Mapping of line/port (Physical Channel constant) to pfi (Terminal Constant)

Hello all,
I am using "Dev1/port0/line4" (Physical channel constant) of my PXI-6602 as a digital input.
Additionally I have set up a counter on that board. I need to arm this counter after the occurrence of an edge on
"Dev1/port0/line4". But the property node only accepts "Dev1/PFIx" (Terminal Constants) as inputs.
I try to avoid defining two constants within my program that practically map to the same physical pin.
What is the best way of converting a "Physical channel" name to a "Terminal Name" ?
Grüße
Phili

Having faced the same problem, I think I can say why there is no mapping.
Channels are for data aquistion, so actually a DAC, ADC, DO-Driver ...
Terminals are used for timing (trigger) and internally routed. So a diffrent concept, and a diffrent circuit.
Actually the same goes if you use analog triggering, you will have a different ADC (I found out because I got only 10-bit on a 18-bit M Series Device).
Felix
www.aescusoft.de
My latest community nugget on producer/consumer design
My current blog: A journey through uml

Similar Messages

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...

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

Physical channel constant and indexing

Hi people,
I need to associate an input channel to a certain output channel. Of course, that led me to the idea of a hash table and as Labview doesn;t have such a structure defined, I thought of using a case structure.
Now a bit of discussion about the Physical Channel constant- I am to add some of them there from which DAQ reads their values. You know the sintax ev1/ai0, Dev1/ai1...
Labview seems to index them according to the order they are introduced in the Physical channel, so one can manipulate them by extracting from the complex signal the array indexed 0, indexed 1, ...respectively.
My purpose in the end , though, is to associate Dev1/ai0, Dev1/ai1(and not the channel's index)... with some certain numbers into a somewhat hastable.
So the question is whether I can extract the string or symbol information of individual Dev1/ai0, Dev1/ai1,... out of their associated index or from somewhere else...
Can one of you envisage some solution?
Thanks a lot,
Dana

Hi Mike,
Thank you very much for the solution. Yes, this is the right way.
I'd come up with another complication.
What if the name of the channel is not available-can I first extract it from the index of the individual signal that I extracted from the complex one?
I made some comments in the picture , it's part of my actual application. Could I have your opinion on that? I placed an icon if the DAQmx channel propery - is this an answer to the question I posed? I cannot link some things in my reasoning, maybe you can help.
Kind regards,
Dana
Attachments:
channel name.JPG ‏153 KB

MAX: how to create a Calculated Channel based on two physical channels?

Good morning,
I need to configure some tasks in MAX with Virtual Channels that are calculations based on physical channels. I saw this article : http://digital.ni.com/public.nsf/allkb/1BFCE6FAD5B3944986256D67006DF7EC but cannot see the equivalent in the newest versions of MAX (V5.1).
As an example I am already acquiring the physical channels Ch1 and Ch2 and I want to build a virtual channel Ch3=E+(A.Ch1+B)/(C.Ch2+D). A,B,C,D,E are constant values. I would then like to integrate Ch3 in a task together with other physical channels that I am acquiring.
Could you direct me to this function?
Thanks for your answer.
Christophe

Hello Christophe,
With the newer versions of NI DAQmx and NI MAX there was a choice made to go from the relatively limited VI Logger options to a more extensive form of configurable applications.
For this purpose (and others) NI Signal Express was created, which allows you to configure applications with a limited amount of programming.
To do similar (and more things) then you were used to do with VI Logger you can use NI SignalExpress
http://www.ni.com/white-paper/5825/en/
http://www.ni.com/white-paper/5827/en/
This specific VI logger functionality for the creation of ""virtual channels" (step 5 to 10) through VI Logger Tasks (directly from inside NI MAX) however does no longer exist.
This also more clearly seperates your Configuration Tools (like NI MAX) from your actual applications made with LabVIEW or SignalExpress.
Would using NI SignalExpress be an option for you?
Kind Regards,
Thierry C - Applications Engineering Specialist Northern European Region - National Instruments
CLD, CTA
If someone helped you, let them know. Mark as solved and/or give a kudo.

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 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
My latest community nugget on producer/consumer design
My current blog: A journey through uml

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

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

Labview is no longer recognizing my physical channels. Corrupt subvi?

For some reason, whether the subvi has become corrupted or who knows, my mx create channel VI is no longer recognizing my physical channels. When I run the vi I get a -200099 error which says there may be no physical channel specified. I have the channels set up correctly in mx and they Vi ran fine previously, but now all the sudden..nothing. If I use the Daq assistant I can get the readings I want, which is strange. Anyone had something like this happen?
Tim

Hello Tim,
I'm not sure what is causing your physical channel to no longer be recognized by that DAQmx VI but there are several things we can try to figure out what is going on and possibly resolve the issue.
1) Have you tried using the "DAQmx Create Virtual Channel.vi" in a different program to see if it can properly recognize the physical channel? The DAQ assistant uses this DAQmx VI in its underlying code so I don't suspect that the DAQmx VI itself has become corrupt.
2) Right-click on the DAQ assistant and select "Convert to task name constant". Close the DAQ assistant wizard (you can make any changes in the wizard that you would like) and you should have a task name constant on your block diagram. Right-click on the task name constant and select "Generate Code >> Configuration". This will create a subVI that shows how the DAQ assitant created the virtual channel for the task. Compare your code the configuration code generated from the task name constant and see if there are any differences.
3) If you do think it is a corrupt subVI, reinstalling the DAQ driver support for LabVIEW should overwrite the subVI with a new copy from the installer.
Hopefully we can narrow down what is causing the problem!
Take care,
E.Lee
Eric
DE For Life!

Physical channel

hello,
i have a labview 7 and both IN-daq mx & traditional IN-daq. I take a vi from one of my friends. He wrote down the program 4 years ago and my labview can still open it. But in his program, the physical chanels are named as 0,1,2,..(like in attachment named "b") But in my lab we have sc-2345 so i have SCC1Mod2/aio,ai1 &scc1mod1/ai0,ai1.( total 4 channels)
my question is , how can i apply data using the same program? how can i convert his physical channell types (0,1,2..) into mine?
if we can do that, how can we connect it to the aiconfig.vi . I think the wire types does not match
thank you so much
batur
Attachments:
b.vi ‏25 KB

If you have configured everything correctly in Measurment and Automation Explorer you should be able to right click and create constant on the AI Config. This will then give you an array of I/O constants which you will be able to select the configured information form MAX for each channel. Hope this helps.
BJD1613
Lead Test Tools Development Engineer
Philips Respironics
Certified LV Architect / Instructor

Physical channel choice .exe

Hello,
I have built a .exe (and it's setup) for a data acquisition system. My problem is that depending on the computer it is installed, the physicall channel to read may change (not the ai, but the Device number; that is, Dev1/ai7 to Dev2/ai7, depending if there are any previous devices installed).
I want the user to be able to select the Physical channel, but, my problems come here: I cannot make the program 'wait' for the user to set the channel before starting the acquisition (it takes the default value, and gives an error since it won't match).
I have tried looping the whole program and using a case structure so that when the physical channel is selected then the user should press a button to start the acquisition, but then I get an error (sorry can't rememeber the code), saying something like 'Attemped to read samples that are no longer available... try increasing fs...'.
Any help?

Hi usuario,
The other way of doing this is...
- you need min 1 spare terminal on your device
1) Scan your system for all H/W of type x (Product Type)
2) Scan specified lines on all devices you have just filtered out - get line status
3) Ensure that the H/W pull the input of the specified device up (out of default state) on selected channel.
You can now detect which if the device is attached, and programatically determine it's name - very difficult to simulate though.
Using boolean logic you can add more lines for more devices
1 line = 1 devices
2 lines = 3 devices
3 lines = 7 devices
etc...
Try coding up Phil's example and see what it does when you add new devices - simulated or real. You'll learn lots and see it's not that complicated really.
James
P.S. - You have a race condition in your code between the input and the property node, just wire the output of the physical channel straight into the string stuff. You could do it simpler as well, like this:
Edit: -correct spelling of a name
Message Edited by James W on 05-20-2010 10:33 AM

Why can't I get a Physical Channel to show up?

I have a USB-6008 and LabVIEW 7.0. When I try and use the provided examples I can't seem to change the Physical Channel. When I click on the drop down menu I get the Browse... option. Then when I click on Browse... I get a blank window. It looks like there should be some sort of a menu but there isn't.

Check out this KB.
-Alan A.

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

Save physical channel information in a configuration file and reuse it in another VI

Dear all,
I would like to do a pair of VIs. The first VI configures all psychical channels and store the task information (or physical channel name information) in a file and the second VIs can access this file and use the saved information.
Can anybody show me a good example of this type of application? I've prepare a simple code, but it does not work now. I am not sure if I am using the right functions.
Attachments:
Configuration.vi ‏18 KB

You can use Measurement I/O>>NI-DAQmx>>Advanced>>DAQmx Utilities>>DAQmx Flatten Channel String, and DAQmx Unflatten Channel String.

Mapping of line/port (Physical Channel constant) to pfi (Terminal Constant)

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