Is this anything to do with the 2.4 ghz & 5 ghz being broadcast by the AEBS getting all mixed up with just the 2.4 ghz being broadcast from the Linksys??? Both 2.4 & 5 ghz are broadcasting the same SSID.
Any help appreciated.

OK - fixed this now. By setting the 5 Ghz channel on the AEBS to a different SSID and putting this to the top of my priority WIFI connections on the MacBook Pro then it ignores the conflict between the 2.4 Ghz networks being broadcast by the Linksys & AEBS. No more hanging connection when I resume the MBP

Cubes - how to extract a single dimension and save it in a table

Hi,
I am new to the cubes concept, although I've used it several times in the past to analyse the data but never explored options beyond that. using excel, I can get different dimentions from the cube such as customer information, location, etc.
is there a way to extract (automatically) a single dimension and save it in a table...? e.g I want to pull customer name and revenues only from the cube, how would I do it?
Thanks

Hi,
tparvaiz wrote:
Hi,
I am new to the cubes concept, although I've used it several times in the past to analyse the data but never explored options beyond that. using excel, I can get different dimentions from the cube such as customer information, location, etc.
is there a way to extract (automatically) a single dimension and save it in a table...? Sure, you can do that.
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A cube is a table with many dimensions. You're interested in only one of those dimensions, so what can you do? You can write a query with a WHERE clause to include only the dimension you want to see.
e.g I want to pull customer name and revenues only from the cube, how would I do it?Exactly how to do it depends on the table(s), your requirements and your Oracle version. As the others have said, post a little sample data (CREATE TABLE and INSERT statements to simulate what your real table looks like), and the results you want from that data.
Always say which version of Oracle you're using (e.g. 11.2.0.2.0).
See the forum FAQ {message:id=9360002}

Extract automatically a portion of a signal

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