measurement of frequency via scb - 68

Similar Questions

• With the help of the meter from 6525 to measure the frequency: is there a more orderly way?

  I am currently using the high speed on a module USB 6525 meter to measure the frequency of an object in rotation via a sensor hall-effect.

  I was wondering if there was a simpler way / more effective this encoding than that?

  Everything that I currently perform the current meter reading, wait a second, take another reading, and subtract one from the other. The result is the frequency in hertz.

  Is there a way to get the 6525 to return the number / change County after 1 second?

  Thank you

  

  On the 6525, you have a country of the event and you can't make a measure of frequency.

• Measurement of frequency with the NI 9402

  Has anyone successfully was able to measure the frequency in SignalExpress with the NI 9402 module? I have the 9402 connected to a tachometer (on a centrifuge) which puts a TTL signal. For now, I can get the light input line to work. (Right click on the project, acquire signals: DAQmx Acquire: digital input: input line.) When the tachometer completes the first round, light or the 'blip' lights indicating the sensor then goes back to the shore for the rest of the round. I would like to read the frequency of this "blip" instead. I can't understand the required parameters in Signal Express. I tried (right-click project, acquire signals: DAQmx Acquire: entry of meter: frequency) but maybe I do not have the correct settings. This centrifuge works usually between 0 and 3 hz. I have attached a picture of what I have. I am doing this correctly, with incorrect parameters? Or is there a better way to do this? I need to read Hertz over time. Thank you!

  Hi Choover,

  Even if you use the 0 meter to measure frequency, your singal acts at the door of the on-board clock source to measure the length (and thus frequency).  This is why you must use PF1 to connect to the door of the meter.  You can learn more about how DAQmx takes measurements of meter in any manual of cDAQ chassis: http://digital.ni.com/manuals.nsf/websearch/2C061605E17C7D04862578D200677B90

  

  Brian

• Measurement of frequency with CompactRio

  Dear all

  I have an anemometer which sends digital signals. I'm trying to analyze the signal to determine the speed of the wind.

  I have one NOR cRio-9024 and NI 9205. When I connect the anemometer, it gives me some positives square rear tension (see attachment). I wonder if I could turn this to the readings of frequency because it is linear to the wind speed.

  I tried to follow the link below, but my module does not have the option of digital Configuration specialist

  http://digital.NI.com/public.nsf/allkb/C9088DFDF803CD8B862575F3007C40FD

  or I should have another module OR who could measure the frequency of the signal directly?

  I would like any ideas or suggestions. Thank you very much!

  LabVIEW Newbie

  
  

• Measure the frequency of the pulses PXI-6624

  Hello.  I work with a PXI-6624 and am interested to make measurements of pulsed frequency for frequency and duty cycle on its inputs using DAQmx.

  When I go to create the virtual channel, however, I have error-200431:

  "Physical channel selected does not support the type of measure required by the virtual channel you create."

  ' Asked the value: pulse frequency.

  «You can select: frequency, period, pulse width, period of Semi, separation of the two edges, Position:...» »

  Is this card really not capable of doing these measures of pulse frequency?

  Yes, the "Pulse" (not to be confused with "Pulse Width") measure was introduced with STC3 of OR including CompactDAQ and X series devices.

  Measuring the pulse:

  

  However, you should always be able to measure the frequency and the duty cycle on your card with a half measure:

  The half measure:

  

  The images are in the X Series user manual.

  The difference between these two modes boils down to how the data is stored and implemented in buffer on the map - with the period semi method that the material does not distinguish between high and low samples and puts everything in a single buffer.  However, if you start the meter on the song (see below the node property), then you would know the order of low and high samples in software, and are easy enough to calculate cycle frequency and the duty of this.

  

  Best regards

• How to measure the frequency of NOR-DAQmx RPM tasks

  Hello

  I'm trying to measure the frequency using the NI DAQmx task and then convert it to a RPM if possible.

  I have the following material available to me.

  I have a block SCXI-1327 terminal, as well as a 6289 PXI multifunction data acquisition Module SCXI 1126.

  I wired in a mag ai7 sensor on my 1126 and then of the passage of an object metal I get a range of 6-8, so I am able to read the mag sensor.

  What I'm trying to do is somehow convert this analog measurement a RPM using the NI DAQmx task only.

  Any help would be appreciated.

  Hi, smooth,

  Yes, you would select linear, then put in the result of this calculation of the slope.

  The Manual recommends a minimum frequency of at least 15 Hz for setting low range. This card is not really designed to measure the frequency for a single pulse over a long period of time.

  The number of LAPS down (assuming one pulse per turn) that we recommend that you measure with the 1126 is so 900 RPM. If you need measure low revs, and you cannot increase the number of impulses per turn, you could consider either read the signal as an analog waveform, or if it's a digital pulse, using a counter to basic task. In this way, you can use any method you want to handle the situation where there is only a single pulse in a long time.

• How to measure the frequency of a clock using meter in LabVIEW?

  Hi guys,.

  Someone knows how to measure the frequency of a signal introduced in LabVIEW (in the FPGA PXI-7813R), using a counter in LabVIEW?

  Essentially, I want to use this counter as a kind of Logic Analyzer.

  Thank you, Anoop

  I don't know what you mean by "manual".  It is all managed in a housing structure.

  

• Measurement of frequency with the NOR-6221

  Hello

  I would use the OR-6221 to measure the frequencies of the order of 200 Hz to 12.5 Mhz.

  Is this possible?

  Can you guide me were to start?

  There are notes of application with examples?

  The required accuracy is not high 0.5 percent more or less...

  Thank you

  Rafi

  
  

• measurement of frequency for ELVIS

  I use Elvis and I want to measure the frequency of an analog input signal.
  I use this program I found in a manual form OR.

  I'm using LABVIEW 8.0.

  The problem is that the program is not read the frequency. No mather how often I try to read always indicates r = the same thing.

  I have attacheted the program below.

  Americanu22,

  A couple of things that you will want to consider:

  1. to ensure the frequency information is correct, you must be 2 sampling * [highest frequency in your Signal].

  2. you can consider an ongoing acquisition with a configuration like this (' this example can be found in Help "" example Finder under material input and output "analog measures DAQmx'):

  Good luck!

  Kind regards

• Measurement of frequency triggered? NEITHER 6259

  I'm trying to work out how to implement a measure of frequency (of a pulse train) which will be triggered by another external pulse to a different channel.

  I have an encoder that is attached to a rotating shaft, that generates square pulses 5V on two different channels: the first string gives one pulse per revolution of the shaft (my planned trigger pulse), the second string gives a pulse all the 1/2500th of a revolution (IE all 0.144º)

  Seeing a pulse of "channel one" (the pulse of a time-by-rev), I want the system to begin to measure the frequency of the pulses on the 'two way '. This isn't the average frequency during the ENTIRE revolution I'm after: what I'm shooting looks more like an angle vs revolution frequency waveform graph, for a ride (IE with 2500 data points).

  It does not matter if the processing time means that the system of "lack" an impulse to start on the next revolution, because it can always wait for the next. The most important thing is that the beginning of the frequency measurement is triggered at the right time.

  So far, I have used L'Express VI/DAQ Assistant to implement a measure of the frequency of the pulse 0.144º: I'm wiring these impulses to PFI9/CTR0 of Council 6259. I used a continuous acquisition of 2500 measures. The expected frequency range is about 40 to 200 kHz (2500 pulses per rev at between 1000 and 4000 RPM.)

  That works very well, and I can establish a curve of angle vs. frequency of revolution, BUT... For now the beginning of the acquisition is completely arbitrary; That is, it starts when I type 'run '. I can't understand the best way to trigger the acquisition of the OTHER channel impulse.

  There is no external trigger options in the DAQ assistant page, so I wonder if this is still possible using an express VI - do I have to use lower level stuff?

  I am convinced that this should be easy!

  Thanks in advance

  Theo

  Rico, Brad,

  Thank you very much for your comments, I'm pleased to say that we have sorted in the end.

  The first question concerned the fact that the Board I was using (PXI-6133) is not able to make a measure of frequency of trigger in this way.

  It was a big problem because even if the LabView code was right it works always, leading me to doubt the code and become even more confused! However, using the same code on a Board 6259 worked like a charm.

  I used the DAQmx blocks to set up a channel to measure frequency and a trigger, set the shutter button using the property with an arm.start node as in your example.

  Thanks again for your help!

  Theo

• input analog trigger on the door of the meter to measure the frequency of generation

  Hello

  I want to measure a frequency on the analog input, but it doesn't seem to work.

  I'm trying to work with DAQmx with the use of the ansi c standard.

  The first step, I've done was acquiring information on the analog input. With the use of a simulated device, it shows a sine wave on the entry.

  My next step is to generate a trigger for the meter signal, but this doesn't seem to work.

  I don't see how it is possible to connect the trigger on the entrance to the analog meter.

  For the creation of the analog input and relaxation, I use the following code:

  DAQmxErrChk (DAQmxCreateTask("",&taskHandle));
  DAQmxErrChk (DAQmxCreateAIVoltageChan(taskHandle,"Dev1/ai0","",DAQmx_Val_Cfg_Default,-3.0,3.0,DAQmx_Val_Volts,NULL));
  DAQmxErrChk (DAQmxCfgSampClkTiming(taskHandle,"",10000.0,DAQmx_Val_Rising,DAQmx_Val_FiniteSamps,1000));

  DAQmxErrChk (DAQmxCfgAnlgEdgeStartTrig (taskHandle, "Dev1/ai0 ', DAQmx_Val_RisingSlope, 0 '"));

  For the creation of the meter, I use the following code:

  DAQmxErrChk (DAQmxCreateCIFreqChan (taskHandle1, "Dev1/ctr1", "", 1 January 2000, DAQmx_Val_Hz, DAQmx_Val_Rising, DAQmx_Val_LowFreq1Ctr, 1, 4, "");)

  I hope someone could give me a hint.

  I also tried the examples that come with DAQmx but well I know this are only examples to counter with the help of the digital inputs.

  Thanks in advance.

  Hello

  You must use the exit event of comparison at the entrance of the meter. Change this property after the configuration string function.

  DAQmxSetChanAttribute (taskHandle1, "", DAQmx_CI_Freq_Term, Dev1/AnalogComparisonEvent);

  Kind regards

  Bottom

• How to measure the frequency of sampling (s/s) in LabView FPGA?

  Hello

  I am trying to find a way to measure the sampling frequency (s/s) during which I read from analog input in LabVIEW FPGA. I know that the sampling frequency is specified in the data sheet of the module HAVE, but I want to measure in LabVIEW.

  Any suggestions?

  A screenshot of the example code would be greatly appreciated

  Hey phg,.

  If you have some time loopand in this loop, you export a sample by iteration of loop via an I/O node. You can't out two samples on the same I/O node within an iteration, it's always one!

  So if your loop takes 1 second to run you have a sampling rate of 1 Hz output. The same goes for sampling of entry. How long your loop takes to run can be calculated as explained above.

  Samplerate [s / s] = 1 / [s] while loop

• Measurement of frequency data USRP

  Can any body guide on the next post.

  https://forums.NI.com/T5/LabVIEW/datarate-measurement/m-p/3252364

  Thanks in advance.

  Hey Joseph,.

  Wouldn't it be dependent on the rate and the IQ modulation system used?  To calculate the data rate, you take your IQ sampling rate and multiply by the number of bits per sample (depends on the modulation scheme).  For example, if I was using binary phase shift and the data rate should be equal to the rate of IQ because we get a bit of information for example.

  I would like to know if you think that I misunderstood the question.

• Table of channel adds channel list «»

  Hello

  I did apply for a measure of frequency via a HP34970A.

  Closed HP34970A 101--> HP5313 port measures--> and then HP34970A open port 101 again. Continue to port 102.

  I want to use #101 & #102 but # "" is added as well and gives me a timeout 50sec.

  The probe for a list of the input channels watch 101, 102 & «»

  On the output, it gives me

  #101 5 bed, 8ms

  #102 bed 1, 6ms

  # "" bed 0,0000000

  How can I remove ' ' from the list of channels? I don't know that it is not in the list itself, only 2 channels there.

  Thank you

  Hello again

  I ended up remove the entry from the chain and recreate. There wasn't any 'spaces' or anything in the figure of an i, but recreate fixed.

  Thanks for the comments.

• PXI-6608 fairer frequency measurement

  The attached VI measures the frequency of a known Hz 24,575,000 signal. When measured with a meter of frequency of 3 GHz Agilent 53181 A-010, that measure 24,575,999.4 Hzsignal. When the same signal is measured with the PXI-6608 meter, this signal is 24,576,149.3 Hz. The two instruments are calibrated, and the two measurements were performed with a portal of 8 sec.

  I use the more precise measurement technique? My PXI-6608 is defective or out of calibration, although it is brand new?

  various Info. :

  The PXI-6608 is in slot 2 a PXI-1033. I connect to CTR1 via PFI - 35, triggering on the front and I have a door 8 sec for sub-Hz resolution.

  2009 LabVIEW, TestStand 4.2, MAX 4.6.1

  Thanks in advance,

  Sam Broyles