DAQmx task deletion concern

Similar Questions

• Task deletion DAQmx error

  Hello world.

  First of all, note that I'm not very familiar with DAQmx and labview.

  I try to use two DAQmx tasks to communicate with a USB-6008, each task has a unique name, of course.

  Now, I have successfully created these two tasks, I'm trying to do a VI that simply destroy these two tasks (to be used at the end of the program).

  And... no matter how I try, there is no way to destroy any task either programmatically or with the created DAQ assistant.

  First, to test the object, I created a task with MAX (see first photo)

  Then I try with this .vi delete... but it does not work.

  Am I missing something?

  Hello

  I've run the vi you have attached and run.  Yes, it creates a visible task in max.

  I used the function "Remove DAQmx saved task.vi" which removed the 'visible' task of max

  Find the vi attached to this function and it works fine.

• Programmatically, create a multi-channel DaqMX task

  Is there a way to create a task of multichannel DaqMX programmatically, without having a task to copy?

  Yes and it is an easy way to find a way to do it.

  Start by creating a task in MAX (Ben, but I want to avod MAX!) Don't be afraid that it's just a one time event that will allow us to know what are the steps)

  Go to a block diagram and steady decline DAQmx task on the diagram and choose the task you created in MAX.

  Right click and select 'create configuration and example '. LV will create the code that goes with the taks.

  Study the config VI that was created. It will show you what it takes to create a task without MAX.

  I hope that helps!

  Ben

• DAQmx task Read DAQmx with sampling frequency of 10 Hz produced much too much data

  I have a simple configuration with a strain of channel 4 OR-9237 amp holds a carrier of series C of WLS - 9163 (wired ethernet mode) - Details probably does not matter.

  I used MAX to create a DAQmx task associated with which all four gauges samples.  The calendar setting is "Scan Loads" is continuous sampling, 2 k buffer (read samples) and 10 Hz rate.  I guess that this task would generate 40 data values per second - 10 for each channel.

  I have a simple loop of reading using DAQmx Read.vi that works always (without any stimulation time).  Playback is set to read all available data and then pump it into a table.
  In the attached example, I also added a few words of debugging to stop the loop after N iterations.

  As the loop is programmed with a 0.2 second period, I expect each pass of the loop to read about 8 samples or 2 samples per sensor.  Instead, I get hundreds each passage.  It's like reading has substituted the sampling frequency specified in the task of the unit.  I absolutely need data to be material to the rhythm.

  Where have I lost?

  Thanks Adnan,

  I changed your example I selected 'Strain gage' entry analog and then lowered the minimum and maximum thresholds to +-1-2.  What happens is that each other in the loop, I 2048 samples or zero samples.  The display flashes a whole line and then it clears any other past.

  In response to your second post, I understand that the loop cannot run quite right that I select.  I think that, but at a sampling frequency of 10 Hz, I have to sleep on the software side for nearly a minute before I built 2 K samples.

  I played with the frequency of sampling, assigning to various values from 0.1 to 10000Hz.  The behavior is the same until I approach the high rates where available samples remains to 2048-4096 sometimes, the display becomes continuous.

  Ahhh, Darn.  Yet another search was this link that points to the root of my confusion.  The 9237 can taste arbitrary rates using its internal clock.  Duoh!  I wish that the pilots are smart enough to warn you if there is a discrepancy between the selected sampling rate and capabilities of the device

• How to add DaqMX task to an existing project

  I use Measurment Studio 2010 with Visual Basic. I created a NI Daq Windows application with an element of task Daq to analog input.

  Now, I have to add additional DaqMX tasks (tasks in digital and Digital Out) to the existing Visual Basiic project.

  How can I do this?

  Thank you

  Mike

  Hello

  Here is a link that shows how to add a task to a .NET project

  http://digital.NI.com/public.nsf/allkb/290D84D10809D4C086256FF20076F8B8

  Curt

• How to set up wizard DAQ or DAQmx tasks using an external text such as a CSV file?

  I work in an environment were we have a lot of users VI. I develop the VI and technical personnel using the GUI (cover Page) to collect the data. In order to control the input parameters used on multiple hardware platforms, I'd like to develop a generic VI which will import or read a text file I created, and configures the DAQmx tasks to perform data acquisition. In fact, I have the generic VI full and need to understand how to make configurations DAQmx more transparent for the end user as long as the end user has the text file to import. For example, to generate the wizard DAQ DAQmx tasks based on information from text file?

  I don't have time to do more than just a small example. The VI below contains a table with table fixed index functions. This would have changed to get automatically the correct rows and columns, but I hope that you have an idea. I does not have any code to define the type of temperature measurement or to set the correct configuration of Terminal. All of this plus all other possible options will be treated similarly to the definition of the type of channel and min/max which is located in the example.

  Edit-attach VI

• SE AcceesViolationException NationalInstruments.DAQmx.Task.UnregisterAsyncWaitHandle

  Hello

  I use my own .net application which communicates with NationalInstruments.DaqMx.dll (version 9.7) in order to activate NiDaq in the following configuration:

  Chassis PXI-1033 at two locations PXI-6284, measure differential voltage. This app worked already for a few months and has been tested under high performance - high sampling rate and long hours, without no problems so far. Recently, we tried a new use case - short sessions (60 min) measures running in sample rate = 100 and samples per channel = 100 after a few iterations, we continue to get access violation exception:

  Exception info: System.AccessViolationException

  Battery:

  to NationalInstruments.DAQmx.Task.UnregisterAsyncWaitHandle (System.Threading.WaitHandle)

  at NationalInstruments.DAQmx.Internal.DaqAsyncResult.AsyncOpDone)

  at NationalInstruments.DAQmx.Internal.AnalogMultiChannelMemoryOptimizedMultiSampleReadAsyncResult.WorkItem (System.Object)

  at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context (System.Object)

  at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)

  at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object, Boolean)

  at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem)

  at System.Threading.ThreadPoolWorkQueue.Dispatch)

  at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback)

  Keeping the sampling rate 100, but his definition of samples per channel at 1000 seems to solve this problem.

  Can someone explain to me what is the cause of this exception?

  Thank you

  Hadas

  
  

• Convert DAQmx task IDS in a string

  I'm using LabVIEW to perform a generation analog DAQmx and I call my LabVIEW of CVI code via a dll.  I want to make two separate calls, one to start a task DAQmx and one to stop the task, so I need to either:

  (1) move a task ID DAQmx CVI and then again to LV

  or

  (2) convert a string of the ID for the task, pass it to CVI and then back to LV and then convert back to a task ID in LabVIEW.

  I'm sure that option 2 is the easiest option, but I don't know how to convert back and forth between a string and a task ID DAQmx.  Can anyone help with this?

  Thank you

  Joe

  Nathand is correct, it's pretty easy convert from/to the task DAQMX and String.  The two below

  

  Hmmmm is note expected or a bug?

  Feedback probably need an expert of DAQmx to answer that - I think it might be related to level DAQmx tasks

• How to store a DAQmx task properties effectively?

  Hello everyone and happy new year!

  I would like to be able to keep track of all the DAQmx task settings (and canals) in a file, regardless of the content of the DAQmx task / channel is. So far, the only way I've found is to use a task DAQmx / channel property nodes and treat every property possible. However, since they are so many properties, each being is not valid for any material or task / channel type, it's a really big job and I'm rather lazy

  So I ask here if someone has already dealt with THIS or have any idea?

  Hi Hillman,

  Thank you very much for the link. Related documents Silly me had neglected tdm... Your link is indeed very useful, as I do right now exactly the same way it's done the:

  • DAQmxTaskInfoQuery.vi
  • General info.VI DAQmx TEDS

  As part of the download in the link you gave.

  Exepted this code is much more readable than mine, so I guess I don't need to view my ugly code incomplete. Many things interresting, thank you very much. I'll be back if I have something better to give as a reference.

• DAQmx task: MAX or lvproj?

  Experts,

  What are the benefits to declare tasks DAQmx either in the lvproj or Max?

  My question because I'm calling a VI of TestStand test, and when the DAQmx task constant is declared in the project (lvproj) which holds the criterion VI, it does not perform properly, saying can't find the reference or something.

  If I change the DAQmx task to be a global task in MAX everything works as expected.

  What is the best practice to do this kind of things?

  Thank you very much

  LR2

  TestStand does currently not support execution of VIs a project. So unfortunately, we expect the behavior that you see where to call a VI that uses a DAQmx task defined in a project does not work. For now, if you do want to keep your configuration of the task outside the source code and you want to use these task for TestStand, you must store the Max.

  We are looking for by adding support for the performance of screw a project in a future version of TestStand.

  David Rohacek

  National Instruments

• Cannot rename the old DAQmx tasks via NI MAX

  Hello

  I NI MAX 15.3 and DAQmx 15.1.1 installed.

  I am facing a strange problem. When I try to rename any task DAQmx via NI MAX, I get this error message:

  

  The thing is, the chosen name is NOT in use and does not contain illegal characters! (I tried several names, including "X" and "MyTask"). The same thing happens to the tasks associated with devices, simulated and real devices.

  The other weird thing is, I can create a new task from scratch, and I can rename this task without any problem. However, I am still not rename my old tasks.

  I suspect some sort of corruption of database NI MAX. How can I find the cause and fix?

  EDIT: more signs of corruption: if I delete something 'new', nothing happens. If I delete something 'old', NI MAX silently crashes to the desktop.

  Thank you!

  You can reset the database to MAX through the link below: http://digital.ni.com/public.nsf/allkb/2C7480E856987FFF862573AE005AB0D9

  Also make sure the backup and try if it works.

• DAQmx tasks name variable

  Can someone explain why use a variable LabVIEWIOControl to keep the name of the task of DAQmx, Labview causes the sequence editor to become extremely slow. The vi attached does nothing more to open a chan (output on a pxi-6723) and its closure via the parameter of OPERATION enum (see teststand sequence).

  To simulate the problem, right click on the Action step and select "define the module." Once the tab "module" is open, click back and forth between Action 1 and 2 of the Action (1,2,1,2, 1.etc). You should see some delay, pulling up info from module of step up 2-1.

  My 'real' application works well, but a step of editing may take 10 seconds to get the info from the module. Note: This is the type of variable only what causes this problem that I have used cluster, string, enums, tables ect in the past without problems.

  I have attached a seq teststand advocating the vi.

  Görz

  There is a slowdown in TestStand, known while choosing a 8.6 VI, which has control of e/s on the side of the connector.

  See the following link for more details and a fix - http://digital.ni.com/public.nsf/allkb/1E3C0A420D28B60E862574C8004D9062

  Concerning

  Anand jegou

  National Instruments

• Extract single channel DAQmx task

  Hello

  I created a task DAQmx output, which contains two channels.  Is it possible to extract the individual virtual channels of the task to be dealt with by two parallel processes?  I tried to bring out the ownership of channels using a task property node, but then I get the error that the channel is not part of an active task (see excerpt)

  Could someone advise on a better approach, or how to obtain this feature - if that's possible?

  Concerning

  Dave

  Sorry, that VI does not have much sense. You must use a unique DAQmx writing for both channels and 1 sample mode, simply build an array of signals as shown below.

  

• DAQmx tasks for Subvi of good practices

  Hello

  I wonder about the best way to create the subVIs that don't repeatitive entry analog and digital output several times in a program. Specifically, should I create a new task using DAQmx create channel in the Subvi or should I create the task in the main VI and put the task in the subVIs? Create and delete a new string into a Subvi would affect the States of digital output line (for example to change a line in the default state) after that the program will stop at the Subvi?

  I'll collect digital 6-channel analog inputs and 2 outputs to control a magnet. The program only collects analog inputs for 5 seconds each time (based on the user's selection) and active the magent or not based on the analog input.

  I update an old program LV traditional data acquisition functions allowing to use the new DAQmx features. The old program was written in LV 8.6 and used the DAQCard-6036E card and I update it LV 2013 and the USB-6212 mass unit.

  Thank you

  Frank

  If you call this VI a good amount, then I create the task in advance and pass it in.  Re-create the task just request in trouble, especially since I don't see you close either.

• DAQMx task does not clean up properly after the execution of

  I have two screws which are designed to write in different lines of digital output (digital output card OR PCI and PCIe of NI DAQ) who will order the DUT / s.

  The channels are hardcoded and I a VI to write to DUT #1 and another to write to DUT #2.

  Each VI creates a task, it starts, writes in the lines (twice) of output then stops and deletes the task.

  When I run them in LabVIEW... in any order a combination everything behaves as expected.

  When I run in Teststand, the first iteration of the sequence "PASSES", but whatever it is then "FAILS" the first time, it is called.

  Error Msg:

  DAQmx create task.vi2

  Task name: DIG_OUT_FPP_2_1B

  The name of the specified task of conflicts with the name of an existing task.

  I ignored all the other steps in the sequence other than the screw (attached), but the error persists.

  Somehow, Teststand is compensation not properly the tasks.

  Any advice would be appreciated muchly. Thank you!!!

  Hello

  It looks like the device may need to be reset. I have attached some information on below.

  http://digital.NI.com/public.nsf/allkb/124D580AE300335E86256FDD006CE798

  I hope this helps!