RTD CDAQ mod 9217 low sampling frequency

Similar Questions

• Sampling frequency for digital sampling (cDAQ-9172 & NI 9401)

  Hello!

  I have a cDAQ-9172 with NI 9401 C-series (digital) module. I would like to taste the digital inputs with a sampling frequency of e.g. 400 or 200 kHz. My problem is that I can only choose a clock 100kHzTimebase and therefore only get a sampling rate of 100 kHz. The 20MHzTimebase clock is too fast, as it gives me a sampling rate of 20 MHz). Is it possible to get a defined user e.g. 200 kHz sampling frequency, dividing for example down the clock of 20MHzTimebase?

  Thank you! Last post and this article using the internal one or cDAQ chassis counters has solved my problem.

• Default sampling frequency NI9235/9236 equipment in scan mode.

  Hello

  I am currently using NI9235 with cRIO under scan mode, which allows sample rates up to 500 Hz. I realize that the card module has 12.8 MHz internal and under mode FPGA software and hardware time base combined anti-aliasing filter will be adjusted automatically depending on the installer of data rate, which is a set of values from 10 kHz to 794 Hz. Unfortunately, I do not have the FPGA package for now.

  My question is that what will be the flow of material data, if NI9235 the samples at 500 Hz in the scan mode. The anti-aliasing filter still works just below half the data rate material?

  Marco

  BMT WBM

  Hello Marco,.

  When it is used in scan mode the 9235 and 9236 are configured to sample at 10 KHz.  Unfortunately, this parameter is not configurable in scan mode.

  Let me know if you have any other questions.

  Sebastian

• Cannot set the < 1609 sampling frequency

  Hello

  We have recently upgraded to LV 8.6 and 8.7 DAQmx and then you have problem with the acquisition of data that uses the DAQmx API. For example, we have a module HAVE cDAQ-9172 and 9239. The device can be specified by the user and a typical configuration could be a continuous CQI, one sample at 10 Hz. After the upgrade of the 200279 error "attempt to read samples that are no longer available... crushed" came little after the task was started. It turned out that the property sampleclkrate is not affected by the value that is put in the DAQmx Timing.vi, except if it has been set > 1612,9, if you set 10 100 or 1000 or whatever the sampling frequency will be always 1612,9 when you read in the property of timing.

  If the buffer then of course becomes flew, but the question is why there is a minimum sampling frequency like this? Earlier, it was fine it set a value of arbitray and the acquisition would be at this rate.

  There are a lot of solution to get around this (faster reading, etc.), but it is strange that the behavior of the code can change from one version to the other like that...

  / Henrik

  I see a flaw in your program, you have the hardware timing and calendar in a software loop. The loop is limited by the expectation of the software. (I think it's on purpose for the demonstration).

  I looked at the Manual for the 9239 and page 18 notice that the minimum entry rate is 1613kS/s

  So that is explained, the only problem is that the timing DAQmx VI does not return an error or a warning when you set a too low rate.

  Tone

• USB 6008 DI sampling frequency

  Hello

  I would like samples N to a digital input on 6008 channel. In the port of GOT it, it is possible to put samples/channel and sampling frequency, but I couldn't find a way to do the same for the channel of DI.

  If I use MAX to read the N samples on request, I can increase or decrease the number of sampels to read but rates of mutation has no effect.

  using the:

  DAQmxErrChk (DAQmxCfgSampClkTiming (g_TaskHandle, "", samplesPerSecond, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps, sampsPerChan));

  also gives me error.

  I don't know who do :-(

  Concerning

  RB

  Hi RB,.

  Digital I/o on the box USB-6008 are "static", meaning that they are controlled by the software. There is no sample clock to set the time a sample is read/written. Your software provides synchronization for DIO.

  Measuring mode 'Samples on request' refers to avoiding.

  Hardware timing (a sample clock) is available on most of the products OR providing DIO. As a low-cost product, the USB-6008 housing does not hardware timing for DIO.

  Best regards, Topp

• How to specify the sampling frequency? Must use "measurement & Automation Explorer '?

  I use to measure the input current analog OR cDAQ-9171 (chassis only location USB) and NOR-9207. I have 2010 NOR-installed DAQmx and LabVIEW.

  How can I specify the sampling frequency?

  If I use M & A Explorer to create the task, I can specify the flow rate (Hz) on the Configuration tab-> sync settings.

  For the acquisition of data NOR, it is mandatory to use M & A exploring?

  If I don't want to use M & A Explorer, how can I specify the rate (Hz)?

  Hello

  You can specify the sampling frequency with "DAQmx Timing.vi" located in the function palette DAQmx (read context-sensitive help on how to use wisely).

  You do not have to use M & A exploring (MAX) to create a task.

  A simple and quick way is to use DAQ Assistant (same configuration as in MAX) to configure your measurement.

  Another is to use blocks of DAQmx function to manually build your application code.

  In my experience Assistant DAQ is ideal for simple tasks (one measure), with regard to the more complex measures (synchronized the analog and digital inputs).

  I tend to use function blocks because they give you more freedom about code execution.

  Note: You can also build DAQmx code from a wizard configured DAQ task.

  Best regards

  Matej

• Synchronization of the inputs and outputs with different sampling frequencies

  I'm relatively new to LabView. I have a NOR-myDAQ, and I am trying to accomplish the following:

  Square wave output 10 kHz, duty cycle 50%.

  Input sampling frequency of 200 kHz, synchronized with the output that I get 20 analog input samples by square wave, and I know what samples align with the high and low output of my square wave.

  So far, I used a counter to create the square wave of 10 kHz, display on a digital output line. I tried to pull the document according to (http://www.ni.com/white-paper/4322/en), but I'm not sure how sample at a different rate than my clock pulse. It seems that this example is intended rather to taste one entry by analog clock pulse. There may be a way to create a faster clock (200 kHz) in the software and use that to synchronize the analog input collection as well as a slower 10 kHz output generation square wave?

  I eventually have to use the analog inputs to obtain data and an analog output to write the data channel, so I need the impetus of the square wave at the exit on a digital PIN.

  How could anyone do this in LabView?

  Hi Eric,.

  All subsystems (, AO, CTR) derive from the STC3 clocks so they don't drift, but in order to align your sample clock HAVE with pulse train that you generate on the counter, you'll want to trigger a task out of the other. I would like to start by a few examples taken from the example Finder > Input and Output material > DAQmx. You can trigger GOT off the train of impulses, start by Gen digital Pulse Train-keep -you probably already use a VI like this to generate 10 k pulse train. AI, start with an example like Acq Cont & chart voltage-Ext Clk - Dig Start.vi-you'll want to use the internal clock so just remove the control of the "Source of the clock" and it uses the internal clock. From there, simply set the "Source of the command" either be the PFI line generates the meter, or ' //Ctr0InternalOutput '-assuming that you are using the counter 0. You'll want to make sure that the start of the task HAVE faced the task of counter I is ready to trigger off the first impulse. They should be aligned at this point.

  For debugging, you can use DAQmx export Signal to export the sample clock - you can then brought the train line and the PFI pulse to make sure that they are aligned.

  Hope this helps,

  Andrew S

• Change the value to trigger record data for 1 s sampling frequency of 50 KHz

  Hello

  I have a VI with NI9215 and cDAQ-9178 chassis hardware. The function of the VI came out an instruction to RS232 interface and record 1 second of data every time that the set point is changed.

  The procedure is

  (1) modify the policy to the flow regulator

  (2) wait 2 seconds.

  (3) record of 4 channels for one second to the sampling frequency of 50 KHz.

  At present, the problem is for the first edition of this program, two seconds (rather than) data was saved and corn, the error message 200279.

  

  II. I revised for the second edition of the structure of the producer and the consumer who can increase the speed of the buffer.

  The question is how to configure the trigger to start the backup of data and limit data save for one second whenever the set point value changes.

  

  (1) which edition is best for my application?

  (2) how to trigger the data record?

  (3) how to record only a second of data?

  I also checked this announcement and the elapsed time seems not to work for this case.

  Any help would be greatly appreciated!

  Melody

  Hello

  you have not used properly the nodes property.

  1. replace the case structure in the first loop, with DAQmx features, with a structure of the event. Change the event fires for a worth of control of the setpoint change.

  Edit: as stated in your first post, use the structure of the event, but put inside the while loop.

  2. DO NOT connect error output from the stop command property node. Replace it with a local variable for the stop button.

  Try these and let me know.

• sampling frequency

  Dear all!

  I hope everyone is doing well!

  Well! I am a student in first year of Labview and would like an expert on this VI opinion I did. I'm learning by doing! This VI is to see the effects of sampling at different frequency. I have a LABVIEW 8.5 and uses an express VI to simulate signal, two assistant screws DAQ etc. I also play a little with the number of samples and sampling frequency.

  Come to the points that I did not understand!

  1. the present VI crashes and I am not able to understand what is the reason?

  2. the time scale itself changes as I raise the number of samples, even if I keep the same frequency sampling.

  3. in addition, the peak frequency changes with the number of samples! Why?

  I hope to have your kind response!

  Thanks for your time!

  Tajim

  Hi Tajim,

  Sorry for the late reply. I made a few changes to your VI and it works very well.

  You can start with the choice of the same sample rate and the number of samples of the three waveforms. In this way, all will synchronize initially.

  After that, you can try to change the sampling rate and the number of samples for the waveforms. However, you should becarefull when setting very large number of samples. If you have a low sampling rate, say 100 Hz and a high number of samples, say 1000 samples it will take 10 sec to acquire all the samples. If the second DAQ assistant is running at the highest sampling at the same time, you will have an overflow of buffer of data acquisition and it may hang. Of course it is a means to avoid this by implementing different structures in LV, but for the purposes of this test, you should be ok if you just keep this in mind.

  Thank you!

• DAQmx task Read DAQmx with sampling frequency of 10 Hz produced much too much data

  I have a simple configuration with a strain of channel 4 OR-9237 amp holds a carrier of series C of WLS - 9163 (wired ethernet mode) - Details probably does not matter.

  I used MAX to create a DAQmx task associated with which all four gauges samples.  The calendar setting is "Scan Loads" is continuous sampling, 2 k buffer (read samples) and 10 Hz rate.  I guess that this task would generate 40 data values per second - 10 for each channel.

  I have a simple loop of reading using DAQmx Read.vi that works always (without any stimulation time).  Playback is set to read all available data and then pump it into a table.
  In the attached example, I also added a few words of debugging to stop the loop after N iterations.

  As the loop is programmed with a 0.2 second period, I expect each pass of the loop to read about 8 samples or 2 samples per sensor.  Instead, I get hundreds each passage.  It's like reading has substituted the sampling frequency specified in the task of the unit.  I absolutely need data to be material to the rhythm.

  Where have I lost?

  Thanks Adnan,

  I changed your example I selected 'Strain gage' entry analog and then lowered the minimum and maximum thresholds to +-1-2.  What happens is that each other in the loop, I 2048 samples or zero samples.  The display flashes a whole line and then it clears any other past.

  In response to your second post, I understand that the loop cannot run quite right that I select.  I think that, but at a sampling frequency of 10 Hz, I have to sleep on the software side for nearly a minute before I built 2 K samples.

  I played with the frequency of sampling, assigning to various values from 0.1 to 10000Hz.  The behavior is the same until I approach the high rates where available samples remains to 2048-4096 sometimes, the display becomes continuous.

  Ahhh, Darn.  Yet another search was this link that points to the root of my confusion.  The 9237 can taste arbitrary rates using its internal clock.  Duoh!  I wish that the pilots are smart enough to warn you if there is a discrepancy between the selected sampling rate and capabilities of the device

• Sampling frequency of HAVE is incorrect for simulated ENET-9213, WLS-9213, and USB-9213

  Hello

  ENET-9213, WLS-9213 simulation and devices USB-9213, I'm able to correctly get the sampling frequency of I = 1351 samples/s using DAQmxGetDevAIMaxSingleChanRate, which is incidentally on the value of spec'ed of 1200 s/s.

  However, when I create a task and add a voltage channel and then HAVE the sampling frequency of the task of query, I get a sampling rate of only 9 samples/s. I tried the same code with other devices and I get the sampling frequency corresponding to the device data sheet, it seems THST this problem is limited to 9213 devices.

  Why sampling returned by the task using DAQmxGetSampClkMaxRate rate returns than 9 s/s.

  And why the rate of conversion of DAQmxGetAIConvRate only 18 s/s.

  I enclose the test code which may be used to reproduce this problem.

  Kind regards

  whemdan

  The MathWorks

  Hello

  When I tried this with a USB-9213 simulation, I used the Sample clock Max Rate, as well as the Rate.vi of AIConvert:Max property node.  I could see that for 1 channel, I could spend up to 675.67/s, and I couldn't for 16-channel get79.49S/s (which total is equal to 1271 S/s, which is in the specifications).  The multichannel and single channel, I could get an AIConvert Max Rate of 1351.35.

  Something that could happen is that you do not explicitly set this device runs in mode high speed.  You'll want to set the property Get/Set/rest AI_ADCTimingMode channel at high speed, and you should see much better results in this way.

  Something else to note - I use DAQmx 9.0

• WLS-9163 and 9211, sampling frequency of evil?

  Hello!

  I have a WLS-9163 with 9211 mounted module. I have connected a single thermocouple type K to the analog input 0.
  I can connect and perform measures wireless. However, I can make only 7 s/s without error message.
  I get the following error message when I try to taste 14 s/s in the configuration of WLS-9163.

  Error-200081 occurred to the DAQ Assistant
  Possible reasons:
  Sampling frequency is greater than the maximum sampling frequency for the number of specified channels.
  Reduce the sampling frequency or the number of channels. The increase in the conversion rate or reduce the period of the sample can also mitigate the problem, if you define one of them.
  Number of channels: 2
  Sampling rate: 14.000004
  Maximum sampling frequency: 7.142857
  Channel name: _WLS-14049AF-2/_cjtemp

  When I use the 9211 in a cDAQ-9172 configuration I can acquire up to 14 s/s of a single channel with no problems at all.

  Somehow he thinks that I chose to take measures to channels, that is not the case.

  I use Labview 8.5.1 with hardware drivers of 2009-10 with Windows XP SP3.

  Is this something you've heard before?

  Best regards
  Mattias

  Mattias salvation,

  Your task is also reading the CYC on the unit once for example, if you are done reading of two channels.  Reading of the CCM (it's the .../_cjtemp in the error message) is required to return a value of temperature measured from a thermocouple.

  Kind regards

  Kyle

• How to acquire with NiScope at different sampling frequencies and lengths Records?

  I need to acquire the data of 2 channels of the NI PXI-5114 map two different sampling frequencies high, at the same time. Also, I put 2 different record length. Is this possible?

  I understand that 'Vertical' settings can be configured for individual chains because the function 'Vertical niScope Configure' has 'channels of entry with which we can assign the desired channel. But for horizontal settings such as "min sampling rate" and the record min length, I could not find such an option to specify the channel. Would it not common to both channels?

  I hope that the device is capable of simultaneous sampling and therefore channels can be configured individually to different sampling rate.

  Hi AJ_CS,

  Why do you have to be distinct from sampling frequencies on channels separated from the digitizer even?  What different sampling rate do you want?

  But for horizontal settings such as "min sampling rate" and the record min length, I could not find such an option to specify the channel. Would it not common to both channels?

  You do not have an option to configure the settings of hoirizontal on a channel by channel basis because this concept does not exist in the traditional sense of the use of a scope.  Compatible with the concept of IVI, an oscilloscope traditional benchtop will have only a button or a set of buttons for setting the parameters of synchronization of the unit.  There is therefore no horizontal configuration to separate channels on the scanners NOR.

  I hope that the device is capable of simultaneous sampling and therefore channels can be configured individually to different sampling rate.

  Similar to a traditional benchtop oscilloscpe, the device is capable of simultaneous sampling.  But as mentioned above, the channels can not be configured for different sampling frequencies high.

  However, you can ignore data that you think is not relevant.  For example, if you assign 100MS/s CH0 and CH1 to 50 MS/s, then you throw all other samples.

  Alternatively, you can use separate scanners (a channel on each digitizer) and configure them to taste at different rates.  You can set frequencies of sampling on scanners NOR separated and even synchronize them with TClk.

  -Andrew

• How to acquire the signal to very high sampling frequency

  Hello world

  My name is Luke Ho. I am trying to acquire the signal with Labview (Sthelescope). The signal comes from sensor acoustics, then filters and amplifiers to adapt to ADC rank (0 - 5V). Thus, the maximum frequency of the signal is 40 kHz.

  According to the Nyquist theorem, I sampled at least 80 Khz signal.

  Is there a sampling frequency devices like that? or y at - it another way of better? I used the Arduino before, but it was about 10 kHz.

  I need your advice.
  Thank you all and have a nice day.

  holucbme wrote:

  Thanks for your recommendation

  But is it possible without USB Data Acquisition, it is quite expensive for me.

  This is the cheapest option to NEITHER. I tried to look for options to other companies, but more I found in the same price range, or not answering is not your condition of sample rate.

• AI PXI-6255 sampling frequency

  Hello

  We use a simulated PXI-6255 device and with the LabVIEW example, apparently, that we can achieve a sampling rate of 20 kHz to 50 channels without warnings or errors.

  The spec is the number max of 20 kHz channels must be approximately 38 channels (750000 / 20000).

  
  
  
  
  
  
  
  

  1.25 single channel of MECH. / s multi-channel of 750 ksps / s (aggregation)

  The simulation cannot not representative of the unit or the real PXI-6255 does support a higher rate that we expect?

  Hi jharris66,

  It is not a limitation of the driver to the sampling frequency, so a simulated device reports any error in this case.

  In this example, I think that the limit of 750 kHz comes to the multiplexer.  I don't expect to see the same error messages with the real device, but your accuracy will probably not to spec because not allowing enough time settling between the channels.

  The limit of 1.25 MHz is the maximum ADC sampling frequency.  You can probably exceed this number somewhat, but once you go too far beyond 1.25 MHz you will eventually receive a synchronization from the hardware error when the ADC cannot follow.

  Thus, the specification is still technically 750 kHz for channels multiple acquisitions.  You can probably run at a higher rate than this (even on real hardware), but I wouldn't say that it is supported.

  Best regards