Acquire 2 signals with different sampling rate?

Hello,
i am using first time labview signal express together with a NI pci 6251 & NI Scc 68 device.
There are 2 signals I wish to acquire over a 2 week time period. They should be saved in several tdms files. One is a dc Voltage.(sampling rate 100Hz) The second is voltage given by an acceleration Sensor. (sampling rate 4kHz)
When I try to acquire them I couldn't figure out how to set the sampling rate for each signal, only for all signals.
When I created two DAQmx assistant acquire tabs. An error occurs always: "the specified resource is reserved".
So my question is is it possible to do this?

hello markus_umd,
no, it is not possible to create different samplingrates for individual channels on one daq device.
if you want to record one channel slower, you must reduce the samples for that channel in your program.
if the channels have a common divisor, you could implement your task. you find more information here:
Sampling Different Channels at Different Rates with NI-DAQmx
kind regards,
robert h
NI germany

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Parallel acquire 2 signals with different sampling rate on 2 cards

Hi NI,
I have cDAQ-9178 and NI 9221, where sample rate is 10kHz and NI 9219, where I need sample rate about 10Hz, it's possible this confiruration for parallel acquire?
Thank you.
Neolker

Hi Neolker,
Do the tasks need to be synchronized or are totally independent tasks?
If the tasks are independent, than you basically have to create two different tasks, even in two different loops that will run with different sampling rate.
You can have them in the same loop the reading if you assure that the data are transfered in chunks to application memory according to tha sampling rate (Ex. for 10kS/s rate you can transfer data with 1kS chunks and for 10S/s rate with 1S chunk).
If you want to synchronize them, you will need a counter that will divde the sample clock from 9221 and route it to 9219.
Let me know if you need more help.
Best regards,
IR

What's the best way to sample multiple AI's with different sampling rates under one task?

I'm using a PCI-6221 card and CVI 7.1.
I have a tri-axis vibration sensor and two other pressure transducers.
I want to take 10k samples from each vibration axis at 80 kHz. This is
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Hello Nobody,
If you configure your task timing to acquire a finite number of
samples, then you can only read the number of samples that you
specified in your configuration. Once you try to read more
samples, you will receive the error you are seeing.
If you configure your task timing for continuous acquisition,k then you
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How can I add a curve with a different sample rate behind another curve to show it like one in the report

I saved two curves with different sample rates with signal express in waveform.
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Hello MReizner,
Both the DIAdem VIEW and REPORT panel use the time information from your Waveform channels (make sure they actually have the waveform symbol, not the numeric data channel symbol in the Data Portal) to plot the data in the same axis system.
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I hope this answers your question, please let us know if further clarification is required ...
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Business Development Manager
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Austin, TX - USA
"For an optimist the glass is half full, for a pessimist it's half empty, and for an engineer is twice bigger than necessary."

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)
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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

Different Sampling rates for different channels in Analog Input

Hi,
I would like to acquire data at different sampling rates on different channels say ACH 0, ACH 1 and so on. I have a PCI 6052E board and NI DAQ 6.9.2. Also is it possible to simultaneously perform Analog output on two different channels along with the Analog input? What will be the problems/consequences as far as the system resources are concerned. I am a beginner in this area and would greatly appreciate any help/pointers for my queries.
Thanking you in advance
Deepak

Search the eaxamples that ship with LV.
Theer is one called simultaneous input and output or something like that.
It will get you started.
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Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Wave form chart for different sampling rate

Hi
All,
I have to use different sampling rate to get pressure data. Can I use the waveform chart to monitor the pressure data with time?
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Different sampling rate than what? A chart or graph can be used. Depends mostly on how you want to update it.

How can I edit multiple clips with different frame rates on the same timeline

how can I edit multiple clips with different frame rates on the same timeline

You do not want to edit material from different frame rates on one timeline. You CAN do this, but it is a very bad idea - and this is why.
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Hello matttgic,
What kind of signal do you want to acquire/generate?
For exemple, if you want to acquire an analog input, you should use the architecture use in the file "Analog_input attach to this email.
As Johnsold told you, you can find some code for your device in the "find exemple" section of LabVIEW.
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Attachments:
Analog_input.PNG ‏13 KB

How can I continuously streaming data to disk with 1MHz sampling rate with PCI 6110?

I can only save 3 seconds data with 1MHz sampling rate using PCI 6110. Is it possible to continuously save longer time data (say 1 minute)?
Many thanks

if the binary file is big the ASCII file is very very very big.
1 measurement is coded in a I16 => 2Bytes ( 4bit is not used 611X is 12bit
card)
if you use +/-1V range the quantum is (2 * 1V) / 4096 = 0.0004883V or 0.4883
mV you need to use 8 digits minimum.
And If your binary file is 1 Mo your ASCII file is 4 Mo.
You can use this VI for inpiration you need to add the translate I16 to DBl
to make a real value before saving.
For Help you can mail inthe newsGroup.
I'am a french user and my english is not good Sorry..
Fabien Palencia
Ingenieur d'etude ICMCB CNRS
"StephenZhou" a ?crit dans le message de news:
506500000005000000A5AF0000-1031838699000@exchange.ni.com...
> Hi, Fabien Palencia
>
> The program is great.
Do you happen to know how to convert the big
> binary file to ascii file? Thanks
[Attachment recup data I16.vi, see below]
Attachments:
recup_data_I16.vi ‏57 KB

NI 5761 with low sampling rate

Hi, is it possible to change the NI 5761 sampling rate without programming FPGA? Thank you very much!

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Alejandro | Academic Program Engineer | National Instruments
Attachments:
Capture.JPG ‏256 KB

How to acquire data from 2 chs of the same DAQ card at different sampling rate

I am using single DAQ card (either 6013 or 6014) in my system i want to acquire data from 2 (or more) channels with following requirements
1. sampling rate of each channel should be independant of each other (say one is 20 Hz and other is 15 kHz)
2. data from all the channels should be acquired simultaneously.
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can somebody help me out to solve this problem.
i will appreciate if somebody can post the sample code as my deadline is approaching
Tushar Jambhekar
[email protected]
Jambhekar Automation Solutions
LabVIEW Consultancy, LabVIEW Training
Rent a LabVIEW Developer, My Blog

Hi Dennis Knutson
Thanks for your suggestion.
Tushar Jambhekar
[email protected]
Jambhekar Automation Solutions
LabVIEW Consultancy, LabVIEW Training
Rent a LabVIEW Developer, My Blog

OMF - Mixing Different Sample Rates

Hello -
So, I've got an OMF file from a FCP project that I opened in Logic and have been mixing without any issues. Interestingly, all of the audio files associated with this project are 44.1 kHz, but I am mixing in 48k. But everything is right (sounds right, looks right, syncs with video correctly).
But... if I open the same files in an external editor or quicktime, they play back incorrectly. And if I save a file in a different program, even if it is still at 44.1, and bring it back into logic, it plays back incorrectly. This is problematic if I need to edit an audio file somewhere other than within logic (say I want to do some noise reduction in soundtrack pro).
Anyone run into this issue or have any ideas about how this happened?

There are a few ways to look at this.
1) Regions in the arrange all play back at the session sample rate. Example: 44k session, 96k audio file in arrange=slower playback
2) Logic automatically converts output sample rate so you can record independent of CA devices. Example: You have a session recorded at 96k, your interface is not connected, Logic will load Built in Audio, Logic runs tyhe sessions at 96k and converts the SRate of the session to match the supported sample rate. So you can run sessions at unsupported sample rates, this rarely makes sense if you cannot capture your audio at session sample rate (if needed).
3) There are a few other options for handling this, such as EXS24, which automatically handles SRC.
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Understanding compositions with different frame rate

Hey everyone,
I am working with AVCHD footage with a frame rate of 25.
If it drop my footage into a new compostion after affects sets everything
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I'd now like to what happens to my avchd clip if I change the frame rate
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Relink project clips with different frame rate

Somehow the clips in my project sequence ended up with a different frame rate (25) than the original media files (23.95), and they are no longer linked -- maybe this happened during import from iMovie. When I try to relink project files to source media, I get an error message saying they cannot be relinked because they have a different frame rate. I changed the sequence framerate to 23.95 (by creating a new project with 23.95 as the frame rate, then copying and pasting the other timeline into it), but all the clips remain at 25, so the problem remains.
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The media got unlinked importing the project and events from iMovie to Final Cut.
I've attached screen shots with all the specs.

Acquire 2 signals with different sampling rate?

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