Similar Questions

• Storage of samples of several analog channels (life-long)

  I use a USB6356 to read 5 analog channels (more digital input port A)) simultaneously until you press a stop button. The idea is to represent all the signals captured on a temporal scale after the acquisition.

  I am convert and storage of the 2D array that is captured in each iteration of the loop in another 2D array in order to have an output of 5 table lines (one for each input signal).

  However, Labview can not handle so much treatment in so short a time table (I think that the main bottleneck is the 2D Transpose VI table) and accidents very soon (I have to kill the entire process and restart Labview). Is there a better way to do this?

  See you soon

  Your problem is that you have horrible memory management here.  Whenever you add in the table, more memory is allocated, then the table is copied.  You are basically out of memory.

  1. use samples of N, N channels, 1 table D of waveforms for your Read DAQmx

  2. change your chart to a chart and move it to be inside the loop.  Maintain chart, a story, so you can still see the X last samples on it (1024 by default).

  3. save your data in a file.  I recommend using the DAQmx configure connection before starting the task.  This allows the stream directly to a TDMS file for further processing.

• The irregular sample in PDM data storage

  I have a request where I capture data (DAQmx) waveform of several cards of analog interface as I am data capture irregularly timed to an Ethernet network.

  The irregular data comes in as an array of values from layer to about 250 Hz with each sample set precisely time-stamped.  Synchronization between the sample is so important so that these data cannot be stored as a waveform.  It should be kept as an array of pairs of channels/timestamp or timestamp value / (array of string values).

  DAQmx data, of course, are given waveform with only the timestamp and necessary delta departure.

  Then, there are suggestions of popular community (recommended ways) of:

  1. Set a TDMS file for irregular data
  
  
  2. Create a single TDMS file for irregular data and DAQmx waveform data in a common format

  Thank you

  XL600

  In this case I used my first string be 'Time' and it is stored as an array of timestamps, where every hour is a value on this index to another channel.  There is a function in the LabVIEW on waveform palette which will take a waveform and generate all the times associated with the values Y.

  Oh and so I usually have a new group for each sampling frequency, then you might have DAQ as a group at a rate that is regular, and there a Time column, and another group might be called the series that has a column of data and time to a non-regular rate.

• I want to buy a flash with lightning connector data storage.

  I want to buy a flash with lightning connector data storage.

  I'm between Transcend JetDrive™ Go 500 and iXpand SanDisk Flash Drive.

  What do you suggest me? Do you have another?

  My first priority is speed and iOS app use of data transfer.

  Hello

  To get the advice of a large sample of existing users of each product, you could more usefully read ratings on Amazon.com and reviews of products.

  If your questions are not answered there, you can also post a question of your choice.

• Scope of digital storage of the homebrew: falling for the third time.

  I worked on an extended application of digital storage 5114 with most of the features of the NiScope

  Soft front and making little progress. The only approach I could think of was to start with an example provided

  and then modify it. I need to acquire several second waveform non-repetative @ 125ks/s, which is equivalent to 500 k

  samples. The Acquisition example configured to trigger dashboard will make me the waveform, but there over time. I need an application that will acquire the waveform, whenever it is triggered and hold until the next trigger. The applocation Soft Front Panel does well.

  As to why I'm just not using the S.F.P is twofold:

  1. I need to be able to isolate sections of the acquired waveform and calculate the effective as voltage peak to peak

  sections. I also want to make the integration of point by point to the area under the part of the envelope of the waveform.

  2. I tried to save the data of the S.F.P., but so far haven't had any success even open files.

  Koutcheens

  Attached is an example of NOR-SCOPE (which never shipped) that implements the exact algorithm used to extract data by the NO-SCOPE Soft Front Panel (SFP).  Essentially, it starts an acquisition and uses only an extraction when the acquisition is known to be complete.  It will never expire.

  By default, the SFP OR-SCOPE records in the format of hierarchical storage OR waveform (OR-HWS), a binary format.  "" "You can find OR HWS screws in the measure i/o" OR-SCOPE "Utility Functions" OR hierarchical waveform storage palette.  NOR-HWS is based on HDF5, so can be opened and read by all who reads HDF5.  The internal format is very similar to The SCPI-DIF, but put in a wrapper HDF5.  If you want more details, please ask.

  Example is saved in LabVIEW 7.0.

• storage, reading and writing data to the file

  Hello world

  I am new to the Labview and his community.  Asked me to acquire data on the measurement of the pressure using Labview.  I could build the code and got it working, but when I look at my data that has been collected, there no stopping point.  I just spent a lot of time looking at the data in the place where it begins and where it ends.  The question I ask is how to create a code to read the pressure, storage, in memory until there finishes, collect data and then to write in a .csv file.

  I use the NI USB-6009 case and hook upwards to ai0 and ai4.  See the attached code so uncertain.

  I want to record 100 data points and the system stops after these collection.

  Thank you

  John H.

  You have a certain time which means your VI will continue to run until you press your button to stop the loop.

  The DAQ Assistant is already set to 100 samples.

  Just delete the while loop!

• Internal error of screw, PDM file storage

  I use LabView 8.5.1, DAQmx 9.0.2. and a module OR USB6216.

  I have set up on my request a task as follows: 15 channels activated with a sampling rate of 1sample/10 s (very slow). My purchase has to work for a few days or more.

  Sometimes, I get the error "Internal storage screw" (code - 2500). so I can't read my file TDMS (see attached file) and I can't deal with my data.

  You know the exact meaning of this error on the case of a PDM file. Yo have a solution to process my data?

  Best regards, Daniel.

  This tdms.dll was released with LabVIEW 2010. TDMS.dll is backwards compatible, it means that you can still use this dll with LV 8.5.

  You can right-click on tdms.dll and choose "details" to see the version.

• On a NOR-6363: how many digital samples can be acquired at once?

  Hello

  I use a NOR-6363 with meter 3 configured for pulse generation finished.

  I created a digital input channel to acquire digital values (on P0.16 and P0.17) with counter3 as the sample clock.

  The idea is to acquire a finite number of digital samples (even as the number of finished pulses generated on counter3).

  Currently, I'm trying to figure out if I can get about 1000 samples (requirement of my request).

  The data sheet indicates that the FIFO size for a digital input is 255. Is this to say that I can not acquire more than 255 samples at a time?

  I tried to use high values up to 1000 but no error occurs.

  Is this to say that the reading of values will be correct?

  Or im guessing it might be a circular FIFO that overlooks the same values reading values of more than 255.

  Should I worry about this limit of 255 at all?

  Thank you

  Since no one answered this yet and I posted my question there are times, I'll take a stab at a helping hand.

  The FIFO on the digital input is the place on board where the samples will be kept until their transfer on the bus in the RAM. So, the question becomes what controls when these samples are pushed to the RAM. If I remember correctly, this card has 8 DMA 1 channel who will control when these samples are transferred on the bus. I don't think there is a way to control when the DMA channel completes his transfer, but the first transfer is likely before you fill up the first 255 samples. DMA transfers will continue to occur until all samples have been transferred to the PC RAM.

  Once some or all samples have been transferred to the bus and reside on PC RAM, you call then call DAQmx read. Then, the samples are in your Application development environment (ADE) RAM, if you use them in your program. You have 3 separate storage locations: FIFO on board, PC memory, memory of the ADE.

  You shouldn't have to worry about the limit of 255. Maybe if you were doing a very fast acquisition, this could be a factor...

  Kind regards
  Eric

• How to estimate storage data acquisition needs

  How can I estimate the size of my data files, so I can implement the correct size device (such as a USB hard drive) storage given;

  Type of measure: accelerometer mediated to tension

  Frequency range: 0 to 800 Hz

  Measuring range: +/-10 g

  Channels: 12

  Sampling frequency: 1.652 kech. / s

  ADC: 24 bit

  FSR: +/-5V

  Time: varies, and may vary depending on the size of the storage space

  This is the configuration I am considering either a cRIO 9030 with three modules-c NI 9234.

  

  Thanks for the pointers - John M

  How do you plan to store data?

  Assume that PDM, that allows to store the data a slna.  12 channels * 1,652 k samples per second * 8 bytes/sample = 158592 bytes/second = 154,875 kb/s.

• Storage of PDM in one group or many?

  Hi all

  I'm designing a verification tool to the work of an RFID device. I have a PC dedicated box with the NI PCIe 7841 DAQ for this tool.

  Question

  My question is about the segmentation data in the TDMS files between files/groups and channels. How to choose size maximum file to penetrate storage? Is to store in a single group of very long effective channels, or you should break you up into smaller groups in order to improve reading access both later?

  The event definition

  My request to store 'events' is defined by the following fields (each event has these fields):

  • [U64] Timestamp FPGA
  • [U16] Type of event
  • [32] Event SeqID (seqID is based on type and assure all the events recorded in the storage file)
  • [U16] Value0
  • [U16] Value1

  Activity rate of events

  These events are acquired at an average rate of ~ 50kEvents/s and will be processed offline. Sample sessions will last about 1-2 hours, which gives ~ 7-8GB. Sample sessions that occur 1-3 times / WK.

  Storage method

  Forget the FPGA-> mechanism from the host for a moment and just consider the storage of these data. What I have here is a continuous flow of these events. My method of storage is so far:

  • Break the TDMS files to 250 MB (selection of arbitrary size)
  • A group by file
  • 5-way group, each embodying the parameters listed

  Summary of the last Question

  What is a good way to store data? I have a few questions here:

  • Should I break into 5 groups of 50 MB, or a single group, with very long strings?
  • What considerations should I do regarding the max file size? What information about my drive HARD, the PC and the PDM can help choose a reasonable file size? I prefer to store as much as possible.
  • How does the length of a string affect access time afterwards?

  Thank you!

  -Reina Justin

  Hey Justin,

  That seems like a reasonable use configuration.  Storage of each of these entities in the channels with each event corresponds with a single point in these channels seems to be the simplest layout.

  You asked to be split into several groups in the same file:

  I see no need for it in your case.  If, however, you have a distinction you want to keep between the sets of data, it seems that it would be useful; for example, if you see an interesting event and you want to keep track that something is different with the following points, creating a new group would keep logically separate data sets.

  To the extent where storing this amount of data in each file, which looks very good.  The only thing to keep in mind is that when processing the file, you will not be able to load that much data in memory at the same time, so you will need for the fragmentary treatment.  With regard to the determination of what that magic number of samples per file that you want to place in each file, it is a bit arbitrary.  I don't know of a good formula to determine where you should partition data sets, but generally only make sure to consider:

  (1) the overhead in the passage of the files (opening/closing/write a new header)

  (2) how you want to process the data

  (3) your risk tolerance: If something were to happen to a file (deletion, corruption of volume, etc.), what is the most acceptable balance for your needs between the file size and the number of files.

• Accidentally deleted all the files of internal storage and sync new files of internal storage

  Hello

  I was installing FolderSync to sync some folders to my internal phone storage. My mistake was to choose the root of internal memory, which has deleted all folders of files and synchronize folders for internal storage. I tried to reset the phone factory, to recreate the folders and files originally placed on the internal memory, but not luck. I only used the phone a few days and did not want to spend time trying to recover files/folders, because I guessed that syncinf files of internal storage would undermine the 'old' files anyway. Is it possible to recreate the internal memory of the State when I used the phone? For example, instructional videos and sample photos reappear when I do a factory reset (also by placing the tick for the removal of the internal memory).

  BR

  Frank

  After doing the full recreated factory reset your phone will be clean and ready for use with the root folder. But... demonstration videos and examples of photos are not part of the firmware. It's cleaned depending on content of available region until the phone is factory or user deletes them.

  So to recover these files, you need to find any other user with the same phone as you and kindly ask him to share these files with you (if these file sharing is legal in your country).

• Cordova/Phonegap for WebSQL Storage API does not not on BB10

  I use the API of storage for WebSQL to Phonegap with BB10 but his does not work.

  And not able to see the logs in the web Inspector. I have test code on system Z10 bb OS 10.2.

  And cordova 3.1.

  Is there a sdcard is required in the device? Currently, there is no SD card in my camera.

  Or is there any other requirements. Please help me as soon as POSSIBLE.

  Please find my code below:

  index.html

  Example of

  Database

  You use the document originally of a variable

  window.addEventListener('load', function () {
      document.addEventListener('deviceready', onDeviceReady, false);
  }, false);
  

• Permanent storage - multiple data items

  Hello

  In my application, users enter text in an EditField and click on a 'button '.  I wish that the content of the EditField is stored in persistent storage - no problem.  However, if a different pieces of text is entered in this same EditField, I would like that it too to be stored in a persistent storage.  For the most part, I would like to create a historical data that have been entered in this one EditField, which will then be loaded later - every piece of data that is stored in the history is loaded into a new EditField

  I looked at the samples, but none seems to be something similar to what I do.

  Does anyone have any suggestions?

  Thank you!

  You may be able to store the history as a vector?

  Something that I found effective is to use a hash table for the object that I am explicitly store, then within this hash table I keep the key / value.  Eventually in this case, you can have a key like 'CurrentFieldValue' which is a string; and a second key as 'HistoricalFieldValues' which is a vector.

• How to use the persistent storage

  Hello... Can we use persistent in blackberry webworks storage... I don't want to use SQLite... Any suggestions...

  joygupta wrote:
  Thanks for your reply... you can give a sample of the same...

  Now, things you need to know:

  -creation of Javascript Extension in the development of Blackberry Webworks.

  -How to set up a persistent Java development storage

  You can do a search on Google for more include some documentation and samples.

  As a sample of a documentation:

  http://www.Scribd.com/doc/39084892/lab-building-a-BlackBerry-widget-JavaScript-extension

  or an example of project: http://na.blackberry.com/eng/developers/devbetasoftware/Lab_Widget_Extension.zip

• WebWorks and persistent or storage SQL Lite

  Hello

  I'm looking for more help write webworks app for persistent storage or SQL lite storage,

  Anyone can throw some light on this.

  Thank you.

  Hi tububerry,
  You can see https://developer.blackberry.com/html5/apis/Database.html
  https://developer.BlackBerry.com/HTML5/APIs/localStorage.html

  and here's the example source code: http://blog.darkcrimson.com/samples/localdb/darkcrimson_localdb_demo.zip

  A Pham