Waveforms vs DDT?

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• get the values of the different acquisition channels

  Hello everyone,

  I finished my project and I want to do something and I did not how. I am acquising three signals from three different pressure sensons with the use of the DAQAssistant configuration to acquire form three analogue ports (there is a screenshot it below) and after it is shown in the same graph (second picture below).

  This works fine, but my problem lies in the fact that I want to measure the maximum value and the value of the minimum pressure of each channel and always it is measured the first of them. I divided the measures in time-slopes as it is shown in the last picture. I have tried every single Vi of part manipulation of the function range signal, but I'm still not in the way of their use or I'm totally wrong actuing in this way.

  Could someone give me a hand?

  Thanks in advance.

  Best regards

  Miguel.

  Really, we do not have enough information to give you good advice, but I can give you some generic advice.  If you want the max and min an array of values, values use the Max & Min table from the palette of Array.  Unfortunately, the DAQ assistant returns the type of dynamic data, which can be either a table of waveforms or waveform unique depending on how you do.  Configuring your DAQ Assistant, it seems you are getting a picture of waveforms, but to use it as a form of single wave.  Just after taking the data, convert your dynamic data type data type in a table using waveforms the DDT express VI in the Express-> palette of data manipulation.  It would probably break a lot of your code, and it's a good thing.  Broken parts are parts that are probably causing you problems.  You can now use the index table to get the individual waveforms to the table and get elements of waveform for the picture of the waveform data.  Use this table with table Max & Min to actually find your max and min values.

  Alternatively, you can use Split Signal of the Express-> palette Manipulation of data to split your output into three unique waveform signals.  Each of these signals can be plugged directly into the table Max & Min (LabVIEW will be script in the necessary converter).  However, I highly recommend that you do NOT.  It leaves you the problem that your data type is not defined yet, as this is always a type of dynamic data.

  Also note that the use of globals as seen in the pictures of your code is a bad habit that can lead to all sorts of problems.  However, I can't offer a lot of advice on how to fix it without the rest of your code (Tip: will probably involve some shift registers).  Please post your screws if you have questions, so we can offer the best advice.

• How to draw a picture of waveforms?

  The computer on which I build my VI doesn't have internet access, so I can't post my code (so I'm going to use as much detail as possible)

  I take the DAQ measures for four devices that come as (I think) an array of dynamic data type. I split the signal and I have each its own dynamic data type output channel. After an interval of time specified by the user, a timed, while the loop will trigger data acquisition to a measurement and write the data to a file and plot the data. Writing file was easy, but I'm stuck on the appearance of tracing.

  What I have: given that efficiency will not be a problem (average time delay of ~ 15 minutes), I created a dynamic data type shift register. Each iteration of the while loop, I add the data newly acquired an array of dynamic data by using the function BuildArray. I have to be able to take this and it draw in a graph, but each time I try it tells me that the dimensions of the source and the receiver do not match. Also, I need it for each of the four data sets (and put them on the same plot).

  What can I do to get plottable data in my shift register?

  I can't open files .VI, then I would really appreciate if I could get answers in images of diagrams or text. Thank you.

  Hi nc61,

  stay away from DDT (dynamic data type) and you'll be fine. Especially trying to collect data by setting up arrays of DDT (which probably is not what you really want)...

  -Use DAQmxRead to get the data tables or waveform (s). BuildArray use for simple data or functions of wave shape of waveforms to collect data on the move of the registry. It will be easy with these tracking data!

  -There's the finder of the fine example known in the LabVIEW Help menu. Try it...

• How to transfer data from waveform for a sub vi

  I'm seeing plots in a Subvi when I want. In my test, the waveform in the main VI display several plots of channels as I expected, but the Subvi shows only a single parcel. Joint programme.

  I can simply convert the dynamic data in table 2D Digital to display several plots, but I will loss the timestamps I really want to show in the plot than in the main program.

  Thank you

  hrwang wrote:

  Thank you. I tried to follow your instructions.

  In fact you have not.  You did not create an indicator of waveform bays to copy onto the Subvi bays of waveform control.  See attached Subvi that I modified.

  However, it still shows a plot in the sub vi and plot begins time 0. The new program is attached.

  This is because you have created a table 1 d double which means only 1 field and no data delay

  I think that the 2D table are necessary to have several plots.

  No. a table 1 d of waveforms can be used for several plots.

  I want to run the program for the day, so it is convenient if I see the date/time in the x axile, like the one in the main program, instead of from the time 0. Dynamics of the data type is complicated and I don't want to deal with its structure, that's why I use a waveform as a control chart, hoping the information all dynamic data is transferred to the Subvi plot properly. Apparently, it did not work.

  If you don't want to use dynamic data, then do not use the DAQ assistant.  The DAQ assistant, is what gives you dynamic data.  I see that you did to a conversion of DDT in a table 1 d of waveforms, which is good.  Now you just send this table 1 d waveform to the Subvi.  Because you used a table 1 d of doubles in the Subvi, you have a conversion point.

  All solutions?

  Thanks again.

• Detection of peaks of waveform data

  Hi people.

  It is probably obvious, but I can't understand it. In the attached VI sine wave detector summits are determined from a simulated signal. I want to be able to do the same thing with a waveform data (DBL), but it won't let me. How can I extract the signal of the LDM to feed the rest and make the waveform work VI right Ridge detector?

  Thank you

  Select this option.

  Use of DDT, found in the range of Signal handling, to change the dynamic thread in a waveform.

  Bob Schor

• Not sure what type (Variant) to wire in Datasocket read to a waveform.

  Hello

  I have an accelerometer attached to a housing NI USB-6008 and I try to send the readings taken with it to the server datasocket, (see attached files).  I'm not sure what information and variables are necessary to be wired data read vi (Variant) type so that it displays the information on a waveform graph.

  The accelerometer is just by the way an analog voltage.

  Any help appreciated.

  Hi Ultramar,

  How Datasocket got out before the dynamic data Type was created, it doesn't have full support for this type of data. There is an easy solution that you can apply, which converts the DDT into a table 1 d of waveforms. Screw seal (in the zip file) will show you how to proceed.

  You will also need to add an element named 'test' for Datasocket Server Manager, I've included a settings file, you can import into the DS Server Manager.

  Finally, you will need to run the DS server and you will get the communication.

  I wish to indicate that the 6008 is not the best map to read the values of acccelerometer, but the above steps will allow you to send the data. You will need to change the physical hardware DAQ channel in the publisher.vi DS because I modified the DAQ assistance to work with my setup of the computer.

  Concerning
  JamesC
  NIUK and Ireland

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• Table of waveform does not change with time

  Hi all

  I have attached the VI I'm working. I haven't done any progress with VI after watching a few tutorials and read. I probed the entrance to the waveform graph, and it is simply not chaning over time (x-axis). What should I do? Data works very well.

  Sorry end that.  Here, it's in 2010

  Dynamic data wires are blue SNO - they can take almost all data - (some of us older users despise them as much as express screws) hang a DDT directly by a waveform chart to your question the WC provided by default Datatype DDT.  Conversion of the scalar measure express vi everyone downstream forced to accept that the data was just a simple DBL.

• use the time stamp value find value Y in another waveform

  Hello, there, I'm using labview 2013 sp1. I'm sorry that I can't use a picture to describe the problem.

  The wizard sampling DAQ 2 waveforms of 2 channels to HAVE

  Want to use mounted on board one of the waveforms as the triger to get the value of Y to another waveform (as was done with an oscilloscope)

  I tried method 2:

  1. the useto separate a waveform to and use to get the time of adjustments

  2. always use

  and use to get the timestamp.

  are - this method works?

  the problem is how can I use the value of time I've learned very well the value of Y in other waveforms?

  Thank you much in advance.

  I'm sorry you use screw Express, and I'm even more sorry that you are using the dynamic data type.  Using these are not your fault, it's that NEITHER recommend for new developers, but you tend to not have as much control then you type using more stringent data and write the code yourself.

  Using Split signals you can withdraw all of your signals since the type of dynamics and process data of each.  Don't know why you would use signals select but which, in my opinion, they do the same thing.  Then, you use DDT to to get your data into a format that is more useful.  Select the Conversion of a single waveform.  The explanation I gave in my previous post is valid.

  Joined a VI that does what you want.  You can see that once you have a waveform and its components, you can do a much better job.  Like finding the Min and Max of a wave by using table functions.  It searches the first place where AI0 went above your trigger and then gets the value that AI1 was at this same level, which will be at roughly the same time.  Don't forget not that served it one after the other, so no two samples will be taken at the same exact time for most of the DAQ cards.  Few are simultaneous sampling.

• FFT waveform (file converted from Matt file lvm) - how to overcome the error dt < = 0?

  Hello

  I use a lvm file after conversion of Matt file. I wanted to get the fft spectrum. I get this error message this dt waveform<>

  How he overcome?

  I have attached the matte file and the vi that I used.

  Best regards

  FESMI

  The Forum is a bit special files that can be attached. Creating a zip file often works. Sometimes, you can change the .txt extension. If you change the extension, please indicate in your message which was the extension of the moose.

  It seems that data in the file has a time column and a column of amplitude. The LabVIEW waveform data type is a cluster of a table of amplitudes (Y), sampling interval (dt), from the time (t0) and optional attributes. That's what the power spectrum VI requires as input. The t0 values is not used if the default is fine. the value of dt can be calculated by the difference of the two adjacent values in the time column. Given that the first value is equal to zero, the second value is equal to dt.  Use the primitive to build a waveform of the palette of waveform.  Expand it to view the dt element.

  In the VI attached all lines is an indicator that contains your saved default file data. Graph XY plots that data.  After subtracting the way to get rid of a continuous component, the data is converted to a waveform. The power spectrum is calculated and displayed using the same VI as in your program. It also uses extract several Information.vi tone for the frequency and amplitude of the main peaks in the data.

  Interestingly, the lower frequency of the spectrum a harmonic of 60 Hz while the tops are almost sharp space 4 kHz ~ 100 Hz apart.  The broad peak near 2.1 kHz does not seem to have noticeable components to 60 or 100 Hz.

  How to avoid the Type of dynamic data (DDT)? Stop using screw Express! For reasons known only to EITHER screw Express a deliver their outputs via the DDT. Except when you open the block diagram of the express VI, there is no way of knowing what the underlying data structure on a thread of DDT.

  Lynn

• Viewfinder LUT vs exposure tools (Zebra / waveform)

  Hi guys,.

  Discussions on our new found access to MLUTs and the AE CINE was great, thanks for all the info fascinating so far. So forgive me if this has already been covered, but I have two questions:

  (A).. .for MLUTs in the viewfinder to be of any practical, why use the waveform monitor and the Zebra reacts to the MLUT when applied, as opposed to the same as if the MLUT has not been applied to all? IE - as an image in the viewfinder as slog2 sgamut my Zebra / wave give me information of the exhibition which is very useful (next to my light meter) but when I apply, say, the REC709 MLUT of the VF, news of Zebra and waveform to adapt to the new image - so REC 709 points out, blow and my zebras tell me now that the parts of the image is blown... But I'm still recording to SxS cards like sLog2 sLog2 - so, in reality, this info is not get blown at all.

  So what I mean: the REC709 MLUT is ideal to boost the brightness etc. in the viewfinder and makes the image easier on the eye than the image dark sLog2, but I always feel like my tools of exposure to expose properly for the image being recorded to the card (in this case sLog2). I hope that all makes sense... Accept others, or am I missing something here?

  and the second point is:

  (B).. .throughout all the upgrades for the camera by setting the number 2 zebras at 109% don't turn on for me in the VF, despite an image being obviously blown. No more than 108%, or 107%. However the zebras behave corectly to 106% and will show the 'Zebra lines' when the image is burned.

  Is there a reason why 109% zebras does not illuminate, or am I missing something here too?

  Thanks for all your comments guys - happy shooting.

  Tom

  www.tomdavid.com.au

  
  

• How to open file audio waveform

  We have a file on a USB audio waveform.  iTunes will not play it... any suggestions or recommendations on another application to use or download?  Thank you!

  VLC download it here: VLC for Mac OS X

• Scale of waveform

  In case others were too curious, our fantastic Canadian camera Sony rep gave us this scale of waveform.

  

  Currently, you cannot activate the display full screen, we are looking at this for a possible future update

  Concerning

  Peter

• Number of averages for time waveform acquisition

  Hello

  It is on the configuration of the device - settings of the acquisition.

  in the parameters of the collection file, can I know is there a way to feed the number of averages and % of overlap between averages aquire waving time.

  Thank you!!

  BR

  Pattabi

  In version 3.0 of InsightCM, we will support an average and overlap on the data of the spectrum Viewer.  These settings will be applied only to the visualization of the spectral data and will not apply to calculations on the waveform or spectral data form.

  This will meet your needs?  Or are you interested in doing an average and are superimposed on the spectral data to then be used for calculations that are based on spectral data - such as 1 x Magnitude, etc.. ?

  Thanks for the question.

  -alan

• Restart waveform immediately start trigger

  I create a waveform 50 ms with an SMU-5451 in SMU-1078 chassis with a controller of SMU-8840 running Labview RT.  The waveform is currently triggered by a pulse of a counter of data acquisition because the timing of the wave must be closely synchronized with data on the acquisition of data collection.  However, this approach is problematic because it is difficult to produce a continuous of the 5451 signal when it is triggered in this way.  If the waveform is exactly 50 ms long, will miss the start trigger.  I can tolerate losing at the end of the wave, but I can't tolerate having a gap in the output, and I need the waveform to start exactly on the edge of outbreak of 50 ms.  I can configure the 5451 to accept a trigger start and restart the wave immediately rather than wait for the current iteration of the waveform to complete?

  I guess I could use a complete the 5451 event to trigger the acquisition of data instead, but I guess there is a way for me to do what I want.

  Are you familiar with the mode "script"? You might be able to use this example script:

  script restartWhenTriggeredScript
  
    Repeat forever
  
      generate wfm
  
      break on scriptTrigger0
  
        Repeat forever
  
          generate wfm
  
        end repeat
  
      end break
  
    end repeat
  
  end of script

  Basically, the idea is that, when it receives a trigger, it stops the execution of the inner loop and finish the iteration of the outer loop. Then it will start again from the beginning and to the inner loop.

  Please let us know if that fixes the problem.

• Arbitrary waveforms with LVM file

  Before, to import a file of arbitrary waveforms to VirtualBench environment was carried out thanks to an option in the toolbar of the menu drop down and the Import Wizard allows import of files LVM. Since a more recent firmware update, it is now accomplished in the Panel containing the options for the function generator, but forced the wizard to import the files .txt and .csv only. Has anyone found how to load an arbitrary waveform as file LVM in the most recent update of the firmware?

  Jesse wrote:

  Before this function arbitrary waveforms, it was possible to load a file of .lvm for a waveform on the channel (1 or 2) and display it in the GUI of VirtualBench.

  You can load a waveform in the ASM or another instrument in the VirtualBench GUI?

  The only similar device that has VirtualBench is a waveform of reference for the scope, which was also added in 15.2. The post office announced that I linked above has a video showing this feature as well.

  You have screenshots of previous undergraduate design projects? I still think that we are badly understand each other.