Calibrating DAQ Assistant

Let's say that I take a signal from my MPX4015A and measure it with analog input 3 on my DAQ board. I go to DAQ assistant and find the previously-configured scaling for my MPX4015A to convert the voltage signal directly to kiloPascals.
Now, how do I calibrate for a little bit of sensor inaccuracy? I can go ahead and create tons of custom scalings, but it seems like there should be a little extra field that lets you calibrate the sensors using a certain measurement.

Hello bmunden,
I am unfamilar with the MPX4015A sensor. I tried looking for a data sheet for this device and was unable to find any information on it when I did a Google search.
What does this device do? Does it measure pressure and then output a small voltage? Does this device measure sound pressure or physical load pressure?
DAQ assistant does have the something called the Virtual Channel Calibration, refer to the following link.
NI-DAQmx Virtual Channel Calibration
Please give this a try and let me know if this resolved your issue. Else please clarify and I'd be glad to assist you.
Sandra T.
Applications Engineer | National Instruments

Similar Messages

Simple DAQ assistant problem

This is probably a simple fix that I am screwing up, but I can't get changes that I make in the DAQ assistant to apply. Primarily changing the channels that the assistant reads, I will make the change, exit the assistant, and when I enter the assistant again the onlt connection found is ai/0. Is there something that I can do to fix this?
Chris O.

Also, when I run the program, i receive Error -50103, which is not in the error guide, I have attached my program to this message, any help would be greatly appreciated, I am still trying to figure LabView out. The program is used to measure a voltage from a 4 wave gages, and create an 11 point calibration curve for each gage. The user should be able to select a position, define the water depth, and click measure to measure the voltage. Once 11 measurements have been taken and the user is satisfied with the results, the user will click a "calibration complete" button which will fit linear curves to the data and export the slope and intercept of the lines. The secondary calibration listed assumes that the slope has already been measured, and calculates the intercept based on one iteration of data. I am using a USB-6008 right now to figure the program out, and eventually will change to a higher quality DAQ board when the programs have been written successfully.
Attachments:
Linear Wave Gage Calibration.vi ‏917 KB

Simulated device in MAX, self tests without error and has working Test Panels, but doesn't show up in DAQ assistant.

I'm trying to create a development machine where we can test new code without using our physical hardware. I've followed this guide in setting up a simulated device. I can get to step 3.2b, but the device does not show up in the DAQ assistant. In MAX, the device self tests and self calibrates successfully, and when I open the test panels, I see some sort of signal. I assume this is a default simulated input since I haven't told the device to look for anything? Note that the two devices I'm trying to create show up in the Devices and Interfaces section, but that even after running Self-Calibrate, the Self-Calibration date is still unspecified.
When I try to test the device and create a voltage input according to the guide, I am unable to see either device in the DAQ task creator.
Steps 1 and 2 of this guide are obviously satisfied. Step 3 is not, but this is unsurprising since a simulated device wouldn't be found in the Device Manager anyways. Also, I am not running RT, so step 4 is satisfied.
Does anyone have any ideas?
Solved!
Go to Solution.

That would be because the PXI 5124 is a digitizer not a analog input device. You need to use the NI SCOPE driver not NI DAQmx
Jeff

Signal express tc calibration to daq assistant calibration

I ran some calibrations in Signal Express for K-type thermocouples. I didn't realize that those calibrations don't carry over to other NI programs. I would like those same calibration values to be used in the DAQ Assistant, rather than completing all my calibrations over again. Is there a way that LabVIEW can grab the Signal Express calibrations and use them?

Hi Jdezman,
I will try and help you with this aspect of hardware calibration.
NI-DAQmx will allow you to do a system calibration. Once creating your task in signal express, there will be a 'Calibration' tab under the 'Thermocouple Setup'. This will direct you to the 'Calibration Wizard'. This Wizard is the same in both Signal Express and the 'Measurement and Automation Explorer' (MAX).
There is a KnowledgeBased article which will guide you through this process:
http://zone.ni.com/devzone/cda/tut/p/id/4224
Hope this helps with your system calibration. Please let me know how you get on,
Regards,
Aaron. E
Applications Engineer Team Lead
National Instruments
ni.com/support

Acquiring pressure data using daq assist

Hi all,
I want to use DAQ Assist to measure the pressure.When i select DAQ Assist>Acquire Signals>Analogue Input>Pressure>Pressure(Bridge) then is says 'no supported devices found'
What should i do?
thanks

I have Trafag pressure sensor anyway i give up doing it by daq assistant.I did it by using another daq tools.But now i have a new problem in calibration of sensor so i will post a new question

New project using Daq Assistant or not ?

Hi everybody,
I need to create a software to do some realtime acquisition & analysis.
I trained myself a little bit on c# lessons to get use to this programming language; I’m also discovering Measurement Studio & Visual Studio. (I’ve background in C++).
My software will have 2 modes :
Continuous acquisition, signal plotting + signal processing & plotting (fft, 1/3 octave band filter)
Triggered acquisition, signal plotting + signal processing & plotting (fft, , 1/3 octave band filter)
I have examples in my National Instruments directory which don't use daq Assistant and code is different from generated files with daq Component.
If I use Daq Assistant ( http://www.ni.com/tutorial/4652/en/ )
I know that the code to create channel is stored in DaqTask.cs
Plotting :
NationalInstruments.AnalogWaveform<double>[] acquiredData = daqTaskComponent1.Read();
waveformGraph1.PlotWaveforms(acquiredData);
When I look to examples, like "MStudioVS2010\DotNET\Examples\DAQmxWithUI\SpectrumAnalyzer\cs "
all code to create channel is generated in Mainform.cs, there is no Daq Assistant (http://www.ni.com/tutorial/5409/en/ )
and there is a slight difference between acquired type :
private AnalogWaveform<double> data = new AnalogWaveform<double>(1000);
data = reader.EndReadWaveform(ar);
acquiredDataWaveformGraph.PlotWaveform(data);
Questions :
What is the difference between AnalogWaveform<double> and AnalogWaveform<double>[] ? why it's not the same type ? I need to do some signal processing with this signal, so what type should I use for my application ?
I didn't succeed to configure my 2 modes in daq Assistant (continuous and triggered acquisition) is it possible or should I create 2 Items in my solution, one for continuous acquisition and on for triggered acquisition ?
Kind regards,

Check out the downloads section of iLounge.com. There are a handful or two of applications that will help you transfer songs from the iPod to the computer.
Another option is to network the two computers together and transfer the iTunes folder to the new Mac. All you need is an ethernet cable and to turn on file sharing in the Sharing preference panel. Depending on how old your "older" Mac is, you might need a crossover ethernet cable.
A third option is to hook up the two computers using a Firewire cable. On the older Mac make sure it is shut down, hook the two computers up, turn on the older Mac while holding down the "T" key. On the new Mac you should see the old Mac's hard drive show up. Just find the iTunes music folder and copy it over. You could also use the Migration Assistant which will be in the Utilities folder of the new Mac.
Hope this helps.

I have a DAQ Assistant configured to read multiple channels at the same time. When I wire a graph indicator to the output, I see all of my signals jumbled together. How do I split them up into seperate signals?

I have a DAQ Assistant configured to read 2 channels at the same
time. When I wire a graph indicator to the output, I see the 2
signals jumbled together. How do I split them up into seperate signals?
When I wire any type of indicator it is showing just one output of a single channel.
I want 2 indicators showing 2 different signals as expected from the 2 channels configured. How to do this?
I have tried using split signal but it end up showing only 1 output from 1 signal in both the indicators.
thanks in advance.
Solved!
Go to Solution.

Yes you are right. I tried that but I did not get the result.
I just found the way. When we launch split signal, we should expand it (split signal icon) from above and not from below. It took me a while to figure out this.
thanks

How to use DAQ Assistant to display two analog channels in a XY Graph

Hi,
I am new to LabVIEW. I have been assigned a project in which i have to display two analog signals from an analog potentiostat i.e. voltage and current (also a voltage signal) on a graph using labview. I am using a myDAQ device to acquire these analog signals and I am using labview 2013 to display these signals on a graph. I am using DAQ assistant to configure these signals. Rightnow I have separate graphs for each channel. However, I want a single XY graph to display one voltage as a function of the other i.e. I want to have voltage on the X-axis and current output on the Y axis. Any kind of help is greatly appreciated.
I have attached a screenshot of the VI. that I have made.
Regards,
Max
Attachments:
New Microsoft Word Document (2).docx ‏32 KB

Thanks for the quick response. I was able to make a X-Y graph. However, I can only see a dot floating around. It's not drawing anything. I want to see it making a plot as it collects data. Also, I want to see the complete waveform formed when I stop the VI.
Thanks,
Max

How do I use DAQ Assistant to output DC on an AO?

My background includes 15 years of programming PLC's. AO's were simple. You passed the AO a value between preset ranges and it output a proportional voltage signal based on the hardware capabilities.
I foolishly thought LabView and DAQ AO's would be about the same. I built a vi to generate a DC signal which I could control the amplitude of. I also tied it to a chart to monitor how it worked. I managed to draw some very pretty ramping pictures on my chart, but when I put a DMM across the physical terminals I see no voltage.
Then I used MAX to test the channel and measured it again. Now I see voltage on my DMM. I was attempting to use the DAQ Assistant to do this. Do I need to force it to re-read the changing value I am sending it? All of the examples I find show me more primitive methods, and I could not seem to get any of them to do what I want either. I need to send a speed reference to a DC drive.
My incorrect method was to recursively add a value for ramping the signal up or subtract to ramp down. This method works perfectly on an industrial PLC. I connected a chart to the signal just as it entered the DAQ Assistant, but the only way I could check the actual was with the DMM.
Are there any examples that use the Assistant? If not then I guess I will have figure out how to use the primitives anyway.
technomage

Hello technomage,
It looks like we have discussed this problem in another thread (found here). If you have any other questions about it, please post there.
Regards,
Jesse O.
Applications Engineering
National Instruments
Jesse O. | National Instruments R&D

How to select signals from the output of a DAQ assistant

Hi!
I am a new user of Labview 8.5 and I am working with a USB-6210. I have two different instruments connected to the same USB device, half of the channels are being used for pressure transducers where I only need to reed and save the data, while the other half are associated to TCD detectors where I need to perform some analysis to the signal to obtain and save the data. I am in the first step of building the block diagram, After I define each of the signals which its corresponding channel using the DAQ assistant, I need to select and separate the signals coming from the pressure transducers from those coming from the TCD detectors, before I can continue drawing the block diagram. I am trying to use the Select Signal function but I am not sure how to do this. Can anyone please let me know at least in which manual can I find a good explanation? I have been reading the Getting Started and the User Manual for LabView but they have not been very useful so far.
Thanks!
Solved!
Go to Solution.

Wire the Select Signals express VI to your DAQ Assistant and run the VI once (this allows the signal names to propegate). Then when you open the Select Signals configuration you'll be able to pick out the channels you want by name instead of just "Signal 1" etc.
It sounds like you'll probably want two Select Signal Express VIs, one for the TCD detectors and one for the pressure transducers. Something like this:
If you right click on the VI and select Help or click on the Help button within the configuration dialog you will bring up the LabVIEW help page for this (or any other) VI. Are you looking for some other information that isn't documented in the help file?
Hope this helps,
Simon

DAQmx driver for DAQ 6009? Need DAQ Assistant in Block Panel palette.

Do I understand things right? The Ni USB DAQ 6009 is supported in DAQmx base and not DAQmx, or is this only true for the 6008? I need the DAQ Assistant in my LV 2009 Block Panel palette. Do I go to my Ni-DAQmx 8.8 CDs, or do I download something. Maybe I have the DAQmx base already? I'm going to search my palette and NI Max. I am also going to look at http://www.ni.com/support/daq/version_portable.htm#du. If I'm going about this all wrong, please help.
Thanks
Norm

Hi Dennis
My DAQmx Cds are 8.8. I don't have a selection for the DAQ Assistant on my block panel palette, so I'm looking to get an update for my DAQmx driver for my USB 6009 DAQ that I'll be using with my student software for LabVIEW 2009 version 9.0. I've looked at a NI document "NI-DAQmx and NI-DAQ Driver Support: Portable Devices" that was published on Jan 17, 2013. It says for Windows 7 I should be using 9.6mx, but this document make no reference to a version of LabVIEW. The date of the document is 1/17/13; maybe it is refering to only to version LabVIEW 2013. Can you help?
From what I've read I believe I need to use DAQmx and not DAQmx base, but I can't help wondering if the DAQmx base has something to do with the "NI DAQmx Device Basics" that I see on the right side of the screen when I'm in NI MAX getting ready to run the test panels. ?????
Thank you for your time
N.D.

I'm trying to set up a DAQ assist just to measure some voltage, how do i get the graph to start from 0 (time) every time I press run

Hi all,
I am trying to set up a simple DAQ assist to measure some voltages (currently a 9 volt battery to aid set up), when choosing to use a waveform chart to log the voltages the graph doesnt start from 0 (time seconds) how do I do this and get it to reset every time I press run or even stop.
What I want to see at the end is a chart for the full lenght of the test showing voltage against time in seconds.
Any ideas peeps
many thanks
Shane

Hi Shane,
Look at this VI
Here, I clear the chart before running the VI, using a 'history data' property node ( i pass an empty array to clear it)
In effect, each time you run the VI, the chart will begin at 0:00
Hope this helps
Regards
Dev
Attachments:
chart_start.vi ‏20 KB

Error message from labview when trying to set up the DAQ assistant

I recieve a message from labview when I try to set up the DAQ assistant and select a channel to use. The error I get states "An exception occured within the external code called by a Call Library Node. This might have corrupted LabView's memory. Save any work to a new location and restart labview". Labview then freezes. I have reset the DAQ device in trying to slove this but I still get the same message. How do I solve this?? thanks - mars2006

Hi Mars-
It sounds like your NI-DAQ installation may have become corrupted. I would suggest uninstalling and reinstalling the DAQmx 7.4 driver to correct this problem and ensure that you're up to date. This download is available here: NI-DAQ 7.4
If the problem persists you may want to uninstall and reinstall LabVIEW and then NI-DAQ in that order. The error message will usually give an indication as to which VI the error occurred in. Please let us know which VI is failing if you're unable to avoid the error with these suggestions.
Have a good day-
Tom W
National Instruments

How to deal with the Error-89130 about the DAQ assistant?

Once prss the "test" button of the DAQ assistant, the "Error-89130 occurred at DAQ Assistant" show up. It`s no doublt that the labview programme with a DAQ assistant can`t be run and instead the " Error-88303 occurred at DAQMx star Task Vi:1" or " Error-88304..." show up while other labview programme without DAQ assistant can run corrrectly. I have reseted or reinstalled the DAQmx, but it didn`t work. Any other ideas for troubleshooting this? Thanks

Please refer to this KB, and see whether it works. If problem also exists, please tell the DAQmx version and the DAQ card name.
Haifeng Xu
NISH AE

How to properly read data from one DAQ-assistant and write simultaneously with another DAQ-assistant (which is inside a loop)

Hello.
I'm a newbie working on my Master's thesis conserning a project that is based on old G-code made by another newbie so bear with me.
I need to create a sequance of output controls. For this I'm using a for loop that eventually creates two triangular ramps during a period of 90 seconds. I've confirmed that this function works properly by measuring the actual output of the DAQ-decice (NI USB 6353).
The problem is the following: During this controll-cycle I need to simultanously collect data from the same DAQ-device. At this point there is only one DAQ-assistant output-block in the main loop of the program and all the signals are derived from it to where they are needed.There is a case-structure (the bottom case structure in the picture) that contains the functions needed to collect the data during the test cycle. However these two actions, outputting data and inputting data, are not synchronized in any way which may be the reason why I get the 200279 error or alternatively the 200284 error during the test cycle. I've tried changing the sample rate, buffer size and the timeout time as adviced but nothing seems to help.
What would be the simplest way to solve this problem?
Help is greatly appreciated!
Attachments:
problem.jpg ‏206 KB

Thanks for quick reply.
However, I did try it (see the picture) but I still have a problem: I only get 100 samples / channel during the test sequence (all from the first seconds of the sequence) in total even though I've set the data aqcuiring DAQ-assistant as "continous" and "samples to read = 95k" and rate is 1000Hz.
Edit.
And lastly, I have trouble adding this "extra" DAQ-assistant to the vi. because I get an error about a resource (The 6353) being reserved, even though I connected a false constant to the "STOP" -input of the main DAQ-assistant.
Attachments:
is_this_what_you_meant.jpg ‏212 KB

Calibrating DAQ Assistant

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