Generate analog output waveform finish on request

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• How to determine the number of highlight ' to write ' for DAQmx generate analog output?

  On the configuration of the stage for DAQmx generate analog output, there is a field "value to write.  I can't find any explanation for what it is, how it determines the value to enter, nor what he writes.  I am trying to go through the tutorials and it cling.

  Someone would give an explanation?

  Hello

  To write value specifies the value to write in the channels, lines or ports selected in string parameters. In other words, this value will be the value of your DC output (for example if you enter 5, your output will be 5V). To get information on different fields in SignalExpress, access help"context-sensitive help. A pane will appear in your work environment that displays the coordinates of the field when you place your pointer over them.

  For new users of SignalExpress:

  Generation of DC signals with NI DAQmx devices: step in the DAQmx build, select 1 sample (on request) in the generation Mode dropdown. You can select a programmatic input to generate, or you can remove the check mark from the check box use programmatic input and specify a value for generating in the field of value to write . NOR-DAQmx help also provides additional information about the data generation.

  Best regards

  M Ali

  Technical sales engineer

  National Instruments

• Generating analog output signals 4 with different frequencies

  Hi all

  I was trying to say to generate 4 different signals at different frequencies

  1. first waveform is a sine wave with 5000 Hz,

  2. other with 8000Hz,

  3. third, one is a square with 25 Hz waveform and

  4. fourth one with triangular waveform 50 Hz

  all waveforms must be generated simultanoeusly.

  I tried to generate with the task unique analog output and sample clock (clock rate is 100000). Cross in scope that I see only 5000 and 8000 Hz we generated correctly and the rest two waveforms show the incorrect frequency.

  I guess that's due to the frequency of high clock to sample for more low frequencies for ex 25 Hz and 50 Hz. If I reduce the clock rate to get the lower frequencies properly so I can't generate frequencies higher correctly. (there's a clsh between frequencies and the clock frequency)

  Is it possible to use DAQ board master sample clock and its magnitude downward revision (everywhere where it is necessary for each waveform separately) to generate all the signals at different frequencies at the same time in a single task?

  
  

• Generate analog output with the software "Timing" on 6009

  I see that the 6009 does not support the synchronization of the internal clock.  We need to generate an analogue waveform which changes very slowly, it performs a cycle every 10-20 minutes.

  I saw an old post on the use of calendar software, but can not find a way to do this using SignalExpress.

  Any ideas or references to examples of messages, etc. are greatly appreciated.

  Analog output clocked by the software (DAQmx) in SignalExpress

  I hope this helps.

• C++ PCI-6703 generate analog output

  Hello

  I'm new on Measurement Studio for VC ++ and I need your help.
  I have a PCI-6703 with a box-CBS 68.
  I installed the drivers necessary for NOR-DAQmx measurement & motor with Solution Explorer.
  I installed the software measurement Studio 2009 (trial pending the validation that my project leader buys the full version).
  I work in Visual Studio 2008 and VC ++ (I can't use LabView (if it was not easier) to synchronize the codes for the entire project).

  I want to generate analog voltages (10V) at the exit of the PCI-6703 for SCB - 68 box. This will send signals to an eCard to turn lights.
  I tried these lines of code, but it does not work (I am inspired by the codes I found on the forum):

  #include
  #include "windows.h".
  #include

  int main (int argc, char * argv [])
  {
  TaskHandle daqmxhandle;

  If (InitCVIRTE (0, argv, 0) == 0)
  Returns - 1;    / * memory * /.

  DAQmxCreateTask ("", & daqmxhandle ");
  DAQmxCreateAOVoltageChan (daqmxhandle, "Dev1/ao0", "",-10,0, 10.0,)
  DAQmx_Val_Volts, "");
    
  for (int i = 0; i)<>
  {
  DAQmxWriteAnalogScalarF64 (daqmxhandle, 0, 10, 10.0, 1);
  Sleep (3000);
        
  DAQmxWriteAnalogScalarF64 (daqmxhandle, 10.0, 1, 0, 0);
  Sleep (3000);
      
  }
      
  DAQmxClearTask (daqmxhandle);
  return 0;
  }

  -----------------------------------------------Error----------------------------------------------------------
  1 >-rebuild all started: project: test1, Configuration: Debug Win32 -.
  1 > deleting intermediate files and output from 'test1' project, configuration ' Debug | Win32'
  1 > compilation...
  1 > test1.cpp
  1 > c:\program files\microsoft sdks\windows\v6.0a\include\winnt.h(7256): warning C4005: 'THREAD_BASE_PRIORITY_MIN': macro redefinition
  1 > c:\program NIUninstaller instruments\measurementstudiovs2008\vcnet\include\cvidef.h(140): see previous definition of 'THREAD_BASE_PRIORITY_MIN '.
  1 > c:\program files\microsoft sdks\windows\v6.0a\include\winnt.h(7257): warning C4005: 'THREAD_BASE_PRIORITY_IDLE': macro redefinition
  1 > c:\program NIUninstaller instruments\measurementstudiovs2008\vcnet\include\cvidef.h(143): see previous definition of 'THREAD_BASE_PRIORITY_IDLE '.
  1 > manifest compilation of resources...
  1 > version of the compiler Microsoft (R) Windows (R) Resource 6.1.6723.1
  1 > copyright (C) Microsoft Corporation.  All rights reserved.
  1 > Linking...
  1 > test1.obj: error LNK2019: symbol _DAQmxClearTask@4 referenced in function _main outstanding external
  1 > test1.obj: error LNK2019: symbol _DAQmxWriteAnalogScalarF64@28 referenced in function _main outstanding external
  1 > test1.obj: error LNK2019: symbol _DAQmxCreateAOVoltageChan@36 referenced in function _main outstanding external
  1 > test1.obj: error LNK2019: symbol _DAQmxCreateTask@8 referenced in function _main outstanding external
  1 > test1.obj: error LNK2019: symbol _InitCVIRTEEx@12 referenced in function _main outstanding external
  1 > C:\Documents and Settings\Default\Mes documents\Visual Studio 2008\Projects\test1\Debug\test1.exe: fatal error LNK1120: 5 unresolved external
  1 > build log was recorded at the 'file://c:\Documents and Settings\Default\Mes documents\Visual Studio 2008\Projects\test1\test1\Debug\BuildLog.htm ".
  1 > test1 - 6 error (s), 2 warning (s)
  = Rebuild everything: 0 succeeded, 1 failure, 0 was ignored.

  Hi AndriRavo,

  I have seen that you had the cvirte library.

  You can't use it with Visual Studio. This library and functions such as InitCVIRTE are used when you program with CVI.

  Just use DAQmx features but remove all features CVI for example you found.

  #include "windows.h".
  #include

  int main (int argc, char * argv [])
  {
  TaskHandle daqmxhandle;

  DAQmxCreateTask ("", & daqmxhandle ");
  DAQmxCreateAOVoltageChan (daqmxhandle, "Dev1/ao0", "",-10,0, 10.0,)
  DAQmx_Val_Volts, "");
    
  for (int i = 0; i)<>
  {
  DAQmxWriteAnalogScalarF64 (daqmxhandle, 0, 10, 10.0, 1);
  Sleep (3000);
        
  DAQmxWriteAnalogScalarF64 (daqmxhandle, 10.0, 1, 0, 0);
  Sleep (3000);
      
  }
      
  DAQmxClearTask (daqmxhandle);
  return 0;
  }

  Kind regards

• generate the output waveform on 6259

  Hello

  I would like to generate signals of "simple" digital square output 3 6259 NI Board of Directors of 80 Hz.

  Because of the wiring of my test tool driven 6259 Board, I can't use the output of the meter, but I need to plug into 3 output lines.

  I re-used an existing vi and made by a subcontractor, but the generated waveform on my DUT does not have the expected frequencies (although it seems OK on the generated graph). Indeed, there are some forms of square waves, but not continuously. A sort of "pomade" and "elected" frequency does not match the measured frequency. If someone has an idea to help me, I have not experience on labview yet!

  Thank you!

  You have 4 unique digital States aimed at bike.  Each cycle produces 1 full period of each of your square waves.  If you want the output to 80 Hz, you must set the sample to run 4 * 80 = 320 Hz clock.

  The other thing you see on the scope is that there are short bursts of pulses with parent long time between bursts.  The calendar during the bursts are what control tasks.  The time between bursts is caused by using the button "run continuously.  Also that according to them, you complete vi almost immediately rather than waiting until they run awhile.  Put an end to the execution of vi initiates self-cleaning of LabVIEW.  These things represent the time brief burst and the ISH between bursts.

  -Kevin P

• How to write constantly to analog output and read from analog inputs

  Hi all -

  I had a question about writing continuously to analog output reading simultaneously an analog input.

  It's my first time to post a message to the community, so please let me know if I made mistakes.

  I use Labview 2011 with a NEITHER-DAQ USB 6215.

  I'm looking to generate a waveform and write it continuously in an analog output. It is then connected to an entry on the acquisition of data, where I am trying to sample the analog signal. (I realize, there is a system of trivial, but I'm hoping to build on it once I have run).

  The task of reading from the analog input works fine, as I tested it in several other cases. I have a problem writing to the analog output.

  For this task, I tried to follow the "Gen Cont Wfm Clck Int' VI to generate the wave form and start the task. I then try to write to the output of the analog timed loop. However, it does not seem to transmit a signal and doesn't give me any errors.

  I have attached the VI but also a screenshot.

  Please let me know if anyone has any ideas. I would really appreciate the help!

  Thank you

  Peter Borgstrom

  We will review your tasks one at a time.  First of all, the task of generation/Analog output Waveform.  Generate you a waveform (I'm unsure of your VI if it is a fixed waveform or not) and send it to a defined output function to produce a waveform continuously, using N-channel and samples of N (where you set not these previously).  You should not put this inside has timed loop, as the DAQ hardware has its own clock - if you simply put it in a while loop (with a stop to break out of the loop), the loop will call the function for the first points of N, wait until all N have been taken out, then call it again to another N points (up to what you press Stop).

  Now, suppose that you have the output connected to a load voltage (say a decent resistance).  You can wire the input terminals of your A/D converter through the same load and set up a similar analog input loop, running in parallel (i.e. in its own independent of the OD loop, while loop).  You pourriez start together (with, say, a merged error since the initialization code line loops HAVE and AO become lines of error in "loops of sampling" described above), but you might want to delay loop (a little) the AI so that the OD has a chance to set the voltage before the bed.

  I hope this helps.

  BS

• Simulate the analog output of arbitrary waveforms

  Simulate it Arbitrary Waveform VI Express can be used to generate analog signals to the physical channels in analog output mode systems such as the NI 9263? I am trying to use the VI arbitrary signal generator to produce a signal used to excite the magnetic coils.

  Why don't you just try and see what happens?  As far as I know, it should work.

• Redeclenchables/continuous to a custom waveform analog output?

  Hello

  I try regular output an analog signal using the box USB-6211 and Labview2009. I looked at various examples of waveform, including the retriggerableAO.vi example, but I can't seem to understand how to send a 'waveform' custom stamp (terminology is perhaps the question). In all the examples (including waveformbuffer), I ran across the single waveform, the options are sine, square, etc.  Previously, I posted on this forum looking for hardware suggestions (link here) and explained what I try to do and got the big help. To sum up, I would like to read a 'waveform' from a text file, send it to the usb-6211 buffer and then continue to an analog channel. At the same time, I'll use the beginning of the analog task to trigger a digital signal once per cycle as well.

  I got in what concerns the establishment of the waveform, but am stuck to figure out how to get into the buffer and setting the frequency, etc.

  Thank you

  Gabe

  Hi Gabe,

  Dennis is correct that it will take some room to modify the existing screws to fit your need.  As he says, the Con Gen tension Wfm - Int Regeneration.vi Clk - no example provided with LabVIEW.  In the example, it can be shown that there is a custom VI used to explain the problems that arise when a waveform of a given frequency to a frequency of sampling and outputs analog specified.

  With all that said, it seems you want to read from an existing waveform file that you created and this waveform to an AO output channel.  There are a few things that will be needed to know before proceeding:

  -What is the waveform as you try to output (5000 samples, 10 k, 100 k, etc.)?

  -What pieces of the size of the wave you want output (100 samples at a time, etc.)?

  -you want to again and again, or simply run through once the waveform looping?

  Assuming that you already have the waveform and will only step by step, here's what I would like:

  -break the large waveform into smaller pieces of waveform of standard size

  -import the waveforms in LabVIEW and create an array of waveforms

  -bring the waveform in the example Dennis mentioned previously with automatic indexing enabled on the tunnel

  -Remove the generator of wave functions existing the while loop

  -wire your indexed table of waveform for the data of the VI DAQmx of analog output terminal

  It is possible that you will have to play with the settings of your waveform and timing of your VI, but this should be a good starting point.  Please let me know if something is not clear or if I have misunderstood your original message.  Have a beautiful reast of the day.

  Best,

• generate a square on the analog output wave

  I use a PXI-6229 DAQ card and I need to generate a square on ao0 wave.  I'm programming in c# and have found an example of the expedition, which generates a sine wave.  I need to be able to modify the function generator that was provided with the example of the expedition to produce a square wave 7.2 kHz with duty cycle of 50% and 2 v peak-to-peak.  I enclose the code generator to function.

  Thank you

  After a lot of trial and error and adapt the example to generate a sinusoidal signal, I have the solution to generate a square signal of analog output.  I enclose the code.

• LabVIEW 7.1 Analog Output is incorrect, computer crashes and often generating output resignations

  Try to put in place an old pc with Labview 7.1 NT with an AT-MIO-16 x card... everything is loaded, I can load OR-DAQ 6.1 examples and Configuration DAQ ESPECIALLY utility works correctly.

  In the config utility, I can put all the settings are correct, but I get the dreaded "the device does not respond to the first IRQ setting" for all the IRQ numbers acceptable that I choose 7,9,10,11 as 5, or 15. Others are simply not available, and all those who are to generate the same message.  However I can run the test panels and get an analog output, for example, fine, tested with an LED.

  So I moved upward to load an example VI, the function generator... Sort of works, it breaks easily, or stops, generating a total, if I hit the stop button and restart, and its output looks nothing like one of the square, etc. in sawtooth, sinusoid, shapes, watching on a scope, it is just hard hitting high then low, sometimes spitting a gust of sinusoid for half a second or so.

  I suspect this is related to the issuance of the IRQ, I searched all knowledge bases, come up with nothing that solves this problem.  Thought maybe someone could lend an idea.  LabVIEW is really more stable than this right?

  Well I've tried a bunch of things and success. Looks like my MIO Board is kaputt.  Good thing I have 3 of the guys. The other set up fine in config and short decent for the torque screw daq example I tried.

  Continuation and thank you very much for answering.

• variable phase shift between two analog output signals

  Hey! I would drive two different piezo elements with an sine - / square signals and have a phase shifted output signals. After some trail and error, I was able to get a second analog output on my card PCI-6221 (using LabView 8.2) also allowed me to have different amplitudes for both signals. However, I could not output signal having a frequency different and most importantly to my request to have one of the signals variably shifted phase.

  Thanks for the very useful suggestion. I have attached the file .vi installation I've run so far.

  Hello!

  A way to generate waveforms is using the analog waveform Toolbox. I created an example VI that is attached and that shows you a way to use the base generating function VI. I saved for LabVIEW 8.2.

  I hope this helps!

• Bad analog output help Every_N_Samples-NI-9263 cDAQ-9172 chassis (works with cDAQ-9178 chassis)

  Hello

  The NOR-9263 analog output voltage geberation works correctly with the cDAQ-9178 chassis but gives wrong result using the chassis NOR cDAQ-9172.

  In the attached code example, a single cycle of a sine wave is composed of 40000 samples and came out in the background using Every_N_Samples at a rate of production of 5000 samples per second.

  The output buffer size is set to 10000 samples.

  Prepare us the buffer writing 10000 samples 1, then write the remaining data in the background using the Every_N_Samples callback.
   
  Bug: Using the cDAQ-9172 chassis, to the 5000 s/s sampling rate with the help of an external field (or through closure to another HAVE), we observed that 1 10000 samples came out twice, followed by the rest of the waveform. The last 10000 samples are never exits. If you are working properly, we would expect to see 1 full cycle of a sine wave.

  The bug does not occur with the chassis NOR cDAQ-9178. I use the driver NIDAQmx v9.2.1f0 on Windows XP
  The bug does not happen with simulation devices, so you will need to use harwdare real to reproduce.

  Please find attached an example of code C based on the example program OR "ContGen - IntClk.c" to reproduce this bug.

  Thank you

  whemdan,

  The MathWorks

  Hi whemdan,

  By default, DAQmx regenerate old samples if no new data is available.  To give the correct behavior, you can:

  Use DAQmxSetWriteRegenMode to disable the regeneration (DAQmx_Val_DoNotAllowRegen).  In most cases, this is recommended if new data are written continuously in the buffer as the build is in progress.

  If you just need to generate 40 k samples, you can write them just all at once, rather than in 10 pieces of k (the code you attached probably is just an example, so I'll assume that you have a reason to write the data into segments in your actual code).

  I think the difference in behavior between 9172 and 9178 can if explained by the different way, buffering is set up on each product.  The 9172 uses a buffer of 8 k (on the STC2) in all cases (source).  The 9178 uses an 8 k of memory buffer (on the STC3) If you use regeneration shipped, but uses the 127 samples FIFO cartridge, if you use no on-board regeneration (source).

  Then... on the 9172 8191 samples are immediately transferred to the FIFO.  By default, the hardware is going to request new data when the FIFO is less to fill (this is configurable with DAQmxSetAODataXferReqCond).  I'm not sure what the transfer data request size is in your case (you can set the maximum value with DAQmxSetAOUsbXferReqSize), but obviously it is bigger than the other 1809 samples that you have not yet sent to the Board of Directors of your first entry.  At this point, the pilot will regenerate 10 existing k samples so that sufficient data will be available to meet the demand of data transfer.

  The 9178 however use the FIFO of 127 smaller samples so you will not have the same behavior in your case.

  In summary, the behavior is explainable by the difference of material.  If you want to avoid to regenerate old samples, you should ban the regeneration using DAQmxSetWriteRegenMode.

  Best regards

• Analog outputs with different time scales

  I use products AO of a card PCI-6731 for an application scan head and I have some difficulties to achieve peak performance, that I need. I am contolling the map with nidaqmx drivers in c ++

  Basically, an output controls scanning in the direction Y (which is a line of scanning and is very fast) and the other in the X (increment once per scan line, so much slower). The complication is that both exits start at an external trigger, because positioning is synchronized to a separate data acquisition card.

  Now, what I do is:

  -write the scanline for 0 output waveform

  -set output 1 to a given position

  -say next Trigger output card

  -hangs at the end and stop tasks

  What I really want to do, it is just tell him to start with on each external trigger output waveform of scanline 0 and output 1 increment to the next position. So I could do a complete 2D scanner with a minimum of control software.

  Any ideas on how I could best achieve this? My understanding of the nidaqmx drivers I don't see an elegant way to do it.

  I could potentially do some operations on the done callback, although it makes me a little nervous because the control PC running windows, it is not a real-time operating system.

  Hmm I do not know exactly but there are a couple of things (it is close)...

  The output frequency of meter in your example 5 MHz (20 MHz, 2 high ticks, weak 2 ticks), which is faster than holders 6731 for a sample clock.  I thought that this would have given a material error... are you looking for errors once the task runs (for example using DAQmxIsTaskDone)?.  There is a DAQmxCreateCOPulseChanFreq if you want to set the clock frequency directly (it will use the appropriate default internal time base).

  The task of counter generates 1000 pulses per trigger, is what determines the number of samples generated by the trigger (I assume that you want it to be 1024 aka "numSamples").

  The analog output task must either use:

  (1) calendar continuous if the output will repeat indefinitely as several triggers are acquired.

  (2) finishes pitch (N * numSamples) samples where N is the number of lines that you want to exit and numSamples is the number of samples per line.  In this case, the task will end once the lines were triggered.

  Best regards

• To input analog shutdown when the analog output is completed and synchronization

  Hello

  I'm trying to get my LabVIEW program to send analog output to a computer and read acceleration using the cDAQ-9184. Chassis output that I use is the NI 9263 and the chassis of entry is the NI 9234. I generate a signal of white noise using LabVIEW Express signal generator.

  The first problem I have is the synchronization. I had an old VI that has begun to measure the acceleration just about a second after the entry has been given to the machine. I used the LabVIEW tutorial on how to sync the analog input and output, only to discover that it does not work with two different hunts. Then I found another tutorial that shows how to synchronize different frames between them.

  The second problem is the cessation of the LabVIEW program. What I want to do is to generate the signal and then simultaneously send and read the input and output analog, respectively. It is because I don't want a phase difference or any shorter signal for a direct comparison. But as soon as the signal is sent to the machine, I want the entry to stop analog playback and then then the LabVIEW program must stop. I want to be able to choose any length of signal to be generated and stop as soon as the entire duration of the signal has been sent to the machine.

  I tried 'DAQmx stop', "DAQmx Timer" and 'DAQmx's task made?' and none of them have worked for me. It is also my first time on a forum posting, so I hope I gave enough information. I enclose my VI as well. The VI shows I read an entry for the analog input voltage, but I am only using this to try to get to the work programme.

  I'd appreciate any help I could get.

  Thanks in advance

  Peter

  Hi Peter,.

  I have some recommendations for you that I think you will get closer to your solution. First of all, I assumed you meant that you had 1 chassis (cDAQ-9184) who had two modules in it (NOR-9263 and NOR-9234). My next steps are based on this assumption, so if it's wrong, please let me know.

  For your first question about the synchronization, the code you provided is very close to what you need. You need to do, however, implement architecture master/slave for startup tasks DAQmx functions. To do this, you can add another frame to the flat sequence structure and put the master start task (input voltage) after the start slave (output voltage) task.

  To manage your second question and that the program ends at the point where you, the first step is to get rid of all the logic that you use with the local variable of length of time. Rather than use this logic, just wire the node "task performed?" of "is task performed?" operate to stop the loop. This will cause your loop to stop as soon as the signal is sent to the machine.

  I have some other recommendations for you that will increase the performance of your program:

  (1) rather than writing on file inside the last loop, you can use the DAQmx Configure Logging (PDM) .vi. You will place this VI between DAQmx Timing.vi and DAQmx Start Task.vi to the task of the analog input voltage.

  (2) after the last while loop, you want to stop the task and analog outputs as well with another DAQmx stop Task.vi.

  (3) rather than using a local variable for the entrance of displacement and wiring it in the DAQmx Write.vi, you can wire directly from the output waveform of the wave to build function node.

  That should help you get started in the synchronization of these tasks.

  -Alex C.

  Technical sales engineer

  National Instruments