How to stop a single channel of data acquisition while continuing to monitor another?

Similar Questions

• How can I know how much memory is on my card data acquisition OR 6133?

  I have a NI 6133 data acquisition card, but I don't know if this is the model megaechantillons 16 or 32.  How will I know?

  Thank you

  Kevin Brown

  Hey Kevin,

  You should be able to find it by reading the attribute Input.OnbrdBufSize (property node DAQmx buffer in LV, DAQmxGetBufInputOnbrdSize in the C API).  To do this, you will need to create a task to HAVE.

  Dan

• 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...

  
  

• How to import a single channel of different TDMS files?

  Hello

  I have several tdms files which have the same structure of channel (ch1 - chx). Each channel by tdms file has a stored value.

  I would like to see the same channel, lets say ch1, of EVERY file of PDM, in order to have a responsible for all the tdms files 2D field

  the data portal.

  If I drag a channel from a PDM file, loaded on the data portal, I see a value of course. I would like to drag lets say five

  channels at once to get a 2D-plot in the display section.

  Is there an easy way to solve the problem?

  Thank you in advcance

  Hi Norick_17,

  I think you could do that with advanced search in the browser of DIAdem.

  Configure advanced as the attached picture. You can configure the search, so that you find ch1 on all files. Also, the select the minimum/maximum/average as additional search criteria.

  In the list of results, you will see a Channel.Maximum column. You can select this column and drag & drop it into your data portal. Each maximum value will be concatenated to a string.

  Best regards, Stephan

• How to stop "the transfer of video data" display on Twitch full screen?

  When switching to full screen when viewing a stream of shaking, a collection white/status box appears in the lower left corner of the saying of the screen "to transfer video data. "# {a kind of address}.
  Passage of the mouse causes the box to reach the bottom right.

  This does not happen to contract full screen in other browsers (IE and Chrome)

  Found, with the help of reddit.com/r/firefox/
  Mode full-screen status-4-Evar/advanced/Detect uncheck...

• How to control the sampling time during data acquisition

  I managed to manually collect 16 channels of analog signals (writing custom file VI) using a command Boolean start/stop.  I would like to allow the user to set a term of the sample on the front panel (for example, 20 seconds) and initiate sampling by clicking a start button.  The user can also put an end to the reception of the data before the end of the set time by clicking a stop button.  I looked at several examples of countdown timer, but could not figure out how to integrate it with my VI.  All suggestions and examples will be very appreciated.

  You are far too complicated. On the one hand, there is the function elapsed time on your palette. Secondly, as already mentioned, there is a relationship of basic arithmatic between samples per second and the number of samples to be read. Use you will get samples more than this as requested anyway. Finally, your code shows two analog read tasks. You can do that, unless there are two separate devices.

• How to stop a new dialog box to come while I get my master password?

  When I first get a Web page with a password on file Firefox invites me for the password. I was having repeated trouble with a new master password dialog box opening and taking emphasis until I have finished to enter the password.

  Now that I know what is happening I can cancel the new dialog box and complete my entry, but it is
  really annoying and distracting.

  Any help would be appreciated.

  FRED.

  Your post gave me the necessary idea. I simplified the start as much as possible by defining a blank home page. Now if I wait a few seconds a single guest, which I suppose is the one who me, disrupted for the password appears. It seems maybe because I have sites with connections saved on My Favorites bar. I intend to investigate further.

  In all cases, it is a more comfortable solution that the insertion of an add-on.

  Thanks for your help.

  FRED.

• How to know the number of USB data acquisition device

  There are 2 devices and user can plug in different port each time.

  But the program uses the same string of device and may have errors.

  They can auto detect and generate the device chain, thank you.

  Is this something similar to this (using) you need? If so, please go from the link to Andrew post (a 2nd). Post if you need something else.

  Thank you

  Mathan

• Sample of high acquisition rate of data using data acquisition and continuous data backup. Also I would chunck data into a new file in each 32 M

  Hello:

  I'm very new to LabView, so I need help to find an idea that can help me to record data continuously in real time. I don't want the file is too big, so I would like a new file in Crete in each 32 mega bytes and clear the previous buffer. Now I have this code can save data of voltage in the TDMS files and the sampling frequency is 2 m Hz, so the amount of data very fast increase and my computer have more ram 2 G, then the computer hangs after 10 seconds, I'm starting to collect data. I need some advice you briliant people.

  Thank you very much I appreciate really.

  I'm a big supporter of the architecture of producer/consumer .  But this is the place that I recommend.  The DAQmx Configure Logging does all that for you!

  Note: You will want to use a table instead of a graph here.

  

• When I watch bbc iplayer after 20 minutes the screen will become blank until I move the mouse how to stop what to do please... .thanks

  How to stop my laptop goes into mode 'sleep' while watching TV on the iplayers for my sins, I am running vista it wake up if I

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  I suggest you to change the power Plan settings to solve this problem.

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• 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

• Multichannel data acquisition and 2D signals

  Hello

  [Use of labview 2011 license academic with NI9234 and cDAQ-9178].

  I'm trying to read, display and record the signals from two isotronic accelerometers and a microphone at the same time for future signal analysis (FFT, etc.).   I wish to display data of vibration and noise signals in real-time at 44100 Hz sampling frequency and display a waveform of final sampling, which takes about 40 years.  I would like to then write the data to a file.

  The associated block diagram, attached vi.  I could view real-time each accelerometer and sound using iterations of the loop and split the signal.  Unfortunately I record three channels of data in a table unique 1 d-wave form.  It seems that the data is saved as iteration1 (ch0) .iteration1 (ch1) .iteration1 (ch2) .iteration2 (ch0) .iteration2 (ch1)... and so on.

  Although I could show all three signals separately in the waveform graph, but I prefer these data to save as table 2D-waveform (each channel in a separate column).

  I believe that this issue has been raised here (http://ni.lithium.com/t5/LabVIEW/Concatenate-2D-data/td-p/873409) unfortunately no solution has been proposed.  How can I record the signals of data acquisition in 2D waveform?

  Thank you.

  I think to represent vi attached a solution architecture producer consumer for the problem mentioned above.  Just thought I'd share to those who can live a similar situation that I had been faced.

• How to control several input channels analog daqmx for data acquisition trigger (all on the same SMU-6368)

  Using the SMU-6368 module, I would like to monitor the analog signal on multiple channels and trigger on several channels - relaxation and acquisition channels is all on the same device. Probably going to be sampling at 200 kHz and more. FM LV 2009 2012, with SV toolkit in Windows 7.

  If SW trigger is the only way to follow, there example code shows how to manage the block size, etc.. ?

  jkessler,

  Yes, the example was in 2012.  I didn't get what you asked for in your first post because I didn't know you wanted to ANY channel to trigger acquisition of all channels.  It is not possible at the hardware level, because you cannot specify four channels as the command source. This will be implemented in the software.  I recommend the reading of all four channels and neglecting data until you determine that one of the channels reached your threshold value.

  Kind regards

• How to stop compensation labview my data output by a fixed amount of 0.125 seconds of every second iteration 1?

  How to stop compensation labview my data output by a fixed amount of 0.125 seconds of every second iteration 1? (I have my DAQ Assistant contained in a while loop so that I can control the number of iterations and therefore the time of sampling).

  My apologies for such a badly phrased statement of problem. The question I faced which was the sign that I was getting a pair of accelerometers and through an amp. in my DAQ board felt an offset in voltage for a short period every second iteration 1. It turns out that the problem is that my laptop and the AGP were grounded. Once I disconnected the signal ground in the shift of the signal amp went.

  Thank you for your messages.

  Kevin

• How to find the time between two channels of entry in the data acquisition card or pci 6036

  Hello

  I read a lot-related posts on the simultaneous measurement of two input voltage of similar channels in map data acquisition. I know that the best material is "simultaneous measurments of the Series DAQ cards" but I only pci data acquisition card 6036 and I try to understand what is the time between the reading of the two channels . This period is always constant? (must it rely on a voltage (amplitude, frequency, waveform..). I send the sine wave (s) to the two channels and read the values of V, if they read the same value, the difference should always be zero but I get-0,002 to 0.002 Volt difference (I must find a way to convert it in time). A screenshot of my VI is attached. I wonder how I can accurately measure the time delay between the channel.

  I am open to any suggestion, my final goal to read exactly two channels at the same time ((ou connaître le délai exact donc je peux correspondre les données correspondantes étant donné le temps de retard))

  Hi spinup,

  better you should post your question in the forum of LabVIEW, LabWindows/CVI is used

  Good luck.