6608 period or frequency limit of sampling frequency

Similar Questions

• Is it possible to read my frequency more frequently?

  Hello

  I was hoping I'd be able to read a frequency of 50 Hz (period time = 20ms) with three samples if my program had a cycle of 60ms (or at least two). Unfortunately, I can only recover a sample during this period.

  I built a *.vi to experiment a little with this. He considers the time of a while loop a loop and allows the user to change the number of samples, timeout, etc.. As you might suspect I'm a beginner, and I hope that there is a simple way to solve what I'm missing.

  Is it possible for me to acquire/closer more samples of the frequency to 60ms entry? Do I have to use solutions in time real (unavailible for me at the moment)?

  Any help is appreciated!

  Will be

  Hi again

  I had not included the (implicit) schedule Vi and this caused the problem.

• Frequency of signal and pulse duration varying as to reduce the duty cycle

  To sum up my problem, I am creating a period and the controlled voltage pulse sequence, but as I decrease my cyclical report, the distance between each pulse begins to become irregular. More precisely:

  I want to have three pulses, each a positive amplitude specified, long, with 23 ms between each 80 microseconds. After these three impulses, I would have a negative pulse of 3 * than amplitude, followed again by Ms. 23 this cycle must be repeated 260 times.

  I tried first of all to create the positive impulses to help simulate Signal VI, assigning a square wave with a frequency of 43.327556, an offset of 0.5 and the amplitude of 0.5. And the operating cycle as the default value of 50%, the signal seems to be normal (constant frequency and the duration of each pulse is equal;) "I'm in a position with an oscilloscope).  However, when you set the duty cycle for. 3466%, the time between each pulse varies and some legumes are longer than others. I wrote the data able to file directly from fake Signal VI to ensure that he was not only a problem of scope, but it seemed that writing to a file of measure has not sample enough points for me to accurately measure. Even decrease the market barely 10% factor, I see the question arise already.

  So my question is, I'm doing something wrong here? It is a kind offset of Labview to try to perform a duty cycle that small? And are there any alternatives to the way I have this set up? I thought I would try to use a train of pulses instead, but I'm not very familiar with this and I know, you can't control the amplitude of the pulses.

  Any help is appreciated! Thank you very much.

  My guess is that you are limited by the sample rate. If the difference between the two signals time is less than the sampling period (1 frequency / sampling), you will not be able to generate the signals you want.

  Please tell us the sampling rate, you use and the settings that work and those that do not. If your data file is not too big, please post so that we can see some data. Post your VI can help too. Check the default settings before you save the VI.

  Lynn

• integration of sampling time 6351 vs rate

  I would like to know how the X-series Renault 6351 sample and other. More precisely, given a sampling rate of v and a p sampling period, the integration of each sample time must be less than p. My question is, during the sampling period, what actually happens? It integrates into all of the p? Y at - there a break-in? Is the integration time same p? Are there settings to affect how data acquisition uses the sampling period?

  Basically, what I'm looking for is a complete description of what happens during the p, something like "p/3 running, integration time of 2 p/3.

  So, there are two relevant 'rate' at the time of sampling on a MULTIPLEXED Board like the 6351 OR.  There is the "sampling rate" which is the rate to which we take a sample for each channel, and then there's the 'conversion rate' which is the rate to which each channel is connected to the multiplexer in order to take a sample.  I tried to show below
  :

  Whenever a sample is to be taken, each channel must be connected to the ADC in turn.  Clock convert determines how fast it happens.

  The conversion rate depends on the sampling frequency.  If you choose a sampling frequency that is slow, we wait 10uS between convert each channel to allow more break-in.  If the rate is too fast for waiting 10uS between each layer, we convert as fast as necessary to reach you sampling rates.  At the maximum rate, the jury through each channel as quickly as possible in order to continue.

  During the period of conversion, we do a number of things.  Pass us the multiplexer to the channel, wait for a short time to resolve (this time it's what varies according to the sampling frequency), then we perform the conversion with the ADC (this is what you call 'integration time').  Time and Astro conversion are not user controlled; only the running varies according to your sampling rate and convert clock frequency settings.

  It is not a forumla that I can give you for each of these pieces of how long takes.  The best you can do is read the property of DAQmx Timing "I convert rate.  This will tell you the total rate of switching, settling and conversion.

  What do you need to know the time of integration for?

• Query on sample no. and the rate of NI9233

  I use NI9233 to acquire signals. Given that the node "DAQ assistant" that only entries of no.. samples and the sampling frequency. I thought that the sampling period is equal to n. samples/sample rates but couldn't always get the correct acquisition time. So, what is the quantitative correlation of no.. samples and the sampling frequency? How would I calculate the acquisition time once I put these two parameters?

  Thank you very much.

  The NI 9233 has a limited number of sampling frequencies discreet as described in the specifications under 'Debits '.  If your chosen sample rate is not supported by the module, DAQmx will force second.  For example, a sample rate of 48 kHz will be forced to 50 kHz.

• Duration of the individual sample - OR-6220 and NOR-6723

  Hello

  We are acquiring data through NOR-6220 and NOR-6723 Renault in our laboratory. The data acquisition process through Data Acquisition Toolbox of Matlab, where we put the sampling rate of the analog inputs to 10 kHz - or 0.1 sec per sample. Now, we wonder what is the time of the sampling process, i.e. the period during which an individual sample. Is there an average process for the duration of the sample (0.1 s), or during a window much shorter? In the latter case, how would know us the exact duration, and it would be possible to control it?

  In our case, we see resistance jumps in our system. Even if we get a range of resistances, we suspect that these jumps can actually be between two distinct levels; It is possible that the process of averaging during the sampling results in obtaining intermediate values between these resistances. Have a shorter window of sampling would be useful in addition to interpreting the results.

  It seems that this could be a trivial question, or who might be a Matlab thing rather than a thing of the card. Bear with us in these cases; We have made an effort to research on the problems on the forums and elsewhere . Thank you!

  There is a sample circuit and hold on the device.  The clock to convert marks the beginning of the sample interval, while the complete signal of cale HAVE mark the end.

  I don't know if the waiting time is nowhere specified, but you should be able to measure like this (example LabVIEW... I don't have MATLAB or the Data Acquisition Toolbox unfortunately):

  

  On my PCIe-6351, I get a waiting time between 440 and 450 ns.  The 6220 can be different, but I hope that gives you an estimate.  This setting is not adjustable.

  Having said all that I don't think it's relevant to your question.  If your input signal varies between different levels and you want to try that once it has established a new value, you must ensure that the task of IT is synchronized to what generates the signal.

  Best regards

• Can I change the time sampling real Graphics Performance

  I am preparing a demonstration and want to display the allocation of resources in real time using vSphere performance dashboards.  Unfortunately, the default sampling rate and an average of periods are not optimal for display assignments for resources with our demonstration.  Can someone tell me if there is an easy way to change these default values?

  The sampling rate for the graphics in real time is 20 seconds, which is probably OK, but I WOULD change for 10 seconds.  However, the main issue of concern is the number of samples in which this average is calculated.  This value seems to be very high (I think I saw 300 in a document).  Because this number is very high, the changes I make say every minute (for demonstration purposes), allocation bands don't really show up very well in vSphere performance dashboards.  For example:

  If my host has had 10 GB memory active during the last 5 minutes and my demo releases suddenly a very large part of this memory, the performance table the sudden deallocation with the last word on average 10 minutes of data and shows a gradual decline in the allocation of memory.

  This behavior is probably what is desired in a system of monitoring, BUT for my demonstration, I want to show a more realistic view of the allocation of resources using vSphere performance dashboards.  This could be accomplished if periods of rate, for a sample mean are configurable.

  Any help is greatly appreciated.

  On the other hand, I think it's that they do not change settings realtim. It's good for my purpose

  I do not know the slow answer due to the memory alloc/dealloc.

  BTW if you think the answer above resolved your problem, you might mark it as response.

• passage on zero power

  Hello

  I'm usign zero crossing.vi to measure frequency, and 1/2 (RMS)

  In addition, I need a release supplement that provides a logical output for each passage of zero.

  Maybe it's pretty easy, but I'm not good in labview.

  waiting for your help.

  Thank you.

  The output of zero crossing points by zero Crossing.vi are passing zero as the samples index position in the block of input signals. You can convert the index zero crossing zero-hour crossing by multiplying the dt of the wave. Then you can generate the digital 1/0 output based on the time of zero and calculate the number of crossings per second.

  The frequency is calculated according to the points of passage of zero because the period (1/frequency) signal sinusoidal can be determined from both zero time of crossings.

• Modbus reading on request

  Is there a way to read only a modbus on request? I want to be able to click a button 'Get Data of the controller.

  Also related, I just want it write on command. I currently have a trigger/relay for writing data, but I can't tell if modbus is always send the "write" command (using the previous value of the line) or not.

  I'm reading through the modbus test data. It seems that additional orders would limit the sampling frequency, leading to lost data. If I read that data registers, the data have no recurrence. With other commands, I get up to 10 blocks of the same value.

  Thank you.

  You take the input module in a relay with option of data block.  Only when you raise the output of the command, you will be allowing the flow of the module.

  This average thagt unless you trigger the relay, the module will not process and ask for value

• data acquisition won't taste at the specified rate

  Material: C - DAQ 9178, AI 9239, inside a servo and an encoder potentiometer module

  Setup: I use the 9239 to measure the angular position of my servo and encoder of trees by streaming came pressure pot of the servo and my encoder. I put the sampling frequency on the DAQmx - Schedule VI to 100 Hz.

  Problem: I don't think that my DAQ is sampling data at 100 Hz because my VI registers more than 10 000 data points for a 10 second test. In addition, every time I have save my data in a text file, the vector of time my test data resets after a number of iterations.

  To debug, I tried the following configuration:

  I've defined the sampling frequency of 100 Hz (or is that s/s?), the samples per channel (size of buffer for continuous mode) at 2000 samples, number of samples per channel up to 10 and loop milliseconds timer on my VI at 10 m accordingly, data acquisition would send 100 samples per second (or 1 sample every 10 ms) on my PC buffer (which could store 20 X that amount). Then LabVIEW would read up to 10 samples per loop iteration (which is itself ~ 100 Hz) and work with these 10 samples inside the loop. However, since the loop is operating close to the sampling frequency of data acquisition, then LV should only work with 1 sample each iteration of the loop (100 Hz / 100 Hz)-not the 10-sample-max that I specified.

  However, I stumbled on "error-200279: the application is not able to cope with the acquisition of material" when I ran the program. Why?

  My code and materials should be easily able to cope with data acquisition - at least the way I put it in place

  This whole situation wondered my fundamental understanding of data acquisition timing, so I would really appreciate an explanation of exactly how to deliver DAQmx uses data synchronization, why my DAQ sample at 100 Hz, and how can I fix the calendar specified by the user.

  Thank you!

  aeroAggie wrote:

  The C - DAQ 9178 there some minimum sampling rate I will not meet?

  It's actually the 9239 that limit your sampling rate.  Read the data sheeton page 5 there's available data rates.  In short, your data rate allowed is 50kS/s / n, where is goes from 1 to 31.  50 k/31 gives you 1.6kS / s.  So, it's the minimum sampling frequency that can be used.

• Disk Cleanup stalling on temporary files for more than 3 hours and eat memory!

  So, whenever I checked my C drive I get different numbers on how much space is left. I deleted 45 GB (sent to remove trash and Perm.) data I didn't need and I always as much as before, if not less. I then tried to run the disk cleanup for that drive and it keeps blocking on "files temporary scanning", which since more than 3 h and no other programs other than windows base and Trend Micro are running and system keeps using more memory. EX: below

  RAM used: 3.1GB/4.0GB

  cache in the processor (i5): 4.2mb/7.7mb

  CPU usage has been the use of 80-90% during this period

  Frequency Max CPU is 109%

  This all started a few days after a windows update.

  It is using 25% CPU usage... as to what it is I don't have any idea. I've used it before and it scanned in less than 45 min.

  Anyone have any suggestions to correct the program that is not responding?

  System information:

  Manufacturer: AUSTeK computer Inc..

  Model: ASUS U52F Notebook series

  Processor: Intel (r) Core i5 CPU M 460 @ 2.53 GHz

  Installed memory (RAM): 4.00 GB

  System type: 64-bit Operating System

  OS: Windows 7 (updated)

  Hello

  This free program allows you to see what is taking place.

  http://www.Jam-software.com/treesize_free/

  Also check how much space system restore uses:

  http://Windows.Microsoft.com/en-us/Windows7/how-much-disk-space-does-System-Restore-require

  _____________________________________

  You can clean your hard drive using these two methods.

  "Delete files using Disk Cleanup" (use CCleaner for now instead of Disk Cleanup)

  http://Windows.Microsoft.com/en-us/Windows/delete-files-using-disk-cleanup#delete-files-using-disk-cleanup=Windows-7

  Using the free CCleaner program:

  http://www.Piriform.com/CCleaner

  In NO case use the registry cleaning Option in CCleaner

  _____________________________________

  Download, install, update and scan your system with the free version of Malwarebytes AntiMalware:

  http://www.Malwarebytes.org/products/malwarebytes_free

  See you soon.

• Connect by level using the count of the records collection

  Hello:
  
  PROBLEM:
  ...
  ), (select rownum number months of double connect by level < = Cnt)
  
  Causes not valid ORA-00904 identifier. Why can I not use "Cnt" of my main as request by using a constant in the works?
  
  The value of count is determined for each date range in the section, I return the records that I need?
  
  Thank you, Sidney
  
  BACKGROUND:
  I have to be able to display a list of tax returns to my users and the status of these statements. There's no physical feedback so it is necessary to create data dynamically records using appropriate selection. It's not hard and I thought that would be enough to use a connection by level to give me the date, statements of information so that I can calculate and display the individual. However oracle gives me an ORA-00904 when I try to send the "Cnt" value to connect by level. Everything works fine when I provided a constant instead of "CNT". The "CNT" value is determined by a complex process that calculates start and end for several types of return dates, etc as well as the number of periods and frequency of production. The data must be generated dynamically using a master record, which then gives the history of coding in which my collection of basic records is selected. Here is the result of this process:
  
  TaxpayerNo, TaxClass TaxCode, FilingFequency, StartDate, StopDate, Cnt, frequency
  
  10 S 1 M 12-18 6/1/2007-11/30/2008
  10 S 2 M 12 10 30/11/2008-9/30/2009
  10 S, 2 Q 4 3 11/30/2010-8/18/2011
  L 10 8 6/1/2007 9/30/2009 3 1
  L 10 8 11/30/1 / 2010 8/18/2011 1
  
  According to the results, I have needs a record for each every month, quarter, etc. ie:
  
  10 S 1 M 6/1/2007 11/30/2008 18 12 6/1/2007
  10 S 1 M 6/1/2007 11/30/2008 18 12 7/1/2007
  10 S 1 M 6/1/2007 11/30/2008 18 12 8/1/2007
  10 S 1 M 6/1/2007 11/30/2008 18 12 9/1/2007
  ...
  10 S 2 M 30/11/2008-9/30/2009 10 12 11/30/2008
  10 S 2 M 30/11/2008-9/30/2009 10 12 12/30/2008
  ...
  etc.
  
  DOES NOT WORK
  Select y.*, MonthNo, Add_Months(StartDate,MonthNo*Frequency) in)
  Select x.*,
  (case when FilingFrequency = am' then Ceil (Months_Between (StopDate, StartDate)))
  When FilingFrequency = 'Q' then Ceil (Months_Between(StopDate,StartDate)/3)
  When FilingFrequency = 'A' Ceil (Months_Between(StopDate,StartDate)/12) then
  0 otherwise
  end) NTC,
  (case when FilingFrequency = am' then 1)
  When FilingFrequency = 'Q' then 3
  When FilingFrequency = 'A' then 12
  end) frequency
  de)
  ... a code complex to calculate values of start and stop dates required above...
  ) x
  ), (select rownum number months of double connect by level < = Cnt)
  ERROR MESSAGE
  The result is ORA-00904: "CNT": invalid identifier. I do not get an error if I use a constant:
  
  WORK WITH THE HELP OF A CONSTANT, BUT MUST HAVE THE VALUE OF THE ACTUAL CNT
  ... Same code for generating data...
  ), (select rownum number months of double connect by level < = 3)
  
  How can I get it works using the "CNT" value instead of a constant?

  A technique like this should solve your problem.

  TUBBY_TUBBZ?with data (col1, cnt) as
    2  (
    3    select 1, 3 from dual
    4      union all
    5    select 2, 2 from dual
    6  )
    7  select
    8    d.col1,
    9    t.column_value
   10  from
   11    data  d,
   12    table(cast(multiset(select level from dual connect by level <= d.cnt) as sys.OdciNumberList)) t;
  
                COL1       COLUMN_VALUE
  ------------------ ------------------
                   1                  1
                   1                  2
                   1                  3
                   2                  1
                   2                  2
  
  5 rows selected.
  
  Elapsed: 00:00:00.00
  TUBBY_TUBBZ?
  

  Contrary to what you have now, which is basically this

  TUBBY_TUBBZ?with data (col1, cnt) as
    2  (
    3    select 1, 3 from dual
    4      union all
    5    select 2, 2 from dual
    6  )
    7  select
    8    d.col1,
    9    level
   10  from
   11    data  d
   12  connect by level <= d.cnt;
  
                COL1              LEVEL
  ------------------ ------------------
                   1                  1
                   1                  2
                   1                  3
                   2                  2
                   1                  3
                   2                  1
                   1                  2
                   1                  3
                   2                  2
                   1                  3
  
  10 rows selected.
  
  Elapsed: 00:00:00.00
  TUBBY_TUBBZ?
  

• I have a new desktop computer w / McAfee installed LiveSafe Central

  Please tell me why/why not to keep this installed system or one other product would be better? It will always be free? I can't find this information in my documents.   Thank you

  McAfee LiveSafe Central won't be toll-free after the initial period.  It is a sample program, more than likely, with a free trial as a gift.  When it expires, he will ask for money to extend the trial into a paid version.  You are your own choice between buying an extension or go with another software antivirus of your choice.

• Statement on the date of a virtual machine has been created

  Is it possible to report on the date on which a virtual machine was created?  This info is stored anywhere with the virtual machine?  Otherwise, he'll find newspapers in VMware Server to say how many virtual machines have been created last year?

  Thank you

  The Get-VIEvent cmdlet gets its information from the database of vCenter. To be more precise in the VPX_EVENT table. You can only return in time with respect to the first record in this table. To retrieve this date, you can use the following code:

  $eventMgr = Get-View EventManager
  $filter = New-Object VMware.Vim.EventFilterSpec
  $eventCollector = Get-View ($eventMgr.CreateCollectorForEvents($filter))
  $eventCollector.RewindCollector | Out-Null
  $eventCollection = $eventCollector.ReadNextEvents(1)
  $eventCollection[0].createdTime
  $eventCollector.DestroyCollector()
  

  The downside to the use of the Get-VIEvent cmdlet is that you must specify the number of records to be returned (100 by default) with the - MaxSamples parameter, and all these records are retrieved from the database. If you find events and you don't have a period, you must provide enough samples to include yours, and it can last forever. The event table can grow very large. In my environment, there are 8 million + records in this table.

  For the search of the database of events, I prefer to use the SDK instead of the Get-VIEvent cmdlet. That way I can start research until my records are found, and I can use specific filters to retrieve only the records that are of interest. I also pick up only as many records of the database if necessary. You can search the crΘation from a virtual computer by using the code below:

  $vm = Get-VM "myVM"
  
  $eventNumber = 100
  $eventMgr = Get-View EventManager
  
  $filter = New-Object VMware.Vim.EventFilterSpec
  $filter.Entity = New-Object VMware.Vim.EventFilterSpecByEntity
  $filter.Entity.Entity = $vm.ExtensionData.MoRef
  $filter.EventTypeId = "vim.event.VmCreatedEvent","vim.event.VmClonedEvent","vim.event.VmDeployedEvent"
  
  $eventCollector = Get-View ($eventMgr.CreateCollectorForEvents($filter))
  $eventCollector.RewindCollector | Out-Null
  $eventCollection = $eventCollector.ReadNextEvents($eventNumber)
  $matches=@()
  While ($eventCollection) {
    $matches += $eventCollection
    $eventCollection = $eventCollector.ReadNextEvents($eventNumber)
  }
  $eventCollector.DestroyCollector()
  $matches
  

  See you soon,.

  Arnim

• New feature (filter on reports)

  I just noticed that there was a new feature added in the last patch of OATS v9.10, so that you can filter reports based on a range of time. This is extremely useful, especially if you want to 'ignore' no ramp-up/ramp-down period and just take a sample while the test runs at the desired level.
  
  However, it doesn't seem to be a similar filter for graphics. Anyone know if this is possible? If this isn't the case, I hope that the service can be extended to graphs in a later version?

  Hi Ian,

  Scope time custom graphics is already available. Once a graph is rendered, click on change-> select the axis (x or y). You can change the min and the interval of maximum time for a graph (if any) or any other unit.

  See you soon
  REDA