What is the data throughput in labview. I want to use the parallel as acheap digital i/o to drive a stepper motor.

I am trying to use the parallel port on a win xp machine to send data a@ up to a 3k rate. This is for the the purpose of driving a stepper motor. I have tried the port.out vi and placed this vi in a loop and it on a scope it looks like I am limited to a a 200hz rate. What am I doing wrong??? Can labview do this or is it too slow ???
Thanks

snook wrote:
> what is the data throughput in labview. I want to use the parallel as
> acheap digital i/o to drive a stepper motor.
>
> I am trying to use the parallel port on a win xp machine to send data
> a@ up to a 3k rate. This is for the the purpose of driving a stepper
> motor. I have tried the port.out vi and placed this vi in a loop and
> it on a scope it looks like I am limited to a a 200hz rate. What am I
> doing wrong??? Can labview do this or is it too slow ???
Basically the way the Port I/O VIs are implemented they call through a
device driver for each port access. This slows down the maximum port
accesses to something like 1000 times per second depending on the speed
of your CPU.
There is a way to do it faster but that is a little more trick
y. The
idea is to use a device driver to enable particular port addresses to be
accessed directly from the application level instead of always going
through the kernel.
I have written such a VI library and accompagning DLL and device driver
and made it available on OpenG. It is not yet part of the standard
binary distribution packets so you will have to get it from the CVS
repository.
Go to:
http://cvs.sourceforge.net/viewcvs.py/opengtoolkit/portIO/built/portio/
and download all the files in there including the ones in the
subdirectory "ogportio.llb" and if you like "docs"
If you want the nitty gritty technical details you can also look at
http://cvs.sourceforge.net/viewcvs.py/*checkout*/opengtoolkit/portIO/c_source/Description.htm?rev=1.5
On my 866 MHz Pentium mobile I can increase the number of port accesses
in this way from 440 ms for 4000 read byte port accesses (100us ms per
access) to 20 ms for the same number of read accesses (5 us per access).
Rolf Kalbermatter
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Similar Messages

  • I have two iPads. With two functioning iPads. Is it possible (on the same ID) to sync two of them differently with the same account. So I want to use the new iPad for all my current functions. The old iPad for just my music collection?

    I have two iPads. With two functioning iPads. Is it possible (on the same ID) to sync two of them differently with the same account. So I want to use the new iPad for all my current functions. The old iPad for just my music collection and remove all the other stuff?

    Very easily. I have an iPod touch and iPad on the same account with totally different content.
    If you use iTunes, connect each iPad to your computer and open iTunes and deselect any automatic updating/syncing. If you don't sync with iTunes but have them set up independently, under the settings, App Store, turn off automatic downloads for apps, etc.
    I'm old fashioned, I set up and sync my iPad and iPod to my computer and iTunes. Each device has a different name  and I manage content manually and only allow sharing on what I want shared.

  • I'm using a Mac.  I "upgraded" to LR5 from LR4.  I do not want to be a member of the "Creative Cloud".  I just want to use the software I purchased, specifically to upload to my SmugMug account.  Is there a way to use an add-on to do this?  Aperture and L

    I'm using a Mac.  I "upgraded" to LR5 from LR4.  I do not want to be a member of the "Creative Cloud".  I just want to use the software I purchased, specifically to upload to my SmugMug account.  Is there a way to use an add-on to do this?  Aperture and LR4 were easy but I'm finding it impossible without subscribing to CC.

    Sorry, maybe I don't understand, but why do you feel compelled to subscribe to CC if you already have a permanent Lightroom 5 licence?
    For the SmugMug plugin, a simple Google search ("smugmug lightroom plugin") gives this link to download the plugin:  http://help.smugmug.com/customer/portal/articles/121321
    Another way is to click the button "Find more services online..." in the the Publish Service section of Lightroom, and to search for SmugMug in the Adobe Add-ons portal; you will find a link to the latest plugin: https://creative.adobe.com/addons/products/1755

  • HT1408 I have just purchased a mac book pro.  I've linked this to my windows pc to transfer the data from my windows to my mac using the migration assistant.  The serial code comes up on both computers but having commenced transfer it then stops!  why?

    I have tried to transfer data from my old Windows PC to my new MacBook Pro via Ethernet cable.  The function starts to download and then aftera  while it stops unexpectedly and both computers say they are "trying to reconnect">  This transfer  has failed on three attempts so far. What am I doing wrong?  Help please.   I am simlply tyring to transfer my itunes library and photos to the new Mac.

    Forget Migration Assistant. Just copy the files you want to transfer to an External drive and then move that drive to the Mac and copy them over to the Mac. Does matter what the external drive format is as OS X can read from NTFS, Windows, formatted drives.

  • I accidently changed the format of my Mozilla firefox so that the top part of my wall paper is showing I want the whole page to be the browser but I do not want to use the f11 option so that I am not able to see the top toolbar and i have no idea how

    The part above the tabs shows my wallpaper and I have no idea how to change it back to what it was like before.
    Thanks

    First of all, Excel file can't save to iBook.  (iBook only can view PDF files). That's why you don't see it in "open in" options.  In order for you to save excel, you will need a third party app like Numbers, Office2.  There are a few free apps that can use to view.  I used Office2 from Byte2, because I can not only store and view later, I can do some edit too.  Especially when you want to edit a few numbers and re send them to my office or clients will be very useful for me. 

  • I am trying to decide what gig i need. I want to use the Ipad for my books for college.

    I need to know what gig to get... I want to use the ipad for my college textbooks to take them to class on it. How many etextbooks would the ipad hold?

    Caveat to the above: books that have a lot of pictures or graphics can be quite large; many megabytes. If you can find out from your college program what books you'll need, check to see if 1) they're available; many textbook publishers have yet to provide textbooks as e-books and 2) if they are available (from one of the e-book providers; you can use Kindle, Nook and Google books on your iPad in addition to Apple's iBooks) how large they are. Then you can add the sizes up, figure out what else you might want on your iPad (movies, for instance, take up a lot of space) and determine what capacity you'll need. When it doubt, buy more capacity than you think you'll need; an iPad can't be expanded later if you run short.
    Regards.

  • 2 users want to use the same folder

    which is the best way when 2 users want to use the same folder.
    i know that i can use the public folder
    or
    create a folder and change the protection so that the 2 users have all rights
    is this correct or exist more solutions for this problem?

    you could consider a solution such as Dropbox ...

  • Problem: i want to use the Nokia ones while listen...

    Hi, I bought a Nokia 5300.
    I noticed that to get the FM Radio working i have to insert an enhancement (AD-50) into the side of the phone (this was supplied in the box)
    Now i want to plug in my (Nokia HS-47) headphones (which was also included in the box). Where do i plug this into?
    -Because the port where i usually plug it into is now occupied by the FM enhancement.
    -And it is too thin to fit properly into the enhancement.
    PS. If i use standard headphones the 3.5mm ones. I can plug it into the FM enhancement. But i want to use the Nokia ones while listening to the FM radio.
    Can this be done???
    Do i need a special adaper for my nokia headphones?
    Should this already be supplied in the box?
    Please help I have no clue!

    just use the Nokia headphones without the 3.5-2.5 converter piece (which you seem to call "enhancement" ).
    I mean, just try it.Message Edited by fred_be9300 on 01-Nov-200702:43 AM
    My Nokia history: 5310 (Sep 2008), 5300 (Jan 2007), 6610 (June 2003), 3310 (2001)

  • TS3899 Email keeps defaulting to the at.me account. I want to use mtY btinternet account. Can anybody help. Thanks

    Email keeps defaulting to the at.me account. I want to use the btinternet account. Any suggestions.

    Settings >> Mail, Contacts and Calendars >> Default Account.
    This only works for Apple Mail. If you have a different client, you need to find the settings for it.

  • How to stop automatic pop-up window "Firefox wants to use the font "Stone Sans Sem OS ITC TT Semi"?

    Everytime I open Firefox I get the irritating pop-up window "Firefox wants to use the Font "Stone Sans Sem OS ITC TT Semi" on the volume, the font is not installed. I installed the font, but I still get it.
    The window gives me options "Do not ask again" "Show in Finder" "Don't Allow" "Allow".
    I click "Do not ask me again" and "Allow" but I keep getting this every time. How to stop it?! Thanks.

    See [https://bugzilla.mozilla.org/show_bug.cgi?id=567552 Bug 567552] – Fonts on External drive are activated by Firefox, and preference to not ask again is ignored
    please do not comment in bug reports

  • I have written a binary file with a specific header format in LABVIEW 8.6 and tried to Read the same Data File, Using LABVIEW 7.1.Here i Found some difficulty.Is there any way to Read the Data File(of LABVIEW 8.6), Using LABVIEW 7.1?

    I have written a binary file with a specific header format in LABVIEW 8.6 and tried  to Read the same Data File, Using LABVIEW 7.1.Here i Found some difficulty.Is there any way to Read the Data File(of LABVIEW 8.6), Using LABVIEW 7.1?

    I can think of two possible stumbling blocks:
    What are your 8.6 options for "byte order" and "prepend array or string size"?
    Overall, many file IO functions have changed with LabVIEW 8.0, so there might not be an exact 1:1 code conversion. You might need to make some modifications. For example, in 7.1, you should use "write file", the "binary file VIs" are special purpose (I16 or SGL). What is your data type?
    LabVIEW Champion . Do more with less code and in less time .

  • I have a mid year 2007 24 inch iMac and will be purchasing a new 27 inch Retina iMac, what is the easiest way to transfer the data and files from my old machine to the new one?

    I have a mid year 2007 24 inch iMac and will be purchasing a new 27 inch Retina iMac, what is the easiest way to transfer the data and files from my old machine to the new one?

    Following up on this thread,
    I have a new iMac on the way and my current is from 2008, never had a problem but I am sure there are internal issues that I would prefer not to transfer.
    I have no issues other then the slowness in certain programs and that is the main reason to buy a new one.
    Programs like numbers and pages seem to take a longer time to open after I update to Yosemite.
    I only use 272GB of 500 GB, my memory is 4GB and I am upgrading to 8Gb and bought the 4.0 processor.
    Question:
    Is there a way to manually transfer items or would that be a waste of time in that if there are issues they could be anywhere and would transfer anyway?

  • I am subscribed to iCal Jewish Calendar but the dates of holidays etc. do not appear on the calendar. They used to, but now there is nothing. What can I do to make the festivals show again?

    I am subscribed to iCal Jewish Calendar but the dates of holidays etc. do not appear on the calendar. They used to, but now there is nothing. What can I do to make the festivals show again?

    jd,
    Instead of using the Apple supplied Jewish Holiday Calendar, try http://www.hebcal.com/ical/

  • On octuber 31th I called the adobe office to buy creative cloud, I can use photoshop but y cant use lightroom. I have already payed o thah date i have mencioned but I cant use the lightroom. what can i do?

    hola
    como me aseguro de bajar lightroom? ya pagué y no encuentro la manera de bajar este programa

    Can you send me te serial number Please? My orden number is
    c0057916628MX
    I am desperate, I hace to do my homework, I am a student of photography.
    Thanks
    Vero
    Enviado desde mi iPad
    El 14/11/2014, a las 9:04, JimHess <[email protected]> escribió:
    on octuber 31th I called the adobe office to buy creative cloud, I can use photoshop but y cant use lightroom. I have already payed o thah date i have mencioned but I cant use the lightroom. what can i do?
    created by JimHess in Photoshop Lightroom - View the full discussion
    Why can't you use Lightroom?
    Will Lightroom not install?
    Do you have Lightroom 5 standalone version installed?
    Please provide more details, and I'm sure we can help you sort things out.
    If the reply above answers your question, please take a moment to mark this answer as correct by visiting: https://forums.adobe.com/message/6929696#6929696 and clicking ‘Correct’ below the answer
    Replies to this message go to everyone subscribed to this thread, not directly to the person who posted the message. To post a reply, either reply to this email or visit the message page:
    Please note that the Adobe Forums do not accept email attachments. If you want to embed an image in your message please visit the thread in the forum and click the camera icon: https://forums.adobe.com/message/6929696#6929696
    To unsubscribe from this thread, please visit the message page at , click "Following" at the top right, & "Stop Following"
    Start a new discussion in Photoshop Lightroom by email or at Adobe Community
    For more information about maintaining your forum email notifications please go to https://forums.adobe.com/thread/1516624.

  • I have a VI and an attched .txt data file. Now I want to read the data from the .txt file and display it as an array in the front panel. But the result is not right. Any help?

    I have a VI and an attched .txt data file. Now I want to read the data from the .txt file and display it as an array in the front panel. But the result is not right. Any help?
    Attachments:
    try2.txt ‏2 KB
    read_array.vi ‏21 KB

    The problem is in the delimiters in your text file. By default, Read From Spreadsheet File.vi expects a tab delimited file. You can specify a delimiter (like a space), but Read From Spreadsheet File.vi has a problem with repeated delimiters: if you specify a single space as a delimiter and Read From Spreadsheet File.vi finds two spaces back-to-back, it stops reading that line. Your file (as I got it from your earlier post) is delimited by 4 spaces.
    Here are some of your choices to fix your problem.
    1. Change the source file to a tab delimited file. Your VI will then run as is.
    2. Change the source file to be delimited by a single space (rather than 4), then wire a string constant containing one space to the delimiter input of Read From Spreadsheet File.vi.
    3. Wire a string constant containing 4 spaces to the delimiter input of Read From Spreadsheet File.vi. Then your text file will run as is.
    Depending on where your text file comes from (see more comments below), I'd vote for choice 1: a tab delimited text file. It's the most common text output of spreadsheet programs.
    Comments for choices 1 and 2: Where does the text file come from? Is it automatically generated or manually generated? Will it be generated multiple times or just once? If it's manually generated or generated just once, you can use any text editor to change 4 spaces to a tab or to a single space. Note: if you want to change it to a tab delimited file, you can't enter a tab directly into a box in the search & replace dialog of many programs like notepad, but you can do a cut and paste. Before you start your search and replace (just in the text window of the editor), press tab. A tab character will be entered. Press Shift-LeftArrow (not Backspace) to highlight the tab character. Press Ctrl-X to cut the tab character. Start your search and replace (Ctrl-H in notepad in Windows 2000). Click into the Find What box. Enter four spaces. Click into the Replace With box. Press Ctrl-V to paste the tab character. And another thing: older versions of notepad don't have search and replace. Use any editor or word processor that does.

Maybe you are looking for