Outputting different analog signals across 4 outputs

Hello All,
I need some help outputting 4 different analog signals from the PCI 6711 board. I plan to use the function waveform vi from the analog generation pallette. My goal is to be able to enter in the 4 necessary functions, there sampling information, and then output them from the four available analog outputs available on the board. I've seen the example code for outputting across multiple lines, but it doesn't seem like it is able to create unique waveforms across the outputs, they are all the same waveform. I've attached what i thought would work, but i can't get my number of lines in data to match my number of lines in task.
Solved!
Go to Solution.
Attachments:
Analog program.vi ‏34 KB

More specifically, choose the polymorphic instance of Analog->Multiple Channels->Multiple Samples->1D Waveform.
Your current instance that you chose is for just a single line.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
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Similar Messages

How to generate two different analog signal in two different VIs

I'm using a PCIe-6321 board and a SCB-68 connector block. As it has two analog output I would like to use one of these output in one Vi to generate a square waveform and the other output in another VI to generate a sine waveform. Each VI work perfectly separatly but if I run one then the other, the second one doesn't send any signal. Since I don't want to merge the two VIs (It's more convenient to operate them separatly), how can I figure out to make them work together (sometimes).
Solved!
Go to Solution.

I assume you get error -50103 (resource is reserved) at either on vi.
It's not possible to run two AO channels independetly from each other with different VIs since both Tasks are trying to request the same timing engine at the DAQ device.
Christian

How to input/output a digital signal and acquire an analog signal at the same time?

Dasylab, version: 8.0.04
Acquirement Card: PCI1002L
When I use DasyLab to acquire the analog signals is no problem without digital inputs and outputs,
and when I use DasyLab to input or output a digital signal is no problem also, but when I do that at the
same time, DasyLab tell me the rate is too high and stop.
so, I searched the manual book1 (user guide) for that, it showed me :
To internally equalize measurement time and system time in the analog input, digital input and counter
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the problem is, if I set the Sampling rate to 5Hz, the speed of the acquirement datas is not enough for my
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so, how to improve it? who can give me a example programm for me. thanks!
by the way, I come from China, my English isn't good, I'm sorry.
Allen, China.

Hi,
Have things changed over the years?
I need to syncronise a digital output (Modul NI9474) and an analoge input (AI-Modul NI9203) module. I need to measure time intervals from a flank in signal A to a flank in signal B. I would like accuracies of the order of 1 ms. Currently, the signals are not synchronised, with errors of the order of 2 times the block length (block size x sample rate), sometimes much higher. The best I got so far was a block size of around 20 with a sample rate of 1 kHz.
If I use the master and slave settings on the RTSL settings, my program doesn't run properly.
If I use digital signals for input and output, I can syncronise them with RTSL settings and everything is good, but I can't always do that.
Also, if I do anything in the GUI (such as scrollowing something or going to another window), my output gets screwed up properly.
1. What can be done to synchronise AI with DO?
2. Is there something that can be done to avoid messing up the output when something happens in the user interface? (I know that I am messing up the outputs as they make some valves switch and that is loud).
Thanks in advance!

SB X-FI Titanium.. Digital output works but Analog Signal M.I.A.

@SB X-FI Titanium.. Digital output works but Analog Signal M. I.A. Hi Guys,
I recently installed a new hard dri've on my machine after my power supply failed and fried it. After reinstaling Vista 64 and my drivers I noticed that my sound card was not working properly.
In.. control pannel > Sound > Playback I see my soundblaster listed but only the digital out is showing. There are two other icons listed.. one is for "Digital Output Device 2-High Definition Audio Device.. and one for a 3-High Definition Audio Device. I don't remember these being listed when my sound card was working properly before the HD crash.
No icon representing my analog output (Left/Right, Center, and Rear?Speakers)?is displayed. I reinstalled the drivers, updated the drivers, reformatted my HD and started all over again but nothing works.
I made sure that my motherboard sound card is disabled.. I am really stumped.. The sound card used to work quite well.. Has anyone else had this problem and been able to fix it's
Here is my system info:
Motherboard: Gigabyte GA-MA790FXT-UD5P (Realtek Audio Disabled)
Sound Card: Internal Sound Blaster X-FI Titanium
Any advice is much appreciated.

DRe: SB X-FI Titanium.. Digital output works but Analog Signal M. I.A. High definition audio device is what your card is detected as until you install the original CD driver or the Daniel K 2.0 support pack. Then you can update to the newest Creative drivers. I tried to format just like you and thought that I would just download Creative's newest driver and start from there. No Go!!? The newest Creative driver seems to install, but then after reboot like you, I have multimedia audio device.
So take out your CD if you have it, and run the driver setup only. Then using just this driver you can install all of the newer Creative updates. The Creative auto updater is installed along with your original driver and you will see it detect all available updates.
Easiest solution of all,
Try this pack and save yourself a load of hassle........
http://forums.creative.com/t5/Sound-Blaster/SB-X-Fi-Series-Support-Pack-2-0-05-5-2009/td-p/527485
This will install a very proper Creative driver, and applications that will work very very well on your system compared to the CD orignals

Is there a VI availible that will allow one to interact with an analog signal

Hello all,
I am new to the sight and look forward to participating. I have a project that I’m working on and I would like to ask for your thoughts and direction if you’re willing. I have a few weeks left before completing an electronics program degree and Labview is one of the classes. The project I have chosen is to illustrate the differences between a micro controlled system and Labview controlled environment. I will be acquiring a signal through a ultra sonic distance sensor. The analog signal will be produced after which acquired through a SCB – 68 connector block and converted using the pci-mio-16E. The sensor operates at 40 kHz emitting a 5v pulse (burst) then falling to gnd for a short period followed by a 5v rise and staying high for a period of time waiting for the return of the frequency. This time period represents 3 inches to 27 ft in distance. I would like to interact with this signal through the distance period (portion) and output a string displaying a numeric value of the distance on the front panel obtained from an array built from different periods of the signal. I am not clear on what Labview function offers this type of control. I am hopeful in utilizing a vi or some type of trigger that allows me to build an array produced by some math functions. Any help would be appreciated.
Thank you, dhitch

First thank you for your response, I will have an opportunity to make a capture tomorrow in class. I believe I have run across the waveform measurement VI in my searches and am sure it’s a very good choice. The trigger VI you suggest, going by the name, should be my ticket. Would you imagine a delay or decreasing time after the capture, allowing the trigger VI time to respond to an output configuration be required?
If I remember correctly the sampling rate capabilities are 500K samples/ second with 12 bits of resolution and as I say that it seems some of the capabilities rely on the processing speed of the computer. I guess I will kick the tires tomorrow hey. There are 2 class periods remaining to finish our projects @ 2 hrs / class and my anxiety is a bit high. Wish me luck and thank you so much.
dhitch

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 to make a synchronous acquisition of two analog signals with a one channel DAQ ?

Hi !
It is the first time I use Labview. I have just made some easy VIs, and now, I do not know how to deal with my problem...
My problem : I have only one acquisition card (DAQ Ni 6034E) and I would like
to acquire simultaneously two analog signals. It seems to be possible, in a quasi-synchronous acquisition if the card acquires one point of the first signal, then the first point of the second signal, then the second of the first signal, and so on ... I thougth that I could made two sequencies with a VI of data acquisition in each sequency, with the AI MULT PT. But with this, I think that I will lose the precision of the sampling frequency. And I have to know the sampling fre
quency ...
Thanks for your help !
Carline

Hi Carline,
A PCI-6034E is a low-cost board, which only has one Analog to Digital Converter (ADC).
With only one ADC you can't acquire different channels at the same time. That's why you find a multiplexer before the ADC in this type of board. This enables you to acquire multi-channels at the same rate quasi simultaneously. The samples of the different channels will be interleaved as it is explained in the following knowledge base :
- http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/9379ea091c264b7c86256bc90082ca5d?OpenDocument.
With this method, the sampling frequency is the same for all channels. The sampling frequency of one channel is determined with the "scan rate" parameter. There is only a small delay between the samples
of each channels. When you perform an interval scanning acquisition, this delay depends on the "sample rate" that you specify. To have more informations about this terminology, please refer to the following KBs :
- http://digital.ni.com/public.nsf/websearch/4D1435DF82EF494186256D8A006DD6D4?OpenDocument.
- http://digital.ni.com/public.nsf/websearch/4D1435DF82EF494186256D8A006DD6D4?OpenDocument.
To easily perform such a multi-channels analog acquisition, you can use the VI named "AI Acquire Waveforms.vi". You also can use an example provided with LabVIEW. You just have to browse the NI Example Finder in "Harware Input & output >> Traditional NI-DAQ >> General".
Best regards,
Benjamin
National Instruments France

How to introduce dead time in analog signals?

Hi, I'm new to LabVIEW and I want to introduce a dead time in the analog signals that I have attached in this post. The time difference varies, so I could not introduce a time delay in the signal
for instance, the attached waveform, i want the first signal to be seperated from the second signal. so i got 2 different signal at the end of the day for analysis. during the no signal time no signal is not recorded.
thanks in advance for all the help
Attachments:
Time delay.JPG ‏37 KB

Hi skydew,
It is possible to introduce a delay in an analog output. This is best done by specifying a trigger and then beginning the output when that trigger occurs.Below is a link to an example program developed for LabVIEW that waits a specified number of seconds and then triggers analog output to begin.I think this is what you mean as dead time.Take a look at this example and try to build from it for your code. If you have any further questions on this issue, let me know.
Analog Input with Delayed Analog Output
Also see some links below:-
http://forums.ni.com/t5/LabVIEW/Finding-the-time-delay-between-two-signals/td-p/2125100
http://forums.ni.com/t5/LabVIEW/calculating-time-delay-between-two-signals-aquired-from-DAQ/td-p/849...
Thanks as kudos only

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

How to acquire analog signal and send a TTL pulse at the same time based on PXI 6123

Hi,
I am using a PXI-6123 data acquisition card, as the picture show in the attachment ,I want to acquire the analog signal of ai0 through reference analog window and at the same time send a TTL signal to trigger my camera. I have tried two methods, one is using the DAQmx Export signal.vi another is using DAQmx connect terminals, but when the data acquisition card acquire the analog signal, the DAQmx Export signal.vi and the DAQmx connect terminals sometime can send an TTL pulse ,sometime can not.
I don’t know why? or some other method that can achieve my arm is appreciated.
Regards
chunlei
Attachments:
method export signal.vi ‏21 KB
method connect terminal.vi ‏36 KB
Send a TTL pulse.JPG ‏288 KB

Hi,
Have things changed over the years?
I need to syncronise a digital output (Modul NI9474) and an analoge input (AI-Modul NI9203) module. I need to measure time intervals from a flank in signal A to a flank in signal B. I would like accuracies of the order of 1 ms. Currently, the signals are not synchronised, with errors of the order of 2 times the block length (block size x sample rate), sometimes much higher. The best I got so far was a block size of around 20 with a sample rate of 1 kHz.
If I use the master and slave settings on the RTSL settings, my program doesn't run properly.
If I use digital signals for input and output, I can syncronise them with RTSL settings and everything is good, but I can't always do that.
Also, if I do anything in the GUI (such as scrollowing something or going to another window), my output gets screwed up properly.
1. What can be done to synchronise AI with DO?
2. Is there something that can be done to avoid messing up the output when something happens in the user interface? (I know that I am messing up the outputs as they make some valves switch and that is loud).
Thanks in advance!

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

How can I delay analog signal?

I have an analog signal, the frequency is less than 1kHz. I want to get a delayed analog signal. Is it possible to realize analog delay generator using labview (daq card is PCI-6115)? I hope I could specify the delay time.
Any suggestion will be greatly appreciated!
Stephen

Hello Stephen,
It is possible to institute a delay an analog output. This is best done by specifying a trigger and then beginning the output when that trigger occurs.
Below is a link to an example program developed for LabVIEW that waits a specified number of seconds and then triggers analog output to begin. This code performs analog input as well, but for your program you could remove that portion. The trigger that is used is RTSI pin 0. After a specified period of time, the RTSI pin 0 is set to 1 and then the analog output begins.
Analog Input with Delayed Analog Output
Take a look at this example and
try to build from it for your code. If you have any further questions on this issue, let me know.
Regards,
Scott R.
Applications Engineer
National Instruments

SONY Handycam DCR-HC19E, Capable of Passing Digital Analog Signal?

Hi
I wondered if my Sony Handycam DCR - HC19E (miniDV) is capable of sending an analog signal through firewire to my computer as I wish to monitor my progress on my tv.
And:
Should I be on record or play/edit mode on camera?
What to do if I wish to playback my videos on FCP 5?
Any help would be greatly appreciated.

I don't know what settings on the camera, but this is the playthru checklist:
#8 External Monitor Viewing.
Shane's Stock Answer #8:
A simple path is mac > firewire > camera or deck > rca cables > tv
Then start up your camera and tv, then open fcp.
Then go View > External video > all frames
Video playback should be Apple firewire NTSC (If you are using an NTSC set)
Audio playback should be Audio follows Video
Techinially, this should send synched video to your TV
If for some reason you can't view your timeline on your external monitor, there are a few things to try:
1) Make sure that the camera/deck is connected and powered on BEFORE you open FCP.
2) In the Final Cut Pro menu select AUDIO/VIDEO Preferences and make sure your signal is being sent out thru Firewire DV.
3) Go to the menu and select VIEW>EXTERNAL>ALL FRAMES.
4) Click in the % box above the image and select FIT TO WINDOW.
5) Go to VIEW->refresh A/V devices
6) Make sure the Log & Capture window is closed
If you want it to play in both the canvas and the external monitor you need to go to the FINAL CUT PRO menu and select AUDIO/VIDIO settings and make sure MIRROR ON DESKTOP is selected under the PLAYBACK OUTPUT section
Shane

Filtering Analog Signals

I am currently using a PXI 6025E board to read an analog signal from a weigh station. The items that are being weighed are in motion so the signal contains some vibration from the item being in motion as it crosses the scale. I would like to be able to filter the analog signal so that I just get the pure weight and not the noise from the vibration. What is the best way to filter the signal using LabView?

Another method is the store a number of results and calculate the
average of these points.
Do sample fast to get more data and you will get a better result.
The method with the best results depends on the noise expected, on its
spectrum and amplitude distribution.
Median is fine if you have a lot of good data and a few wrong ones far
away from the 'real' result..
AVG and Lowpass is fine for symetrical noise.
DC / AC is fine in the same case, but the parameters cannot be chosen by
yourself.
Good Luck
Urs Bögli
preston johnson schrieb:
>One method is to use a "median filter" this is a statistical median
>of the data you have collected over a brief period of time.
>Presumably, you will have a good number of cycles from the vibratory
>motion. Use th
e statistical function for median. This will sort the
>data from most to least and produce a number in the middle of the
>list.
>
>A second method is to use a low-pass filter to filter all data above
>say 1hz.
>
>A thid method is to use the DC and RMS function and take the DC output
>of the function.
>
>Try all three to see which produces the best result.
>
>Sincerely,
>
>Preston Johnson
>
>

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!
Go to Solution.

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.

Outputting different analog signals across 4 outputs

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