-> Corresponding DAQmx data acquisition

Similar Questions

• DAQmx data acquisition with persistent error of nyquist

  Hi, I created a multi channel data acquisition vi (accelerometer 2 and 1 sound pressure) using models for producer.   The vi is attached. Thanks to labview 2011.  I get the error of nyquist (2 enclosed) when you make a bandpass filter between 50 to 5000Hz.  This happens despite having put my sampling rate to 22050Hz.  When I checked the output of wave I noticed that the signal has a dt 1 s.  The text output to check the result.  I could not understand how this is so since I had set the sample rate to 22 k Hz.  Any help will be much appreciated.  Thank you.

  I would do something like that.  You must calculate the dt of the set (with the recipricol) sampling frequency and use to initialize the shift registers.  This way you only need to change 1 constant if you need to change your sample rate.

  

• Problem to stop the task of continuous using API C DAQMx data acquisition

  I'm doing the acquisition of data in the PCIe-6536 continuously using DAQMx C API. But whenever I try to erase the task and put end to my application, program stops and it is not completed by the Task Manager and task killer applications. Can someone help me with this?

  Sameer

  Hi John,.

  Thank you for your concerns. the example attached also created the same problem. Then I run the test of the device to the MAX and it failed. Then I realized that there is something wrong with the installation. I simply uninstalled the card and installed on the other PCI-e slot. This time, self test has been successful and so did my request.

  So my problem has been resolved

  Again thank you for your quick response.

  Sameer

• Data acquisition tool NOR-DAQmx with Matlab R2012a

  Hello

  I'm trying to control NI USB-6211 of Matlab 2012 using NOR-DAQmx Data Acquisition tool:

  http://zone.NI.com/DevZone/CDA/tut/p/ID/3005

  I'm working on win7 64 bit. And I see the device AND Measurement & Automation Explorer.

  The tool does not work: DAQ_Demo_Browser do nothing. And I got the error "unexpected or unbalanced parenthesis or support" of AcqNUpdates_nonUI.m

  What is the problem?

  Thank you and best regards,

  Arthur Shulkin

  Hi Arthur,.

  Tools OR DAQmx for Acquisition of data with the Software Inc. MATLAB® from The Mathworks, supports up to the 2008 version of the MATLAB® software.  In order to use our products DAQ Multifunction with MATLAB® software, you could get back to 2008 or earlier, or instead use the Data Acquisition Toolbox provided by The Mathworks, Inc.

  Another option would be to import your ".m" files in a node MathScript in LabVIEW and use the functions of NOR-DAQmx everything in the LabVIEW development environment.  For more information on the Module LabVIEW MathScript, you can consult the information available on this link:

  Inside of the LabVIEW MathScript RT Module

  MATLAB® is a registered trademark of The MathWorks, Inc.

  Katie

• LabVIEW data acquisition Setup Multifunction DAQ

  I have doubts as to the acquisition of data in the LabView environment. I used the block diagram (Figure 1) below to review the update of the readings for the execution of a loop.

  Block 1 has been used to enable a task (first steps) with 3 channels (al) analog input AI3 and even set up the channel. In this case, the data bus (data-block 4) are construindos by 4 columns of data (provided by task 3 AI3 more).

  Block 2 is used to set the sampling rate in this case is 1 Hz (1 sample per channel x 1 rate).

  In this case, it worked as I expected (Figure 2). This allows to conclude that the interval between each sample was 1 second. The saw took a second in the iteration.

  The second step was to change the amount of data sampled in accordance with Figure 3 channels in block 3.

  Now, each channel showed 10 samples, while there are 4 channels configured, we have 40 samples. In this case the iteration totalled 10seconds (point to 1 Hz and 10 samples per channel-figure 4).

  The first question is what is the time between each sample obtained by channel?

  In this type of configuration (multiple channels), block 3 provides 10 samples in each channel, as well as the sampling is done, IE, the block gets 3 10 samples from a channel and passes to the next channel or gets 1 comp each channel and repeat this process up to 10 samples per channel?

  What is the best way to make sure that the interval between each sample is constant?

  If anyone knows any text that explains what the function blocks of data acquisition information please.

  Thank you

  Gabriel

  Well, there are several ways to read the signals of multiple signals, and each of them has different behavior. I couldn't see how you get mutiple channels, because in the two codes, you set a channel in your codes. Take a look at this figure:

  

  Here you can see how to set multiple channels using DAQmx, using commas to separate the channels. About the ways different ways that you can read the signals, you can look at the links I sent in my first post to learn more about them.

  In a few words, the time between samples from the same channel is T = 1/Fs, corresponding to the sampling frequency Fs. It is not a rule to determine the interval between samples from different channels, because it will depend on how you did your code, and as I sad, there are different ways to do. You can acquire the samples at the same time, or you can configure your code to read a fixed number of points of a channel and then read another fixed number of samples to another channel (https://decibel.ni.com/content/docs/DOC-28279). You can acquire a finite number of points, or you can acquire all the time. Yet once, take a look at the material that I have already sent. It will help you find the best solution to achieve your code according to your application.

  Kind regards

  Pedro

• 2 channels of AI on a data acquisition with the range of different sensitivity

  This vi is based on the 'new project' state machine on the home screen at the start of LV.

  A time loop is parallel to the main loop of the state machine, shown in the picture.

  It works continuously until you press the Exit button.

  The problem seems to be in start this... > read >... stop start > read >... stop along the error line.

  The reason for this clumsy arrangement power is measured voltages are in two lines of different sensitivity.

  The shunt voltage is small and needs-. 2 to the range of V.2. The load voltage is greater and 09:50 V range is good.

  In the initializing state, two separate vi 'create a channel' have been used to specify the range of voltage to the physical channel. The corresponding tasks are sent via via local variables.

  DAQmx errors happen randomly, sometimes the first iteration, sometimes the 50th.

  I tried to disable one or the other start > read > stop for the shunt voltage or load.

  I tried replacing them with the DAQ assistant.

  I tried various DAQmx vi: "wait" and "accomplishment of the tasks by resource cancel selected".

  But error-50103 "specify resource is reserved" keeps popping up.

  Is it possible to create two tasks on the device even when they are not used at the same time?

  The only reason is to measure in two voltage ranges.

  Win 7 Pro 64-bit

  2014 LV database

  Data acquisition equipment: USB-6210

  Thank you.

  This has been discussed many times. Do NOT use separate tasks. You can use different ranges for different channels with a single task. Just wire the task from one channel to another channel to create task.

  You also use local variables when they are certainly not needed.

• Real-time display at the high frequency of data acquisition with continuous recording

  Hi all

  I encountered a problem and you need help.

  I collect tensions and corresponding currents via a card PCI-6221. While acquiriing data, I would like to see the values on a XY graph, so that I can also check current vs only voltage/current / time. In addition, data should be recorded on the acquisition.

  First, I create hannels to analog input with the Virutal DAQmx channel create, then I set the sampling frequency and the mode and begin the tasks. The DAQmx.Read is placed in a while loop. Because of the high noise to signal, I want to average for example every 200 points of the current and acquired for this draw versus the average acquisition time or average voltage. The recording of the data should also appear in the while loop.

  The first thing, I thought, was to run in continuous Mode data acquisition and utilization for example 10 k s/s sampling frequency. The DAQmx.Read is set to 1 D Wfm N Chan N Samp (there are 4 channels in total) and the number of samples per channel for example is 1000 to avoid the errors/subscribe for more of the buffer. Each of these packages of 1000 samples should be separatet (I use Index Array at the moment). After gaining separate waveforms out of table 1 d of waveforms, I extracted the value of Y to get items of waveform. The error that results must then be treated to get average values.

  But how to get these averages without delaying my code?

  My idea/concern is this: I've read 1000 samples after about 0.1 s. These then are divded into single waveforms, time information are subtracted, a sort of loop to sprawl is used (I don't know how this exactly), the data are transferred to a XY Chart and saved to a .dat file. After all that's happened (I hope I understood correctly the flow of data within a while loop), the code in the while loop again then 1000 samples read and are processed.

  But if the treatment was too long the DAQmx.Read runs too late and cycle to cycle, reading buffer behind the generation of data on the card PCI-6221.

  This concern is reasonable? And how can I get around this? Does anyone know a way to average and save the data?

  I mean, the first thing that I would consider increasing the number of samples per channel, but this also increases the duration of the data processing.

  The other question is on the calendar. If I understand correctly, the timestamp is generated once when the task starts (with the DAQmxStartTask) and the time difference betweeen the datapoints is then computed by 1 divded by the sampling frequency. However, if the treatment takes considerable time, how can I make sure, that this error does not accumulate?

  I'm sorry for the long plain text!

  You can find my attached example-vi(only to show roughly what I was thinking, I know there are two averaging-functions and the rate are not correctly set now).

  Best wishes and thank you in advance,

  MR. KSE

  PS: I should add: imagine the acquisition of data running on a really old and slow PC, for example a Pentium III.

  PPS: I do not know why, but I can't reach my vi...

  
  

• data acquisition won't taste at the specified rate

  Material: C - DAQ 9178, AI 9239, inside a servo and an encoder potentiometer module

  Setup: I use the 9239 to measure the angular position of my servo and encoder of trees by streaming came pressure pot of the servo and my encoder. I put the sampling frequency on the DAQmx - Schedule VI to 100 Hz.

  Problem: I don't think that my DAQ is sampling data at 100 Hz because my VI registers more than 10 000 data points for a 10 second test. In addition, every time I have save my data in a text file, the vector of time my test data resets after a number of iterations.

  To debug, I tried the following configuration:

  I've defined the sampling frequency of 100 Hz (or is that s/s?), the samples per channel (size of buffer for continuous mode) at 2000 samples, number of samples per channel up to 10 and loop milliseconds timer on my VI at 10 m accordingly, data acquisition would send 100 samples per second (or 1 sample every 10 ms) on my PC buffer (which could store 20 X that amount). Then LabVIEW would read up to 10 samples per loop iteration (which is itself ~ 100 Hz) and work with these 10 samples inside the loop. However, since the loop is operating close to the sampling frequency of data acquisition, then LV should only work with 1 sample each iteration of the loop (100 Hz / 100 Hz)-not the 10-sample-max that I specified.

  However, I stumbled on "error-200279: the application is not able to cope with the acquisition of material" when I ran the program. Why?

  My code and materials should be easily able to cope with data acquisition - at least the way I put it in place

  This whole situation wondered my fundamental understanding of data acquisition timing, so I would really appreciate an explanation of exactly how to deliver DAQmx uses data synchronization, why my DAQ sample at 100 Hz, and how can I fix the calendar specified by the user.

  Thank you!

  aeroAggie wrote:

  The C - DAQ 9178 there some minimum sampling rate I will not meet?

  It's actually the 9239 that limit your sampling rate.  Read the data sheeton page 5 there's available data rates.  In short, your data rate allowed is 50kS/s / n, where is goes from 1 to 31.  50 k/31 gives you 1.6kS / s.  So, it's the minimum sampling frequency that can be used.

• DSA maxing out CPU data acquisition

  I'm developing an application on a PXI-8196 (Windows XP) controller that uses a card PXI - 4472 DSA to read a single microphone and a FFT signal analysis. I need solve the two frequencies of 36kHz (and), so I've planned for sampling 96 kech. / s. I wrote a simple loop of data acquisition, configuring NI44xx DAQ/read screws using read the string unique at this rate, but when I run it, it immediately pegs my CPU 100% usage. So far, I did have problems with missing samples or the system crashes, but I am a little concerned that only data acquisition uses all my CPU time. Y at - it tricks that I can implement to reduce the CPU load?

  I tried to vary the parameter samples per channel - with sizes ranging from 1000 to 48000 samples - buffer but I do not seem likely to reduce the CPU usage. Changing the sampling frequency affects the CPU usage (up to about 40% to 48 ksps / s; ~ 75% 72 ksps / s), though. According to this KB: http://digital.ni.com/public.nsf/allkb/D9DDF9FA02D1C18A86256EBC0016C93D

  "A controller Embedded PXI-8176 can compute all the time of the spectra of FFT power on 8 channels for PXI-4472 clocked at 102.4 ksps / s »

  so I think with my 8196 I should have no problem at all to read only one channel 96 kech. / s.

  Anyone have any suggestions to reduce my CPU Overload? Thank you!

  Here is a link to some good information on how to OR-DAQmx 7.4 and later behaves with respect to the use of the processor: Default CPU use with NOR-DAQmx Version 7.4

• measure the angular speed, angle and trigger using a gyroscopic sensor breakout board and LabView data acquisition

  How to measure the angular velocity, the angle and trigger using a gyroscopic sensor breakout board and LabView data acquisition?

  There is a single channel data acquisition code which measures the angular velocity, angle and flexibility using a gyroscopic sensor breakout board and acquisition of LabView data attached to this, I need a help to creat two-channel data acquisition code?

  Hello

  Attached is a vi that you can use in order to read the measured angular position of an encoder.

  If you need more examples on the tasks that you can develop with NOR-DAQmx and LabVIEW, you just need to open LabVIEW and click Help > find examples > Input and Output material > DAQmx > entry counter.

  Kind regards

• data acquisition stops automatically

  I want to stop assistant DAQ automatically after a period of time, so I created this VI.

  When I start the program, it work and after reaching the value of time specific 50, the graphical indicator ' looks like "stop, but wait after 9999 second, the graphical indicator suddenly see a lot of data that seems to be taken for the 9999 seconds, what is happening? After that, it gives an error saying:

  Possible reasons:

  Attempted to read samples that are no longer available. The requested sample was already available, but has since been replaced.

  Increase in the size of buffer, most frequently the reading of data or by specifying a fixed number of samples to read instead of reading all available samples would correct the problem.

  Property: RelativeTo
  Corresponding value: current playback Position
  Property: Offset
  Corresponding value: 0

  Task name: _unnamedTask<100>

   

   

  Data acquisition cannot be stopped like that?

   

  Thank you

  Not quite.  Like this.

  

• Data acquisition - DTR

  I need to perform data acquisition for my sensor of temperature RTDS (PT 100). My sensor is first attached to the converter temperature Broderson PXT 10, then to BNC-2090 - NI. national instruments DAQ board.

  PXT 10 gives 0 - 10V DC output, which is then provided to BNC-2090.

  While BNC 2090 reads only the voltage, data acquisition give some readings of voltage. I want to know how I can convert the resulting voltage reading DAQ corresponding temperature.

  Currently I use Callendar Van Dussen equation for conversion. As I take a very low current exciation, conversion gives me a thousand ohms resistance values, and that's why I don't get the value of the correct temperature.  I have attached a reference image.

  Can someone please help?

  Thank you.

  Raphael,

  Even if the plug is not explicit, the implication is that output (0-5 V) is linear in the selected temperature interval. So 0 Volts would represent - 50 C and + 5 V would be 300 C or C 100 depending on the range. All you will need is linear (m * x + b) scaling for temperatures.

  You must run probably some simple calibration verification tests to make sure it works that way.

  Lynn

• Data acquisition in LabView for other suppliers DAQ cards that NEITHER

  Hello

  I am a beginner in LabView programming. I have a 32 channels base PCI card DAQ (i.e. PCI-1602 of the manufacturer, ICPDAS) and I want it to interface with Labview 8.5.

  So how cards DAQ in Labview 8.5, which are manufactured by other suppliers that NEITHER? Should I DAQmx (or some other driver) for that?

  What are the other drivers/components required to access of data PCI-1602 (device) of LabView 8.5 acquisition card?

  (1602-PCI card driver are installed in my win XP and dispalyed in Device Manager).

  Please provide some tutorial above mentioned the problem to interface.

  Please guide me in this regard. Thank you

  Waqar123 wrote:

  Hello

  I am a beginner in LabView programming. I have a 32 channels base PCI card DAQ (i.e. PCI-1602 of the manufacturer, ICPDAS) and I want it to interface with Labview 8.5.

  So how cards DAQ in Labview 8.5, which are manufactured by other suppliers that NEITHER? Should I DAQmx (or some other driver) for that? You will need the drivers from the manufacturer, of the Board of Directors.  In your case, "ICPDAS.

  What are the other drivers/components required to access of data PCI-1602 (device) of LabView 8.5 acquisition card? Same as above.

  (1602-PCI card driver are installed in my win XP and dispalyed in Device Manager). Ok.  Then take you care of my 2 answers above.

  Please provide some tutorial above mentioned the problem to interface. To learn more about LabVIEW, I suggest that you try to watch some of these tutorials.

  Please guide me in this regard. Thank you

  According to what you do with the DAQ cards, they can do the job however, from experience, there are some functions that I could achieve with the cards NOR that I couldn't with 3rd-party maufacturers.  This does not mean that this is your case. However, it is worth noting that it took me a while to understand why the code has worked with a single data acquisition card (NOR) but not another (Non-OR).

  The drivers that you have installed may or may not include examples and code in VI.  They may be DLL.  If this is the case, you can write LabVIEW "Wrappers" around these functions, as it will simplify your life.  If the drivers are in the form of DLLs, and there are no examples of LabvIEW or available VI, you must read on node library function call.

  R

• Data acquisition component

  I am writing my first app Measurement Studio DAQ but the model NI DAQ component not available under PROJECT > add new item.

  -Execution of Visual Studio 2008 with VB and Measurement Studio Professional 2009.

  It seems that I do not have access to the DAQ Assistant of Measurement Studio.

  Download

  More ms-help://MS. VSCC.v90/MS. VSIPCC.v90 / NOR. MeasurementStudio.2008/DAQIntegration/XML/Create_NET_DAQ_Component.html

  1. Open the project in which you want to create a component of data acquisition. ... Ok
  2. "SELECT project ' add a new item to launch the add new item dialog box.  ... Ok
  3. In the categories pane, select Visual Basic components if you use Visual Basic .NET. Select Visual c# project items , if you are using Visual c#.  ... NO... "Visual Basic items" is not part of the list of categories
  4. In the Templates pane, select OR DAQ component... Not available in the models pane

  Help, please!

  -David

  Hello Panorama,

  After installing Measurement Studio, OR-DAQmx have you installed?  If so, you should make sure that the Measurement Studio for VS2008 component is selected to be installed.  You can select the custom Setup option to check this setting.

  Kind regards

• How to increase the speed of data acquisition?

  Hey, currently I using 6210 OR of data acquisition and control switch. I used labview to periodically check the 7 switches and read data from 7 channels in the meantime (1 sample on request). I ran 70 loops for 10 groups of data, the cost of the time looked like 2.2 seconds.

  I would like to end a 700 loops in 2 seconds, is it possible to improve?

  Thank you

  PEM

  Look at the Terminal stop of the DAQ Assistant Express VI. You are starting and stopping of the task for the acquisition of data on each iteration of the loop.

  Starting from the help file:

  Stop

  Specifies to stop the task and release device resources when this Express VI ends execution. For ongoing tasks, this entry is FALSE by default, which means that the task is running until the application terminates. To stop the task, you can use the device again in the same application, wire control wire you the Conditional stop this entry to the same terminal of the while loop. For single-point and finished tasks, this entry is TRUE by default, which means work stoppages after all samples are acquired. To optimize the performance of single point when using this Express VI into a loop, wire control wire you the Conditional stop this entry to the same terminal of the while loop.

  Also from the help file:

  Continuous single point of entry or exit, the of VI Express DAQ Assistant cannot allow optimal operation. See Acq & chart voltage-Single Point optimization VI in examples\DAQmx\Analog In\Measure Voltage.llb for an example of techniques to create more powerful applications, single point of I/O.