Remove channel from DAQmx AI task - reconfigure existing task

Is there still no way to remove an AI channel from an existing DAQmx task? I know that it's possible to add a channel to a task using DAQmxCreateAIVoltageChan.
Removing seems to be possible only by clearing the task and creating a new one, but this ends up in error -50103 (The Specified Resource is Reserved.) at creating and clearing a task continuously (after ~ 100 - 1000 iterations).
Measuring device is USB-6225.
Any idea ?

Unless you want to learn how to do this with the Excel add-on called Measure, you should post to the much more appropriate Multfunction DAQ board.

Similar Messages

How to remove channel from DAQmx Task

I need to add remove channels from the task programmatically. How can I achieve it.
Also while downloading my program to RT controller my system stops responding if I have DAQmx timing VI in my program. My program is running fine on windows system with DAQmx Timing.

How are you using the DAQmx Create Task.vi? Are you using it to include a global channel or copy a task that was previously created in Measurement and Automation Explorer (MAX)? If this is the case the only way to remove a channel would be to delete the global channel or modify the physical channels for that task in MAX. If you are creating a new task you can use the DAQmx Create Channel.vi to specify the physical channels that you would like to include or exclude.
Regards,
Andy F.
Applications Engineer
National Instruments
National Instruments

How to remove channel from DAQmx create Task.vi

Vikas H. Kumthekar
ASE
Tata Consultancy Services
Pune-1

How are you using the DAQmx Create Task.vi? Are you using it to include a global channel or copy a task that was previously created in Measurement and Automation Explorer (MAX)? If this is the case the only way to remove a channel would be to delete the global channel or modify the physical channels for that task in MAX. If you are creating a new task you can use the DAQmx Create Channel.vi to specify the physical channels that you would like to include or exclude.
Regards,
Andy F.
Applications Engineer
National Instruments
National Instruments

Extract single channel from DAQmx Task

Hello,
I have created a DAQmx output task, which contains two channels. Is it possible to extract individual virtual channels from the task to be processed by two parallel processes? I have tried bringing out the Channels Property using a Task Property Node, but I then get the error that the channel is not part of an active task (see attached snippet)
Could anyone advise on a better approach, or how to acheive this functionality - if it is possible?
Regards
Dave
Solved!
Go to Solution.
Attachments:
split out channels from DAQmx task.png ‏34 KB

Sorry, that VI does not make much sense. You have to use a single DAQmx Write for both channels and for 1 Sample mode, you simply have to build an array of the signals as shown below.
Attachments:
two channel write.png ‏12 KB

How can I read channels from different SCXI modules simultaneusly?

Hello.
I have a system that consists in:
- Three E-series DAQ boards (PCI-6034, PCI-6052 & PCI-MIO-16E)
- One SCXI chassis (SCXI 1001)
- 4 SCXI modules for voltage measurement connected to PCI MIO 16E
- One SCXI module for strain gauges connected to PCI 6034
- One SCXI module for accelerometers connected to PCI 6052
I have to develop a software application that reads all the channels at the same time or at least in the same program cycle. I have tried to create only one DAQmx task containing all the channels, although they belong to different DAQ boards (and SCXI modules, of course), but it seems to be impossible to use channels from different devices in the same task.
So I have created three different DAQmx tasks, one for each device and its channels. I have used one "DAQmx Start Task" VI for each task at the beggining of the loop in order to use them independently, reading their channels inside the loop in every program cycle.
When I have run the program I have get the following error:
"ERROR -200619 ocurred at DAQmx Start Task.vi
Chassis cannot be used for more than one scanning operation at the same time.
Do only one scanning operation or combine multiple scanning operations into a single operation."
What is the problem? How can I combine these multiple scanning operations? What can I do to read all channels at the same time?
Thanks.

Hello pablomendana,
it's ok that you got an error when trying to use more than one device on the same task. According to the setup you have, I agree that 3 tasks should be put in place.
The key question I have is... Have you configured manually at MAX the SG and accel. modules to be in Parallel mode?
I would not expect the error you get if they are in parallel mode (in which you could even read directly from the DAQ board, using DAQ device channels instead of SCXI channels).
Unfortunately, I haven't been able to setup a system similar to yours, but I would like to know more details on what you've tried so far.
Also, I recommend you that if still need help on setting up the system, use NI's SSP program to get support from your local NI Application Engineering organization, as this will be faster than the forum.
Regards,
Jorge M.

Change a DAQmx channel property for a single channel from a channel group

Hi,
I'm doing some digital output, and I'd like to tristate certain lines in each port. However, I'm having difficulty figuring out how to specify which individual lines to tristate. I input a port and a line range, e.g. PXI-6533/port0/line0:7, specify to use one channel for each line in the DAQmx Create Virtual Channel VI, retrieve the channels from the DAQmx Task Property, and try to operate on the individual channels that way. However, this results in the following error:
Error -200428 occurred at Property Node DAQmx Channel (arg 1) in tristate_test.vi
Possible reason(s):
Measurements: Value passed to the Task/Channels In control is invalid.
The value must refer to a valid task or valid virtual channels.
Task Name: PXI-6533/port0/line0
The NI knowledge base article that deals with this error code talks about creating a task with the DAQ assistant, or ensuring that a task has been created. However, I'm not using the DAQ assistant, as my I/O is pretty complicated; I'm just using a bunch of virtual channels.
Is there a way to specify individual channels to changethe properties of without having to create additional virtual channels? I have 48 digital channels I plan to use, so the less virtual channels I have to create the better.
Please reference the attached VI, which demonstrates the problem I am facing.
Thanks for any assistance.
Attachments:
tristate_test.vi ‏11 KB

You can only software-time tristate for the 6533/6534. Have a look at the attached example.
Adnan Zafar
Certified LabVIEW Architect
Coleman Technologies
Attachments:
tristate6533.vi ‏58 KB

Error Code -50150 from DAQmx Create Channel (AI-Voltage-Basic).vi

I have an executable, built from Labview 7.1 VI's. All it is doing is reading 6 voltages back from a 6008 USB-DAQ, and reporting the results back. Occasionally, it is throwing an Error -50150 from DAQmx Create Channel (AI-Voltage-Basic).vi. The full error message is:
Error Code: -50150
DAQmx Create Channel (AI-Voltage-Basic).vi<append>
<B>Task Name: </B>_unnamedTask<0>
Can anyone shed some light on this problem?
Cheers.

Hi fellas,
I have a really similar problem to the one Neilelph had, but I can´t see how to solve it from your answers. I attached a picture of my main .VI.
It´s basically a photodiode measurment system working as follows:
1. First the moving stages for the system get ready (X-Y moving stages for the Photodiode and Z stage for the Laser). That´s the CONFIG subVI in the left.
2. Then there is a For Loop, that repeats N times depending on the Initial Z, final Z and step values. So in this .VI the laser moving stage is the only one changing.
3. In each loop, the stages go to the X,Y,Z(t) posiition (MOV subVI), wait for the movement (WAIT subVI) and read the position. After that, the DAQmx acquistion part starts. I just sample the output DC voltage coming from the Photodiode (Dev1/ao1), 1000 samples in 1 second, and then I make an average of all of them with the Basic DC/rms block. So at the end I have 1 position of Z and one DC value. And it worked perfectly. At least for small number of iterations I have no problems.
The problem comes with small steps and a great number of iterations. For example last night I ran a measurement. 10000 iterations, the whole range of Z, and today i checked it. It worked fine until 5000 give or take, the half of the range. From that point, the DC ouput recorded in the .lvm file is just 0.00000. It´s the second time it happens, so I´m wondering what´s wrong because I´m affraid to make more long measurments and obtain the same results.
The error message I obtained is the same than in the thread title: -50150 DAQmx Create Channel (AI-Voltage-Basic).vi:6<append> <B>Task Name: </B>_unnamedTask<53BC>
Maybe it would be useful to mention that, sometimes, there is no error and I have some DC Output Voltage value, for random Z potitions, but since the first error message, that barely happens. The output is almost always 0.
Sorry for my writting skills in English. I hope you can understand my situation.
Thank you in advance.
Kind regards,
frilance.
Attachments:
Diagram.JPG ‏83 KB

Impact of selecting "Removing Query from Selection List" in 2 channels.

HI All ,
I have customized a query in one channel (My Agreements and Contract Documents query in Master Agreements List channel) and have removed the standard query from the channel by checking the "Remove Query from Selection List" and introduced my custom query in that query group .
But it resulted in break in chain for "Master Agreements" link in "Contracts To Do List" channel as the link was pointing to standard "My Agreements and Contract Documents" query and is displaying "The query can not be executed. Contact your system administrator" when ever I click on that.
Any pointers on how to overcome above scenario wud be gr8!
Regards,
Uday

Hi Uday,
In order for To Do List channel to work, the query definition should be in the Master Agreement List query group. Do you still want the standard query in the To Do List? If so, you would have to leave it on the Query Group as To Do list is pointing to it. May be change the display name of the query so you can differentiate between the 2 queries. The other option is change the To Do channel to point to the custom query.
Regards,
Vikram

Removing DRM from existing purchases

Hi all,
I love iTunes, but could never stand the DRM that came bundled with purchases. Now DRM's been removed from music I'm loving it again. I've made half a dozen purchases already today and I'm delighted with how easily my existing MP3 software was able to convert the M4A files to MP3.
One question though, is there a way within iTunes to either re-download past purchases, or to remove DRM from purchases made before Apple stopped including DRM with music?
Thanks.
Lex.

Access the iTunes plus upgrade screen from either the right hand top in the store in the upper box or by clicking on the iTunes plus advert in the middle of the store screen near the free download screen.
If you have none of these links it may mean that none of your past purchases is currently available. The entire store will not be DRM free until near April, currently only close to 8 Million tracks are available, though I think new are still be added daily.

How to remove recently accessed channel from desktop session in sun one 7

Actually we are facing one issue with the desktop session . We created a container and then deployed our jsr 168 portlet in that. Now if we are accessing that portlet through http://host:port/portal/dt?provider=<containerchannel>/<channelfor jsr168> we are actually able to see the portlet. Now we kept the link in one of the menu items of enterprise sample. Now if we click on that link our portlet gets displayed in new window. But the problem is if we refresh the enterprise sample page then it is showing our portlet instead of the content that should be shown in enterprise sample. Can we remove the channel from the desktop session.
Any help will be highly appreciated
Edited by: user8941231 on Nov 17, 2010 4:59 AM

Change your iCloud ID password and the old device will no longer have access to your iCloud account. You can change it here: https://iforgot.apple.com/iForgot/iForgot.html. After doing so, you'll need to change it on all your devices too.

My IPhone is asking me to type in my password for my old Apple ID that does not exist anymore. I cant set up ICloud without typing in a password to a Apple ID that does not exist, so do I have to remove everything from my IPhone and start over?

my IPhone is asking me to type in my password for my old Apple ID that does not exist anymore. I cant set up ICloud without typing in a password to a Apple ID that does not exist, so do I have to remove everything from my IPhone and start over?

Hello miamat2017
You should see an option to skip that step and then sign out of it when looking in Settings. Check out the article below for more information.
iOS 7: If you're asked for the password to your previous Apple ID when signing out of iCloud
http://support.apple.com/kb/ts5223
Regards,
-Norm G.

Users still exist after on POA after removing them from eDir

Hello All,
I created a test PO/POA to add in 5000 users to test some load issues. when the test was done i ran a tool to have the users removed however it only removed the eDirectory Account, the users still exist in the POA. I tried to rebuild the POA however, that did not help.
Is there a way to have all the users removed? i can evenm part with removing the entire PO if needed.
the only way i can see currently is delete the user one by one from C1.

turbobes wrote:
> When i select all the duers and delete i get a error that the Edir
> counterpart does not exist. Once i select Ok it closes out.
>
> I got fetup and reinstalled the test Lab. Used SUSE thistime and i
> tried 8.0.1 HP.
>
> Thanks for the help
>
>
Install the good old API gateway and write an API that first lists then
rewrite that results to an API that removes the GW accounts.
Gert
Novell Knowledge Partner
Owner, independent consultant
www.GWCheck.com
"the best GW site" - Tay Kratzer
[email protected]
Skype, Twitter, Facebook: GWCheck
How come, when my wife says
"we need to talk", it is never
about Drupal? ;-) - Dries Buytaert

Question about using for-loop to generate array from DAQmx. Thanks!

I have a laser system with a frequency of 1kHz, I am using this 1kHz signal to trigger the DAQmx and get the data from a photodetector, e.g. I will get 1000 data points during 1 second from DAQmx, but I need to separate this 1000 data points into the even and odd list, which is two list of 500 data points, e.g.. The 1st, 3rd, ... 99th data is one array, the 2nd, 4th,... 10th data is another array, then I will do further calculations based on these two arrays.
To seperate the even and odd data, the only way I can find is put these 1000 points into an array and then seperate them afterwards.
Can I do things like this pic?
I don't know the speed of the for loop, because the 1kHz trigger is always there, once it is triggered, the DAQmx read will give a data point, if the speed of the for-loop( the time from the end of a loop to the beginning of the next loop) is slower than the 1kHz trigger, then the for-loop will miss data point, then the ordering of the 1000 points in 1 second will be changed.
Or I need to put everything, e.g. AI Voltage, Trigger, sample clock, into the for-loop and then return a Y? Thanks!

Clarification:
The VI you have posted will work as following:
1) The task will read 2 analog inputs (ai0, ai3).
2) The acquisition starts, oncece digital signal (trigger) is detected on PFI0
3) The sampling rate will be as specified in "rate" control - it is continuous analog input acquisition, which means that after trigger is received (point 2), the board will start to generate hardware clock with frequency you specify as "rate"
4) with each rising edge of that hardware clock, the measurement is taken, and stored into buffer of driver.
5) DAQmx read will try to read "number of samples per channel" number of samples each time is called - and if there is not enough measurement stored in buffer (step 4), then DAQmx read will wait until DAQ card will measure reaquested number of samples (or timeout occurs before requested number of samples has been acquired)
6) DAQmx read will be then called 1000 times - so totaly you will read 1000 * "number of samples per channel" number of samples.
You do not have to be worried about speed of the loop. In fact, if you need to read just 1000 samples, with 1kS/s, then you can remove for loop and you can change measurement mode from continuous to finite samples, and specify number of samples to read to be 1000. You will read them all properly. I recomend you to read User Manual for your DAQ device - lets say M Series User Manual.
I hope it is clear now.
regards,
stefo

Remove custom scaling DAQmx

What I am working on is a calibration VI so that a user may come up with scales for different channels in their DAQ tasks which they create in MAX. When I start my VI, I create a copy of the existing task from MAX because that task includes the channels to calibrate. But, in creating this copy, my virtual task includes the scaling. I want to remove this so I get raw voltages. How can I do this?
Essentially I want to programmatically set <No Scale> the same way you can in MAX.
My not-so-valid attempt. I was hoping "no scale" was a custom scale.
CLA, LabVIEW Versions 2010-2013
Attachments:
scaling.PNG ‏20 KB

I actually have tried that and it seemed like it didn't work. But I will try again. I tried just to make a scale that went by increments of 1. I was somewhat rushed so I may have had something set up wrong, but from what I remember the data was still being scaled.
CLA, LabVIEW Versions 2010-2013

Removed user from group, user no longer has access to documents even though user is owner of documents

I'm running a server 2012 std domain and I'm in the process of rebuilding our fileserver after we had some pretty serious permission issues. Bad permissions (Everyone had full access to user documents share) were migrated when we move to the new server and
then by some strange Monday morning freak out all users lost access to their documents. I restored from backups, redirected everyone's folders back to local computer and started to reconfigure the share permissions. I moved our administration group back to
the server after securing proper permissions for folder redirection (permissions copied from https://technet.microsoft.com/en-us/library/jj649078.aspx?f=255&MSPPError=-2147217396 table 1, only difference is instead of creating a new security group
for redirection users, I used the everyone group) to test and everything went perfectly. The GPO created the users folders under the root and redirection was good to go. Along with that, other users cannot access other users documents anymore which was the
intended outcome.
Last night I was looking at security groups and see that our administration group (back office group: accounting, HR, etc..) was a member of the domain admins. I removed them from the domain admins group and added them to the administrators group (they do
need regular admin access) then went on like normal. This morning, all users in that group can no longer access their documents on the server. I immediately think that permissions were broken again and started to get angry, but then realize that all the files
are still accessible on the server (no lost permissions like before) and the user is still shown as the owner with full permissions, but the files are inaccessible to those users. I re-added them to the domain admins group, logged out, logged back in and documents
are back and accessible by the user. Remove them from the domain admins group, log out, log back in and the documents are inaccessible again. Re-add to the domain admins group and back to normal.
Which leads me to now. If the users are part of the domain admins group, they have access to their files. If they are removed from the domain admins group, they lose access. When they lose access, they are still the owners of the files/folders with full
permissions, yet they can't access their documents. Also, just to add, the domain admins group has no specified permissions on the files or folders. See screenshots below..
Here is the root share.
And the user's desktop folder. The folder is owned by the user with full permissions. This is the folder the redirection GPO created.
Any ideas why removing the group from domain admins would drop access to their files? They are still the owners of the files and should have full access but they don't. Is there something I'm not seeing here?

Effective Access shows the user has full control of the Desktop folder
This is a problem with the Effective Access tab when using CREATOR OWNER. As you have noticed, the user doesn't really have the access that the tab says it does. This is because of how CREATOR OWNER works.
CREATOR OWNER is only evaluated when a file/folder is created.
IF a user can create a file/folder, then the permissions assigned to CREATOR OWNER are copied to a new permissions entry for that user.
To see this:
Logon as an administrator and create a file in the Desktop folder in your screenshot.
Examine the permissions of the new file.
You'll see that there is a new entry for the account you logged on with.
CREATOR OWNER is gone. CREATOR OWNER would still be there if you created a folder (because of "subfolders and files").
In the Desktop folder (in your screenshot), only SYSTEM and Administrator can create/access files.
To fix this, you need to grant the users the ability to list the directory contents and create new files/folders. This corresponds with the suggestion of Table 1 in the document you found.
I see what you're saying about Administrators domain group. I'll just add them as local admins via GPO and that should solve that issue.
No, scary! This will grant those users administrative permission on your server. They will be able to see any file anywhere on that server.
If your goal is to provide a place that is private for each user, then the simplest approach is to grant each user permission to their own folder. Like this for Test User:
Notes for above:
I set the user's permission to Modify because there is no good reason why the user should change these permissions
The owner of this folder is unimportant. I leave it set to Administrators
You can, and I do, remove CREATOR OWNER. It adds no value in this situation and just causes confusion.
As for the second screen shot, the *-Admins folder is the root to which Everyone has special permissions on and can create folders. The folder for M* was created by the GPO, which makes M* the owner to which they have Full control of subfolders and files.
The GPO also created the Desktop folder, giving owner full permissions of subfolders and files. Inside the Desktop folder, permissions remain Full control for owner for subfolders and files. Even if it was the case that they only had permissions on subfolders
and files, wouldn't each subfolder under that one be considered a subfolder and file of the top folder?
If this works as you say, then Yes, it should work. But, I don't see the entries for use M*. Remember, there should be entries for the M* user that is a duplicate of CREATOR OWNER.
I suspect that Group Policy is creating the directories (elevated) and then changing the owner to M* afterward. This does not duplicate the CREATOR OWNER entries as needed. If this is the case, I consider it a flaw because your permissions do
not allow user M* to create files/folders, and group policy shouldn't bypass security.
I'm not saying your wrong, I'm just curious why the technet article would advise Creator/Owner giving full control of subfolders and files only if that were not correct. I can add the permissions for the users easily, I just don't see why I need to give
explicit permissions to access something when the GPO created those folders for me, which Microsoft recommends you allow. If the GPO can create folders and the folders are owned by the user, then the user can obviously add/create/modify/view those files and
folders.
When I restored the data, no permission were reset. Permissions were restored to the wonky version where the Everyone group has full access to everything. Ownership of the files/folders remained the same.
A couple things:
The article instructed the use of Folder Redirection Users group that had permissions to create files. Your examples didn't have that. Because of this, your user could create new files.
The article assumes that the directories you are creating will be empty. Existing files will be unreadable to everyone except Admins.
If you follow the directions in the article, then anyone in the Folder Redirection Users group can write files to anyone else's directory.
One benefit of the document's approach is that all the users could be redirected to the same folder using the article, and it would work. A benefit, I guess.
But, I like my user's separate and unable to see each other's files -- at all. This is why I recommend replacing CREATOR OWNER with the specific user.
I believe this document is a "how to get it done" document, not necessarily a best practices document. I see it as a starting point, and that's why I didn't follow it exactly.
Lastly, CREATOR OWNER permissions are useful but confusing. I avoid them unless I have the rare circumstance where they are perfect.
When I restored the data, no permission were reset. Permissions were restored to the wonky version where the Everyone group has full access to everything. Ownership of the files/folders remained the same.
To summarize:
In the user's directory, you need to provide permission to list and create new files/folders, and you need grant the user permission to the existing files.
-Tony

Remove channel from DAQmx AI task - reconfigure existing task

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