sampling time changed the buckle timed

Hello world

I use the timed loop to control the DC motor with the vi of PID. in the loop and the sampling time are defined as 0.01 s. However, after I added a few other screws in the loop, for example, writing of measure file.vi, to collect the errors between the angle and the practical perspective of the engine for the time histroty the movement of the motor, we find that the sampling time changed, not always 0.01 s before the vi has been added, but 0.01 or 0.02 s. the entire program desinged to be fininshed with 7 s, now's done it at 9.4 s, that is, execution of the loop time is extended.

Another thing is, if the sampling time is defined as s 0.05, the sampling time is always 0.05 s and the execution time of the loop is always 7 s as predined, regardless of writing custom file.vi is added in the loop or not.

As a result, I think that if the complexity of the loop is incresead and time of sampling sets is small, then the actual sampling time will be modified due to the design of things load in the timed loop. What is the reason? If so, are there methods to solve?

It is important: the collection of the angular error of the engine in the time histrory is very important, which will be used to show the correctness of the settings KP, KI and KD.

A friend suggested using the queue vi, but I don't really know how to use them. Can someone give some instructions?

Thanks a lot!

See you soon

Cram features in a timed loop is like stuffing 5 books you know that in a book bag 3. The timed loop is only really practical on a rt system, but even in this case, if the code inside requires more time than the period of the loop, there is no magic that the loop can do to increase the execution time. Just point out you that the loop is late. The solution is to remove features from the inside of the loop. Writing to a file of measure is one of the worst if you write to a text file. Look at the producer/consumer model of design that you have examples of. There, you will have a normal loop that you will write to a queue, and a second loop will process data in the queue. Use file > open...

Tags: NI Software

Similar Questions

  • Windows 7 "do not have permission" - Internet Time - > change the settings

    I have Windows 7 Pro 32 bit installed on my laptop. I have only one configuration of account which I am the administrator of the computer.

    When you try to access the control ' Change settings ' to 'Date and time'-> 'Internet time' I'm stuck with the following message:

    "UNABLE TO CONTINUE - you are not authorized to perform this task." Please contact the administrator of the computer to help. »

    What is happening and how to fix this? It seems a little silly that I as the administrator have blocked access to this.

    Your thoughts and your advice on this would be appreciated gratefully.

    Thank you

    Matell

    Matell salvation,

    Welcome to the Microsoft answers site.

    Step 1:

    First of all, I suggest that you enable the default administrator on the computer and check.

    To activate the default Administrator account, follow these steps:

    1. Click Start and type CMD in the start search box

    2. right click on CMD in the list and click "Run as Administrator"

    3. type the following command: net user administrator / Active: Yes

    If it works then it could be a problem with the damaged user profile, go to step 3.

    Step 2:

    I suggest that you turn off user account temporary on the computer and check if you are able to change the time settings on the computer Internet or not.

    1. click on start.

    2. click on Control Panel.

    3. click on user accounts.

    4. click on change user account settings.

    5. drag the slider to never notify.

    6. click on OK.

    Now check if you are able to change the settings, if the issue is resolved, I suggest you turn back to normal user account settings.

    Step 3:

    If the problem persists, I recommend that you temporarily disable the security software and firewall in the security software on the computer and check.

    Make sure that you enable the security software on the computer.

    If the problem persists, I suggest that you create a new user profile on the computer and check because this could be a problem with the profile of the user.

    Check out the link to correct the corrupted profile: difficulty a user profile is corrupted:http://windows.microsoft.com/en-XM/windows7/Fix-a-corrupted-user-profile

    Let me know if it worked.

    Swathi B - Microsoft technical support.
    Visit our Microsoft answers feedback Forum and let us know what you think.

  • Favorite random, one at a time, change the records?

    My problem started with the previous version of Firefox, and continues with the version 26.0. My HP Compaq dc7800p convertible runs THAT XP Pro 2002 with Service Pack 3 installed.

    I'm going to look for a particular bookmark, and it will not be in the right folder. I need to find all of my other bookmark folders until I found and then bring it back in the right folder. This problem occurs only with a bookmark both and about once a week. So far, it has never been the same bookmark, still another.

    Here are three examples:
    (1) a bookmark for filmjunk.com, which is normally under "podcasts", was under my "local" folder I have access to FilmJunk several times a week.
    (2) an article I wanted to read more later from AMC.com, which I placed in a 'general' folder, found under the 'games '. The article has been bookmarked about 30 days before my deciding to read the article.
    (3) a bookmark for citizens Bank filed in 'Betsy', but was found in a folder for my school "ECC." This last bookmark that I hadn't used in over a year!

    I have reset Firefox several times, re - import favorites to Internet Explorer 8. Each time, after a day or two, the problem starts again. There seems to be no correlation between when I used last specific bookmarks and where or even if I initially placed them.

    -waka_Flocka_flame,

    Thanks for the quick response.

    I'll try your second suggestion first, "problems of fixing with bookmarks."

    On this page, under 'Difficulty the bookmarks file' help, I don't have the box 'Read only' ticked, so that the article did not help with my problem. Instead, I'll try the section directly below titled 'create a new file to bookmarks '.

    Given that the problem came back after a few days, I will update with the results soon.

    Thank you once again.

  • MY TIME IS 12:00, NOW IT IS 07:03? PLEASE HELP ME TO CHANG THE TIME IN MERIDIAN, MS BECAUSE SCHMIDT?

    MY TIME?

    [Transferred from Internet Explorer]

    Hello

    From > settings > Control Panel > (clock, language...) > Date and time > change the time and the time zone.

    You should also be able to settings for access by clicking on the time time, in the Systray/Notification area > change Date and time settings.

    Don

  • How can I change the name of a bookmark that's already in my menu other than to delete it and start again.

    I have a number of bookmarks that are long and have misleading titles because I forgot to enter a shorter more concise name when I first set bookmark them. However, I can't find a way to rename the other bookmarks that deleting the current and bookmarking this time change the title to something I recognize.
    For example I have bookmarked Ebuyer and in my bookmarks list it says, "laptops cheap, etc, etc." all I want is 'Ebuyer. I realize that I can delete this bookmark and save it again and this time change the name at the beginning.

    Right-click on the bookmark, click on 'Properties' new 'name' type click Save.

  • External sample clock change takes a lot of time on the SMU-5186

    Hello

    I use the external Lv - niScope EX Clocking.vi example to define SMU-5186 using an external sample clock.  However, it takes a long time, 5-6 minutes, before I can get the first block of data acquisition.

    Then I run the example 'niScope EX Acquisition.vi Configured' to switch to dashboard clock. There are also 5 to 6 minutes on the first acquisition.

    I think maybe the SMU-5186 made some calibration when I change the source of the clock.

    Anyway is to ignore the calibration? Or make it faster?

    Thank you very much

    Yiming

    Yiming,

    Delays in acquisition are caused by calibration routines that must be performed on the engine to sample (ADC) every time that changes sampling rate.  This ensures our justified precision specifications.

    I don't know if you've noticed also calibration of Power-Up, which will take 5-10 minutes to complete when the unit is turned on.  This is mentioned in our specifications at page 18:

    http://www.NI.com/PDF/manuals/373257b.PDF#page=18

    I hope this helps.

    Nathan

  • I signed on XP Pro SP3 as an administrator but you cannot change the timing of Windows Update to 03:00. All options are not enabled. How can I change the time, updates are made? __

    I signed on XP Pro SP3 as an administrator but you cannot change the timing of Windows Update to 03:00.  All options are not enabled.  How can I change the time that updates are made?

    Hi imoffshore,

     

    Welcome to Microsoft Answers Forums.

    We would like to get some more information from you to help solve your problem. You better, please answer the following questions.

    ·         When was the last time it worked?

    ·         Remember to make changes to the computer recently?

    ·         You have security software installed on the computer?

    ·         You get the error message?

    When you open the tab automatic updates in the control panel or My Computer property sheet, all options of configuration of the automatic updates may be grayed out. This happens due to one of the following reasons:

    1. You are not logged as administrator (or equivalent)
    2. Strategy of automatic updates is enabled
    3. Automatic updates (and Windows Update) access is blocked by group policy

    The options available for automatic updates.

    You must make some changes in the windows registry.

    Important: this section, method, or task contains steps that tell you how to modify the registry. However, serious problems can occur if you modify the registry incorrectly. Therefore, make sure that you proceed with caution. For added protection, back up the registry before you edit it. Then you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click on the number below to view the article in the Microsoft Knowledge Base:

    How to back up and restore the registry in Windows

    http://support.Microsoft.com/kb/322756

    • Click Start, run and type REGEDIT to . EXE
    • Go to this location:

    HKEY_LOCAL_MACHINE-SOFTWARE-policies-Microsoft-Windows------WindowsUpdate------AU

    • In the right pane, delete the two values AUOptions and NoAutoUpdate
    • Go to this location:

    HKEY_CURRENT_USER-SOFTWARE-Microsoft-Windows-CurrentVersion------policies------WindowsUpdate

    • In the right pane, delete the DisableWindowsUpdateAccess value

    Using the Group Policy Editor - for Windows XP Professional

    • Click Start, run and type gpedit.msc
    • Navigate to the following location:

    => Configuration of the computer
    ==> Administrative templates
    ===> Windows components
    ===> Windows Update

    • In the right pane, double-click Configure automatic updates and set it to not configured
    • Next, go to this location:

    => User configuration
    ==> Administrative templates
    ===> Windows components
    ===> Windows Update

    • In the right pane, set to remove access to all Windows Update features on not configured

    Change how Windows installs or notifies you of updates

    http://Windows.Microsoft.com/en-us/Windows-Vista/change-how-Windows-installs-or-notifies-you-about-updates

    Halima S - Microsoft technical support.

    Visit our Microsoft answers feedback Forum and let us know what you think.

  • Can I change the time sampling real Graphics Performance

    I am preparing a demonstration and want to display the allocation of resources in real time using vSphere performance dashboards.  Unfortunately, the default sampling rate and an average of periods are not optimal for display assignments for resources with our demonstration.  Can someone tell me if there is an easy way to change these default values?

    The sampling rate for the graphics in real time is 20 seconds, which is probably OK, but I WOULD change for 10 seconds.  However, the main issue of concern is the number of samples in which this average is calculated.  This value seems to be very high (I think I saw 300 in a document).  Because this number is very high, the changes I make say every minute (for demonstration purposes), allocation bands don't really show up very well in vSphere performance dashboards.  For example:

    If my host has had 10 GB memory active during the last 5 minutes and my demo releases suddenly a very large part of this memory, the performance table the sudden deallocation with the last word on average 10 minutes of data and shows a gradual decline in the allocation of memory.

    This behavior is probably what is desired in a system of monitoring, BUT for my demonstration, I want to show a more realistic view of the allocation of resources using vSphere performance dashboards.  This could be accomplished if periods of rate, for a sample mean are configurable.

    Any help is greatly appreciated.

    On the other hand, I think it's that they do not change settings realtim. It's good for my purpose

    I do not know the slow answer due to the memory alloc/dealloc.

    BTW if you think the answer above resolved your problem, you might mark it as response.

  • change the time loop from 5ms to 250 ms?

    are there ways you can replace the loop time 5ms 250 ms? While the test is running?

    sample code in the version of labview 8 are welcome...

    Are you referring to a timed loop? You can simply change the value of dt using the settings on the right.

  • I want to change the file name format "save under" so the date and time are first.

    When I select a few emails and then select "Save as" to keep a copy on my computer, the name of the file that is created has the date and time at the end of the file name of the email.
    Sample "save under" file name: "Habitat Follow Up - Bryan ([email protected]) - 2011-11-15 0744.eml.
    Is it possible to change the structure or format of the file name if the date and time of the email are initially the file name?

    Try ImportExportTools and customize the format of the file name in the options.

    http://chrisramsden.vfast.co.UK/3_How_to_install_Add-ons_in_Thunderbird.html

  • How to change the DAQmx sampling frequency

    Hello

    I'm trying to: record streaming channels (acceleration 21 and 1 tension) using a DAQmx task, then convert the data to a PDM file. The program files and output to the TDMS file very well. The issue I'm having is that I can't change the sampling frequency. I want to record 500samples/s and I can not get the "real sampling rate" of change of 1651.61samples / s. I am trying to use the clock to do this and I succumbed. I also tried to change the settings of "Timing" in the task without a bit of luck. Here is a screenshot of the .VI I created. I've also attached a copy of the file VI. Any help would be greatly appreciated!

    Thank you

    Tony

    You will need to provide the model of your device. You can also look in the sheet/manual to see what the real supported sampling rates. Some devices have limited rates.

  • Change the value to trigger record data for 1 s sampling frequency of 50 KHz

    Hello

    I have a VI with NI9215 and cDAQ-9178 chassis hardware. The function of the VI came out an instruction to RS232 interface and record 1 second of data every time that the set point is changed.

    The procedure is

    (1) modify the policy to the flow regulator

    (2) wait 2 seconds.

    (3) record of 4 channels for one second to the sampling frequency of 50 KHz.

    At present, the problem is for the first edition of this program, two seconds (rather than) data was saved and corn, the error message 200279.

    II. I revised for the second edition of the structure of the producer and the consumer who can increase the speed of the buffer.

    The question is how to configure the trigger to start the backup of data and limit data save for one second whenever the set point value changes.

    (1) which edition is best for my application?

    (2) how to trigger the data record?

    (3) how to record only a second of data?

    I also checked this announcement and the elapsed time seems not to work for this case.

    Any help would be greatly appreciated!

    Melody

    Hello

    you have not used properly the nodes property.

    1. replace the case structure in the first loop, with DAQmx features, with a structure of the event. Change the event fires for a worth of control of the setpoint change.

    Edit: as stated in your first post, use the structure of the event, but put inside the while loop.

    2. DO NOT connect error output from the stop command property node. Replace it with a local variable for the stop button.

    Try these and let me know.

  • How can I change the value of the sample during my simulation period?

    I'm about to set discrete PID profile vi to specify the values of the period of sampling of the order hold block. At t = 0, I wish that the value of 0.5 and then change to 1.0 when t = 5. Currently, only 0.5 goes to the waiting order discreet block. I think it's because the block takes this value and then use it for the entire simulation, do not check to see if the value has changed. Is there a way to tell the block to check this value at each time step and then adjust if necessary sampling its period?

    See code attached for reference.

    What is your overall goal for the sampling period? You will change the value more than once? Or only from 0.5 to 1?

    The PID setpoint profile should allow you to specify a profile for the values to send to the hold. He will see property values. For example if you specify only t = 0 setpoint = 0.5 and t = 5 setpoint = 1, you'll find it ramp the setpoint in 0.5 to 1.0 for the first 5 steps of time. If you want the sampling period of stay up to t = 5 0.5 is reached you will probably want to three elements in the array. set = 0.5 point t = 0, t = 4.99 set = 0.5, 1.0 = set point t = 5.

    If you're just fill one step, (from 0.5 to 1.0) you can use the Index Timestep in the Simulation parameters to determine the sampling period. Is attached a screenshot of what I mean.

  • Model in the loop timed While the elapsed time

    Hello NOR community,

    I'm trying to use a while loop timed to run controller simulated for a mechanical system test. I need the time loop to run at an even 50 Hz to simulate the controller that will eventually drive the mechanical system. To check the speed at which the loop runs, I made a VI that gets a value from each loop clock and subtracts the value of the clock of the current iteration of the value of the clock of the previous iteration. I have eliminated all other codes this VI except for the recovery of the clock, to ensure that no problem with another code in VI. I find that the time between iterations is not constant, but it is consistent. In other words, the elapsed time can change at each loop, but it changes according to a specific model, such that the average elapsed time is equal to the value that I use for the timed loop. The loop will run faster than posed for several cycles, then slow down during a cycle even at the same time. Here are some examples:

    Running at 5 Hz: elapsed switches schedules between 0.203125 and 0,187500 seconds

    Clocked at 8 Hz: time is constantly 0.125 seconds.

    Operating at 10 Hz: elapsed switches schedules between 0,109375 and 0,093750 seconds

    By examining the differences between elapsed time and the stability of the 8 Hz setting, it seems that there is a minimum time of 0,015625 seconds (64 Hz) division. It is much worse than the 1ms accuracy claimed in documentation. This could be the cause?

    I am running Windows XP with LabVIEW version 8.5.1 and have observed this behavior on several computers with different screws

    Thank you!

    Erik

    Your problem is the function that you use to get the current time.  It's just the time of the Windows clock which has a resolution of 16 msec.

    You must use the function of number of cycles as Jarle has pointed out.

  • Type of sample time can be changed to in MAX?

    Hi all

    Try to set up some simple tasks IO digital using the DAQ Assistant, in MAX.  My particular IO device does not support an internal sample clock, so I need to change the 'Type of sample Timing. "  I've seen how go within Labview Signal Express, but can't find where it change in MAX.  Please notify.

    Thank you very much.

    GSinMN

    If your device doesn't support hardware timing, you can not change it in MAX and LabVIEW SignalExpress. If you have actually tried it in LabVIEW SignalExpress, you will get an error.

Maybe you are looking for