5600 lowest frequency

Hello
According to NI 5600 downconverts any frequency to 15Mhz(with 20Mhz bandwidth). but specification says 5600 has a range of 9Khz -2.7Ghz. what if the input frequency is 9Khz or lower than 15Mhz. what does it do .does it upconvert the signal to make 15Mhz or what? i have seen a badpass filter in the block diagram of 5600 (not a low pass which always downconverts the signal ) in inital stage of 5600 does this bandpass act as highpass for lower frequencies than 15Mhz . am i right or no
Regards
Madd

Hi Madd,
You're initial thought is correct. Frequencies below the 15 MHz IF output are upconverted. More interestingly however is that the first mixer stage of the PXI-5600, see the block diagram in the NI RF Signal Analyzer Help or NI-5660 Help, always upconverts the signal.
Let's break down the signal chain portion of the block diagram:
1: The Low Pass filter here ensures that the signal we are manipulating has significant power confined to within the 2.7 GHz range of the device.
2 & 3: This first mixer upconverts the signal to an IF frequency, allowing us to spread out the images and harmonics that result. We can then filter this signal to focus in on the pertinent information as well as ensure qualities such as passband flatness.
4. We then downconvert the result from the BPF in step three to another IF frequency.
5. This BPF is the actual filter which sets the 20 MHz bandwidth of the 5600 device. It also allows us to do further conditioning of the signal.
6. The result of step 5 is then downcoverted with this mixer to the IF frequency you mentioned, 15 MHz +/- 10 MHz.
7. A final LPF is used to condition the IF output signal before it is sent on to a digitizer or third party device.
Hopefully this gives you a better impression and understanding of the signal chain.
Best Regards,
Message Edited by Speedy Badger on 07-08-2008 08:47 AM
Chris Behnke
Sr. RF Engineer
High Frequency Measurements
Attachments:
5600 sig chain1.png ‏6 KB

Similar Messages

Continuous Wavelet Transformation frequency output in columns and rows?

Hi
I´m trying to understand the output of the Continuous Wavelet Transformation Vi. I am only a beginner in wavelet, so is viewing from a Fourier Transformation method with moving windows. For example if I have 8 points say recorded with 1Hz = 8sec of data and run it thought the CWT with 8 scales, I get 8x8 array of data. So as far as I understand I get the frequencies of (starting with column 0 going to 7): 1Hz, 0,5Hz, 1/3Hz, 1/4Hz, 1/5Hz, 1/6Hz, 1/7Hz and 1/8Hz. Is this correct so far?
What I don´t get is how it is possible to make 8 (rows) of wavelet correlations on the columns from 1-7, when there is for example only one possibility to make correlation of 1/8Hz stretched wavelet, because the wavelet must be stretched over 8points (7th column). In picture below is illustration of wavelet where for the largest scale 8 (=lowest frequency) here 1/8Hz there is only 1 value for every 8 values for the smallest scale 1 (=highest frequency) here 1Hz.
I really hope someone can help me!
Best Regards
Jesper

Your current code can be replaced by an autoindexing FOR loop, you only need once instance of the "add array elements" operation. Easiest would be to acquire it as a 1D array with a constant number of samples then use "reshape array" to create a 2D array of the desired dimensions to be used for autoindexing as suggested.
LabVIEW Champion . Do more with less code and in less time .

Frequency Analysis on Adobe Audition CS5.5 for bioacoustics research

Hi everyone,
In need of some help.
I research whale/dolphin sounds, and have previously used Raven Pro for analysis. Ive found Adobe Audition produces a much better spectrogram (think it must be the FFT algorithm) and allows me to visualize a lot of whale calls that I may have missed previously by visual inspection on other software.
I need to measure these calls. Basically I need the duration (seconds), minimum frequency (kHz), maximum frequency (kHz) etc.
I have played around with the Frequency Analysis tool in Adobe Audition, and this cannot compute these figures for me at all. In Raven, it was extremely user friendly, and all you had to do was highlight the call by moving your cursor over and selecting the call, and in the left hand window, it would tell you the min F and max F and duration for that swatch that you had highlighted. Is there any way of doing this in Adobe? I know you can visually see on the right hand side the Frequency axis- but it doesn't give you the exact frequency i.e. I need it to be to 2 decimal places eg. 2.12 kHz minimum etc.
I have inserted a screen grab of what I mean when you "highlight the call".
Is there any way of doing this? I would be incredibly surprized if Adobe Audition does not have the ability to do so. But I have read through the manual and gone through a lot of threads and just can't find any information on it. Any help would be greatly appreciated!!!!!!!
Thankyou so much in advance
Bec.
p.s. Whilst Im asking, is there anyway to change the time format in the "Selection/View" box? Ive seen you can display it many many ways, but I need it in seconds, and the most sensible time format is mm:ss.ddd. Is there anyway I can change it to just ss:ss? There are a bunch of options for frame times, but nothing else for actual time.

becbioacoustics wrote:
I need to measure these calls. Basically I need the duration (seconds), minimum frequency (kHz), maximum frequency (kHz) etc.
I have played around with the Frequency Analysis tool in Adobe Audition, and this cannot compute these figures for me at all. In Raven, it was extremely user friendly, and all you had to do was highlight the call by moving your cursor over and selecting the call, and in the left hand window, it would tell you the min F and max F and duration for that swatch that you had highlighted. Is there any way of doing this in Adobe? I know you can visually see on the right hand side the Frequency axis- but it doesn't give you the exact frequency i.e. I need it to be to 2 decimal places eg. 2.12 kHz minimum etc.
I have inserted a screen grab of what I mean when you "highlight the call".
Is there any way of doing this? I would be incredibly surprized if Adobe Audition does not have the ability to do so. But I have read through the manual and gone through a lot of threads and just can't find any information on it. Any help would be greatly appreciated!!!!!!!
When you highlight a section, in the bottom right corner of the screen you'll find the timing section, and in there the box marked 'duration' will show you exactly how much time you've highlighted. In Frequency Analysis, the way to note highest and lowest frequencies is, unfortunately, manual and involves finding them with the cursor and noting the cursor information (under the display). If you open the advanced window, you'll get more information, including the level of the frequency at the cursor position. Also there's a bug in the display (or more to the point, the way it's calculated) which means that if you highlight just one section in the spectral view, this isn't what the Frequency Analysis display shows - I'm reporting that one.
p.s. Whilst Im asking, is there anyway to change the time format in the "Selection/View" box? Ive seen you can display it many many ways, but I need it in seconds, and the most sensible time format is mm:ss.ddd. Is there anyway I can change it to just ss:ss? There are a bunch of options for frame times, but nothing else for actual time.
No I'm afraid there isn't. I did try a cheat to see if I could at least get the timeline to do this, but that won't work either. Yes I think it should be there as an option too...

T420: CPU periodically switches to lowest speed for no reason

Hi there,
I noticed a strange thing to my T420 - when SpeedStep is enabled CPU switches to lowest speed periodically which immediately affects performance. It switches to lowest speed even when CPU is at 100%. Then after few minutes it comes back to normal.
Anyone knows what why this could be?
Here is a screenshot of resource monitor:
Thanks,
Igor.
Solved!
Go to Solution.

It maybe throttling due to heat. Typically, when the CPU reaches 85 degrees Celsius, it will start to turn off Turbo Boost or go to its lowest frequency.
Use a monitoring software like real temp and follow the settings below. The log text file is located on the same folder as the real temp program. Stress the CPU and see what temperature does the frequency drop.
Lenovo Y470: i7-2670QM | 8 GB DDR3 1333 MHz RAM | Nvidia GeForce GT 550M | 500 GB 7200 RPM Seagate HDD | ASUS PCE-AC56 802.11ac Network Adapter | Windows 7 Professional 64-bit

Low frequency analysis - Big obstacle, easy solution

I'm trying to analyze a signal between 0-2 Hz. The signal is a clean sine curve where amplitude and frequency changes.
I wanted to use the ExpressVI called "Tone Measurement" as I'm not that experienced with Labview.
I've used a signal generator to simulate, and it seems like it works fine for signals above 10 Hz. Lower than that returns higher frequencies and bogus amplitudes.
Please help me out here. The signal I'm generating is sampled at 100 Hz with n=10.
Solved!
Go to Solution.

For a better explanation: Tone Measurements uses FFT internally. The FFT implementation works well for signals having 3 to 5 cycles of the lowest frequency or more. It does not work well for shorter signals. It may work fairly well if you have exactly one cycle of the signal although that is generally not feasible, especially with variable frequency signals.
Lynn

Running your memory the right way/ running 4 DIMM slots on P55 boards

Dear Forumers,
Lately there are a lot of questions, about motherboards from the P55 range not starting on first boot.
This could be due to wrongly arranged memory DIMM's in your slots.
Some people out there, like me, were convinced that you could choose either dualchannel.
Well, its not the case.
Like I was pointed out earlier, you must use a certain slot, otherwise the memory will not be detected properly.
According to Intel specs, DIMM0, must always be populated.
This means that to run dualchannel with only 2 DIMM's, that you must check your manual and look carefully which slot is for DIMM0.
According to the manual, it will be slot DIMM1 on your board, but watch out, this is not the slot closest to cpu, on current MSI P55 boards, (CD-53, GD-41, GD-45, GD-55, GD-65, GD-80 and the Big Bang Trinergy), its the second slot from cpu.
Picture of P55 mainboard:
From a manual from a MSI P55 board:
So for dualchannel with 2 sticks, you must populate the black slots, DIMM1 and DIMM3 and for single channel with one stick DIMM1 most be used.
Please bear in mind that DIMM0 in Intel spec.sheets means DIMM1 on your board.
The link to technical sheet from intel about : i7 8xx cpu's
http://download.intel.com/design/processor/datashts/322164.pdf
A short quote with the relevant data:
Quote
Rules for Populating Memory Slots
In all modes, the frequency of system memory is the lowest frequency of all memory
modules placed in the system, as determined through the SPD registers on the
memory modules. The system memory controller supports one or two DIMM
connectors per channel for unbuffered DIMMs. For dual-channel modes, both channels
must have at least one DIMM connector populated and for single-channel mode only a
single-channel may have one or more DIMM connectors populated.
Note: DIMM0 must always be populated within any memory configuration. DIMM0 is the
furthest DIMM within a channel and is identified by the CS#[1:0], ODT[1:0], and
CKE[1:0] signals.
For more info, please read datasheet
Also, let me remind you that this goes for ALL P55 boards out there, its not just an MSI thing.
This has to do with the fact that the memorycontroller now sits on die on the Lynnfield cpu's.
Im hoping to end the debate, like I had (and I was wrong), about the fact that you should be able to use any channel, like you could on the S775 boards, you just cant anymore.
Update 26 december 2009:
Running all 4 DIMM slots with memorysticks
It seems that a lot of people are having problems running with all memoryslots occupied, e.g. not booting, BSOD and other crazy stuff.
If you have such problems try the following first, before running back to the store to swap stuff out.
- Raise Vdimm to 1.65V, its still a save voltage for the board and this way the memory gets a little more power and in 99% of the cases, this will solve the issue.
- Try booting/installing with one stick first in DIMM1 on the board (see above).
- If it boots/installs, let it go all the way till windows is done.
- Turn off pc and add a second DIMM in DIMM slot 3, restart and let i boot all the way again in windows till its done.
- Do the same again for DIMM2 and last DIMM4.
We know its a bit of a hassle, but it worked for a lot of people, so be sure to try this before anything else.
And again, its not just an MSI thing, there are more manufacturers out there with the same issues, this also has to do with the fact the memorycontroller now sits on die with cpu.
I'll edit if new boards come out.
--I made your images clickable
Click the modify button to see how I did it.
--Mike

Upgrading Mother Board (P55-GD65 with i3 processor) BIOS [/b] from 1.3 to 1.6 corrected my Computer re-starting soon after the Boot sequence began. Putting the four 2GB RAM in one at a time in the suggested order in sequence with the socket numbers fixed the problem earlier, but only for the next, one boot. The problem then returned as long as all 4 DRAM were installed. Raising the DRAM voltage did not improve things.
I used the Forum's program for flashing the new version of Bios using USB Flash Memory for boot into DOS.
Thank you, DaLoona, for your post notifying me this had to do with the motherboard and was probably not a failure, but a "normal" occurance in certain conditions. I was no longer inclined to return the board and perhaps end up with the same error in the replacement, and no longer worried about the rebooting doing damage.
In Bios Setup I had already reduced an entry to do with number of overclocking tries from 3 to 1 (the minimum choice) which reduced the number of re-boots to 1.

[solved]script fails when changing profile through powerdevil.

i use ondemand governor and i want to change up_threshold value.
Whenever i change profile through powerdevil up_threshold gets its default vaule of 80.
what i did was to create a script named threshold containing the lines:
#!/bin/bash
sudo sh -c 'echo 50 > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/up_threshold'
i have also set through /etc/sudoers that this script is passwordless for my user.
if i run the script, it successfully changes the value. It also runs successfully if i put it in startup.
My problem is that it fails to run when i choose it to run when a profile loads through powerdevil. I am refering to the feature shown below :
at first i thought that this function has a problem. so i chose to run kate, and when i changed profile, kate started immediately. So i guess that there is a problem with my script.
Any ideas?
Last edited by mechmg93 (2009-10-20 20:14:30)

I hope someone reads this thread also its already marked as solved...
Anyway, i would like to use CPU frequency scaling, but in the powermanagement settings,
i cant shoose anything for frequency scaling.
What do i have to do to be able to set "ondemand" or "always lowest frequency"?
Wich daemons and/or modules do i have to activate to change the frequency policy?
Would be very nice if someone could help me.

Trouble building kernel module for sensor support

Hi, I'm new here but have been using Arch for a while. Recently, I decided to install Arch on an old laptop (Toshiba A70) and have managed to work out most of the kinks to where it runs nicely. Unfortunately, ACPI support is spotty and the /sys/class/thermal directory gives me only cooling_device0. I installed the lm-sensors package and ran sensors-detect, which yielded no results. Although the laptop runs smoothly otherwise, I would like to know the CPU's temp so that I would be able to set up a fan control scheme and CPU scaling (so far it's stuck at the lowest frequency, and that's kind of a big deal for me since the laptop runs on an archaic mobile P4 chip).
Sorry for the story but I felt some context was necessary. I did manage to find a kernel module that would connect those sensors to ACPI for me (http://sourceforge.net/projects/omnibook/), however I'm having trouble building it on the latest kernel. Here is the output from running make:
make -C /lib/modules/3.16.1-1-ARCH/build SUBDIRS=/root/omnibook-2.20070211 modules
make[1]: Entering directory '/usr/lib/modules/3.16.1-1-ARCH/build'
CC [M] /root/omnibook-2.20070211/init.o
In file included from /root/omnibook-2.20070211/init.c:26:0:
/root/omnibook-2.20070211/laptop.h:25:3: warning: initialization from incompatible pointer type
.callback = dmi_matched,
^
/root/omnibook-2.20070211/laptop.h:25:3: warning: (near initialization for ‘omnibook_ids[0].callback’)
/root/omnibook-2.20070211/laptop.h:34:3: warning: initialization from incompatible pointer type
.callback = dmi_matched,
^
/root/omnibook-2.20070211/laptop.h:34:3: warning: (near initialization for ‘omnibook_ids[1].callback’)
/root/omnibook-2.20070211/laptop.h:43:3: warning: initialization from incompatible pointer type
.callback = dmi_matched,
^
// I left out most of the 'incompatible pointer type' warnings since they repeat for a while.
^
/root/omnibook-2.20070211/laptop.h:1001:3: warning: (near initialization for ‘omnibook_ids[108].callback’)
/root/omnibook-2.20070211/init.c: In function ‘dmi_matched’:
/root/omnibook-2.20070211/init.c:141:16: warning: assignment discards ‘const’ qualifier from pointer target type
laptop_model = dmi_get_system_info(DMI_PRODUCT_VERSION);
^
/root/omnibook-2.20070211/init.c: In function ‘omnibook_init’:
/root/omnibook-2.20070211/init.c:281:3: error: implicit declaration of function ‘create_proc_entry’ [-Werror=implicit-function-declaration]
proc_entry = create_proc_entry(feature->name, pmode, omnibook_proc_root);
^
/root/omnibook-2.20070211/init.c:281:14: warning: assignment makes pointer from integer without a cast
proc_entry = create_proc_entry(feature->name, pmode, omnibook_proc_root);
^
/root/omnibook-2.20070211/init.c:290:13: error: dereferencing pointer to incomplete type
proc_entry->data = feature;
^
/root/omnibook-2.20070211/init.c:291:13: error: dereferencing pointer to incomplete type
proc_entry->read_proc = &procfile_read_dispatch;
^
/root/omnibook-2.20070211/init.c:293:14: error: dereferencing pointer to incomplete type
proc_entry->write_proc = &procfile_write_dispatch;
^
/root/omnibook-2.20070211/init.c:294:13: error: dereferencing pointer to incomplete type
proc_entry->owner = THIS_MODULE;
^
cc1: some warnings being treated as errors
scripts/Makefile.build:257: recipe for target '/root/omnibook-2.20070211/init.o' failed
make[2]: *** [/root/omnibook-2.20070211/init.o] Error 1
Makefile:1333: recipe for target '_module_/root/omnibook-2.20070211' failed
make[1]: *** [_module_/root/omnibook-2.20070211] Error 2
make[1]: Leaving directory '/usr/lib/modules/3.16.1-1-ARCH/build'
Makefile:88: recipe for target 'omnibook.ko' failed
make: *** [omnibook.ko] Error 2
I have honestly no idea what to make of any of this and would really appreciate any help towards a solution. Thanks for reading

Welcome to Arch Linux
That looks like it is a 2.6 kernel module
http://sourceforge.net/p/omnibook/bugs/58/
Did you try either of these AUR offerings?
ewaller$@$odin ~ 1001 %packer -Ss omnibook
aur/omnibook-git 20110911-9 (7)
Kernel module for HP OmniBook,Pavilion,Toshiba and Compal ACL00 laptops
aur/omnibook-svn-zen 268-1 (1)
Kernel module for HP OmniBook, Pavilion, Toshiba and Compal ACL00 laptops
ewaller$@$odin ~ 1002 %
Last edited by ewaller (2014-08-23 23:33:53)

[SOLVED] Intel i7-3920XM Laptop CPU Linux Kernel Support

Recently, I purchased a laptop with an Intel i7-3920XM CPU, with the intention of utilizing it for scientific computing (I've become strongly interested in machine learning and artificial neural networks). Supposedly, the CPU has a variable clock speed of 2.90 -- 3.80 GHz, which would be great, but my kernel has throttled it to 1200MHz. I've tried both the cpufreq performance and userspace kernel modules (configured for performance), but the laptop stubbornly refuses to increase the clockspeed more than 1200MHz; I gave up on cpufreq and have uninstalled it. I've read some accounts that it is possible that the Linux kernel may not support my CPU yet --- does anybody know if that is the case? If it is not, can anybody point me to some literature describing how to un-throttle my CPU?
Last edited by deltaecho (2013-03-03 21:59:30)

runny6play wrote:
Meyithi wrote:
CPU frequency scaling is enabled by default, 1200MHz is fine for your processor as it's lowest frequency I have the 3960x and it's lowest frequency is 1200MHz as well.
You should just leave things as they are, if you can actually feel sluggish performance ( I don't with 6 cores @ 1200MHz) you can try this:- https://wiki.archlinux.org/index.php/Cp … erformance
Which will liven things up a bit at the cost of more battery juice.
EDIT/ compile something and whilst compiling
cat /proc/cpuinfo | grep MHz
to see what's reported at full load, but be aware it still may not report correctly due to turbo.
deltaecho wrote:Recently, I purchased a laptop with an Intel i7-3920XM CPU, with the intention of utilizing it for scientific computing (I've become strongly interested in machine learning and artificial neural networks). Supposedly, the CPU has a variable clock speed of 2.90 -- 3.80 GHz, which would be great, but my kernel has throttled it to 1200MHz. I've tried both the cpufreq performance and userspace kernel modules (configured for performance), but the laptop stubbornly refuses to increase the clockspeed more than 1200MHz; I gave up on cpufreq and have uninstalled it. I've read some accounts that it is possible that the Linux kernel may not support my CPU yet --- does anybody know if that is the case? If it is not, can anybody point me to some literature describing how to un-throttle my CPU?
I would agree with you if that was what the argument was about. I said the same thing about i7z as you just did, which is why i suggested it. as I understand it. your telling him 1.2 Ghz is an acceptable min and i would agree.How i am interperting his thread is 2.90 Ghz is his base. 3.80 Ghz is his max turbo. His CPU under 100 % load will not rise above 1.2 Ghz despite his stock clock is actually 2.90 Ghz. I can honestly say that this is the more likely story because my i7 did the same thing. on battery the max it would clock up to while runing /dev/urandom > /dev/null was 1.2 Ghz, while on Ac it would even turbo correctly. by unloading the module. my proccessor would clock as expected 800 mhz min 3.4 max turbo. and if you look he even used the performance governor to try to increase the clock
Ya, really the OP did not tell us 'how' he was reading his CPU speed....
deltaecho wrote:Recently, I purchased a laptop with an Intel i7-3920XM CPU, with the intention of utilizing it for scientific computing (I've become strongly interested in machine learning and artificial neural networks). Supposedly, the CPU has a variable clock speed of 2.90 -- 3.80 GHz, which would be great, but my kernel has throttled it to 1200MHz. I've tried both the cpufreq performance and userspace kernel modules (configured for performance), but the laptop stubbornly refuses to increase the clockspeed more than 1200MHz; I gave up on cpufreq and have uninstalled it. I've read some accounts that it is possible that the Linux kernel may not support my CPU yet --- does anybody know if that is the case? If it is not, can anybody point me to some literature describing how to un-throttle my CPU?
runny6play: If deltaecho is also seeing these same slow speeds in i7z then both you and he should look into your BIOS settings. For sure this would be a BIOS setting on a ThinkPad. "If on battery....slow... if on AC...fast".
Yes, it is the Linux Kernel that is no "Reporting" the correct speed. This is a known bug. However, there is nothing wrong with your CPU. It is running at High Speed.. Like this is the read out from my Kernel at idle...
[user@archtop:~]% sudo cat /proc/cpuinfo | grep MHz
[sudo] password for user:
cpu MHz : 1200.000
cpu MHz : 1200.000
cpu MHz : 2901.000
cpu MHz : 1200.000
The BEST way to test your CPU is, again i7z then compile some code... Like change the MAKEFLAGS="-j4" to -j1 for 1 thread, -j2 for 2 threads.... and so on. Compiling software will push your CPU all the way up.
When testing like this, i7z will show on 1 thread my CPU runs at 3.6GHz, on all 4 threads it runs at 3.4GHz, as it should. However, /proc/cpuinfo will only say wacky stuff like cpu MHz: 1200.000 cpu MHz: 2901.000
Last edited by hunterthomson (2012-11-26 09:28:13)

Command line nvidia-settings output.

First off, I'm not sure if this thread should be here or in the hardware section, but since the issue is with the software, i've stuck it here for the moment.
Since nvclock doesn't work with my fermi cards (2 x gtx470s in sli) I'm using the cli of nvidia-settings in a munin plugin. After some faffing around getting the env set correctly and sufficient xhost permissions, everything is working, apart from the clock speeds.
nvidia-settings -tq [gpu:0]/gpucurrentclockfreqsstring
should output the current clock frequencies of the gpu. However, all it displays is the lowest frequencies - for me, the output is always
nvclock=50, memclock=135, processorclock=101
even when the card is loaded (unigine benchmark) and the nvidia-settings gui shows the correct (higher) clocks. gpucurrentperflevel does change, so this is what I'm using at the moment, although I would prefer actual clock readings rather than 0-3.
Is this experienced by anyone else with nvidia (fermi or not) cards? And should I file a bug for arch, or upstream?
Thanks

Thanks Both...
Psychomania, I do remember one of the Nokia updates having a problem when I initially started to play with the phone. I've just gone through all the QR codes above and got the attached message for 'Display and Touch'.
This was exactly the problem I had initially and looks like the cause or the error in my settings.
FYI. I am updating over my home wi-fi, so there shouldn't be any connection issues.
Attachments:
wp_ss_20130122_0001.jpg ‏129 KB

How to judge correct rap in impact test

Hi,guys
   I get a trouble during my impact test project.
   I use PCI-4472 and one module hammer connect to channel 0 and one accelerometer connect to channel 1.
   hammer as trigger of accelerometer to get impact response.
   My question is
   1) I need make sure the rap of hammer only once in each impact action. if yes, then record related response from accelerometer, if no, I need repeat impact action without record response. how can i check that?
   2) for this case, if I need average yet? ( I saw the SVXMPL_impact test(DAQmx).vi, it take some average computed for data, but for my application,since the impact only once each time, then if I can ignore the average function? I have few knowlegae about average theory.)
   3)how much samples I should use?
Thanks for any help
Tim

To 1)
How do you see a double rap?
I assume you take a look at the hammer signal and look for more than one peak. Well do the same in LabVIEW. Hint:
Waveform Peak Detection VI
Owning Palette: Waveform Monitoring VIs
Requires: Full Development System
Finds the locations, amplitudes, and second derivatives of peaks
and valleys in Signal In. Wire data to the Signal
In input to determine the polymorphic instance to use or manually select the
instance.
This VI is similar to the Peak Detector VI.
If you search the overall max or min with
Waveform Min Max VI
Owning Palette: Analog Waveform VIs and
Functions
Requires: Base Package
Determines the maximum and minimum values and their associate time
values for a waveform.
you can determine a useful relative threshold.
To 3)
What is the lowest frequency you want to detect? You should at least capture 1 period. Together with pretrigger and windowing go for 2 periods
What is the highest frequency you expect? For impact choose your sample rate at least 10x better 100x times higher. (Some say choose the highest you can get to avoid phaseshifts due to the aliasing filter)
Both values will give you the number of samples.
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

Third octave decomposition

Hi!
I’m working about third octave decomposition with a vibration signal.
I’m using the sound and vibration toolkit.
The sample frequency of my signal is 2400 Hz.
I use the vi “1/n octave IEC decomposition” and I would like to know if I can selected the frequency range “1 to 400 Hz” in third octave decomposition? I think the results are strange in a low frequency (1 to 4 Hz)
In fact, for example, the BW of the first 1/3 octave is less of 0.3 Hz!!!!
So it’s possible to begin the third octave decomposition at 1 Hz?
Thanks for your help.
Bastien

thank...
But I would like to analyse a short signal (5 to 10 second) in the frequency range [1Hz to 400Hz].
When you begin the third octave analyse at 1 Hz you must to have a vibration signal with 17.24 s minimal length in time.
this minimum time is say in the user manual of the toolkit "sound and vibration":
Filter Settling Time :
When starting or resetting the filtering operation of the fractional-octave
filters, a certain time is required before the measurements are valid.
This time is called the settling time and is related to the bandwidth of any
particular filter. The lowest frequency band has the smallest bandwidth and
defines the settling time required before you can consider the complete
fractional-octave measurement valid. In the Sound and Vibration Toolkit,.......
settling time is defined as five divided by the bandwidth of the filter used
for the lowest frequency band.
..........The filter settled indicator returns TRUE as soon as all the filters are settled.
When you begin analyse at 1 Hz, the first BW is 0.29. So, 5/0.29 = 17.24 second.
My vibrations signals are too short (5 to 10 second) and I can't have more long because this signals are due to train course and it’s very fast.
I don’t know how to catch information in a low frequency (1 Hz) with a short signal.
Thank for your help
bastien

Should I buy a Nano or regular iPod?

I was just curious to know someone's opinion on whether I should buy an iPod or a Nano. I do like the sleek, smallness of the Nano and the fact that it's cheaper. However I do have a lot of music and would like to be able store other files and photos. Also it seems that the regular iPod has more features (correct me if I'm wrong).
I was also curious as to which is easier to find cases and an FM Modulator for? Any suggestions and recommendations would be greatly appreciated.

No, not a 40Gig iPod, but a fourth generation 20 Gig iPod. It's more than I really need, but it works fine for me.
As far as skins and cases are concerned, go to:
http://www.ilounge.com/
and you'll be able to see a large number of protections available for whatever model you choose. There is a catalog listed somewhere that you can download. It really is a matter of personnal choice.
As far as FM transmitters are concerned, I had the Belkin first generation, and I didn't like it all: there is a remarkable loss of bandwith, i.e. you loose a lot of the highest and lowest frequencies, so that was too much of a loss of sound quality for me. So I gave it away when I had a special module installed in my Volvo.
* Guy

This might get rid of your crackling and popp

I know many of you have tried this so just ingnore, this thread. I went to bios and changed my pci latency. I couldnt believe I didnt think of that a long time ago. I was so fixed on believing it was the drivers (which I still do) that I didnt think of my settings in the bios. My card isnt working like it should but its a whole lot better than it was. I can play cod 2 with eax3 with no prob. Before I couldnt even have 2d sound with the lowest frequency. Now all Im waiting on is the new drivers which will probably come out after they release a new card. This thread is just for someone who doesnt know about bios settings or someone who just forgot.

No matter what supplier you go to they use outsourced call centres also by the nature of forums they carry complaints and problems because those that are happy do not bother to post you can go and look at any isps forum and you will the same complaints
If you want to say thanks for a helpful answer,please click on the Ratings star on the left-hand side If the reply answers your question then please mark as ’Mark as Accepted Solution’

Flashplugin freezing your system? Maybe it's not what it seems...

I'm posting this detective story in this subforum because the issue discussed seems to be happening mostly with laptops.
The symptoms:
You are happily surfing the internet with your laptop when you decide to watch a flash video. After some minutes, your nightmare begins: suddenly the video playback becomes choppy, your browser slows down and the whole system becomes painfully slow and unresponsive. You check cpu usage and it seems that both firefox and flashplugin are wreaking havoc. You close/kill the processes but to no avail. It seems as if flashplugin is haunting your laptop from beyond the grave, leaving you no other option but to reboot.
You then start a pilgrimage through Google and linux forums to seek a solution, but none of the answers provided seem to fix this annoying behavior. It turns out that something more subtle is going on...
The real deal:
Flashplugin is not the cause of your problem, it's just the trigger. I came across this revelation while gzipping several dozens of big (4Gig+) files: exactly the same behavior emerged and flashplugin had nothing to do with it.
A hunch told me to check the cpu behaviour and after running "cpufreq-info" I find out the real problem:
analyzing CPU 1:
driver: acpi-cpufreq
CPUs which run at the same hardware frequency: 0 1
CPUs which need to have their frequency coordinated by software: 1
maximum transition latency: 10.0 us.
hardware limits: 800 MHz - 2.20 GHz
available frequency steps: 2.20 GHz, 2.20 GHz, 1.60 GHz, 1.20 GHz, 800 MHz
available cpufreq governors: ondemand, performance
current policy: frequency should be within 800 MHz and 800 MHz.
The governor "ondemand" may decide which speed to use
within this range.
current CPU frequency is 800 MHz.
Notice the cpu stuck at the lowest frequency?
It seems that there is some widespread problem in linux with some combinations of hardware and kernel/cpufreq-utils that causes the cpu-throtling to misbehave whenever the cpu is subject to some stress. As soon as the cpu usage goes 100% for some prolonged period of time, the cpu gets stuck at the the lowest frequency and any cpufreq command issued trying to fix it will be ignored by the system.
The solution:
Until this gets fixed in kernel26 and/or cpufreq-utils, there is a simple workaround to the problem:
Issuing the following command will ease the pain while your system is running:
echo 1 > /sys/module/processor/parameters/ignore_ppc
(You might need to restart whatever cpu-throttling daemon you are using, and you might also need to do some easy voodoo with cpufreq-set to reset the cpu maximum frequency and/or governor.)
To fix it permanently, add this boot parameter to your kernel line in /boot/grub/menu.lst :
processor.ignore_ppc=1
Final considerations:
While researching this problem in different forums, I found out that a lot of users are incorrectly blaming flashplugin and don't know what's really going on with their cpus. For average/everyday computer usage, flash video is probably the only thing that will subject the cpu to a 100% usage for enough time to trigger the problem; therefore causing the incorrect diagnostic and subsequent frustration.
I'm pretty sure that this is not a hardware problem, as it has been reported in different laptop models. Although it does seem to be more frequent in Dell laptops.
I know that my cpu-throtling used to be fine some time ago, I'm sure because is one of the first things I always make sure to set it up correctly the first time I install linux on a new laptop. Sadly, I can't pinpoint the exact version change of kernel26 and/or cpufreq-utils that started this whole mess. I took me quite time to narrow down the problem and rule out flashplugin or firefox as the causes.
If you check with Google, it seems that this issue is not only limited to Archlinux, several other distros are experiencing the same problem. For us, Archers, the bug (or something quite similar) is reported already here.
One final call: if you happen to suffer this issue and you thought it was a case of flashplugin misbehavior, please take some time to report or confirm the cpu-throttling bug. It seems to be really widespread but poorly reported, and without proper understanding of the large number of users suffering it, it will not be fixed as soon as is desirable.
Something related to cpu-throtling is awry in cpufreq-utils or kernel26 , and without your support it will pass unnoticed and blame will fall unto poor flashplugin.
Cheers

Thanks a lot for this detailled post. I already fixed the issue on my laptop in july, but it's good to spread the word.
Regards

5600 lowest frequency

Similar Messages

Maybe you are looking for