How many samples does a pt-by-pt filter need to start?

I'm using a 2nd order low pass butterworth filter on some real-time data. I've found a phase shift by plotting the data, but would like to know how many data points the algorithm needs before working.
Thanks

Hello Graham
After doing some further testing with the function and opening up the function vi's to look at the code inside I have a few more ideas for your development.
The vi uses previous values to do the analysis, so although it is called point by point the analysis occurs using previous data as well. At the beginning of the analysis the previous reference is 0 so it takes time to ramp to the actual value.
I recommend that you create a case in your code that detects low readings. When you reach the low points, where your data is not being transferred you can choose to ignore a set of data to avoid the initial ramp, or you could preempt these values by forcing similar values to those that you read to 'initialise' the analysis and reduce the ramp effect.
If you choose to ignore the data or overwrite the erroneous readings I would suggest that the first 10 reading s should be ignored so that you avoid the ramp as much as possible.
If you have any further queries about this function, please let me know.
Good luck with your development
Regards
Stephanie L
Applications Engineer
National Instruments UK and Ireland

Similar Messages

  • Hi guys, this might sounds stupid but how many employees does apple have?

    hi, how many employees does apple have worldwide? i need the answer for college.
    sorry for my bad english
    greetings maurice

    Currently approximately 60,000 employees at Apple worldwide.
    Hope this Helps

  • How many users does HFM support?

    Hi,
    how many users does HFM support(Maximum)? and why we are choose HFM compare to Hyperion enterprise?
    thanks
    Edited by: user10919054 on May 18, 2009 3:07 AM

    There is no limit, as long as you pay for the licenses and make sure you have a robust system to support user connectivity and demand.
    Hyperion Enterprise is the previous Consolidation tool most commonly used by many companies. Think of HFM as the "New Generation"....

  • How many hours does a brand new battery last after fully charged. I have a late 2008 Macbook Pro.

    How many hours does a brand new battery last after fully charged. I have a late 2008 Macbook Pro.

    clintonfrombirmingham is right, there is no way to exactly tell. But from personal experience, a new battery on a 2008 will last for about 2 1/2 hours with a higher screen brightness and doing something taxing to the battery (like gaming or running lots of 3D programs). But if you're just listening to music with the brightness all the way down, and no programs running, you could get up to 12 hours. So for average use, it should last you a whole business day (assuming you don't use it more than 30% 0f the time). Hope this kind of gives you more of an idea of what to expect:)

  • How many pictures does a 30 GB ipod video hold?

    how many pictures does a 30 GB ipod video hold? and i know it is probably somewhere on the website but i couldnt find it. could someone please answer me soon, thank you.

    A 30GB iPod will hold as many photos as will fit in 27.75GB of space. If some of the iPod's capacity is used for music or other purposes, fewer photos will fit on the iPod. Apple's site specifies 25000 photos.
    (13341)

  • How many times does the JDBC sender adapter retry ?

    Hi All,
    How many times does the JDBC sender adapter retry in the  ' Retry Interval' specified .
    I know that it retries after the time specified in the ' retry interval' , but if it again fails after the first retry will it retry again and again .And while doing it will it block the next Select query which should get executed.
    Thanks & Regards,
    Rahul

    Hi,
    The no of times to be retired on failure of message is default 3 times.
    You can set this in Visual Administrator->Server->Services----> SAP XI Adapter
    Thanks
    Swarup
    Edited by: Swarup Sawant on May 30, 2008 7:19 PM

  • How many records does SAP object BAPIE1VARKEY contain

    Hi Folks,
    I have just started learning ABAP.
    And i have following queries in mind.
    how many records does SAP object BAPIE1VARKEY contain?
    regards,
    Nithin

    Going on an interview? Going to try to fool a savvy tech manager?  I hope not...  How about you tell me why the answer is not two?

  • How many records does JDBC adapter can obtain in one polling?

    Hello everybody,
    I need to do an interface between legacy system and SAP ECC, the legacy systems have a DB so i use the jdbc adapter (sender) and receive the information to SAP ECC with proxy, so i need to activate the polling option from my jdbc adapter working as a sender, i read a table with lot of records, and i need to know how many records does jdbc adapter support when the polling is executed, because is necessary read all records from the table and change the status of the processed field.
    Is possible to get all the records from that table in one polling interval (50,000 records aprox)?, or i need to do the polling by blocks of records until finish all records from the table?, the second option, i dont have idea how can i do it.
    Regards,
    Vicman

    Hi again!,
    i still working on that, but i have a question, is possible to handle Store Procedure in jdbc adapter?? is supported?, like PL SQL, because i was working in the next query but i don't know if it works and where do i need to locate the query in the Query SQL Statement or in Update SQL Statement field or both? but how?.
    DECLARE c_cursor CURSOR FOR
    SELECT * FROM tablename
    WHERE processed=0
    OPEN c_cursor
       FETCH NEXT FROM c_cursor
    WHILE @@FETCH_STATUS = 0
    BEGIN
       update tablename set processed=1
       FETCH NEXT FROM c_cursor
    END
    CLOSE c_cursor
    DEALLOCATE c_cursor
    Regards,

  • How many sessions does SAP allow you to have ??

    Dear Memebers,
    How many sessions does SAP allow you to have ??
    a) 3
    b) 6
    c) 9
    d) 12.
    I guess the right answer is B and C but in choices I have to select only 1, which answer will you pick and Why ??
    Thank You.
    Madhu.

    > I wanted to know for sure what is the answer.
    Hi Madhu,
    If you are going to ask questions such as these, then please indicate that you have searched and what you do already know and where & why you have a doubt somewhere which is worth discussing in the forum or sharing opinions or experiences on.
    Just asking for the answer only so that you don't feel too alone when answering 6 in the interview is of little value.
    Normally such "answer a, b, c, or d only or be quiet"-type-threads (like certification tests are) are deleted. That is the rules, and we have them for a reason.
    Anyway, you guys seem to have sorted this out amongst yourselves so there is no reason to interfere here IMO. Thanks for that.
    Cheers,
    Julius

  • How many minutes does the iPad 2 record in the video mode of the camera?

    How many minutes does the video mode on camera (ipad2) record?

    It should only restart once, see this article:
    iTunes: Restoring iOS software

  • How many sites does the 35.99 get you

    Hello with business catalyst how many websites does the 35.99 get a client? I am a new partner and want to be sure I am giving correct information. Am i reading this right that it gives you 5 sites?

    Hi there,
    If you are a creative cloud account holder and paying the monthly for that you get 5 very basic versions of BC.
    For that price you mention:
    http://www.businesscatalyst.com/pricing/yearly
    You get one webcommerce package (1 site)

  • How many Hz does my ipod touch 4g's screen have?

    HEllo
    i was wondering how many Hz does my ipod touch 4g's screen even have i searches around on google and didnt really find much . And also what resolution and ppi's does it have
    thanks

    Lcd screens do not have refresh rate.
    The 4G uses
    PowerVR SGX535 GPU[45]
    GPU. You can go here to gend some details on the GPU.
    http://en.wikipedia.org/wiki/PowerVR#Series_5_.28SGX.29

  • HOW MANY SONGS DOES A 30 GB REALLY STORE

    Hi-how many songs does a 30 GB really store--currently on approx. 1140 and I'm near half way full--I am concerned I think perhaps I should have gotten the 80GB

    "Also is there a way to buy songs from the iTunes Store in apple lossless?"
    Unfortunately no. That is one of the, several, complaints about the iTMS. First you have "protected" files that are not convertible to other formats (not directly anyway; you can burn to Audio CD then reimport), are not portable to other music players (again, not directly, work arounds exist), and to top it all off, they are advertised as "CD quality" but really you are buying a rather low bit rate for about the same as if you just went out and bought the physical CD instead. Of course, with CDs you can not buy just the tracks you want.
    Hey maybe that is what Apple should do. Sell individual songs at 128kbps/MP4 but if you buy the full album you instead get 192+kbps/MP4s. Then you encourage the real audiophiles to buy albums, not singles. And artists can not complain that the iTMS method only sells their main hits and allowing users to not discover the other songs on their albums.
    Patrick

  • How many bytes does a DATE use?

    Having trouble finding this in the 10g documentation. How many bytes does a date data type use?
    thanks.

    Take a look to the online documentation linked below :
    Oracle® Database SQL Reference
    10g Release 2 (10.2)
    Part Number B14200-02
    Oracle Built-in Datatypes
    expecially code datatype 12.
    Valid date range from January 1, 4712 BC to December 31, 9999 AD. The default format is determined explicitly by the NLS_DATE_FORMAT parameter or implicitly by the NLS_TERRITORY parameter. The size is fixed at 7 bytes. This datatype contains the datetime fields YEAR, MONTH, DAY, HOUR, MINUTE, and SECOND. It does not have fractional seconds or a time zone.
    Nicolas.

  • How many speakers does laptop 2000 have it doesnt seem to play as loud as it did

    how many speakers does laptop 2000 it doesnt seem as loud now

    You are correct, here is what Apple Says:
    http://support.apple.com/kb/TS3775
    I was able to find these instructions, however they referr to 2009-2011 27" iMacs. I think it's the same, if it's not then contact Apple directly for instructions. If either of the machines is less than 90 days old or covered by AppleCare then call AppleCare tomorrow for help, they should be able to easily answer this for you. You will find the number in your manual or you can use the AppleCare Contact Info link.
    Your iMac should automatically recognize the presence of a digital video signal at the Mini DisplayPort and enter Target Display Mode.
    If your iMac does not automatically enter Target Display Mode, press command + F2 to manually enter Target Display Mode.

Maybe you are looking for

  • Can't attach/share a file to email from MS Office applications.

    A couple of months ago I stopped being able to attach a file I am working on from Word, Excel or Power Point.  I usually went to File-Share- email as attachment.  When I do this now, the Mail app launches but the new mail window will not.  If I reboo

  • Access StreamTransformation values in Java initialisation section

    Hi, I'd like to access the StreamTransformation parameter SENDER_PARTY in the Java initialisation section of my message mapping. Does anyone know how I can do this? Regards, Pete

  • Help with critical error in console log?

    this is the message i got today: Mac OS X Versjon 10.4.9 (bygg 8P2137) 2007-06-04 20:50:54 +0200 2007-06-04 20:51:02.049 SystemUIServer[244] lang is:nb Jun 4 20:51:02 thomas-dahlens-maskin diskarbitrationd[63]: SystemUIServer [244]:20227 not respondi

  • Using time capsule along with offsite backup?

    hello, thanks for taking a look at my post. for my office, we want to use time capsule to backup all of our computers, but are looking to then have that information backed up off-site in case of possible theft/fire/etc. at the office. does time capsu

  • Outlook - Andriod - iPad 2 - PC - Google: Calendar issue!!!!!!

    Yes I am one of those guys. I updated my iPad 2 and signed up for iCloud assuming it would make my life easier. Now my andriod calendar and google calendar have been deleted. I only have my icloud calendar in my outlook but it doesn't sync with my go