Generating sawtooth in Analog Output

Dear Mr.
I am programinning in labview and I would like to generate from my DaqPad 6020E sawtooth signal. I have a problem becouse I can generate virtually but not in Analog Output. Please verify my program which is attached to the mail. If you can please write your simple program which generate sawtooth signal in analog Output. I was checked programs (examles) in ni.com but i can generate one. I know that AO works becouse i checked it sending sin (as trigonomethry sig) and there was no problem.
Best regards
Tomasz Olszewski
PS. If You speak Polish we can talk in Polish language.
Attachments:
ct03.vi ‏124 KB

Have you verified output in the Test Panels of the Measurement & Automation Explorer (MAX)? Simply wire analog output 0 to analog input 0. In the test panels, generate a sine wave on the analog output pin. If you can read in the signal on the Analog Input tab, then the board is operational and something is wrong in the code. Check the code to make sure you are referencing the correct device # and channels. Have a great day!

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Usb 6009 continuous analog output

Hi
I'm pretty new to Labview, so you may have to bear with me. I have a USB-6009 and I want to generate a continuos analog output voltage. I've got the example you have posted 'Gen Mult Volt Updates-SW Timed_LV7.1 (0 to 4).vi' working and it outputs a continuous sine wave.
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Hi there,
I'm guessing the VI you are using is the one from this KB:
http://digital.ni.com/public.nsf/allkb/6F2C2B49A89D685C8625711D007BDD64
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I hope that helps!
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I am using an NI PCI 6024 E board device for an analog output application. Can I generate two independent waveforms, one on each analog output channel?

I am using an NI PCI 6024 E board device for an analog output application. Can I generate two independent waveforms, one on each analog output channel? In attach I send a example of my vi to control one chanel, but i need to control both but with diferent waveforms.
Is the vi correctly programed to this propose?

Yes you should be able to do that. look at the signal generation examples shipped with LabView
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To have different frequencies, you need to have say, on wave form with one cycle per buffer, and the other waveform have 2 cycles
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Error when generating waveform analog output on NI 6704 card

Hi, I am trying to understand why NI 6704 card appears to be incompatible with what I'm trying to do.
I want to use a waveform to generate an analog output voltage on a NI 6704.
I have a vi in the style of the waveform buffer generator in this example:
http://zone.ni.com/devzone/cda/epd/p/id/4837
which creates the waveform. In my main routine I attempt to create and write a DAQmx ao task using the waveform information, but get this error:
Possible reason(s):
Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.
Property: SampTimingType
Requested Value: Sample Clock
You Can Select: On Demand
Task Name: _unnamedTask<7D>
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Thanks in advance!

The error has everything to do with software timing. Your device does not have a hardware clock so you get an error when you try to configure it. To output a waveform, you have to do out one point at a time. You can only do this at a low frequency and it will have considerable jitter.

Using DAQ generate a 38kHz on an analog output on and off for ms using labVIEW

I wish to generate a 38kHz pulse on an analog output of a mydaq to drive a infrared led. The 38kHz signal is not continuous but is on for 1ms and off for 1ms.

Hi pat,
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Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

How can i synchronize analog output and analog input timings to generate and measure voltage at the same time.

how can i synchronize analog output and analog input timings to generate and measure voltage at the same time.

Read this Tutorial
http://zone.ni.com/devzone/cda/tut/p/id/3615#toc3
And also refer to this link where You have repeated this question.
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Simultaneous analog output 1k sine wave and data acquisition

Although many topics of simultaneous analog output and input can be found in NI Developer Zone, I have not found a case similar to my project. I'm trying to generate a 1kHz sine wave by using the analog output of NI DAQPad-6070E, and acquire one channel input signal simultaneously. I found most of the examples can not work properly above 100Hz. Any suggestions are welcome. Thank you.
Jian

I have sucessfully solve the problem when I observed the increase of
scan backlog number. Simply increase the buffer size of AI/AO and you
can make the 1kHz sine wave output and data acquired properly.
On Tue, 3 Feb 2004 09:03:07 -0600 (CST), jujian wrote:
>Although many topics of simultaneous analog output and input can be
>found in NI Developer Zone, I have not found a case similar to my
>project. I'm trying to generate a 1kHz sine wave by using the analog
>output of NI DAQPad-6070E, and acquire one channel input signal
>simultaneously. I found most of the examples can not work properly
>above 100Hz. Any suggestions are welcome. Thank you.
>
>Jian

How to avoid delay during analog output generation by changing its frequency?

Windows XP
LabVIEW 7.1
PCI-6036E + BNC-2120
Hi,
I am going to create a vi to generate an engine speed sensor signal (a simple square wave with specific missed pulses, in my case 58 pulses “teeth” and 2 missed pulses “missed teeth”) as an analog output but in addition give me the opportunity to control parameters for example frequency online to simulate the engine speed changes during running that vi. For this purpose I have started with “Continuous Generation.vi” which is available in NI Example Finder under the following path:
Hardware Input and Output > Traditional DAQ > Analog Output > Continuous Generation.vi
Then I modified it towards above mentioned goal, all related vi s are attached. The main vi is: "Motor Signal Generator_1.12.vi"
At the first try it looks that it works properly but when have a look on that more accurately with Oscilloscope (fortunately I have a good one: Agilent 54621A – 60 MHz, 200 Ms/s) obviously there is a gap (delay or Jitter) whenever I change the engine speed. It is also attached in Signal generation_problem report.doc file.
Note: Small gaps are OK and related to predefined missed teeth but the big one is happened during changing engine speed.
As far as I understand it is related to the time which case structure in AO C-GEN sub-vi needs for AO reconfiguration each time after changing the engine speed (update rate). How can I get rid of this delay or gap during signal generation and generating completely continuous signal?
I have to mention that obviously I changed the frequency by changing the update rate. The other possibility is to change the number of updates in one period (refer to "generate arb frequency.vi" in NI site: http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3E48F56A4E034080020E74861) which resulted in no delay however then I can not change the frequency continuously but step by step (for example jump from 5Khz to 2.5KHz immediately) and this can not pass to my application.
Any hint is appreciated.
regards
Attachments:
Signal_generation_NIsupport.zip ‏81 KB

Hi Roozbeh,
The following example will allow you to vary the pulse train frequency during run time.
Thanks,
Lesley Y.
Attachments:
GenDigPulseTrain-ChangingSpecs.vi ‏75 KB

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 switch analog output between two waveform frequencies

Hello,
I'm using a fairly simple VI to generate a square wave at our analog output board. I have the square wave controls in one panel of a sequence structure, and a "release" function in the other panel of the sequence. Currently the VI is programmed to switch from the original square wave to -10V when the Boolean control is switched.
What I'd like to do now is to modify the VI so that I can swtich between a square wave of a given frequency, say 100 kHz, to a square wave of a different frequency, say 10 kHz, or to DC -10V. But I'd like to be able to vary each frequency and amplitude independently.
Could anyone give me some programming pointers?
Thanks,
Michelle

Thanks to the three of you for the suggestions. I started trying a few of them, and then realized that what I had already built will work pretty well to update the frequency. I didn't realize that it would update the waveform in "run" mode -- I thought it would only do that in "run continuously" -- so I've found that I can change the frequency of the waveform by doing that. This doesn't allow me to change the frequency and the amplitude simultaneously, but I'm not sure yet whether or not I will need to do that -- I so will probably go ahead with the experiments I need to do with this set-up, then modify it if I find that I need to control both frequency and amplitude simultaneously.
Thanks for your help!
M.

NI-DAQmx VisualStudio C++ 6 Single point analog output

Specs: NI-DAQmx 7, VisualStudio C++ 6.0, PCI-6722,8channel AO
We have a very simple application: set a voltage (actually 6 channels) and keep it until we want it changed again, perform the change very quickly in response to an image capturing algorithm. So I don't need any waveforms or buffering.
In this forum post http://forums.ni.com/ni/board/message?board.id=231&message.id=3283&query.id=18094 you talk about an AOOnePoint example, but I get an error that the NI-DAQ driver does not support my device.
I may need to use NI-DAQmx, but how? I would like to use something like AO_VWrite(,,), maybe for 6 channels in one call. But I can't find it in NI-DAQmx. It seems I need to setup buffers and frequencies. I have a working sample, but it seems a slow and certainly overkill of this simple application:
// Link with \DAQmx ANSI C Dev\lib\msvc\NIDAQmx.lib
#include "NIDAQmx.h"
double[2] data;
int taskHandleAnalog;
int written;
void Init()
    DAQmxErrChk (DAQmxCreateTask("",&taskHandleAnalog));
    DAQmxErrChk (DAQmxCreateAOVoltageChan(taskHandleAnalog,"Device and Channel Info","",0,10,DAQmx_Val_Volts,NULL));
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    DAQmxErrChk (DAQmxStartTask(taskHandleAnalog));
void SetVoltage( double voltage )
    data[0] = voltage;
    data[1] = voltage;
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Hi,
It looks like you simply wants to output voltages on the analog output channels, but only wants one update at a time with no waveforms or buffering in DAQmx.
As I'm sure you know there are really just 3 types of measurements. Single Point, Finite, and Continuous. Since you want a single value at a time it's just a Single Point operation.
You can find DAQmx examples for single point operations in this path:
C:\Program Files\National Instruments\NI-DAQ\Examples\DAQmx ANSI C\Analog Out\Generate Voltage\Volt Update
Simply place the DAQmx Write Code within a loop and you will be updating one value at a time, but multiple times when "we want it changed again".
Dennis Morini
Field Sales Engineer
National Instruments Denmark
http://www.ni.com/ask

PICe-6259 with DasyLAB 9 - How to do Analog Output

Hi,
I'm trying to get a small project working in DasyLAB 9.0.2 and I need some serious help.
I'm working with a PCIe-6259 and NiDAQmx 8 is installed. I simply want to create a program that uses a slider to adjust the analog output on 4 channels and read the slider value on a meter. This is a fresh installation of DasyLAB.
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I then select: Modules -> Control -> Slider
I adjust the properties of the slider to include the same channels as above.
I then select: Modules -> Display -> Analog Meter
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NI-DAQmx: Error Message
Driver: Task DA00, Version: 0.15
Possibly Reason:
-> The module can process the number of "values to be written".
File: ProcessData_KONTINUIERLICH.H, Line: 39
When I press OK I get:
NI-DAQmx: Error Message
Driver: Task DA00, Version: 0.15
Possibly Reason:
-> The driver does not use all NI-DAQmx task channel names. This is not valid, reconfigure the module to use all task channels.
Note: A NI-DAQmx task for analog / digital / frequency output must not have more than 16 channels. If you need more than 16 channels for the output, you must use more NI-DAQmx tasks.
File: MODUL_DA.C, Line: 2131
Any help to point me in the right direction would be greatly appreciated.
The next part of my program will include acquiring data from the analog channels, but I need to get the AO working first. I've run into some issues with Analog Input as well, but I thought I should start with AO first.
Thanks in advance!
Chris

Here's what I did using the NI-DAQmx simulation mode:
    - create two tasks
            Analog Output - 4 channels, 1k output rate, 100 samples to write, Continuous
          Analog Input - 4 channels, 1k input rate, 100 samples to read, Continuous
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    - Connect Slider to NI-DAQmx AO module, configured for 4 channels.
    - Create AI module. Connect to the AI task that you created.
    Press Start. It should run. I can't verify absolute accuracy in simulation mode, but, I received no errors.
    Your first error is probably the result of the timing being wrong - the Slider defaults to the "Driver" timebase. The rest of the errors seem to be a cascade off the first.
    Note - my simulation did not work without the Analog Input. It generated no data. That may be an artifact of the simulator, but, once I put an Analog Input on the worksheet, it ran okay.
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- cj
Measurement Computing (MCC) has free technical support. Visit www.mccdaq.com and click on the "Support" tab for all support options, including DASYLab.

Synchronizing Analog Output to Counter Input

Hi!
I'm really new to LabView. Pls help!
I'm trying to obtain a set of stimulus signal and response signal from my motor for system identification.
The stimulus signal will be generated by the Ao0 channel and response signal (quad encoder linear position) will be read into counter0.
How can I synchronize the stimulus signal and response signal so that the sampling (n samples) for both stimulus and response starts at the same time?
e.g.
t=0, stimulus sample 1, response sample 1
t=1, stimulus sample 2, response sample 2
t=2000, stimulus sample 2000, response sample 2000
I've attached my VI.
Thanks.
Regards,
Student
Attachments:
Acquiring Linear Encoder Samples.vi ‏44 KB

Hello Htp,
What do you mean by synchronize? Do you want to start the analog and counter outputs at the same time? If you do, you should have both outputs start with the same digital trigger. For the analog output, you can set up the triggering in the DAQ Assistant in the Task Triggering tab. For the counter output, look at Gen Dig Pulse Train-Continuous-Dig Start.vi found in the Example Finder (Help Menu>>Find Examples). Browse Hardware Input and Output>>DAQmx>>Generating Digital Pulses. Please let me know if you have any questions. Have a great day!
Sincerely,
Marni S.

PCI Card for Analog output in the range of 10mv

dear ni,
                I want to know about the PCI card that can be generate analog output in the range of maximum 10mv. i am going to use for caliberation of loadcell, strain gauges devices.
could you tell me on which PCI card will support this type of application.
Regards,
Balaji DP

Try: http://www.ni.com/dataacquisition/
These have analog output voltages < 10V:   http://sine.ni.com/nifn/cds/view/main/p/sn/n12:7604,n3:7853/lang/en/nid/1036/ap/daq
You need something with a high bit count to get good resolution at 10 mV, such as the PCI-6010 which has a 16 bit D/A.
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Minimum Voltage Range
-0.2..0.2 V
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283 µV
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6.4 µV
Message Edited by vt92 on 11-18-2009 07:56 AM
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How to building a multi-channels analog output task in visual c++ 6.0 (without Measurement Studio)?

Hello!
I have a PCI 6251 card, and using DAQmx C function to generate a wavwform. (single channel ).
But, how to creating a multi-channels analog output task, and had a different frequence in each channels?
Thanks.

This is getting to be a common question!
The answer is, you can't.
If the rates have common factors, you can use a higher overall rate. The slower waveform will simply have extra points in it to make up for the higher update rate.
John Weeks
WaveMetrics, Inc.
Phone (503) 620-3001
Fax (503) 620-6754
www.wavemetrics.com

Generating sawtooth in Analog Output

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