3 Simultaneous Frequency responses using PCI-4552

I need to obtain 3 simultaneous frequency responses (Magnitude and Phase) using a PCI-4552 board. Ch 1 is the reference for the 3 FR's. I succeded in obtaining independent FR's, but I cannot configure the vi with the 3 FR's together. I attach my best try, please take a look at it.
Attachments:
zoom4.vi ‏378 KB

I took a look at your VI. It looks like you have two issues.
First, you are using a single stop button's input to stop several loops. The problem is that the output of the button will not allow the consecutive while loops to execute until the first one has finished (they are waiting for the prior loop to finish to get the final value of the button). If you want to read the value of a single button simultaneously in several while loops, you need to use local/global variables.
You should have an example:
Stopping Parallel While Loops with Reset.vi
... included with LabVIEW which will demonstrate how to properly do this.
Your second issue is that the base analyzer can only do two simultaneous channels. If you really need to do more, you'll need to grab al
l the channel's raw data using the DAQ API instead of the DSA API, and feed the individual captures into the "Frequency Response Function (Mag-Phase)" vi. This should give you the same results, but you'll be using the host computer to do the analysis instead of the board.

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Attachments:
fft filter.vi ‏87 KB

If you check the help text for sine wave.vi you'll see that it generates the sine wave based on the following formula:
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If you check the help text for sine wave.vi you'll see that it generates the sine wave based on the following formula:
yi = a*sin(phase[i])
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Is it possible to plot a microphone's frequency response using sound and vibration? If it's possible, can anyone tell me how?
Thanks

Hi popcorn,
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Inquiring about the issue of using PCI-5922 and PCI-5412 simultaneously under Linux OS! Thank you!

hi all,I am lily and I an AE from NI shanghai .Now I confronted a pullze from customer,and I really feel at a loss! Hope some one of you would come and land me a hand,thank you in advance!
The problem is as follows:
Customer use PCI-5922 and PCI -5412 under Linux OS, if they use either of the two cards seperately,there would be OK. but if the use both of the two cards simultaneously, the error will occured as attachment shows. "Error code:-50258 occured at niscope_DAQmx Create Channel (AI-Voltage-Base).vi:2 Possible reason(s):The specified software component failed to initialize."
Can I know is there any solution vs this probelm?Thank you in advance!!
Attachments:
Screenshot-NI-DAQmx Test Panels.png ‏17 KB
NI-NEW_error.txt ‏8 KB
shortsyms.txt ‏973 KB

This is the wrong board for this question, you should re-post here
Regards
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Hello!
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Attachments:
Frequency Response.vi ‏21 KB

Thank you Kyle, this is exactly what I was looking for. I searched the examples that came with labview 2010, the signal processing module, the 8.6 DSP module and the signal anaysis toolkit, but I had not yet installed the elvis cd so I didn't run across these VIs. Thank you once again!

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Hello
Can we make a frequency response analyser using a Frequency generator and frequency counter?
How to add modulation with it? Modulation frequency is to be varied as per the input to given to the carrier!
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somebody have an Idea for this
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"Thanks with regards "
by
..........Gireesh..........

Hello Gireesh,
You can use a function generator to generate frequencies and use the modulation tollkit and other tools availabe with LabVIEW to do the modulation part . Or you can use the analog output ports on the daq card to generate different frequency signals for the same purpose .This should pretty much serve your purpose.
http://zone.ni.com/devzone/cda/epd/p/id/5646
http://digital.ni.com/manuals.nsf/websearch/AF3615F31CE9656C862576070020B8F7

Examples of Transducer Impedance measurements using NI 4552.

Are there any examples available for Impedance Calculations from Voltage and Current Data taken from NI 4552 acquisitions?

Hello,
I would recommend taking a look at the LabVIEW shipping example for NI-DSA called "Frequency Response Example.VI" You could measure the voltage across the circuit using channel 0, and then use a current transducer (probably just a precision resistor) to measure current on channel 1. The results of this calculation would give you the impedence at various frequencies. By switching between magnitude and phase views, you can examine the resistive and reactive components of the impedance.
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MacBook core duo Sept. 2006 - the audio is a mystery. Any analogue out has bass boost with bass distortion. With digital out, by USB or Airport Express Airtunes, the frequency response is normal. Somewhere, Apple put in an analogue bass boost.. why?!

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To receive a flat frequency response and no frequency distortion, I listen on one receiver using Airtunes, (it doesn't matter whether or not the analogue or digital output jack is wired analogue or connected via optical cable.... the freq. response is flat); and I listen on a high-end stereo system using an USB output port to an A/D converter, passing the analogue result using long patch-cords connected to the "line-in" jacks of the stereo. The bummer is that most of my audio sources are not derived from iTunes... hence, I cannot use Airtunes with Airport express for them. I've tried using "Airfoil" without luck. The sound becomes distorted with sibilance and other frequency anomalies.
Question: has anyone else discovered this sound imperfection in any Mac product? And, does anyone know if Apple is aware of it? Finally, has anyone found an Apple fix for the problem; or, at least, come up with better solutions than I have?
Thanks heaps for any impute and answers you may supply!! junadowns

Army wrote:
This might not help you a lot, but if you want a stable system, try using packages from the repo wherever possible, look at the news before you update your system and don't mess things up (like bad configuration etc.).
When it comes to performance, you won't gain much by compiling linux by yourself! Just use the linux package from [core] or if you want a bit more performance, install the ck-kernel from
[repo-ck]
Server = http://repo-ck.com/$arch
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Hmmm, Linux-ck-corex doesn't even load.. I am now trying to install the generic one. Hope it works.
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Last edited by exapplegeek (2012-06-26 18:33:31)

Pulse Train Generation using PCI-MIO-16E-4

I need to generate pulse trains of changing pulse widths using PCI-MIO-16E-4 daq card using Igor Pro.
I have tried to use the CTR functions (but always keep getting errors and it doesn't work). I also used the general purpose counters (GPCTR functions) but cannot visualise them on a CRO. If someone can help in regards to the programming aspect, it will be greatly appreciated.
Thanks
Vakul

Hi Vakul,
Some questions that might help me to get you a solution.
Are you using Traditional DAQ, or DAQmx and which versions are you using?
What operating system are you running?
When you say you can't visualize them on CRO, I assume that you are hooking the counter out to a cathode ray oscilloscope and can't see the pulse train?
Are you going to need more than two different pulse widths for your pulse train?
There are several online knowledge bases describing how to change the frequency of a pulse train on the fly.
This link explains how to use software to create a new pulse width.
http://digital.ni.com/public.nsf/websearch/7B1B0427C39FE33086256CEE00752133?OpenDocument
This link discusses using frequency shift keying, which will only allow you to have 2 different pulse widths.
http://digital.ni.com/public.nsf/websearch/EC1F089252F33B248625696E006FB6FC?OpenDocument
I assume that you are writing this program to compile in Igor Pro using C. I can help you with the C code development, but don't know anything about the Igor Pro API.
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How to use counter using PCI 6259

Hello, users,
I have a PCI 6259 board and use Labview 7.1.
I'd like to repetitively count the photon signals at 10ms integration time. I want cumulative counts in every 1 sec (1000ms) (or 1 min (60000ms)) And I want to save counts into txt.file which is open in excel program.
I am a beginner to use counter using PCI 6259 board.
1. Could you explain default NI-DAQmx counter terminals, i.e., CTR 0 SRC, CTR 0 GATE, CTR 0 AUX, and CTR 0 OUT?
2. How do I use them or how can I connect to count TTL pulse using PCI 6259?
3. As I mention my purpose above, which example is the first step to start working my purpose?
4. If you know good example, could you tell me about that?
5. If anyone has labview example which is similar to my aim, could you give me some tips or your examples?
Any hint, comment or advice would be appreciated.
Thank you so much for your response.
Leek2

I have never used the PCI 6259 but have used counters many times with labview, the coding should be the same independent of the board. What you want to do is finite buffered edge counting using a internal clock. The best way to do this is to look at the examples programs and use the express vi to get started, then you can use this code to customize your program exactly as you need.
To address your questions:
1. CTR0 means "counter 0" the name of the physical resource sometimes listed at GPCTR0. Each counter has 4 connections to the outside world:
source "src"(for counting input TTL signals),
gate (for synchronizing to external clocks and edges),
out (for pulse-train out operations)
and aux (specialty operations such as up/down counting and encoding)
2.For event counting with internal clocking you will only use the src this is the input from the signal you wish to count (ie PMT discriminator for photon counting).
3,4,5. Look at the count edge examples, there isn't one that does exactly what you want but I have done this with a 6602 (it has e counters) where I use one set of counters to set up a finite pulse train in your case 1000Hz with 1000 pulses, and another counter to edge count on an external pulse, with the source of this pulse routed from the out of the other counter. Then you can start the task and read when 1000 samples are in the buffer (about 1 second later).
Hope this helps,
Paul
Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA

Frequency response requirements for headphones with CMSS on XFi ???

Hi,
I would like to know if someone could tell me what kind of heaphones are suitable for the CMSS mode with the XFi.
I mean between : flat response/free-field correction/diffuse-field correction.
Applying HRTF filtering should mean that headphones with flat response is the best option ( same configuration as binaural recordings).
But I have a big doubt that Creative team expects costumers to possess such a pair of headphones, as it is rather for scientific uses (psychoacoustics, audiology etc...).
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To simplify, if we listen binaural sounds with classical headphones the effect of outer pinna is reproduced twice.
So I guess Creative have implemented a kind of normalization/equalization/correction process to deal with the non-flat frequency response of headphones, but do someone know if they have chosen diffuse field or free field correction ?
This post might seem a detail but the issue can be very important for the accurate localisation and the coloration? of 3D sounds with headphones.
Thank you, and please forgive my english!

The only possibility that I can think of is that 2/2. mode is NOT as simple as headphone mode with crosstalk cancelation. Perhaps the HRTF only kicks in for sound sources outside of the arc directly in front of the listener. If that were the case, you wouldn't percei've any distortion for sound sources in front of you.
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MatrixX Build 61mx1411: I get a "Track out of memory" error when I run the Open Loop Frequency Response from the MatrixX pull down tools. What can I do to prevent this? We are running on an HP B1000 with 768 MB of RAM under HP-UX 10.2.

In the old days of Mx say Version 5 and prior the user actually selected the amount of memory that would be allocated. Depending on the size of the model etc. you would have to allocate memory. In version 6.0 and going forward there is no need for the user to manually allocate the memory.
Build {rstack=50000,istack=200000,sstack=50000,cstack=500 000}
If this is a command in a script file that you are running and the error is resulting from that then I would try commenting out everything after the letter d in the word build and then starting it back up.
i.e. only use Build
I don't believe that there is a way to manually allocate the initial SystemBuild Stack size.
I believe initially the stack size is set to 10010.
However, one way
you can manually set the initial SystemBuild stack size,is to create a large StateSpace as soon as you start up SystemBuild. This will prevent piece-meal reallocs while using SystemBuild.
You can created a new SuperBlock in SystemBuild and then drop down a StateSpace Block with 199 inputs and 199 Outputs and 1 State and entered ones(200,200)as the StateSpace Matrix without any problems. This would resize this internal stack to at least 40000.
You really should not have to do this but if that helps then you might think about doing this in your startup.ms file you could use SBA or load the file then you could delete the superblock and begin working.
"Bob" gave me this little tid bit.
Please let me know if any of this is of use.
Garrett
Garrett Thurston
[email protected]
Phone: 781.993.5540

Room frequency response measurements

Does anyone know of a Shareware program available that use your PC's sound card to play pink noise while recording from the microphone, and then display the room's frequency response?
I have a high-end stereo system and am looking for something that will show me what my room modes are doing.
Thanks in advance.

thanks but I'm not looking for pink noise to drown out others. It's to use as a measurement. see my post again.
1.33ghz PowerBook g4, 17-inch Mac OS X (10.4.7) 1.5gb ram

Frequency Response Function & FFT & Inverse FFT (problem of unit Volts-RMS)

Hello everyone,
I am currently working on a VI in order to compare two analog signals : the first one corresponds to the output signal (my reference) which is sent by my data acquisition card to a shaker and the second one corresponds to the input signal recorded by an accelerometer fixed on the same shaker. The final goal of the VI is to correct the analog output signal by using the analog input recorded signal in order to have the vibrations on the shaker which corresponds to what we really want.
To summary, I have a problem of unit with the Volts-RMS...
So this is my method for the VI :
First, I have to calculate the Frequency Response Function between the two analog signals (output and input). For it, I use the " Frequency Response Function (Real-Im).vi " which returns the complex values of the FRF in Volts-RMS (but I don't want to use this unit).
Then, I want to calculate the FFT of the analog output signal (my reference). There are two different blocs which can be used : " FFT Spectrum (Real-Im).vi " and " FFT.vi ".
The " FFT Spectrum (Real-Im).vi " returns the FFT complex values of the signal in Volts-RMS and the " FFT.vi " returns the FFT complex values in Volts (or say me if I am wrong, thank you). I really would like to use the second one because of the unit.
Then, I divide the FFT just calculated with the Frequency Response Function calculated just before.
For the end, I calculate the inverse FFT of that with the " Inverse FFT.vi " which use the complex values with the same unit than for the " FFT.vi ".
I don't want to use the Volts-RMS unit because I absolutly want to use the blocs " FFT.vi " and " Inverse FFT.vi ".
The problem is that I don't find a bloc which use the same unit for the Frequency Response Function. The " Frequency Response Function (Real-Im).vi " returns only the complex values in Volts-RMS unit. Maybe it is possible to convert it correctly? Or maybe there is an other bloc which can be used in order to calculate the Frequency Response Function with the same init than for the FFT and Inverse FFT ? Because I can't mix everything for the moment...
Thank you for your help,
Best regards,
Sebastien

Hello Preston,
No, I have not use the Sound and Vibration toolkit. I have only used the signal processing toolkit with the two toolboxes " Waveform measurement " and " Transforms ".
But I think that what I have done for the moment in my VI is correct (I have finished the complete VI). But I am not sure of the units (Volts, Volts-RMS...) and I would like to understand.
I have tried with the Sound and Vibration toolkit for the frequency response function (because you say me that it deals with all the unit conversion) and I can obtain the same results than with the " Frequency Response Function.vi " of the toolbox " Waveform measurement ".
But I would like to understand the units (see my previous post please). For example, for the FFT (the result is a complex), why sometimes it is in Volts, sometimes it is in Volts-RMS ? Is it possible to convert it ? How ?
If you want, I can attach on the forum my VI and that will maybe help you to explain me. Maybe it will help other people interested.
And if someone else can give me other precisions or advices about it, do not hesitate.
Thank you for your help,
Sebastien

3 Simultaneous Frequency responses using PCI-4552

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