DAQmx physical channel to string

Hi Labview forum,
I have a variable DAQmx physical channel variable.
I would like to write the physical channel used to a file.
Is there a way to convert the physical channel selected to a string for writing to file?
Or to access a property node which stores the channel name in string format?
Regards,
Jamie
Using Labview version 8.0

LabVIEW1234 wrote:
I am not sure how to use "Scan from String" for these unique data types. Where can I find the format codes for physical channels and enums. I guess ENUM is U32 or something like that but I have no idea what a physical channel is.
You have to use the Scan From String to convert your string to the enum. But as Dennis said, just wire your string straight into the Physical Channel input.
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Attachments:
String to Enum.png ‏11 KB

Similar Messages

Problem with DAQmx Physical Channel control

Dear LabVIEW community!
I have installed LabVIEW, v13.0f02, 32-bit on my PC. The problem, which I face, is that DAQmx Physical Channel controls, which are used in VIs inside the LV projects, sometimes don't show me the list of DAQ devices - I can't expand the list at all. I push the button to expand the list, but nothing helps.
But when I create VIs outside the project, and put there DAQmx Physical Channel control - everything works well.
Note: devices are simulated via MAX.
Is it some kind of bug in 2013 vesrion of LabVIEW? Because while using LV 2012 I didn't have such headache.
The only thing that helps now - is to restart PC (laptop) several times; b/c restart of LV doesn't help.
Can anyone suggest, what it can be, and how to fix this problem?
Thank you very much in advance!

Thank you for your answer!
The point is, that this bug is independent from the code. DAQmx Physical Channel controls don't work even when I'm trying to use NI examples - for instance, Strain - Continuous Input.vi; Voltage - Continuous Input.vi, etc.
I have such simulated via MAX devices: NI USB-9213, NI USB-9201, NI cDAQ-9172 with NI 9217, and 4 NI PXIe-4331 modules.
Also, what I have noticed - front panel doesn't visualized fully (I send you the screenshot). When I'm moving mouse pointer over it, those part, which were under the mouse pointer, became clearly seen. And when I minimize, and then restor FP, it becomes fully clear visible.
And also, this story happens when LV project is open. If I close opened projects, and open only single VIs, everything works smooth.
Thank you very much, I hope, that this information will be useful to solve this problem.
Attachments:
Screen 1.PNG ‏87 KB
Screen 2.PNG ‏107 KB
Screen 3.PNG ‏129 KB

How to get intimation about DAQmx Physical Channel invalid value encounter

Can anybody tell me that if a DAQmx Control gets value from a configuration file( .ini file ) and the value is invalid (does not exist in the available physical channels list) than how I can be programatically intimated. I couldn't find any property node of DAQmx Physical channel Control which tells about that the current value feeded to the control is invalid.

Thanks Alan, I have got a better soloution from you in another thread launched by me with title "How to get "Browse list of any DAQmx control in array form". In which u suggested of using DAQmx 8.0, which I have downloaded and used the property node DAQmx-Device>>DO.Lines to get an array of all Physical channels(DO category) of all devices. The value taken from that configuration file is searched in Physical channels array and if no match found than the value is invalid.

DAQmx physical channel constant error

Hi all,
I am trying to get the labview 10.0 working in opensuse 11.4. I installed the components and all of them seem to be working fine.
The PCI card is also detected by labview. When I tpe lsdaq on the command line. I get the following output
Detecting National Instruments DAQ Devices
Found the following DAQ Devices:
NI 6025E: "Dev1" (PXI8::15::INSTR)
But when entering "Dev1/ai1" or "Dev1/ai0:3" in the DAQmx physical channel constant I get an error saying invalid channel name. How do I get rid of this error?
Chiran
Solved!
Go to Solution.

Hey Justin,
Thanks for your reply.
I am working with labview 10.0.
I installed DAQmx 8.0.2 but it did not help. DAQmx is not ideally meant for labview 10.0 and probably that is the reason why it does not work.
The installation also does not seem to go smoothly since it looks for support files from labview 8.6 and previous version which do not exist. I have attached the messages after installation of DAQmx.
Let me know if you find some way out.
Thanks,
Chiran
Attachments:
DAQ_inst.txt ‏5 KB

DAQmx physical channel error message

Hi,
I am new to Labview but I managed to create a new analogue voltage input task in Measurement and Automation Explorer. I am using DAQmx create virtual channel VI but I am getting an error message saying that "required input physical channel is not wired". Any idea why I am getting this error message. Also what is the difference between using DAQmx Assistant and using VI's like DAQmx create virtual channel, DAQmx timing etc.Any help is appreciated.
Thanks
Duran
Attachments:
error2.JPG ‏171 KB

The first VI 'Create Virtual Cannel' has an input called physical channel. This needs an input. Right click on the terminal and select Create>Constant. Then you can select the channel (something like Dev1/ai0).
To your 2nd Q: The assistant is a fast way to configure your measurement. You can later also convert it to the VIs you use now. Using the VIs gives you full programmatically control of the task. (The meaningful phrases are 'configure' and 'full programmatically').
Felix
www.aescusoft.de
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Specify DAQmx physical channels

Hello,
Im trying to specify multiple physical channels with DAQmx driver..Could anyone help me in figuring this out?
Thanks

Have a look at this

Daqmx physical channels supported functions

Hi,
I would like to do a program like the MAX way.
By choosing a measurement type(Voltage, acceleration, etc...), i would like to get a list of hardware that support, or not, the choosen measurement.
I browsed the daqmx property nodes and did'nt figure out how to do this.
Any hints?
Guillaume

All of the information is available with property nodes. You can get a list of devices and from there, what types of channels and how many each device has.
Seems like you might be trying to reinvent the wheel though. You can have a user define a task in MAX and have the program run that task.
Message Edited by Dennis Knutson on 02-16-2009 08:08 AM
Attachments:
DAQmx Properties.PNG ‏9 KB

Selecting physical channel from list with DAQmx

I'm trying to write a simple VI for reading and writing digital data. However, when I have a DAQmx physical channel control, the only options it presents to me are the various analog inputs (and doesn't allow me to type in the port I actually want to use). In other examples, e.g., "Write Dig Port.vi", the apparently identical control instead shows me digital port options rather than the analog in channels. As far as I can tell, there is no real difference between the controls as there is nothing in properties that I can really modify.
How can I get this control to let me choose the channels I want? Or is there some difference in these controls that I am not aware of?

The channel lists adapts to the type of DAQmx Create Channel that you use. Do you see the text below the DAQmx Create Channel? If your channel is displaying only analog input channels, then the DAQmx Create Channel type is AI Voltage. If you want to use digital input channels, change the type to Digital Input. Click on the little arrow on the right side. This is called a polymorphic VI selector. You can do the same thing by right clicking on the VI and do a Select Type.
Mark has a good point. If you change the type of DAQmx Create Channel and you already have a physical channel wired, you will have to go to I/O Name Filtering to change the channel types displayed. If you change the DAQmx Create Channel and then create a channel control by selecting Create Control, you'll get the correct type automatically.
Message Edited by Dennis Knutson on 03-11-2008 12:12 PM

Get physical channels control into separate strings

Hi,
I have a physical channel control with "Dev1/ai0:1" and I wish to separate this to two strings or two channel controls, for instance, turn this Dev1/ai0:1 into this Dev1/ai0 and this Dev1/ai1 programaticaly.
Thanks.
Daniel Coelho
Daniel Coelho
VISToolkit - http://www.vistoolkit.com - Your Real Virtual Instrument Solution
Controlar - Electronica Industrial e Sistemas, Lda
Solved!
Go to Solution.

I forgot, this is my VI just in case someone needs.
Daniel Coelho
Daniel Coelho
VISToolkit - http://www.vistoolkit.com - Your Real Virtual Instrument Solution
Controlar - Electronica Industrial e Sistemas, Lda
Attachments:
Physical Channel to String Array.vi ‏15 KB

DAQmx card channel recognition

I wrote some DAQmx code on one PC a few months ago, then we moved the hardware to another PC and I'm having trouble remembering how I got this code to work before. In MAX, I see my DAQmx 48ch I/O card (24 in, 24 out). (1) Do I have to setup anything, like a task or channels/lines in MAX before going to LabVIEW? (2) I only have one DAQmx card, but whether I have one or more, how do I specify in LabVIEW which card/task/channel I want to talk to?

Yes you will have to do some set up in max just to make sure that the device name, ports and lines are correct in your code. The reason is that you specify the lines input in string format. there may not be such a line on the new PC because it may be set up in max in a different slot or something (ie it may not be set up as PXI1SLOT5 it may be set up as PXI99SLOT3 or something to that affect. What i would do to avoid this and having to set things up in max is to use the daqmx physical channel drop it on the front panel and change it to a constant and pick the correct channel to use in each case or in an array as you have done with the strings in the input and output cases. when I change this is your code to something I have installed I do not get the error so this is definitely a problem with the setup in MAX and the physical lines for the device.
Future reference:
To avoid the hasle for next time once you get it working export a copy of the configuration file for max and then load it on the new machine and it should be OK
Joe.
"NOTHING IS EVER EASY"

Deploying VIs to the RT causes the value in the Physical Channels of one of the VIs to change to an incorrect value. Why?

Hi all. I've been registered to the forum for a couple of years, but this my first post. I'll try to give as much info as I can.
NIPXIe-1082 chassis
slot 1: PXIe-8133 Embedded Controller
slot 2-3: PXIe-6363 X-Series Multifunction DAQ
slot 4: TB-4353 32-Ch. Thermocouple
slot 5: PXI-4496 Analog Inputs 16-ch
(The second 6363 in slot 3 is a recent addition causing the others to move to higher slot numbers.)
Windows 7
LabVIEW 2011
This code is still being developed to run a test stand, but its based on code from a previous test stand that is being modified for the new one. There are three VIs that are opened and then deployed to the RT. On the Front Panel of one of the VIs is a DAQmx Physical Channel control. The control points to slot 5, but when I deploy the VIs, the control changes to point to slot 3. None of the three VIs have been run yet. I can manually "Reinitialize to Default Value" to get the control to point to slot 5 again, but I shouldn't have to.
I realize that there is a lot I still don't know about NI hardware and LabVIEW. This just seems like it should be a really simple solution and I'll probably have one of those DUH moments when I get told the answer. I'll try to answer whatever questions for more information that I can. Thanks in advance.
-Psiber_Space

Yes, it is defaulted to slot 5. After it changes I can Reinitialize to Default to bring it back.
Two things that I've tried during the week. I've deleted the Physical Channel and then recreated it, but it continued to change upon deployment. Then I simply disconnected the Physical Channel, moved it to an out-of-the-way location on the Block Diagram and then created a new Physical Channel. The old Physical Channel is still changing upon deployment, but the new one stays intact. It seems that as long as the old one isn't deleted, this workaround should work. Except that the problem now seems to be spreading to the other controls on the same VI.
Just today I upgraded from 2011 to 2011 SP1, but the problem is still there. After the upgrade, I tried recreating the LabVIEW project from scratch, but that didn't seem to work either.
I'm going to try contacting NI directly, but if anyone else has any ideas, feel free to continue posting.

Physical channels node

Is there a way to get the IEPE or ICP power support and AC/DC coupling support information from a DAQmx Physical Channels Node. If not can this be added to the next version of DAQmx? Some NI boards have different properties for different channels.. For example the NI 4432 has ICP power available for channels 0 through 3 but does not have ICP power for the last channel which is channe #4.

Greetings ed Z!
I was able to programmatically obtain the information about the AC/DC coupling ability of various devices/channels but my efforts to do the same for IEPE support has failed. If you're interested, my method was simply reading the AI.Excit.DCorAC DAQmx Channel property (found from Analog Input -> General Properties -> Signal Conditioning -> Excitation -> Advanced -> DC or AC) and then writing it back with two connected property nodes. I then attached a case statement to the error wire running through the property nodes. No error meant the feature was supported. The error case handled if the feature wasn't supported.
I know this is not an ideal setup and not exactly what you were really looking for. As such, the best thing I can suggest is to head over to www.ni.com/ideas where you can submit this as a LabVIEW feature request.
Hope this helps.
Michael G
Michael G.
Applications Engineer
National Instruments
Self-realization: I was thinking of the immortal words of Socrates, who said, "... I drank what?"

Selected physical channels to array

I would like that after select several channels of differents devices (with DAQmx Physical Channel component), this selected channels will be put in the array.
I look for forum but I didn't find anything.
If somebody already tried to do this, please send me suggestion.
Thx for all
Look in the attached picture.
Leonardo de S. Cavadas
Maintenance Engineer and Inspection - Bureau Veritas do Brasil
Engineer Metallurgist with emphasis in Advanced Materials
Technologist in Computer Science
Attachments:
physicalchannel.JPG ‏39 KB

Chris,
Now you will understand what I want. I didn't expressed well. Look for attached VI
Leonardo de S. Cavadas
Maintenance Engineer and Inspection - Bureau Veritas do Brasil
Engineer Metallurgist with emphasis in Advanced Materials
Technologist in Computer Science
Attachments:
physicaltoarray.vi ‏11 KB

Physical channel to NI Terminal

Hello,
I'm trying to use an external clock to read a digital signal. When I try to connect the clock output (a physical channel) to the DAQmx Timer source, I get the error:
"You have connected two terminals of different types. The type of the source is DAQmx Physical Channel. The type of the sink is NI Terminal."
So, I guess I need to convert a physical channel to a NI terminal. I've tried a number of things, but haven't been able to do it.
Any suggestions?
Windows 7
Labview 2014 32-bit
DAQmx 14.1.0
NI PCI-6535

Hehe, first off your two controls are wired together in that little junction. That doesn't fix the problem, but needs to be fixed.
To fix the problem, you need to replace your Physical Channel control with a Terminal control. You can do this by making a new control, or right clicking it anf clicking Replace > I/O > DAQmx Name Controls > DAQmx Terminal.
Then, you should have to browse for the timing input with a name like "Dev1/PFI0". Check your pinout on your device to match the right channel and make sure its wired right. This naming scheme difference is the reason you need to have a different DAQmx wire type for this input.
Edit: Here's your datasheet. Check out the timing section. Looks like you'll be starting out with PFI4. I can't seem to find a connector pinout which is weird...

How to create multiple physical channels using DAQmx?

Hi, I am new to Labview.
Can anyone please help me on how to create multiple physical channels? I am following the LabVIEW examples in the NI example finder but they are only for acquiring signals from one channel.
Actually, I am using the channels of an SCXI 1520 to measure voltage signals. And one more thing, in the NI Example Finder, they are sample codes there for setting the filter in SCXI 114x.
Will this example work with an SCXI 1520, too?
Thanks!

There are many ways to read multiple channels in LabVIEW. First, if you look at that example that lets you set the filter setting on the 114x and you click on the 'Physical Channel Listbox' then click 'Browse' you can see that you can select multiple channels. After you select the channels and hit 'Ok' it will build a multiple channel string. This is one way to read multiple channels.
Next, you can create a 'Task' in Measurement and Automation Explorer(MAX). When you create this task select all the channels that you need to read then back in LabVIEW simply select a 'DAQmx Task Name Constant' Select the task you just created and wire that to an Input of your first DAQ VI. If you do this you do not need to have a 'DAQmx Create Physical Channel' VI or create
Task because it is already created in MAX.
When looking at example VIs you can tell if a multi-channel read is acceptable by looking at the 'DAQmx Read' and if it says NChan that means it will do a multichannel read. There are tons of example programs that will display the multichannel read capabilities.
This example may not work for the 1520 because the properties that are set could possibly be specific to the 142x. When using the 1520 though it is very likely that the properties will be very similar if not exact. You will simply put a DAQmx Channel property node on your block diagram and then look for the Lowpass filter settings properties that will most likely be in the same location. Now another way todo this without using a property node would be in MAX when you create a task set the filter settings from the Device tab in the task configure window.
Let me know if you need anymore help with reguards to this issue! Have a great day!
Allan S.
National Instrument
s
Applications Engineering

DAQmx physical channel to string

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