Convert a rpm waveform to digital/analog tach signal. Sound & Vibration

Hello,
my question is: How to convert a rpm waveform to
digital/analog tach signal for use with SV application?
Or is it possible to modify the SV - VIs for the use of
a rpm waveform or a speed signal?
Thanks a lot for coming answers.
Thomas Nuding

Typically an RPM waveform is the analog view of a tachometer, such as a proximity probe over a key or keyway, or an index pulse from an electric motor. In most rotor dynamics applications, the phase of the tachometer waveform is compared to the phase of other waveforms, such as vibration, to determine the angular position of the shaft when the other waveform occurs.
The sound and vibration tools have a function for calculating RPM from an analog tachometer waveform. The order analysis toolset go further to add a counter as an tachometer input. The OAT tools also allow for selection of rising edge or falling edge and voltage level for the "trigger". A time instance is recorded when the edge occurs. This time instance is used for phase measurements and for resampling the other waveforms into the angular domain, ie. 360 measurements per revolution.
Preston Johnson
Principal Sales Engineer
Condition Monitoring Systems
Vibration Analyst III - www.vibinst.org, www.mobiusinstitute.com
National Instruments
[email protected]
www.ni.com/mcm
www.ni.com/soundandvibration
www.ni.com/biganalogdata
512-683-5444

Similar Messages

Convert a rpm waveform to digital/analog tach signal. Sound & Vibration

Hello,
my question is: How to convert a rpm waveform to digital/analog tach signal for use with SV application?
Or is it possible to modify the SV - VIs for the use of a rpm waveform or a speed signal?
Thanks a lot for coming answers.
Thomas Nuding

duplicate post

Audio Digital Analog Converter bit resolution

Hello ! i´m looking if I can use IPHONE to make my investigation project. Someone of you know which is the audio Digital Analog Converter bit resolution for a normal audio conversation? 13bits? thank you very much

MonoPrice.com has a digital to analog converter for around $25 although it looks like it is on back order. I would give them a call anyways. Don't get fooled by their prices, they are fast and cheap but good and the place to buy all your audio and video cables. I wired up my sisters entire home theater for less than a quarter of what I payed for my first HDMI cable which I didn't pay much for either.
http://www.monoprice.com/products/product.asp?cid=104&cp_id=10423&cs_id=1042302&pid=6884&seq=1&format=2

Set values for the Lock-In Amplifier's Digital Analog Converter Channel?

If I let my user have the freedom to select whatever values they want to select in order for it to show up as the output value for the Digital Analog Channel then I cannot understand why use ibwrt(...) and ibrd(...). Because ibwrt is going to write a specific voltage at the specified channel since the manual for the Amplifier states you must input the string for writing output voltage as DAC2 3000 (the 2 signifying the channel and 3000 - the millivolts). If this hard coding occurs by using ibwrt then how can I write my code so that the user has the capability to change the voltage value and the channel to the one they want? Thanks in advance.

Do I need a Fmt and ibwrt for both DOutput and VOutput? Because DOutput is indicative of the channels 1, 2, 3, 4 in the Lock in Amplifier and the VOutput is for the amount of volts the user can set (i.e. write to the instrument). Also I found this on the following NI website regarding filling in the value of the write buffer: Write Buffer Value. This website signifies that one must use \002 and end with 003\ which I am not sure I even need for this instance of initializing the writeBuffer[8]. Also I used [7] for the writeBuffer because I thought arrays went 0, 1, 2, 3...so on therefore writeBuffer[7] will give me space for 8 bytes? Is that an incorrect assumption? Lastly, here is my modified code according to the changes you mentioned and it still is giving me Non-Fatal Run Time Errors and not communicating. Is there anything else I am missing out on which I can't find. Seemed like I may be making this code much harder than it needs to be. Thank you for your time.
Sincerly,
Attachments:
SETDAC.c ‏2 KB
setdacwin.h ‏2 KB
setdacwin.uir ‏3 KB

Digital analog in one queue

I want to create one queue for both digital and analog data. The attached vi has two. How would you get the 2 different data type feed to one queue? It would require a digital waveform and an analog waveform to get the data into one queue. Any ideas? I am using cDAQ-9172 and NI 9401 and NI 9205
Message Edited by bassinbc on 05-21-2009 11:42 AM
Solved!
Go to Solution.
Attachments:
Script Chart1.zip ‏51 KB

Ravens Fan wrote:
Please mark Jim's post as the the solution, then.
I thought he didn't like my poetry.
Jim
You're entirely bonkers. But I'll tell you a secret. All the best people are. ~ Alice

Capturing Digitized Analog Video

When sending digitized analog video to iMovie or to another Video editing software, the very first image is clear and bright (for only a split second) then a shade of gray comes over the preview/import window and the rest of the imported movie is grayed over.
Workflow sequence is:
1. VCR Player
2. ADVC-110 DV Converter
3. Mac Pro
4. iMovie or other video editing software
My first try at converting a VHS tape to digital worked fine. This second tape . . . not so good.
Thanks in advance - bob

Paul, when I purchased the Plextor unit, VideoStudio did not come with the package. I notice on the Plextor web-site that the current product does have VideoStudio bundled with the converter. I also notice that both InterVideo WinDVD and VideoStudio are Corel products. Are you telling me that VideoStudio would not conflict with PE7 whereas WinDVD would?

Looking fora camcorder that also has an s-video or rca jack input to convert my vhs tapes to digital

looking fora camcorder that also has an s-video or rca jack input to convert my vhs tapes to digital.

Hi ltcps,
Thanks for writing us!
None of Canon's current camcorders include S-Videos, RCA or other auxiliary inputs.
Did this answer your question? Please click the Accept as Solution button so that others may find the answer as well.

How to convert old VHS tapes to digital

I am hoping someone can give me an overview of what kind of equipment/software is necessary to convert VHS tapes into a digital format that could be saved in iMovie. Do I just need the right cables for the VCR or something more complicated? Thanks!

I recommend that you download the free iMovie HD6 for those with iMovie 08 who do not have a prior version of iMovie HD6. You can get it here: http://www.apple.com/support/downloads/imovieHD6.html
And, do this tutorial: http://www.apple.com/support/imovie/tutorial/
It is more capable of creative editing and you have a quite a bit more control over your iMovie with it.
+So, your method worked using just a VCR, a camcorder, and your computer? No special converters?+
Yes, I just used the AV connectors that came with my camcorder to hook the camcorder to the VCR....which was in a combo TV/VCR unit so I could see the footage on my tv, just to make it easier. The AV connector cable has a special prong that fits into the camcorder, and those white/red/yellow prongs at the VCR end. The TV/VCR is a few years old, certainly not anything fancy or new.
I didn't bother with a converter since I just used the camcorder.
My computer and that VCR are not physically close enough to try to import directly, and since I wanted the digital tapes of the original footage, recording first to the miniDV tapes worked for me. Canopus makes a couple of nice converters...they are around $150-250, I think.
Then, to connect to the computer with the camcorder you will need a 4-6 pin Firewire cable.
+I might do it sooner or I might put it off for awhile while I practice messing around with iMovie.+
The benefit of recording from VHS to miniDV tapes is that the tapes are digital, they store easily and the footage will not degrade before you get around to creating your iMovies and DVDs. iMovies can take up lots of drive space, so don't be thinking that you will just import them all and save them for editing later. You would need a huge amount of space for this. Most of my movies are just under 2 hours, and occupy between 25-40 GB each. A couple of my movies were well over 100-140GB!!!! Yes, that is correct. I have a couple of external drives that I use for my movies while I am creating them. I usually have about two or three that I am working on at the same time.
+We want to put them in a digital format that will be easier to store and play and safer from eroding over time, so I guess the end format I'm looking for is DVDs.+
Because DVDs can break/crack/warp/melt/etc, you should consider exporting your finished iMovies back to the camcorder so that you have the miniDV tapes for more permanent storage and as a backup to your DVDs.
That is one of the big reasons that I don't use iMovie 08---it does not permit exporting back to a camcorder.
Although I do not save my created iMovies on my computer after I have made the DVD and exported the edited movie back to tape, I do save all my iDVD projects as disk images. A disk image can be up to 4.7 GB--even my large movies were automatically compressed down when put into iDVD. The limitation in iDVD is the total length of the movie in TIME, not SIZE. I use single-layer DVDs, which can hold up to 2 hours of content. Creating disk images allows you to have an exact copy of your iDVD projects, self-contained so that you can delete the original iMovies and the original iDVD projects. You can use the disk image to burn your disks when you first create them, and any time in the future. It is a good backup for the entire DVD.
Enjoy being creative with your movie projects! Post back with any more questions, and feel free to email me if you want.
Regards,
Beverly

Read analog trigger signal gated by digital pause trigger

Hi!
I want to use and analog trigger together with digital pause trigger. At the same time i want to see on the scope the analog trigger signal which was gated by gate signal. Is it possible? Can i somehow wire the gated trigger to one of the outputs of the board?
Thanks in advance.

Hi Sergei_phys,
Thank you for the forum post!
I have a few questions about your post:
What hardware are you using? Is it NI or 3rd party? You mention using a scope, is that a NI piece of hardware/module?
In theory you can have a analog trigger to start the acquisition and a digital trigger to pause , but it depends of the hardware.
Thanks,
DanC12

Connect digital analog ground

Greetings.
I have a mixed-signal Multisim design which I have forward annotated to Ultiboard. My Multisim circuits use 2 different grounds - net 0 and net DGND. For simplicity, I would like to prototype a first version of the boards with the grounds logically connected, so I don't need to worry about ground loops being created by the fact that I'm using separate digital and analog lab supplies.
I have checked the box in Multisim under "Sheet Properties -> PCB -> Connect digital ground to analog ground." I have transferred my design to Ultiboard 11 and specified a 4 layer board. Layer 3 is my ground plane, with a large copper area connected to Net 0. While placing components and vias on my board, I'm noticing that the thru-holes and vias I define as connected to Net 0 appear as I expect - with the "+" thermal relief on layer 3. However, vias logically connected to DGND are appearing on layer 3 with large areas of copper removed (I've specified 12 mils clearance on each copper layer). If I change the copper area on layer 3 to net DGND, instead of net 0, I notice the reverse situation. All of my analog ground vias and thru-holes have copper cleared away, and the DGND vias are now filled.
I don't believe a logical connection exists between net 0 and DGND in the forward annotated netlist. Is there some way I can confirm this? Did I miss a step in the process while trying to connect these two?

Thank you for your reply, Mark.
I was going to upload my Multisim project file, but then realized a lot of my components are now in my Corporate Database, so I can keep vendor and manufacturer-specific part numberings and inventory quantities all together in the same place. Instead, I took some screenshots and created a .pdf file. I uploaded the pdf file to transferbigfiles.com, here.
First, I snipped some sections of my design to illustrate the current state of things. On the first page, you can see that my default sheet properties are setup such that digital and analog grounds should be connected. I have an FMC-LPC connector "J17" in my design, with the "DGND" wired to it. The J17B pin actually represents about 40 different SMD pads on a VITA 57 connector. The DGND component is from the Master Database under Power Sources, though I think I renamed it from "DGND" to "GND." As you can see, Ultiboard is showing a lot of DRC errors right now because the vias are set to assume net "0" while the SMD pads were exported as connected to net DGND.
Next page, I unchecked the box "Connect digital ground to analog ground" and forward annotated the changes. Ultiboard found no differences.
Next I thought that perhaps my renaming of the default Refdes from "GND" to "DGND" could be the problem. So I went through my design and replaced all of my "DGND" triangles with the DGND component from the Master Database. As you pointed out, though the component is named "DGND" the Refdes is actually "GND." I left the sheet properties as is, with digital /analog grounds not connected. When I forward annotate the changes, I observe what I expect - the DGND connections are removed and replaced with GND connections. (Next page) The SMD pads are now logically connected to the net named GND instead of DGND.
Finally, I went back to Multisim and tried combining the nets "GND" and "0" automatically by selecting the check box in Sheet Properties. Unfortunately, when I forward annotate, Ultiboard detects no changes.
Following are 2 relevant sections of my .ewnet file I opened in a text editor, after my latest changes.
(net "0"
(trackwidth "6.00000000e+000")
(trackwidth_max "3.93700787e+002")
(trackwidth_min "6.00000000e+000")
(clearance_to_trace "6.00000000e+000")
(clearance_to_pad "6.00000000e+000")
(clearance_to_via "6.00000000e+000")
(clearance_to_copper "6.00000000e+000")
(routing_layer "1111")
(net_GUID "{8704ACB4-9808-4086-9C22-02206D379B13}")
(net "GND"
(net_GUID "{8EFCFB7F-F038-4362-A59D-667354159F44}")
Message Edited by pcurt on 02-22-2010 10:48 AM

How to get analog Tacho signal in PCI 6250 NI card

Dear All,
Iam using Labview 8.6.1 and NI PCI 6250 card. In my application i need to get order power spectrum for particular speed and accelerometer signal. For that iam using labview example program Order power spectrum(Analog Tacho).VI. In my PCI6250 card i configured AI0 as Accelerometer signal and AI 1 as speed signal for analog tacho signal. In that example program i can get Amplitude of Acclerometer signal But i cant able to get Speed Profile. For Speed iam using encoder, from that encoder Digital pulse i connected to analog channel 1. Whether this connection is correct? Instead of giving digital pulse directly i tried analog signal based on 0-10v for 0-1500rpm. This configuration also is not working. Encoder PPR is 1000. Can any one help me to solve my problem.
Regards,
Vijay.
Solved!
Go to Solution.

At 1800 RPM you are rotating at 30Hz. for your encoder pulses are coming at 30,000 Hz. You need to sample the analog encoder channel at 100,000 Samples per second or more. Graph your analog inputs on a time waveform graph to see if you are getting a clean signal.
With the analog tacho vi, you need to provide the number of pulses per revolution, so it can determine the correct speed.
Preston Johnson
Principal Sales Engineer
Condition Monitoring Systems
Vibration Analyst III - www.vibinst.org, www.mobiusinstitute.com
National Instruments
[email protected]
www.ni.com/mcm
www.ni.com/soundandvibration
www.ni.com/biganalogdata
512-683-5444

Does Mini Displayport to DVI adapter support analog VGA signal?

I'm just about to buy a macbook pro. Since the MDP (mini displayport) to DVI and MDP to VGA adapters are £20 a pop, I can only afford to get one. Obviously DVI is better in general, but VGA supports more older hardware, CRTs, and the spare VGA input on one of my displays (where the desktop uses the DVI).
What I'd like to know is does the MDP to DVI adapter also support the analog VGA signal on certain pins (like most physical desktop DVI ports do)? If it does, since I have about 3 or 4 DVI to VGA adapters lying around, I can get the MDP to DVI adapter and use the DVI to VGA adapters with it if necessary, but if it doesn't I might be better off getting the MDP to VGA...

No. Unlike DVI, which in the DVI-I configuration has both digital and analog pinouts, DisplayPort (and mini-DisplayPort) are purely digital. Mini-DP to DVI then DVI to VGA will not work. If you look carefully at the Apple Mini-DisplayPort to DVI adapter, you'll notice it's a DVI-D connector - digital pins only.
The Apple mini-DisplayPort to VGA adapter contains a digital-to-analog converter.
So, you'll have to choose. If you want VGA, get Apple's mini-DisplayPort to VGA adapter.

I need to import a live analog RCA signal into a Macbook Air 13" model A1466 to record on Final Cut. Is this possible? If so, how?

I need to import a live analog RCA signal into a Macbook Air 13" model A1466 to record on Final Cut. Is this possible? If so, what equipment/cables do you recommend pruchasing?

If you want audio and video from your RCA cable source, you would need a converter device. One that I have used is the EyeTV Hybrid from ElGato. You attach to the Mac via USB, and can attach to RCA composite, Coax, or S-Video. You would record into the EyeTV software and later export to Final Cut for editing. This would not go live into Final Cut Pro.

Switching of analog measurment signals

Hello,
in our LabView applications we have to measure several voltages and
currents. We use a AT MIO 16 E 10 DAQ card, but it is not good enough
for 2 voltages 2 currents. Therefore, we use exernal GPIB measuring
instruments for them (Keithley 2000 a.a.).
However, I think we could come along with only one Keithley 2000 since
the timing is no issue (1 scan per sec is enough). I need some switch
controlled by LabView that switches the analog measuring signals to
two Keithley 2000 (analog) inputs (one for voltage, the other for
current measurement, respectively).
I found out that I can't do this with the DAQ card alone. I can't use
the analog outputs since I don't want a A/D - D/A conversion included.
Note that the measuring volta
ges can be ~100 mV.
But I could be wrong since I am actually a software guy so please
correct me if this is possible with the DAQ card only.
My idea is as follows:
I could use the digital outputs of the DAQ card and connect them to
some opto coupler or relais with TTL input. The opto couplers or
relais would switch the analog measuring signals according to the
digital outputs of the DAQ card and finally according to LabView.
I couldn't find such a switcher board in the NI catalog. They have
switchers, but they seem to switch voltages >3V only. But maybe
someone suggests a board from another company which suits better.
I just wouldn't like so much soldering my own board since my knowlege
of opto couplers, relais and hardware in general is really limited.
Best regards
Johannes

Hi Marcus,
thanks for your answer.
I was probably not clear about what I want. The solutions you suggest
seem to be far to complex. As Nirmal pointed out, I actually only need
high quality optocouplers, no more.
On Thu, 25 Mar 2004 09:30:26 -0600 (CST), Marcus G wrote:
>Hello Johannes,
>It sounds like you're setting up a system that requires four analog
>inputs (two voltage and two current), and you would like to use an
>analog trigger to switch between which signals are measured.
No. I just want to use the digital outputs of the DAQ card to switch
optocouplers. The optocouplers will switch between several analog
measuring signals. They should route these signals to one analog input
of a Keithley 2000.
>There are
>several options of
how you can set up such a system.
>In terms of measuring the four analog inputs, you should be able to do
>this with a DAQ card alone. Many of our cards, including the
>AT-MIO-16E-10 (also called a 6020E), have 16 analog input channels
>that have an input range of +/-10V.
I don't want to measure the four analog inputs with the DAQ card since
it isn't precise enough. The input range is too high for some of the
analog inputs and the resolution is too low. Also, I can't modify the
input range of the DAQ card at runtime. Therfore, we are using
external instruments (Keithley 2000 a.a.) for the measurements. My
idea was to only use one instrument for the four analog input signals.
Then I must provide the switching between the four analog inputs. The
idea was to control (switch) some optocouplers with the digital
outputs of the DAQ card. The optocouplers should route one of the four
analog signals to one Keithley 2000. I set the digital outputs of the
DAQ card in the LabView program. Also, t
he LabView program configures
the Keithley 2000 and reads the measuring values from the GPIB. That's
all.
Regards
Johannes

ATV3 - I need to enable dolby digital for optical surround sound (netflix and home movies), but when I do this it stops audio coming through TV speakers

I have a cinema sound receiver connected to Apple TV via optical cable. When I have dolby digital set to Auto it doesn't come through as dolby digital when watching movies on netflix and iTunes (home movies).
If I set Dolby Digital to ON it works as expected, but the sound stops working through normal TV speakers (via HDMI). This is the same for netflix and home movies.
I tried 16 bit setting, but it made no difference.
Any advice on how I can get this working - meaning Dolby Digital always on for when I turn my surround sound on and sound through speakers for normal operation?
Obviously I can change the setting when needed, its just a pain.
Thanks in advance.

Hello everyone,
here is the friendly and signed driver installation method to enable Dolby Digital Plus in your Encore internal speakers only. This is not an official driver, there is no control panel for Dolby Digital Plus or various sound effects, but tested and has much better and richer surround sound quality as before with factory driver. I guess, this driver tweak can work with any Bay Trail tablet also.
How can you upgrade Encore sound drivers:
1. Download signed driver package and extract.
2. Open Device Manager.
3. Upgrade your Sound, Video and game controllers
- Intel SST Audio Device
- Realtek I2S Audio Codec
one by one with "Have a disk" method.
4. Double click enabledolby.reg file and add to your registry.
5. Restart, and enjoy better sound quality.
Thanks.
UPDATE: Official Toshiba Dolby Digital leaked, official driver attached: ToshibaDolby.zip
- Encore with WimBoot -
Attachments:
EncoreDolby.zip ‏310 KB
ToshibaDolby.zip ‏1310 KB

Convert a rpm waveform to digital/analog tach signal. Sound & Vibration

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