High sample rate data acquisition using DAQ and saving data continuously. Also I would like to chunck data into a new file in every 32M

Hi:
I am very new to LabView, so I need some help to come up with an idea that can help me save data continuously in real time. Also I don't want the file to be too big, so I would like to crete a new file in every 32 mega bytes, and clear the previous buffer. Now I have this code can save voltage data to TDMS file, and the sample rate is 2m Hz, so the volume of data increase very fast, and my computer only have 2G ram, so the computer will freeze after 10 seconds I start to collect data. I need some advise from you briliant people.
Thanks very much I really appreciate that.
Solved!
Go to Solution.
Attachments:
hispeedisplayandstorage.vi ‏33 KB

I am a huge proponent of the Producer/Consumer architecture. But this is the place I advise against it. The DAQmx Configure Logging does all of it for you!
Note: You will want to use a Chart instead of a graph here.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
Attachments:
hispeedisplayandstorage_BD.png ‏36 KB

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Linking errors whlie running C examples of data acquisition using niScope and visual C++

hello,
I have an NI PXIe-1071 chassis with 2 PXI 5154 digitizer cards and NI PXIe 8102 controller.
I am trying to acquire data using the same. Right now I am trying to compile some of the C based examples given in the documentation of niScope. But I am unable to do so. for instance when I tried to run "ConfigureAcquisition.c ". I am having many errors like the one given below.
error LNK2019: unresolved external symbols _niScope_init@16 referenced in function _niScope_GenericConfiguredAcquisition@0
for every niScope based function used in the example it is showing the same error.
I have only 2 files niScope.h and niScope.lib. In niScope.h there are declarations for each function but their definition is not there and I came to know that I also require source file of the same to avoid the error. Is this true????
if I dont reqire source file please suggest me how to avoid such errors. and if I require source file from where I could find it as I talked with NI people and one of the application engineer told me that this is not available with them.
Please help me with the same.
regards
Sagar

Try adding the appropriate source files from C:\Users\Public\Documents\National Instruments\NI-SCOPE\examples\c\common. With the errors posted by vijay, I would suggest adding asciiplot.c and GenericMultiRecord.c.
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Product Support Engineer

Standalone application for data acquisition using NI DAQ card

I have made a standalone application in labview GUI for data acquisition and signal processing. if i have to run this application in any other computer what all softwares should be installed other than labview runtime engine...NI DEVICE DRIVER CD alone is to be installed or do i have to install any other software for data acquisition using NI daq card??
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Solved!
Go to Solution.

You should only need the run time engine, The device drivers for the device, maybe need VISA drivers if you are doing serial or something of that nature, You may need the channels or tasks created in NI measurements and automation if you created them there.
There may be other things that you will need depending on what you include in your code and what tool kits that you have installed.
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Johnson Controls
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How to build a array with high sampling rates 1K

Hi All:
Now I am trying to develop a project with CRio.
But I am not sure how to build a array with high sampling rates signal, like >1K. (Sigle-point data)
Before, I would like to use "Build Arrary" and "Shift Register" to build a arrary, but I found it is not working for high sampling rates.
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Attachments:
Building_Array_high_rates.JPG ‏120 KB

Can't give a sample of the FPGA right now but here is a sample bit of RT code I recently used. I am acquiring data at 51,200 samples every second. I put the data in a FIFO on the FPGA side, then I read from that FIFO on the RT side and insert the data into a pre-initialized array using "Replace Array subset" NOT "Insert into array". I keep a count of the data I have read/inserted, and once I am at 51,200 samples, I know I have 1 full second of data. At this point, I add it to a queue which sends it to another loop to be processed. Also, I don't use the new index terminal in my subVI because I know I am always adding 6400 elements so I can just multiply my counter by 6400, but if you use the method described further down below , you will want to use the "new index" to return a value because you may not always read the same number of elements using that method.
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CLA, LabVIEW Versions 2010-2013
Attachments:
RT.PNG ‏36 KB
FIFO read.PNG ‏4 KB

Data acquisition with daq card 6533

Hi all,
i need to develop a c++ (visual studio .net, no measurement studio)
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Thanks for your reply.
I don't know actually whether i need to use counter-related functions. My problem is the following:
I need to sample 8 digital signals with a frequency of 10khz. Every signal have a duration of a few seconds in time, and they come from sensors attached to a train's railway. Acquisition begins on the first rising edge of a signal (which coincide with the passage of the train), and end with user input (which should be after the train has passed).
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Sample rate off the audio input and out devices do not match - what to do?

This is fundamental, I know, but nevertheless I can't find my way around it. I get this error message when trying to recor:
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You're sure you have set BOTH the input and output settings to 44.1 16 bit?
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How can I improve the speed of my VI to work in real-time at higher sample rates?

I am currently trying to implement a multi-channel control system, the vi of which is attached. It effectively consists of a number of additions and multiplications in the processing subvi (also attached), however, for 7 inputs and 7 outputs I cannot get it to work at sample rates higher than 3kHz without experiencing an overwrite error. Does anyone have any tips as to how I can get the processing to work more efficiently such that I can get it to work at higher sample rates?
Attachments:
Simul_AIAO_Buffer(Two_Boards)_control_FXLMS_for_1_leaky_no_SCXI.vi ‏128 KB
FXLMSsub_leak_v2.vi ‏70 KB
filtered_ref_1_chan.vi ‏39 KB

Hi mattwilko,
I believe the first issue that you should address is the building of arrays.
This is mainly happening on the edge of your loops.
This is my reasoning.
Allocating memory in RT to handle an array that is growing will blow away your determinism.
I would suggets pre-allocating all of your storage and work with the data in-place.
In LV 7.1 there are some great new tools that will help nail down issue of this type.
If you have LV 7.1 you may want to upgrade so you can take advantage of the new tools.
Trying to help,
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Ben Rayner
I am currently active on.. MainStream Preppers
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Folks,
In iTunes 7, I could import audio books at 32k mono and they would sound good (after all, it's just someone reading - doesn't need stereo or high sample rate). However, in iTunes 8, for 32k the sound crackles and is distorted. Quality is OK at 64k mono but obviously now the files are twice as big. Am I right in slating the blame to iTunes 8? Is there some way I can use iTunes 7 encoding?

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Is it possible to detect low frequency signals with a high sampling rate?

Hello everyone,
I'm having an issue detecting low frequency signals with a high sampling rate. Shouldn't I be able to detect the frequencies as long as the sampling rate is at least 2 times the highest frequency I will measure? The frequency range I am measuring is 5-25 Hz, and I use Extract Single Tone.vi to measure the frequency. The sampling setting I am using is 2 samples at 10 kHz. Is there a method I can use to make this work?
Attached is the vi.
Attachments:
frequencytest.vi ‏21 KB

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Putnam
Certified LabVIEW Developer
Senior Test Engineer
Currently using LV 6.1-LabVIEW 2012, RT8.5
LabVIEW Champion

Multiple data acquisition using PXI-5124 digitizer

I have a system in which I do data acquisition of the present state of the physical system (using PXI-5124 digitizer),
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Attachments:
PXI5124-data-acquisition.vi ‏46 KB

From the explanation you have given about reconfiguring the digitizer,
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High sample rate data acquisition using DAQ and saving data continuously. Also I would like to chunck data into a new file in every 32M

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