"create analog signal" programmatic control of parameter Duty Cycle

I need to generate a square wave with a programmable duty cycle in LabView (not SignalExpress). I can use "Create Analog Signal" for a fixed duty-cycle signal but I cannot figure out how to get at the Duty Cycle parameter to change it programmatically. I was hoping for something like Property Node access but found that this only works for front panel objects.
Is there a way to dynamically change the Duty Cycle parameter in the "Create Analog Signal"?
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The Square Waveform vi found in Signal Processing - Wfm Generation has an input at the top for offset.
- tbob
Inventor of the WORM Global

Similar Messages

在LabVIEW SignalExpress裡如何使用 Create Analog Signal 產生低頻方波與高頻方波調變的訊號

各位先進大家好:
之前想要利用 Create Analog Signal產生一個低頻的方波與40k Hz的方波調變的訊號，
但不論如何調整 Create Analog Signal裡面block size或是sample rate的值，
所得到的兩個pulse的間距都沒有改變，(例如固定block size的值，調整sample rate，兩個pulse的間距都沒變，反之亦然)
參考下圖:
目前已有成功地產生出上圖的訊號，但卻不知如何調整設定使pulse間距能夠縮短(意即如何改變低頻方波的duty cycle)，
而整體的設定如下圖:
雖然之前已有先進解釋過block size與sample rate的意思，
但在方波的調變上仍然有疑惑，
不知是否還有其他的參數要調整呢?
還請各位先進不吝指教，謝謝~

基本上您在SignalExpress調duty cycle, block size等，調的都是綠色框所示的部分，也就是你產生方波的duty cycle與綠色區塊的block 要多大。
你會看到紅色區域的間隔是由於訊號產生輸出後，軟體重新restart 下一次的任務的間隔，因此才會沒有波形輸出。你可以用post-execution delay來加大他的間隔，以ms來加大(因為PC的clock是1KHz)，但是沒有辦法縮小得更小，因為最小就是0ms，也就是輸出訊號後DAQ close task馬上重新開始下一次task的最小迴圈間隔。
建議您使用Analog Waveform Editor先將波形編輯後(包含無訊號的間隔與有方波的地方)，最後以continuous output連續輸出來達到這樣的效果。
或是單純用LabVIEW來做，也是可以先將欲輸出的訊號寫好進buffer，最後以硬體clock作連續輸出。

Is PCI-6036E suitable for me to send out analog signal to controll a device?

Hello
I need to controll and generate an analog signal to control a nanopositioning stage and I would like to know which one will be better using PCI-7344 board through UMI-7764 or using PCI-6036E board through SCC-68 I/O connector. additional question, I have actualy four wiring pigtailed with LEMO connector, the LEMO connector have two PINs which will be connected to the device, and the 4 wires which will be connected to the signal conditioner, the two pins Ain+ and Ain- with respect to the device, the other 2 wires one is the shield ground and the other one is ground also, the device is CGND, shall I connect the only two differential wires which will be connected in the analog out at the UMI-7764 snd the other one in AOGND at UMI-7764, and the other 2 will be ignored. please may I get any help or advice with full of thanks.
Aneece
Message Edited by Aneece on 04-09-2009 10:22 AM

The XXXXX's means it's recording sys-ex information from somewhere, probably from your Yamaha. It also means you're probably recording onto an audio instrument track, or a MIDI track, not an audio track.
Without assuming too much on my end, I would suggest, obviously, of course, that you spend a day or two really learning how Logic operates. Learn the terminology, really digest it, and take baby steps.
Plug in one MOTU interface, and get audio in and out of that. Then plug-in the Yamaha, and do the same. Once you get that under your belt, set up the aggregate device, and by that point, you should be well on your way.
Focus on the "Getting Started" guide, and after you have a handle on that, try pumping audio in and out of the interfaces, one interface at a time.

Analog signal duty cycle incorrect

I am using an NI PCIe 6535 board to send digital timing signals to a custom PCB.
The signals are digital square wave signals with various duty cycles and phase shifts.
I also need to send a 12 bit ramp signal to the board.
I am having issues with the frequency.
I need the timing signals to run at 833.33333 khz.
I need the lsb of the ramp to run at 416.666666khz.
To create the timing signals I am using "Create Analog signal", so that I can set up the square wave with the appropriate phase shift and duty cycle.
Then I conver from analog to digital.
I am using a DAQmx generate to output the signal to the PCB. I have noticed that the DAQmx gen frequency directly controls the ramps frequency.
However for the digital timing signals there is some scaling factor. The frequency of the digital timing signals can be set in the timing signals them selves. The sample rate in the analog signal also effects the frequency.
To get the frequencies that I need. I had to set the"create analog signal" sample rate at 2.778G S/s, the "create analog signal" frequency to 1.2889GHZ, and the DAQmx generate frequency to 1.66666 MHZ. At those numbers, I get the timing signals to output at 833.333KHZ and the second bit of the ramp at 416.6666HZ (for the ramp I upped it to 13 bit and I don't use bit 0, as it outputs at 833KHZ).
However at these settings all of my timing signals have the same phase, and the same duty cycle, even though I have them set differently.
Can someone please help? I think the issue is that I have the sample rate and frequency of the "create analog signal" block set too high, but if I set them lower my signals will not be at the right frequency.
Attachments:
timing signal 1.JPG ‏44 KB
timing signal 2.JPG ‏47 KB
daqmx gen.JPG ‏55 KB

Hi David,
We found that there seems to be a weird divider between the sampling rate of the analog signal module, the analog signal sample rate, and the f daqmx gen.
After various tests we made a chart of what we observed. Fsignal and sample rate are values set in the "create analog signal" module, Fdaqmxgen is set in the "DAQmx generate" module. We used a "create anaolg signal" module to create the square wave, then convert analog to digital convert the square wave to digital.
We have "repeated signal" and "N periods" checked.
Fsignal
Fdaqmxgen
Sample rate
Frequency measured on the scope
1GHZ
10MHZ
100G s/s
100KHz
100MHZ
10MHZ
100G s/s
10KHZ
1GHZ
1MHZ
100G s/s
10KHZ
10GHZ
10MHZ
100G s/s
1MHZ
100GHZ
10MHZ
100G s/s
10MHZ
100GHZ
10MHZ
100G s/s
5MHZ
The equation we came up with is Feff = (Fsginal/FDaqmxgen)*1000.
To meaure the frequencies were using an HP 54600A oscilloscope, and probing standoff pins on our custom pcb.
We have several versions of the project, attached is the latest one.
Kyle,
How do I set the compression to false?
The picture below looks like labview? We are using signal express.
I can't change the frequency on the DAQ mx gen because I need the ramp to run at a set frequency.
There is a divider between the daqmx gen and the f signal. I have to set the Fsginal in the GHZ to get it to out at the right frequency. The equation we came up with is Feff = (Fsginal/FDaqmxgen)*1000.
Thanks,
Devin

Custom square wave duty cycle in signal express

Hey everyone,
I am using an USB X Series Multifunctional DAQ Model 6361, with labview signal express 11 on windows7 (version 9.3.5) and I am trying to figure out if i can change the duty cycle of a square wave. I need to have one period be at 75% duty cycle and another 25% or something along these lines.
thanks!
Adam

Hi Adam,
I believe another Applications Engineer has corresponded with you concerning this issue already. If you are looking to generate a truly custom square wave where the duty cycle changes from one period to the next then you will need LabVIEW as this functionality is not supported in SignalExpress.
Using the Analog Output along with the Create Analog Signals options will allow you to specify one fixed duty cycle for your square wave, but this will remain constant throughout the generation.
Regards,
James D.
Applications Engineer
National Instruments

How can I measure a 0% or 100% duty cycle signal ?

I want to measure the duty cycle of an input signal using a counter of a 6030-E board.
I work with a PXI Rack under Labwindows/CVI.
My program already works properly for duty cycle between 1% and 99%, but it is not able to detect 0% duty cycle (ie : signal to ground), nor 100% duty cycle (ie : signal to power supply).
The problem is I don't understand how the counter works in such a situation (it cannot detect any edge, as long as the signal is continuous 0V or continuous 12V).
Please have a look on the following code :
1- First, the counter is configured
// Reset Compteur
i_Status = GPCTR_Control(iDevice, iCptID, ND_RESET);
//Definition du type de mesure du compteur (mesure temps impulsion)
i_Status = GPCTR_Set_Application (iDevice, iCptID, ND_SIMPLE_PULSE_WIDTH_MSR);
//Definition de la vitesse d'echantillonage (20 Mhz)
i_Status = GPCTR_Change_Parameter(iDevice, iCptID, ND_SOURCE, ND_INTERNAL_20_MHZ);
//Definition du signal a mesurer (defaut)
i_Status = GPCTR_Change_Parameter (iDevice, iCptID, ND_GATE, ND_DEFAULT_PFI_LINE);
// initialisation du compteur
i_Status = GPCTR_Change_Parameter(iDevice, iCptID, ND_INITIAL_COUNT, 0);
// Preparation du compteur avant de l'armer
i_Status = GPCTR_Control (iDevice, iCptID, ND_PREPARE);
2- Then, every 10 ms, the value of the counter is read, so that I can calculate the duty cycle...
i_Status = GPCTR_Watch(iDevice, iCptID, ND_COUNT, ul_val_cpt);
3- ...and the counter is armed again for the next reading
i_Status = GPCTR_Control(iDevice, iCptID, ND_ARM);
When duty cycle changes from x% to 0% or 100%, the counter always keep the value corresponding to x%.
Even if I reset the counter between each measurement, it keeps this value ! I don't understand how it is possible.
How can I know that the counter didn't see any edge, and so that duty cycle is 0% or 100% ?
Thank you in advance for your help !
FraB

Hi,
Just have a look at this link, it can be interesting for you...
http://forums.ni.com/ni/board/message?board.id=40&message.id=2161&requireLogin=False
Regards
DD

Using labview cosimulation, how to control PWM duty cycle in multisim

I am new to using Multisim with LabVIEW using cosimulation. I want to ask if there is a PWM component in Multisim that can have its duty cycle be controlled using LabVIEW? I have an algorithm in LabVIEW that outputs duty cycle values from 0 to 1, representing duty cycle percentages.
How do I control the PWM duty cycle in Multisim using LabVIEW cosimulation?
Many thanks,
SPECTRE
Solved!
Go to Solution.

Hi Spectre,
In Multisim, search for the parts base on functionality, there are some PWM models in the database. Have a look at this knowledge base if you don't know how to search for parts:
http://digital.ni.com/public.nsf/allkb/7309A5CABC677296862577ED006EC99E
Aslo, have a look at this knowledgebase:
http://digital.ni.com/public.nsf/allkb/EF391C48CF71AE4F862571B900644F84
This article shows how you can get Mutlisim and LabVIEW to co-simiualte:
http://www.ni.com/white-paper/13663/en
I hope this helps
Tien P.
National Instruments

How do create an analog signal from a text or binary file?

I'm trying to output an analog signal from a file on an NI-DAQ 6251 card using labview 8.5. I've found the examples on building a waveform, but I'm stuck at how to read a text file and make a 1-D array to input my amplitudes into the buildwaveform.vi and I can't find any information on how to do so. Any help or direction is greatly appreciated.
thanks,
David
Solved!
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If all that you want in the file is the Y values, then a text file with a value on each line could be read. The Read From Spreadsheet File can be used. It will return a 2D that you can then use the index array function to get a column or if you select Transpose, the returned 1D array would be used.
If you want to create an example, use a 1D array constant in a VI and pass it to the Write to Spreadsheet File.

Niscope for pxi5105, use a digital pulse signal to control analog signal sample

i want to use ni-scope to drive pxi5105. And the PFI1 connect to a digital pulse signal(10KHz, 0-3.3V), to control a single channel analog signal continuous sample(Chan 0). I want a loop when the digital signal falling, the analog singal start to sample, and when the digtal signal rising, the analog singal stop. And by the low level of the digital singal, the analog singal sample (coupling by DC) can get an average and export to txt. I have tried the "start_and_reference_trigger.vi " and it did not work correctly. i need your help, thank you very much.
Attachments:
start and stop triggers for analog sample.vi ‏94 KB

Hi Phil,
The SCC carrier is only conditioning your signals (i.e. if your signals are not in optimal ranges, bandwidth or need external excitation). The actual counters and all digital lines are controlled directly by the M-series board. This means you will never be able to refer to a counter in the SCC module.
If you route the signals of the M-Series board, is as if you had done so externally from the SCC. Look at this example and might give you more insight to how to implement it (This is software timing). The hardware timing would be doing correlation DIO. Here is an example that needs to be modified to adapt to your timing: http://zone.ni.com/devzone/cda/epd/p/id/4414
Hope this helps,
Yardov
Gerardo O.
RF Systems Engineering
National Instruments
Attachments:
Finite Dig Output High.vi ‏31 KB

Problem when combinning PWM signal and Analog signal TOGETHER!

Hello everybody,
first of all i have DAQmx 6212, and i need to run a small water pump (9V-16V) which needs to be driven by a PWM signal; also i have a motor (5V-13V) for a water valve that needs to be driven by a analog signal and it has a built in a force feedback potentiometer, i connected on the extremeties of this potentiometer +5V from the DAQmx and used the output voltage from the third extremety as a diagnose value for knowing the position of the motor.
my VI shows:
1. is a normal Counter output to create my PWMout signal.
2. is an analog input i use it as a PWMin to the LabVIEW to diagnose what is happenning in my water pump through the duty cycle and the frequency.
3. is an analog input from the third extremety of the potentiometer.
4. is an analog output which i have used as a power supply for the motor valve and i have used an AC/DC amplifier to aplify the signal from the DAQmx and drive the motor, between (3. and 4.) i have made a feedback with some calculations i had a P-controller to know the actual position of the motor valve.
My Problem:
when putting 1. and 2. in the same VI alone, i am getting a clean PWM in/out with no problems mentioned;
also when putting 3. and 4. in the same VI alone i can control the motor valve without any problems;
but when i put all these 4 together as found in the attached VI, i have a problem that the motor valve is running continously without stopping even if i change the valve position between 0 and 100 %, i should mention that i am seeing a normal PWM out/in signal on my oscilloscope, one other thing that if i delete one of (1. or 2.) and run the VI the motor valve is working fine without any problems.
so this my problem, if you can think of any solution please let me know.
thanks in advance for your help.
Regards,
Alosh
Solved!
Go to Solution.
Attachments:
pwm.out.in.analog.out.in.vi ‏45 KB

Dear nathand thanks for your reply,
i have ran the vi again and i am have error no 50103 from the (AI, number 3. ) but it is not displaying the error message, the VI keeps running without any error notification.
adding to that, i have tested the VI again today by placing (1. and 2.for the PWM inout) together in one VI and (3. and 4.for the motor valve) in another VI and ran them one after the other, i had another problem. if i turn the motor valve vi, the motor will run smoothly but in the pwm vi i will have a problem in which the AI did not read any value. also doing this vice versa by running the pwm vi first it will work perfect but the motor vi will have problem in reading the measured voltage in AI during this the motor will keep on running without stopping.
so i think now the problem is in AI (2. and 3.) readings they are interfering on each other but i am not discovering where is my problem...
Q: does the AI's seems well build or i can do it in an another way so to get over the interfering?
Regards,
Alosh

Can I programmatically control an xbox 360 console from a PC using a USB cable?

I have an application that may require LabVIEW, some software normally associated with LabVIEW or both...
I would like to be able to programmatically control an Xbox 360, via a PC, and through the use of a USB cable connecting both. I have setup a separate Xbox 360 console as a "dedicated server" for my gaming clan. I would like to be able to have the PC issue scripted commands according to a schedule, that will cause the console to power up, start the specific game (disk in the machine already), and then proceed through a number of Xbox 360 controller button actuations to cause the game to essentially be ready to play.
If possible, I would like to find software that I could install on my PC (currently run with a Windows XP SP2 OS, but I have access to many versions of Windows and also Linux and soon, Solaris Unix).
I have tried using various Infrared devices that connect to and are controlled by my PC, but none so far have allowed the infrared signals to work once the game is launched (apparently, only controller signals generated through a USB cable or through RF from a wireless Xbox 360 remote work once the game is launched - and that probably because the IR signals are meant to control the console as a media device).
I would appreciate any direction that you 'all could offer. Thanks in advance!

Thanks for your replies everyone, and thanks to NI for this great forum!
The last solution appears to be pretty close to what I'd like to do. If I understand you Robert, I would attach a DAQ to my PC via USB and would control that device via software, then the DAQ connects to a digital output controlled relay (looks multiple wires, and screw-on connections) and then there would be separate wires connecting 'channels' (my term) from the relay to individual button wires inside of the gaming controller? The signals coming from the controller following this would therefore appear as normal.
If this is correct, could you suggest any specific devices for this? I see that NI makes several USB DAQ's includng the USB-6501, 6008, and 6009. I also have seen many digital output controlled relays available from different vendors. I could use some assistance with the finer points for choosing the correct ones to purchase.
In case it makes any difference although the controller has analog functions my requirements are for only the digital buttons only as I would simply be proceeding through the Console's menu (left, right, up, down, enter/select, etc.), launching the game, and then within the game continuing to choose among the game's menu items, ultimately according to a script. So, I don't see any need to be able to actuate either of the 'sticks' which are analog in nature.
Thanks!

Analog Signal to Digital a Primer

Many users have analog material sitting around, and they would like to get it into digital form, so that it can be edited. As this material is below SD (Standard Definition) quality, I will address the methods for digitizing it, so that it can be best edited in a DV Project. The output can be a DVD-Video, or other format, depending on what one wishes.
The process of getting this analog material into a digital form, is referred to as Capturing, and it is digitizing the analog material and writing it to a file, that can be edited.
One will need some method of getting the analog signals into digital form, and for connecting the analog output from their analog playback device to the computer. Though the analog signal could come from all sorts of devices, I’ll use a VHS tape deck in this example.
Since a VHS tape deck does not have an A-D (Analog to Digital) processor, and also does not have a a digital signal Out, one needs something in between it, and the computer. That “something” serves two needs: mechanical connection of cables and the ability to convert the analog to digital for use in an NLE (Non Linear Editor). That “something” can be a digital video camera with pass-through capabilities, a device, called a “bridge,” or a capture card inserted into a bus slot in the computer. All three have pluses and minuses.
The first two methods rely on one having a FireWire connection on the computer and will use the Capture module in the NLE software.
The digital video camera route is good, as one already owns it. Having one with pass-through capabilities is getting more difficult. The camera also has to have FireWire (FW, IEEE-1394a, or iLink) output, and the computer must have a matching connection.
An A-D bridge will do the same thing: allow one to connect the analog cables to one end/side, process the analog signals to digital and then output via FW to the computer. There are various such bridges available and two of the most often recommended makes/models are: the ADS-Pryo, and theCanopus/Grass Valley ADVC-110. Products, like the Dazzle lineup, just do not seem to work, or work well. I would avoid such.
A dedicated capture card performs the same task, with one exception. The card will mount into an empty PCI slot on the MoBo, and have inputs for the analog cables. The card will have chips on it, to digitize the analog signals and feed these to the computer via the PCI slot. These do not connect via FW, but have one drawback: they must, in virtually every instance, use additional software to do the actual Capture, as most NLE’s cannot directly see and work with them. Some of the included software Capture programs are better, than others. One common issue with many of these cards is a loss of sync, between the Audio and the Video. This is usually static OOS (Out Of Sync), in that it is usually off by a fixed number of frames, and does not drift over time. This can be fixed in the NLE, but is extra work. This ARTICLE will give you tips on correcting OOS.
Now, we are ready to begin the Capture, as our equipment and cables are all ready to go. We have a big decision in front of us - what format/CODEC do we use to Capture our digital files? Since we are doing an SD Project with non-HD (High Def) material, there is one fine choice: DV-AVI Type II w/ 48KHz 16-bit PCM/WAV Audio, using the DV/DVC CODEC. These files will be approximately 13GB / hour of Duration. Storage will need to be considered. These files are also I-frame, meaning that each “Frame” is rendered and available, so that frame-accurate editing is possible. The NLE will not need to do any processing, or conversion of these files, as even the Audio is ready for DVD-Video. Note: there will still be Conforming and the generation of PEK (Waveform Display) files, but the NLE will be able to do this quickly and efficiently.
Using AVI Uncompressed will get you nothing that you can see, other than larger files. Do NOT use any compressed format/CODEC, like MPEG-2, WMV, MOV, etc., as these will loose data from an already inferior source, and will then need conversion to be used, either with a stand-alone conversion program, or internally by the NLE. You loose quality and then have more work to be done. Do not let the temptation of smaller files lure you into using anything but DV-AVI Type II, and just accommodate the larger file sizes.
With the file format/CODEC decision made, the cables and devices hooked up, we’re ready to start the Capture. The exact operation will depend on what our equipment choice has been. See above for talk about additional Capture software, if one uses a capture card. Otherwise, we should be able to use the Capture module of our NLE. The first issue is that we will NOT have Device Control, as we would with a Capture from a miniDV tape-based digital camera, where we can control the mechanical aspects of the camera, during this process. As our VHS deck is hooked up to the A-D bridge, or digital camera w/ pass-through, via analog cables, our control signals cannot be sent to it. One would cue up the tape in the VHS deck, and then choose Record/Capture in the NLE’s Capture module, starting the Capture. Instantly, they would hit Play on the VHS deck, or via that deck’s remote control. This is easier the second time that one does it. I sit with the mouse in my right hand, poised over the Record/Capture button, and the VHS deck’s remote in my left hand, finger hovering over Play. It’s then a 1 - 2 push, and all starts. One can stop the Capture, if an unwanted section of tape comes up. The Capture module of the NLE will direct us on how to proceed from there, should more Captures be wanted. Some will just start up at a later point, and write an additional file for that portion of the tape, but some might require that one basically sets up a new Capture session One should investigate just what their NLE will require for doing multiple Capture sessions from one VHS tape.
When done, one closes the Capture module, and then navigates to the location that these DV-AVI Type II files have been stored in, and Imports them into the Project. This differs slightly from doing the Capture from a miniDV tape camera, as those Captured files are already in the Project.
Edit away, and Export/Share to the necessary output settings, file type and CODEC.
What about those VHS - DVD decks, the ones that will burn a DVD directly from the VHS tape? They seem so simple to use, and for the most part are. However, those DVD-Video discs, contain pretty heavily-compressed MPEG-2 AV streams. These MPEG-2's, besides being compressed, are in aGOP structure and are muxed (Multiplexed into one file with both a Video & Audio stream), plus there is often some Menus and navigation in the first VOB, the main container components of a DVD-Video. Many NLE’s can Import the VOB’s, and basically rip the MPEG-2 out of them, but that first VOB can be highly problematic, due to the way that most of those decks do the Menus and navigation. It is seldom 100% DVD-compliant by the DVD-specs. This can be a major problem. This ARTICLE will give you some background and tips on DVD VOB's.
Those dual-decks are good for doing one thing, regarding the DVD’s that they produce - provide one with an archival DVD-Video of the VHS tape, and not to be edited. However, the VHS side of these works well with an A-D bridge, just like a pure VHS deck does. I would strongly recommend that one does NOT use the DVD-Video portion of these, if editing will be desired. They cause many more problems, than they solve - just use them for an “archive” copy of the tape to a DVD-Video, for playback on a computer via DVD software or a set-top player, hooked to a TV.
What about film? Well, film is obviously analog, and one needs to digitize this to edit on the computer. The process of this digitizing is referred to as telecineing the film. While one can buy equipment to do this, it is expensive, and involves a lot of setup and testing to get the job done. There are many service bureaus, that offer telecining. Some are better than others. The main considerations are: care in handling of fragile film, how the telecining is done, i.e. frame by frame w/ a liquid gate, or just by straight projection, and then output format for the digitized files. Some of these services will offer a DVD-Video disc. Do not be tempted to do this. See above. Others will offer to write these digitized files to a miniDV tape, and this is just fine. One does then need a miniDV camera, or miniDV tape deck, to then do the Capture from, but the quality and editability will be preserved. The final delivery format would be to put these DV-AVI Type II files onto an external HDD. This saves one from having to do the Capture from miniDV tape, having to have a miniDV camera, or miniDV deck, and only Importing of those files would be required to get them into the Project. Many of these service bureaus will either sell you the external, or use one provided to them. Check out specifications for things like format of the external. FAT-32 will limit the file sizes to ~ 4GB max, and NTSF will have no such limitations. However, if the service bureau is on Mac, and you’re on the PC, their Mac’s can ONLY see FAT-32 HDD’s. Talk this over with the service bureau first, so that there are no surprises later on.
Hope that this helps,
Hunt
PS - also see this FAQ Entry for more detail.

the_wine_snob wrote:
Products, like the Dazzle lineup, just do not seem to work, or work well. I would avoid such.
Although I now have a Canopus ADVC300 I previously used a Magix 'Movies on DVD' USB device. I found the results from this to be particularly good and, to my ageing eyes, I see very little quality difference.
I think this is because Magix use their proprietary high quality codec (from their Pro products) to capture the footage. Like DV-AVI it runs around 10GB+ per hour. This can then, very simply, be exported to DV-AVI Type 2 for use in PRE. Note that there are some sound synchronisation issues with the 'out of the box' settings - but the fix is quick and I posted details to the Magix forum.
Would I revert if I could return my ADVC300 bridge? Probably not - the firewire connection and the PC seeing the box as a camcorder adds to ease of use. In fact I am pleased to have both. There are some things Magix does better than PRE7 (batch exporting each scene as an individual DV-AVI file being just one) and it has smart-rendering which is handy for quick clip splitting/exporting.
Cheers,
Neale
Insanity is hereditary, you get it from your children

How do I set a threshold from an analog signal (4-20ma) coming in on a cfp AI 110, to trigger an alarm on my UI?

I have the alarm set, indicator set, just need a digital trigger from an analog input. I realize I could use an external switch into a digital input, but would rather use what we have. We are using this analog signal for other purposes as well. This application is for controlling a machine. Thanks.....

Hi Bob,
The way you have your Case structure setup now is that the “7” case will only get executed if the value from the wire is exactly 7. This same applies to the “8”. Also, there is no default case, so if value does not match any of the cases then your indicator will not change.
You indicated earlier that you need the indicator to be ON when the value is below 7mA and OFF when above 7mA. You will want some like this:
Alternatively could just use the Not function inside the Boolean palette to achieve the same functionality without the case structure.
You will want to check out the LabVIEW Training Page.
Message Edited by DiscoBall on 03-27-2009 12:12 PM
Message Edited by DiscoBall on 03-27-2009 12:13 PM
Joshua B.
National Instruments
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Attachments:
compare.jpg ‏27 KB

How to send out two analog signals

hi
I'm running Labview 10.0 with a PXI controller 8196 with with an M-series DAQ board 6289 which has 4 analog out ports. What I have done is create a statemachine which controls a multi LED board (57 LEDs arranged in 7 concentric circles, with a centre LED). The state machine moves between various states such as Fixation point on, Fixation point off, Target on, Target off. At the moment I have one Analog out port which outputs a voltage to tell me which state I am in, but I want to know how to configure a second port to say which LED I am turning on. I am controlling the LED with the digital out, and converting a binary to a digital code so I was just going to convert that digital code (by diving it by some factor) and write out that factor to a second port. I've read I can not confiure two Analog out ports on the same board, but instead I have to cluster the outputs together, I'm just not sure now to do that. I've attached my main vi as well as the two subvi's that the main vi calls. I've looked at some of the other threads and the suggestion was to close one port to open the other, that's just not possible in my case as I need to keep both channels open throughout the whole program as the analog out is constantly changing. I'm also recording from up to 25 analog channels at the same time.
Thanks in advance
NB. I could only add two of the sub vi's that the main program calls, so the main vi will not work, so if need be I can post the other sub vi in an additional post.
Attachments:
VisDisplay_v1.vi ‏121 KB
Build Table_v3.vi ‏45 KB
LEDon.vi ‏24 KB

Hi
For one of the channels it is a stepping voltage which changes between +/- 5 volts depending of which state of the statemachine the program is in, so it is not just a constant voltage through out the whole task. On the second channel I want to out put a single voltage that would signify which LED is turning on, that would just be a constant voltage, but it would not be the same voltage on both channels. I'm just about to try something else and hopefully that will work.
Thanks
Sam

Why use FIFO to read analog signal?

Why must we use FIFO to obtain analog signal from FPGA? I can use a normal method of calling the FPGA using Read/Write Control and the results in a waveform chart is much more smoother.

I've uploaded 2 real-time VIs with and without FIFO. MQ convert is the subVI in my computer. Do have a look at it...
My waveform chart is done that way so that I can easily export to excel ( i think) but this is a different problem in a different topic http://forums.ni.com/t5/LabVIEW/3-Waveform-Chart-to-a-Single-Excel-but-in-Different-Spreadsheet/m-p/...
Attachments:
Real-Time With FIFO.vi ‏397 KB
Real-Time without FIFO.vi ‏391 KB
MQ Convert.vi ‏19 KB

"create analog signal" programmatic control of parameter Duty Cycle

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