Empty task out from DAQmx Create Virtual Channel (VI)

Hi,
I'm using a NI USB_6008 in my project and I use ao0 to provide my device with supply-voltage. And I use ai1 to measure voltage on my device. The thing is that I have been using another identical USB_6008 before, and everything worked just fine, but now when I want to use this new DAQ, it doesn't work at all and I get "empty" or "unnamed" task out. I have the right serial-number and device-number in my hardware initiation. And I have used the test panel in "Measurement & Automation Explorer to check that the channels works properly. I have also changed the USB-port and also updated my drives. But nothing has helped.
Unfortunately I can not send the code here since it's too big and complicated but I'll attach a screen-shot of the part the I'm stucked in with the "probe" values.
I'll really appreciate it if someone could explain for me why I get "unnamedTask".

Just came across this while looking for something else.
Your tasks are unnamed because you haven't named them . You can name your task when you call DAQmx Create Task.vi:
In the case of the first VI, the task is being implicitly created when the channel is created, so an "unnamed" task is the result.
Best Regards,
John Passiak

Similar Messages

Daqmx Create Virtual channel timeout

Why almost a minute and a half to get an error message from daqMX Create Virtual channel VI.
I need to find a way to have my executable bleep immediately if the underlying drivers are not installed.
For example, I have LV at home and supposedly have the drivers installed too but no hardware connected.
Sometimes I run a that uses daq, however when it encounter Creat Virtual Channel VI it appears to hang for a minute and a half before finally giving an error.
Anyone else been there, done that?
Thanks

Thanks for replying D-cubed.
Actually Im calling create virtual channel in a state machine to set up the data acquisition.
When using on a machine that has a daq device installed its a piece of cake. no sweat.
However, when I am at home I have LabVIEW but possibly either no daq drivers or no daq hardware.
I believe it may be the second case since I can place a task on the BD so, I will assume the drivers are installed correctly.
There is just no daq hardware in the system.
WHen the create virtual channels Vi is called the PC appear to hang because that VI is executing internally (looking for a device I presume).
The timeout takes 1.5 mins and if not for me waiting the PC would appear to be hung up.
Finally some 'Mig error' message appear contact Ni about and so on.
WHat I am trying to do is have my program error out immediately instead of 1.5 mins later that there is no Daq device in the system.
Thanks again

Why do we get so many vi's when using "DAQmx Create Virtual Channel.vi"?

Hi there,
Could anyone explain me why we get hundreds of sub-vi's when I use the
vi "DAQmx Create Virtual Channel"? This can easily be seen by exploring
the hierarchy of Labview examples such as "Acq&Graph Voltage - Ext
Clk.vi"???
This multitude of vi's considerably slows down my computer, especially at loading. Is there any way to get rid off that???
Thanks in advance for you help!
Jonas

Hi,
the easier you have to program, more subVI´s needed for your kind of application. Because the VI´s from DAQmx are polymorph, so many SubVI´s are included in the VI´s. In traditional DAQ you have several palettes for each kind of measuement method. Analog In, Analog Out, Digital, Counter, ...! In DAQmx you have one VI and that can all.
But, the performance of you application at runtime is not affected. Of course it takes some time to load, but just at development environment not as an application.
Figure 3. Polymorphic VIs simplify the NI-DAQmx API.
Link to Document:
http://zone.ni.com/devzone/conceptd.nsf/webmain/EE47B125BB9E053686256FBC0014C384
Hope this helps.
Alex
NI Switzerland

DAQmx Create Virtual Channel AI Temp TC Deg F Bug

Found a bug in DAQmx Create Virtual Channel AI Temp TC Deg F when using a cDaq-9174 with a NI 9213 Analog Inpout module. When I change from Deg C to Deg F I do not get the correct temperature. In Deg C I read ambient temp of 21.84 Deg C Vs. when I select Deg F I read 18.33 Deg F. When I use the DaqMX Assistant the asssitant returns the correct values. Is this a know bug on the 9213 driver? What is the fix?
Solved!
Go to Solution.
Attachments:
Read one AI Temp Channel in C or F.vi ‏13 KB

Thank You - Found it here too

Comment définir 12 lines digitals ( 8) pour la fonction DAQmx Create Virtual Channel

Bonjour, je voudrais demander l'aide pour deux points suivants:
1 /J'utilise une carte PXi 6537 pour pouvoir faire une acqusition de 12 lines digitals, mais quand je choisis 8 lines du port0 avec 4 lines du port1 pour connecter avec la fonction DAQmx Create Virtual Channel, il y a toujours l'erreur. veuillez m'indiquer comment faire entrer 12 lines dans cette fonction s'il vous plait. (J'essaie avec ces configuration mais cela ne marche pas: Dev1/port0/line0:7_Dev1/port1/line0:3 ou Dev1/port0_port1 ou Dev1/line0:11 etc...etc...)
2/ Dans cette utilisation, je voudrais utiliser la ligne 0 digital comme l'horloge externe, donc avec la fonction DAQmx Timing, j'indique la source d'horloge externe comme /Dev1/PFI0 et soit je connecte physiquement la voie Dev1/port0/line0 vers le borne PFI0 soit je fais le routage par logiciel de Dev1/port0/line0 vers PFI0, dans ce deuxième cas comment je dois faire , par quel noeud propriété qu'il faut utiliser.
veuillez montrer ces deux solutions par une figure simple s'il vous plait, je vous remercie beaucoup et vous souhaite bonne semaine. TuongLinh.

Bonjour,
Et merci d'avoir posté sur ce forum.
Je ne suis pas sûr de ce que vous voulez faire en rebouclant logiellement une des sorties numérique de votre boitier. Vous pouvez néanmoins accéder à davantage d'entrées/sorties en faisant un clic droit sur le terminal de l'horloge externe pour laquelle vous avez choisi /Dev1/PFI0 puis en cliquant sur "Filtrage du nom d'E/S...".
Cochez alors les différentes cases pour avoir le plus de choix possibles puis utilisez une ou plusieurs sorties de compteur pour générer l'horloge dont vous avez besoin.
Cordialement,
Jérémy C.
National Instruments France
#adMrkt{text-align: center;font-size:11px; font-weight: bold;} #adMrkt a {text-decoration: none;} #adMrkt a:hover{font-size: 9px;} #adMrkt a span{display: none;} #adMrkt a:hover span{display: block;}
Travaux Pratiques d'initiation à LabVIEW et à la mesure
Du 2 au 23 octobre, partout en France

DAQmX create virtual channel execution time

Hi,
I am using DAQmX Create Virtual Channel for 70 different Digital Output. It took 35 seconds to execute the DAQmX Create Viryual Channel VI.
What are the steps to make the execution faster.
Valliappan.M

Have you tried creating a global virtual channel with MAX?
André
Regards,
André
Using whatever version of LV the customer requires. (LV5.1-LV2012) (www.carya.nl)

What does DAQmx Create Virtual Channel (TEDS AI Accelerometer) actually do?

Hi all,
I have a basic vibration logging application for which I'm using TEDS enabled accelerometers. I'm configuring a task using the Create Virtual Channel (TEDS AI Accelerometer) to add the correct channels, but none of the data from the TEDS table appears to be getting pulled into my channels.
Does this VI pull scaling information from the TEDS such that the values I read out are scaled to the appropriate unit? Is there a way to force it to drag all the data from the TEDS through so that when I save a waveform to a tdms file they end up as channel properties?
I've included a screenshot of the VI that creates the task for reference. Thanks!
CLAD
Solved!
Go to Solution.
Attachments:
Create TEDS channel.jpg ‏100 KB

They are TEDS 1 accelerometers. I can actually see the entire TEDS table both in MAX and in my code (I read out the bitstream for my own amusement).
To collect the data I'm using a DAQmx Read N Chan N Samp - 1D Waveform. The output waveform array is wired directly to a TDMS write VI. The properties on the channel end up as shown in the attached image; note that no scaling information is carried thorugh.
CLAD
Attachments:
AccChannel Properties.png ‏37 KB

I can't find "DAQmx create virtual channel.vi"

How can I convert a "Channel" to a "Signal" ?

If you have installed the NI DAQmx Device Drivers, In LabVIEW, you will find this function in the location shown in the pic attached
How can I convert a "Channel" to a "Signal" ?
You cannot!
Gramatically and Electronically, you can only 'read or write' a signal on a 'relevant' channel
Attachments:
DAQmx_ Create Virtual channel.PNG ‏50 KB

DAQmx Create Virtual Channel (Custom Voltage with Excitation)

Hi,
My problem is this. I am using the custom voltage w/ excitation for my application, together with the scxi 1520. Of course, you have to put values on the excitation value, say 5 V.
But whenever I turn off the chassis aftr measurements (the LabVIEW program is still open) and then do the measurements all over again, I need to enter a different value at the excitation value, say 3 V, to ensure that excitation will be provided. Otherwise, I get no signal. I can then return to the previous 5 V to do the same measurements again.
Is there a way to solve this problem. Thanks!

Ahh, ok now I understand your question. This behavior is due to a combination of 2 reasons. First the DAQ driver is caching the values for the SCXI registers, so if you set the same values for the registers the driver doesn't write to the hardware again. Second, the driver doesn't get any notification from the hardware that the hardware has been turned off, so the driver continues on as if nothing happened.
So, the best solution would be to do a device reset on the SCXI module before you start the acquisition. A device reset would clear the cache and cause data to be written out again. This would of course make things a tiny bit slower, but if you are turning off the chassis, the that little bit of time probably does not matter.

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

Missing subVI DAQmx Create AI Channel TEDS(sub_.vi DAQmx Create Channel( TEDS-AI-Voltage-Basic). vi.

Hi,
    I have seen several discussion regarding this topic, however it seems that none of the solutions are working for me. Here is my situation, i am using LabView 7.1 which I use to generate my .EXE, when I generate my .EXE I use the Tab Intaller Settings to generate the Setup.msi. I then take the folder which contains the .EXE and the installer and bring it over to another machine which is running VM Ware with a freshly installed windows XP. (to make sure nothing is on the machine and then i get surprise at the custormer's site)
   Once this was done, i would start by lauching the installer and then the .EXE the result was the following, I would get the following message:
Missing subVI DAQmx Create Task.vi in VI instance      1    3tst
.vi.
Missing subvI DAQmx Create channel (TEDS-AI-Voltage-Basic).vi
in VI Instance 1   3tst.vi.
Missing subVI DAQmx Create Channel( AI-Voltage-Basic).vi in VI
instance    1   3tst.vi
Missing subVI DAQmx Timing(Sample Clock).vi in VI instance
1   3 tst.vi
Missing subVI DAQmx Read(Analog 1D Wfm NChan nSamp).vi in
Vi instance   1   3tst
then as suggested in other discussions of this forum I download (537MB) and installed
on the target machine (VM Ware) the nidaq710 which i downloaded from
http://digital.ni.com/softlib.nsf/websearch/C1F802E457EA042586256DD00001B0C9?opendocument&node=132070_US
This did solve some problems BUT I am still getting the following message when I launch the EXE
Missing subVI DAQmx Create AI Channel TEDS(sub).vi in VI DAQmx Create
Channel(TEDS-AI-Voltage-Basic).vi.
Thank you
Maldini

Hi Maldini,
Thank you for posting to the NI forums. Is the VM Ware PC using the same operating system as the development PC? Also, are you using DAQmx 7.1 on the development computer, or are you using a more recent version? When distributing applications, the driver version on the deployment PCs must match the driver version of the development PC.
If this is already the case, then you shouldn’t be receiving any of these error messages. There are few things that may fix this problem.
Reinstall the DAQmx driver.
Perform a repair install the DAQmx driver on the deployment computer.
Upgrade the DAQmx driver on both the development and the deployment PCs.
With Windows XP and LabVIEW 7.1, you are able to use the latest version of DAQmx, which is currently DAQmx 8.5.
After going through these steps, please post back if you continue to have problems.
Ed W.
Applications Engineer
National Instruments

How can I creat virtual channel and traditional devices while my card installed,I can not do?

I installed PCI-6220 card,and I also installed DAQmx and Traditional DAQ in my computer,
but I cannot creat virtual channel at the last step(attachment:TDAQ6220.jpg).
Maybe this is the reason I didn't creat traditional NI-DAQ Device,but I can not creat it.
(see attachment: DAQ Device.jpg,there is no PCI-6220 on list).
What's wrong?What shall I do?
Junwei You

Hello Rainer,
You can see this attachment(6024E.jpg),the 6024E card appears on Traditional NI-DAQ Devices,
but I don't know how can it be created(I don't creat it,we buy the whole system together with the machine).
I tried create a new traditional Device(I want to confirm 6024E), but still I can not see any NI-DAQ device in traditional NI-DAQ device
lists. See the 'Create New....' interface.How can do it?
Thanks!
Attachments:
6024E.JPG ‏128 KB

Do I really need to create virtual channels in data neighborhood in order to access my pci 6034E?

Hello all,
This may sound a little weird, but I would like to know how to configure my 6034E without having to create virtual channels in data neighborhood. Reason being, the data is often lost when users update or search for new instruments in Measurement and Automation.
I have tried using the AI CONFIG.VI, which gives me all the attributes I need...set channel name, device name, device channel, input mode, sensor/actuator type ect.. When I connect the AI READ.VI the value read back is incorrect. Matter of fact as an exapmle, the power supply could be off and I still read 10 Volts. But when I have created a virtual channel in data neighborhood, the data read back is correct.
Is there another way to read back data but not have a virtual channel in the data neighborhood?
Thanking you in advance,
Demo

Duplicate post

Creating Virtual Channel in RMAN

Hi ,
How to create virtual channel in RMAN? I tried googling for this info, however i wasnt able to find any details on it.
Can someone help me with this or direct me to a link.
Thanks

Hi;
Please see:
Integration of RMAN with virtual tape library
Integration of RMAN with virtual tape library
Regard
Helios

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

Empty task out from DAQmx Create Virtual Channel (VI)

Similar Messages

Maybe you are looking for