Speed How to Measure

I realize that my ISP typically supplies a somewhat fixed speed.
I have and Apple TV that synchs with a MacBook Pro on a pure 802.11n network...how can I measure the speed to see if in fact I am getting fast speeds?
In general how can I measure the speeds that the AEBS communicates to the Macs with?

Time the transfer of a large file via your wireless network. Using a sufficiently large file, a watch will do. Then do the math.

Similar Messages

  • How to measure angular speed by RVDT

    Hello,
    I quite new in labVIEW and I am trying to measure angular speed of shaft by RVDT which is able to measure in electrical range 0°-280°. I use NI USB-6008 card and RVDT is also powered by this card (5V). I have already found way how to measure angular position but i do not now how to convert it to angular speed. I tryed to do it by derivation but the result was weird. Could anybody give me an advice how to do that. I would really appreciate that.
    My VI is attached.
    Attachments:
    rot pot.vi ‏154 KB

    Hi kome01,
    The issue comes from the fact you are only acquiring one sample per iteration of the loop, and to differentiate you need to provide at least two values, as well as a time difference between each.
    The Express VI you are using is clever in the way that it can measure the time between samples for you, but you will still need to provide multiple samples. I have changed your VI to continuously acquire samples from the potentiometer, and have provided some notes in the block diagram to help you.
    Hope this helps!
    Attachments:
    rot pot.vi ‏153 KB

  • How to measure RPM using digital I/O

    Please tell me how to measure RPM using Digital Input or please give me a code for this.

    You probably aren't going to find anyone to just give you code. Especially because you don't specify the hardware you're using. Doing this on FPGA is different than using DAQmx to do it. With FPGA you count pulses over a specified time. Using boolean logic from the digital DI node is a common way but there are others. (if you are using FPGA I can draw up an example, but I believe there is one on NIs website if you search google for it),. Then, if you want, you can run the data through an IIR filter, especially if you have a low resolution or slow moving encoder. Either of these conditions can result in very large difference of RPM even if the actual speed is not varying much (if you need an example why I can provide more detail, but some simple math calculating RPM should explain this. Obviously lower resolution will giv eyou less accurate results).
    If you use DAQmx you can set up a frequency task and it will return the number of pulses in a specified time frame; then you can convert this to RPM based on your encoder resolution and take the same steps of running it through a filter to smooth it out if need be.
    CLA, LabVIEW Versions 2010-2013

  • How to measure the frequency of a pulse being generated by a counter

    Hi,
    I am using labview 8.6 to generate 5 evenly spaced pulses for every 1 revolution of my shaft. However, I would also want to know the frequency of these pulses so I can determine the shaft speed. Since I am already generating the pulses using one of my counters, can I still tap into that or task another counter to measure the pulse frequency? If so, how? I have attached my code for generating the pulses and I am using an Ni 9401 module and an NI 9172 chassis. If someone can helo me modify the code to measure and tell me the pulse frequency as well, that would be really appreciated
    Attachments:
    autotrain2.vi ‏19 KB

    You'd probably get a more coherent answer if you didn't bounce around from thread to thread so much...
    How can I generate a pulse train from shaft encoder? (5/13)
    pulse train from encoder (5/15)
    how to measure rpm (5/20)
    How to measure rpm using shaft encoder and labview (5/23)
    This thread (also 5/23)
    I see you ignored my suggestion from the other thread--Kevin's solution is good too but using an encoder task offers more noise immunity (I think this is probably the cause of the problem you reported on the other thread).  You can fix it with digital filtering if you want to keep using a counter output instead of an encoder task.  Noise during transitions is pretty common for a quadrature encoder.
    A finite counter output task uses 2 counters on the 9172 (although you said 9174 earlier at one point--this wouldn't be the case on a 9174) so you wouldn't have one left to make your frequency measurement.  With the solution you have now, you can change to continuous to free up a counter if you don't care about outputing an exact number of rotation's worth of pulses (I'm not sure if you do or not--I didn't read through all of the various threads relating to this application to find out).
    For your actual question in this thread...  Have you tried running one of the frequency measurement examples?  From the code here I can't tell what you have tried (it just looks like a mangled version of the code Kevin gave to you in your other thread).
    Best Regards,
    John Passiak

  • How to measure the baseline of a noisy, pulsed signal

    Hi
    I am measuring the torque exerted by a large motor on a shaft using a load cell and lever arm. The shaft runs at approx 150 rpm. I have attached a drawing that shows the output I get. This is a test rig.
    I have written some code that measures the maximum peak out of a group of approx 5 peaks and writes this to a shift register. This gives me an idea of the maximum torque "spike".
    I also wish to measure the baseline torque (due to the bearings in the machine). Even when highly filtered (my noise filter is set to 49Hz) the signal exhibits this noise which is probably due to vibration in the system. The signal is zeroed when the motor is not running.
    Does anyone have an ideas on how to measure the "baseline" torque? The large spike in torque prevents me from doing a running average. Can anyone think of a way of averaging just the noisy part of the signal to get an average value? I aim to to subtract the average baseline torque from the peak value to get an idea of the torque due to the event which causes
    the spike.
    Any help would be greatly appreciated.
    Many thanks.
    Attachments:
    drawing of torque signal.gif ‏26 KB

    Thanks for the reply. I understand what you are saying. However, I might have to modify my method for measuring the peaks if I choose to implement your idea. I have taken a screenshot of my "peak finder" code and attached it.
    Bascially, the reset terminal is wired to a timer which outputs a pulse every few seconds. This resets the vi (a standard NI one I think) and sets the peak magnitude back to zero. This way, I am windowing the signal and measuring the maximum peak in every window. This is what I need to do.
    So I could use a logical filter to feed data to the running average only if;
    the amplitude of the signal is less than a certain threshold
    and if the current value has similar low peaks either side of it
    How would you construct the code to delay the evaluation so that the values in front and behind of the current data point can be analysed?
    thanks again
    Attachments:
    peak_find_screenshot.jpg ‏45 KB

  • How to measure the performance of Extractor

    Hi,
    How to measure the time taken to by the extractor when executed from rsa3 for a given selection?
    Lot of threads speak about ST05... but these transactions are too granular to analyse.
    How to get the overall time taken.i need the overall time taken and the time taken by the individual SQL statements... please provide specific pointers.
    Thanks,
    Balaji

    Maybe SE30 can help you....
    Regards,
    Fred

  • How to measure the performance of sql query?

    Hi Experts,
    How to measure the performance, efficiency and cpu cost of a sql query?
    What are all the measures available for an sql query?
    How to identify i am writing optimal query?
    I am using Oracle 9i...
    It ll be useful for me to write efficient query....
    Thanks & Regards

    psram wrote:
    Hi Experts,
    How to measure the performance, efficiency and cpu cost of a sql query?
    What are all the measures available for an sql query?
    How to identify i am writing optimal query?
    I am using Oracle 9i... You might want to start with a feature of SQL*Plus: The AUTOTRACE (TRACEONLY) option which executes your statement, fetches all records (if there is something to fetch) and shows you some basic statistics information, which include the number of logical I/Os performed, number of sorts etc.
    This gives you an indication of the effectiveness of your statement, so that can check how many logical I/Os (and physical reads) had to be performed.
    Note however that there are more things to consider, as you've already mentioned: The CPU bit is not included in these statistics, and the work performed by SQL workareas (e.g. by hash joins) is also credited only very limited (number of sorts), but e.g. it doesn't cover any writes to temporary segments due to sort or hash operations spilling to disk etc.
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    alter session set statistics_level=all;
    alter session set timed_statistics = true;
    select /* findme */ ... <your query here>
    SELECT
             SUBSTR(LPAD(' ',DEPTH - 1)||OPERATION||' '||OBJECT_NAME,1,40) OPERATION,
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             CARDINALITY,
             LAST_OUTPUT_ROWS,
             LAST_CR_BUFFER_GETS,
             LAST_DISK_READS,
             LAST_DISK_WRITES,
    FROM     V$SQL_PLAN_STATISTICS_ALL P,
             (SELECT *
              FROM   (SELECT   *
                      FROM     V$SQL
                      WHERE    SQL_TEXT LIKE '%findme%'
                               AND SQL_TEXT NOT LIKE '%V$SQL%'
                               AND PARSING_USER_ID = SYS_CONTEXT('USERENV','CURRENT_USERID')
                      ORDER BY LAST_LOAD_TIME DESC)
              WHERE  ROWNUM < 2) S
    WHERE    S.HASH_VALUE = P.HASH_VALUE
             AND S.CHILD_NUMBER = P.CHILD_NUMBER
    ORDER BY ID
    /Check the V$SQL_PLAN_STATISTICS_ALL view for more statistics available. In 10g there is a convenient function DBMS_XPLAN.DISPLAY_CURSOR which can show this information with a single call, but in 9i you need to do it yourself.
    Note that "statistics_level=all" adds a significant overhead to the processing, so use with care and only when required:
    http://jonathanlewis.wordpress.com/2007/11/25/gather_plan_statistics/
    http://jonathanlewis.wordpress.com/2007/04/26/heisenberg/
    Regards,
    Randolf
    Oracle related stuff blog:
    http://oracle-randolf.blogspot.com/
    SQLTools++ for Oracle (Open source Oracle GUI for Windows):
    http://www.sqltools-plusplus.org:7676/
    http://sourceforge.net/projects/sqlt-pp/

  • Can you tell me how to measure audio signal frequency in measurement studio with visual basic 6.0?

    I'd like to measure two differential input signal(I.e. A+ and A-),below is two test projects,
    1.connect A+/A- to PCI 6052E card's ACH0/ACH8 ,and refer to GND for testing
    2.connect respectively A+/A- to PCI 6052E card's ACH0/ACH8 for testing
    Could you tell me the details of the second project?and give me a illustration in measurement studio with visual basic 6. 0 about the second?
    In addition,I would like to measure the audio signal frequency,could you give me a illustration in measurement studio with visual basic 6.0?
    Wait for your reply!

    Dear kelven,
    Thank you for contacting National Instruments.
    To address your question, there are Analog Input shipping examples that demonstrate how to measure an analog input differentially, as you specify in (2).
    As for measuring the audio signal frequency, you may want to check out the following KnowledgeBase. The link is:
    http://digital.ni.com/public.nsf/websearch/4b08380530d72d3b86256340004c3005
    Let me know if you have any further questions or if this does not resolve your issue.
    Thanks again and have a great day!
    Chad AE
    Applications Engineer - National Instruments

  • How to measure the size of a table ?

    Dear all,
    May I know how to measure the size of a customized table. I have a list of customized table and I want to monitor the growth of the table size on daily basis.
    Please advise how do I do it.
    Your advice and input will be appreciated.
    Thanks.
    Regards,
    Kent

    Go to DB02 -> Detailed Analysis -> Enter the table name under "Object Name" -> Click history to see  the changes in size by day.
    Regards
    Juan

  • How to measure the size of a string

    windows app store how to measure the size of a string?
    string str = "Hello word windows app store";

    if you need the actual width the string occupies in pixels than use (see
    this MSDN link for more details):
    Graphics.MeasureString(String, Font)
    if you only need the "length" of the string i.e. no. of characters than use (see
    this MSDN link for more details):
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    dont forget to bing / google :)
    hope this helps!
    Graphics.MeasureString(String, Font) can not use in windows store app.
    TextBlock has Measure()
    method, as following:
    Size MeasureString(string content, Size availableSize, double fontSize, string fontFamily="Segoe UI")
        TextBlock tb = new TextBlock();
        tb.TextWrapping = TextWrapping.Wrap;
        tb.Text = content;
        tb.FontFamily = new Windows.UI.Xaml.Media.FontFamily(fontFamily);
        tb.FontSize = fontSize;
        tb.Measure(availableSize);
        return tb.DesiredSize;
    Test:
    string str = "Hello word windows app store";
    Size size = MeasureString(str, new Size(800, 600), 40);

  • How to measure the InfoCube size?

    can any body help me regarding this
    how to measure the info cube size?

    1. use transaction se16, infocube table /../f[infocube name] and /.../e[infocube name], count 'number of entries' - total records
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    Re: Lifecycle Implementation
    hope this helps.
    regards
    harikrishna N

  • How to measure the size of an object written by myself?

    Hi all,
    I'm going to measure the performance on throughput of an ad hoc wireless network that is set up for my project. I wrote a java class that represents a particular data. In order to calculate the throughput, I'm going to send this data objects from one node to another one in the network for a certain time. But I've got a problem with it- How to measure the size of an object that was written by myself in byte or bit in Java? Please help me with it. Thank you very much.

    LindaL22 wrote:
    wrote a java class that represents a particular data. In order to calculate the throughput, I'm going to send this data "a data" doesn't exist. So there's nothing to measure.
    objects from one node to another one in the network for a certain time. But I've got a problem with it- How to measure the size of an object that was written by myself in byte or bit in Java? Not.

  • How to measure a current signal with NI 6211?

    How to measure a current signal with NI 6211?

    Hi Clecio,
    This is a charge accelerometer. It is different from the IEPE accelerometers that outputs a voltage signal.
    You need a charge amplifier. Then according to the charge amplifier output we can select an appropriate module to measure the signal.
    It is not possible to measure charge accelerometers with NI 9234 directly.
    Best Regards,
    Rodrigo Schneiater
    Application Engineering
    National Instruments Brazil
    If this information was useful, please click in the 'KUDOS!' beside.

  • How to measure torque on a DC motor using Multisim?

    Hello,
    I would like to know how we measure torque on a DC motor using Multisim Education edition.
    I've searched for the component, "eddy current load brake", but could not find it. Is that component in Multisim?
    Thank you,
    Neil

    Hi,
    Please refer to this forum post.
    http://forums.ni.com/t5/Circuit-Design-Suite-Multisim/PM-DC-Motor-Model-Trouble/td-p/1931859
    Hope this helps.
    Regards,
    Tayyab R,
    National Instruments.

  • How to measure path area in Illustrator CC?

    How to measure path area in Illustrator CC?
    For example I draw a rectangular, how do I get it's area size?
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