Single sampling Point Acq

Hello, a little info on my system and I to start. I'm under LabVIEW 8.6 and using the NI USB-6259 box as my DAQ hardware. I'm new in the world of only having been LabVIEW use this configuration for 3 weeks (but a nice step to the top of the Win95 system I was using).

I'm trying to order and circuit operating at 8 kHz. I want to read in a voltage of the circuit, detect a break in its derivative and then send the output voltage back into the circuit based on its signs at these crossings. To safely control circuit, I need to taste well above 8 kHz.

The issue I'm having is speed limits due to a loop based around a DAQ Assistant of "1 sample (on request). I read a lot of messages saying to use timed HW sampling but I do not think that my DAQ hardware supports it. I used clocks to get a rough idea that my loop runs roughly 25 Hz.

I don't know if the problem is in inefficient coding or limitations of my hardware and software. Attached, you will see my current VI.

You're right, you use the acquisition of timmed softwared, you want to run in continuous mode, The 6259 should be able to acquire up to 1.25 MECH. / s.  Try to put it in place with the daq assistant since you're new to labview, or look at examples of analog acquisition.  essentially, you want to read in a loop using buffered continious CQI, then send the results to your vi loop or slave to the processor.   I would like samples at 5 - 10 times the 8 kHz to get a good representation of the signal you.  faster that the x 10 will give you nothing but too much data to deal with.  8 kHz is not too much data and you might be able to treat it in the same line as your read daq.

Tags: NI Software

Similar Questions

  • Hanging tool select disabled but time always snaps between sampling Points

    Hello

    In the Waveform Editor, when I Zoom in directly on the waveform, the points become visible. I have 3 Q: -.

    1. What are these points
    2. They can be changed
    3. How can I select (with the Selection tool) anywhere on the waveform?
      1. I deselected waspish and yet I am with zoom basically I can only place the time tool (TST) between the points visible, i.e. hearing snaps TST so I can not place exactly there where I want

    Thank you!

    The points show the individual samples in your digital recording.

    Jump to your last question, you cannot place the time between samples picker because samples are smaller individual representations of the original audio.  the lines between the samples are an artificial creation, making a waveform of samples.   There is an excellent video showing how digital audio works - I recommend highly a cup of coffee and a viewing: D/A and A/D | Digital Show and Tell (Monty Montgomery @ xiph.org) - YouTube

    Spacing of samples is determined by the sample selected speed which, in turn, is controlled by the clock system (Word clock).

    As for the editing... not really.  Older versions of hearing used to allow you to enter a sample and move it upwards or downwards, but the results could be unpredictable - under Nyquist theory there is only one waveform (i.e. one correct) which corresponds to the sequence of individual samples.   Changing a single sample (or even two or three) can force the system that analyzes samples and draws the analog waveform by doing a few calculations confusing, incorrect.   If you watch the video above and "read between the lines" you can see why that would be.

  • DAC single sample write response time

    I use the acquisition of data USB-6259. I wrote a simple loop to write permanently a single sample of an output to check the next time of turing analog voltage pos & neg. I have the 'writing analog DBL 1Chan 1Samp' connected to a 'multiply by neg 1 "in a loop. I run the application, and it seems that the response time is about 3msec between +/-. It's far too slow for my application. My application requires constantly reading and setting of the tensions. I get a high sampling frequency if I'm out a waveform. However, I didn't go out a waveform. I went out a voltage in response to a voltage reading. Is it possible to have a shorter response time? Is there another method (using C?) to improve response times?

    Erik,

    Windows is deterministic up to 1 ms, so there is no way we could get this application in the field of speed you need with the current hardware.  I think that you could implement this with an FPGA, and we have many options available.

  • check if a sampling point exists

    The script below is useful for the selection

    Now I would like the same thing to see if the sampling point is

    Thank you

    You can do this even with the sampling point

    1. #target photoshop 
    2. var doc = activeDocument; 
    3. try
    4. doc. Selection.Copy)
    5. //code here if there is something in the selection 
    6. }
    7. catch (e){ 
    8. //code here because if the selection is empty 
    9. }

    If (activeDocument.colorSamplers.length > 0) {alert (' exist color sampler/s / s ') ;}}

  • How do I click option to set a sampling point?

    Photoshop elements 14 does not allow me to use the clone tool, because there is no point source selected. How to set a sampling point?

    Hold down the ALT key, and then click

  • Sampling point frequent

    I have a 6008, accessible by DAQmx.

    I produce a custom feedback loop. As the analogue output has a sampling rate of 150 Hz, this is the maximum rate of the feedback loop.

    I'm trying to figure out how to make my analog readings.

    I have excluded finite samples (if I let up, I pass the same values and more; if I reset, it's far too slow)

    With continuous samples, if I take a unique data point, I'm not synchronized - I don't want to read the end of the buffer, I want the most recent.

    So I try sample N read, with-1 as the number of samples to be taken, that help said is the way to capture the whole buffer.

    I get an error-200279, who says I'm trying to read data that no longer exist because it crashed. But that seems like it should be a nonsense - I just say, give me what you got. Why bother crush if you are never just refuse to put her out in any more data and call a mistake, because you started to crush? It is frustrating especially since I really don't care for the newest item (or recent average for all purposes)

    There are a lot of topics around this error (-200279).

    Have a look here and try to understand exactly why you get this error. You too can share your code so that you can have a careful review and understand what causes the error, specifically in your code.

  • Multi-channel acquisition - simultaneous Acquisition of sampling 1 & 2-channel single sample in a task

    I am able to get a multichannel simultaneous sampling on my acquisition of data (USB-6363) without problem. But what I want to do is make multi-channel acquisition in a single task where sampling requirements are different for each channel. For example, I want I want to acquire a total of 1000 samples on 3 channels in a single task with DAQmx as follows the characteristics of sample:

    • AI0: Analog Wfm 1Chan NSamp (998 samples)
    • AI1 + ai2: 1 d analog NChan DBL 1Samp (1 + 1 sample/channel)

    I know I could do just a regular multiple sampling multi-channel acquisition through all three channels then average down from channels 1 + 2, but I don't have that several samples to spare. AI0 is a bandwidth hog in my application and consumes all the samples of data acquisition (2. MECH / s), but I can save a few samples to make analog measurements further (for example, temperature, pressure).

    Ai0 takes place also permanently so additional analog measures on ai1 + ai2 need to be included in the same task.

    I don't know how to go on this matter or if it is still possible. Any ideas or thoughts would be greatly appreciated.

    Currently I use a second DAQ to read these additional channels at a lower rate but I need to pass a single data acquisition.

    How should continuous ai0 really be?  You of course can enjoy on ai0, and one of the other entries at the same time, then there would be some gap in your data.  In addition, if you want to go to the full 2 MHz, you may sample ai1 ai2 twice in order to allow entry to set (the maximum specified multi-channel rate is only 1 MHz due to compaction of the constraints on the MUX I believe).

    DAQmx sort of you lets set something up like that, if you "cheat" it by configuring each sample as a single channel in your task (see an example similar here).  If your 998 + 1 + 1 (or 996 + 2 + 2) becomes a task of channel 1000 (takes a bit more memory, but should still be feasible).

    I would consider a 2nd DAQ card a better option if ai0 really needs to be continuous.  You can go with a (9174 or 9178) cDAQ chassis a 9223 (only 1 MHz if) for quick entry and your choice of module for the slower entries.  On the cDAQ chassis a module can run a separate task of AI from other modules (up to 3 tasks HAVE by chassis) at different speeds.

    Best regards

  • Merge multiple paths to a single anchor point

    Hello friends,

    I want to create a perspective of illustrator grid to use with other software.

    I would like to know if it is possible to merge several paths to an anchor point unique to a single point perspective grid that can be easily changed by moving the anchor point in the Middle, as in the picture below.

    Imgur: the most impressive pictures on the Internet

    An anchor may reach only 2 segments of track. Your image must at least consist of 2, if it is not not 4 paths. But you can select multiple anchor points (not a path) and use the Panel line up to get them exactly on the same position. Later if you want to draw a rectangle with the direct selection above them, move them around and move these selected elements.

  • Cloud of Pod Architecture and load - single entry Point balancing

    Hello

    I'm looking at our DR put in place for our view environment and Cloud Pod Architecture seems to be the way to go. A question that has popped up and I couldn't get a definitive answer about whether it is possible to use the load balancing of certain aromas to maintain a single point of entry into the environment seen. I would be able to have a connection to the server discovers in A Pod and a login server in View Pod B and then stick a load balancer at the front so that users always connect through load balancing and view.domain.com, they will hit either login server? Would it not possible to use a Windows NLB for that?

    What I want to achieve is to build a second Pod from view in a different geographical location to complete our game existing upward at our headquarters. This new Pod will be alive and actively used instead of a traditional DR implemented whereby all will sit dormant until the sh * t hits the fan. We maintain a single point of entry into the environment and the user gets negotiated at their office floating Linked Clone correct, be it in A Pod or B. Pod

    I hope that makes sense.

    Of the questions let me know.

    Yes, it is definitely possible.

    We currently have a configuration of global namespace for internal and external access.  It appeared linked to a VIP we have on our load balancing programs (Radware currently).  This VIP points to our real servers on both sides.

    Then, we focus on Cloud Pod Architecture configuration dedicated or floating pools.  People can connect and hit one side or both.

    If you leverage GTM or Global Traffic Manager (Smart DNS Round Robin), she may ask the weight or restrictions so when people only struck one side of your data centers until he is not available and then it hits the other side.

    Do not forget that the Volumes of App and RDS Apps are not supported, just virtual offices.

    We currently have two pods between two sites, take advantage of cloud pod and built infrastructure in duplicate for each site to be isolated and independent.

    We focus also on DFS - R on Windows File Services to ensure that the data are replicated and synchronized between the two locations.  Then with the use of DFS Namespace we weight each side sort users to the Site a success files on file to the Site Services and vice versa.

    F5 also has an edition of Big - IP virtual that will work great and deploy GTM, LTM (Load Balancing) and MPA (Access Policy Manager) to work on both internal and external access for you.

  • NI9219 - Possible to read a single sample per read? (ADCTimingMode set to high frequency)

    I'm trying to collect samples every 0.1 second to a NI9219.

    I put in place, and then convert a DAQ Assistant code, because I had to change the AI. ADCTimingMode at high speed. Sampling frequency is set to 10 Hz, and read samples have the value 1. It's in a while loop. However, each iteration of the loop is back 10 samples each one second, not 1 sample per 0.1 second.

    The screws are attached if it helps, LV2011 format.

    Thanks in advance to those who take stabbed to enlighten me as to why it is!

    ACK, the entry 'number of sample' of the DAQmx Read VI had wired upward inadvertently. Do not take into account!

  • Finished samples timed material vs single-point: different speed?

    Hi all

    Although I had several questions about this request before that separately have been resolved, there is one last thing that remains difficult.

    Shortly:

    My application acquires data from 2 analog and synchronous inputs on 2 channels of analog output.

    There is a trigger stop set on a PFI-pipe with a single switch. To make of this

    I had to switch from single-point over acquition timed work material.

    This set works very well when I read not less then a 100 samples once with a sampling of 1000 Hz. frequency (when I go below a sample of 100 to read--> E-200279)

    Ideally, I would like to read about 10 samples with a sampling frequency of 1000 Hz.

    However, using single-point timed equipment acquisition I can easily do that without a problem. Even just reading

    a single sample once with a sampling frequency of 1000 Hz does not have a problem. But impossible to use the block of relaxation of reference as a signal to stop with this setting!

    Question:

    For me, there are two solutions, but so far I could not work on one of them:

    (1) build a stop trigger in an single point of timed material acquisition

    (2) change something in the acquisition of finished so that I can read faster.

    Any suggestions, what causes the difference between the two speeds to be able to read the data and a way to solve it?

    Thank you

    Mark

    Mark,

    I mocked how I think I would like to address the issue and tied it to the top.  The general idea is that we use HWTSP for our analog I/o and counter looking edges on our signal "stop".  Each iteration of the loop, we check if we saw the stop signal.  If we have, then we write zero for the output channels and stop the loop.  If this isn't the case, write us the data of your comments, we have calculated.  I've added some comments on the block diagram that I hope are useful.  I have currently no any material of series E share, so it may not work properly out of the box, but I thought it would point you in the right direction.

    I offer this precaution:

    Windows is not a real-time operating system.  Therefore, it may take the liberty to give as much CPU time to other processes or applications as he likes.  As a result, it is likely that you will not miss a few samples (IE, your loop will not go faster hardware issues are examples of clock).  I configured DAQmx must return a warning you when this happens.

    Hope that helps,

    Dan

  • Filtration of single-point data

    Hello, I'm trying to filter the data of voltage point unique task, but there is an error of frequency... I have set at 120 Hz sampling frequency and I want bandpass filter for example of 30 to 40 Hz...

    So, where is problem? I tried to use a timed loop or "align and re - sample" sampling frequency, but this filter still does not work...

    You know, how to use this filter with single point task? When I do my own filter FIR with the same settings, the results are not same, this is the reason why I want to use this filter.

    If I use DAQ Assistant, there is no errors, but I can't use for other reasons (1) I can't use single point and all daq assistant, daq assistant 2) can't do pressure)

    These images add nothing to the discussion. If you buy a single point at a time, you have NO frequency and cannot use the normal filter function. Do what I said or use multi-sample reading or single reading point and build the table before making a filter. Best is to use the acquisition of data with several samples.

  • Module e/s NI 5761 clock compiled 0 to 100 MHz in single/multiple Sample CLIP examples of projects

    Hello

    I was trying to wrap my head around the CLIP sample NI 5761 Multi (v4.1.0) because the CLIP provides 250 PSM data, but the IO module requires a clock of 200 MHz.  I think, ' NOR should handle the conversion of the clock, fine, but I hope that the diagram is running at 125 MHz... otherwise I'm really confused "so I look at configuring the clock Module e/s in 0 \examples\FlexRIO\IO Modules\NI 5761\NI Getting Started\NI 5761 5761 - to Started.lvproj and to my surprise, it is compiled for 100 MHz.

    I checked the target 7965 in NI 5761 single sample CLIP\NI 5761 - unique CLIP.lvproj and IO Module clock 0 sample was compiled for 100 MHz there as well.

    I do not understand the difference between the flow of data and the selection of clock 200 MHz IO module, and it would be nice to understand it, but not necessary.  Also, I don't understand the difference between data rate and the configuration of the Module e/s 0 clock that drives the SCTL that contains the node IO.  I understand that to move forward.

    Thanks for any help,

    Steve K

    The CLK200 in the selections of the clock is used to excite the parts of the fixed logic that are internal to the CLIP. Some CLIPs FlexRIO may only require a CLK40, this one requires a CLK40 and fixed a CLK200 to properly perform its logic. Thus, it seems that everything is ok in regards to that.

    Unfortunately, the example incorrectly uses IOModClock0. The SCTL AI IO node resides in should use a resource of the clock that says "Data Clock. We've updated the examples in more recent versions of the pilot, but you seem to be using a version of the driver where a CLIP that uses the clock of data is the latest available for the 5761 CLIP, but the example has not yet been udpated to use.

  • High sampling rate for 18 strings in a single task - DAQmx

    Hello

    My current experiences require the acquisition of 18 channels (6 HAVE custom voltage with excitement, voltage AI 12) data at a sampling frequency of 50 kHz. My question is if it is faesible using a single cDAQ-9172 chassis. Used modules are 2 x NI 9237 and 4 x NI 9215.

    The previous researcher on this project used 2 different Renault to do this, but I was hoping that I could reduce it to a single DAQ to simplify the synchronization of all channels.

    I wrote a *.vi (attached) to do this and write to a TDMS file using a structure of producer-consumer; However, when I run the * .vi, I can run for minutes, but the number of samples recorded for the PDM is rarely more than 100 k. Subsequently a buffer size error (attempted to read from the samples that have been overwritten) with less than 200 k samples ever record. I checked the max sampling rate (using a property timing node) with the configured task as in the * .vi and it shows a maximum of 235kHz.

    I can't say if I make just the structure of the producer consumer incorrectly or if I ask too much of the cDAQ-9172 unique?

    Any help would be much appreciated.

    See you soon

    Bart

    Hi bart.s,

    TiTou speaks sampling aggregate not simultaneous, so sampling rate 50kS/s is the same for all channels.

    I see the problem in the loop of the producer. If your sampling frequency is 50kS/s/ch and you read that a single sample/ch you will lose data because the producer loop cannot run so fast. You should read more than one sample. I recommend you also to move your tracing to the consumption loop code and work with larger amounts of data.

    The second problem may be with the error handling in your loop of consumer. Merge the mistakes of loop of consumer and producer and also add a few general for two loops off if the error occurs (for example, using local variable).

    Best regards

    CaravagGIO

  • How many samples timed on a single digital output line

    Hello

    I want to output a pulse of arbitrary shape train on a single digital line (for NOR-USB-6229). The goal is to control acceleration, live performance and deceleration of a motor not not.

    To do this, I'm writing an array of samples ' Dev1/line 2' ('writeArray' in the code below), a single sample per millisecond. However, I see everything that happens on this line. What I am doing wrong? The following C code:

    int numSamples = 3000;

    TaskHandle taskHandle;
    DAQmxCreateTask("",&taskHandle);

    DAQmxCreateDOChan (taskHandle, "Dev1/line2", "", DAQmx_Val_ChanPerLine);

    DAQmxCfgSampClkTiming (taskHandle,"", 1000 / * samplingRate * /, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps, numSamples ");

    DAQmxStartTask (taskHandle);

    samplesWritten of Int32;
    DAQmxWriteDigitalLines (taskHandle, 3000, true / * autoStart * /, 100, DAQmx_Val_GroupByScanNumber, writeArray, & samplesWritten, NULL);

    DAQmxWaitUntilTaskDone (taskHandle, 100);

    DAQmxStopTask (taskHandle);
    DAQmxClearTask (taskHandle);

    All responses will be very appreciated!

    Petro

    Peter,

    It is not that these devices do not have access but rather (from the Manual X 622): "the digital subsystem has no its own dedicated internal synchronization engine. Therefore, a sample clock must be provided another subsystem on the unit or an external source. "Choices would include: Any PFI, RTSI, HAVE sample or convert clock, AO, Ctr n out internal and many other signals sample clock.

    If you current solution works well you should do!

Maybe you are looking for