Data acquisition mx with two Async. Events

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• Configuration of the two of the same model data acquisition

  Hello, community of NOR.

  I'm an intern in mechanical engineering with experience in base with LabVIEW.

  I would like to speak to OR directly on this issue, but I don't have a service contract and my company wants me to understand this before you buy LabVIEW.

  I hope that someone has experience about my question, and I would be very happy to help.

  We intend on purchasing an expansion card for our acquisition of data (OMB-USB-2416), but unfortunately it is offline and no custom would not happen in time.

  So, I need LabVIEW to read voltage HAVE two of the same model of data acquisition, which would amount to about 30 channels.

  Is this possible with LabVIEW?

  Thank you.

  Measurement computing says that the "physical channels" dropdown list is automatically filled in once both devices are configured.

• Input module of data acquisition can be read by two or more LabVIEW vi at the same time % 3F

  I use the DAQ palette in LabVIEW to read the virtual channels of the input data acquisition module. I've done several VI who read many entries of three modules of simulations. The problem appears when I run two or more VI´s reading entries from the same virtual module (for example. first.VI module 1 input ai0 and second.VI bed ai0 entry module 1 bed), when this happens the next errors are shown:

  Error-50103

  Platform AND Services: The specified resource is reserved. The operation could not be performed as indicated.

  and

  Error-200022

  Resource requested by this task has already been reserved by another task.

  It's worrying because I want to get the DAQ chassis and some modules, but if this problem is present with physical equipment my application may be unnecessary. This means that entry module only can be read once at the time?

  I m using global variables in each Subvi to share data with main VI, however, I found the solution in a different way... I just changed to single channel and dbl sample playback mode, so I Don t need to clean up the task of reading in my subVI´s, the zeros isn´t problem here, and the six subVI´s work at the same time!

  Thanks for the tips!

• Sample clock dependence with small signals data acquisition

  Hi all

  I use a NOR-9205 on a NOR-cDAQ-9184 and noticing some interesting dependencies of waveform on my sampling rate selected. It seems that small changes in the sample clock frequency have a significant impact on the measured waveform.

  Quick background, I am in a position a signal with a ripple of mV ~ 10 with V 1.6 bias. I'm not interested in DC, only the AC signal but the NOR-9205 has only DC coupling. The application is a circuit where I expect simulations noise past the circuit must be greater than the higher noise frequencies. In the waveforms attached the background plot is the applied signal, and the top graph is the signal arising after that the signal was mostly annihilated. The two waveforms are measured with the NOR-9205.

  I am aware that this measure is less than the precision of the NOR-9205, which has a maximum precision of ~ 3 mV in his +/-5V range. However, if I can't at least on the basis of shape which is good enough for me. I'm also now pretty curious that data acquisition is actually to create this

  My best idea, is that it is a product of internal multiplexing of the 9205 with the DAC.

  The first plot shows the waveform at 20 000 Hz, which is what I expected:

  

  The second shows the waveform at 20 001 Hz, which seems to be modulated with a backup sawtooth:

  

  The waveform looks as expected for 20 000, 20003, 20004, 20005, 20008, 20009, 20010 and Hz 20011. The waveform looks like modulated to 20001, 20002, 20006 and Hz 20007.

  Ideally, I would like to understand this problem so that I can configure the measure in a stable way that I can count on the basic shape of the wave. Has anyone seen something similar?

  
  

• 2 channels of AI on a data acquisition with the range of different sensitivity

  This vi is based on the 'new project' state machine on the home screen at the start of LV.

  A time loop is parallel to the main loop of the state machine, shown in the picture.

  It works continuously until you press the Exit button.

  The problem seems to be in start this... > read >... stop start > read >... stop along the error line.

  The reason for this clumsy arrangement power is measured voltages are in two lines of different sensitivity.

  The shunt voltage is small and needs-. 2 to the range of V.2. The load voltage is greater and 09:50 V range is good.

  In the initializing state, two separate vi 'create a channel' have been used to specify the range of voltage to the physical channel. The corresponding tasks are sent via via local variables.

  DAQmx errors happen randomly, sometimes the first iteration, sometimes the 50th.

  I tried to disable one or the other start > read > stop for the shunt voltage or load.

  I tried replacing them with the DAQ assistant.

  I tried various DAQmx vi: "wait" and "accomplishment of the tasks by resource cancel selected".

  But error-50103 "specify resource is reserved" keeps popping up.

  Is it possible to create two tasks on the device even when they are not used at the same time?

  The only reason is to measure in two voltage ranges.

  Win 7 Pro 64-bit

  2014 LV database

  Data acquisition equipment: USB-6210

  Thank you.

  This has been discussed many times. Do NOT use separate tasks. You can use different ranges for different channels with a single task. Just wire the task from one channel to another channel to create task.

  You also use local variables when they are certainly not needed.

• Real-time display at the high frequency of data acquisition with continuous recording

  Hi all

  I encountered a problem and you need help.

  I collect tensions and corresponding currents via a card PCI-6221. While acquiriing data, I would like to see the values on a XY graph, so that I can also check current vs only voltage/current / time. In addition, data should be recorded on the acquisition.

  First, I create hannels to analog input with the Virutal DAQmx channel create, then I set the sampling frequency and the mode and begin the tasks. The DAQmx.Read is placed in a while loop. Because of the high noise to signal, I want to average for example every 200 points of the current and acquired for this draw versus the average acquisition time or average voltage. The recording of the data should also appear in the while loop.

  The first thing, I thought, was to run in continuous Mode data acquisition and utilization for example 10 k s/s sampling frequency. The DAQmx.Read is set to 1 D Wfm N Chan N Samp (there are 4 channels in total) and the number of samples per channel for example is 1000 to avoid the errors/subscribe for more of the buffer. Each of these packages of 1000 samples should be separatet (I use Index Array at the moment). After gaining separate waveforms out of table 1 d of waveforms, I extracted the value of Y to get items of waveform. The error that results must then be treated to get average values.

  But how to get these averages without delaying my code?

  My idea/concern is this: I've read 1000 samples after about 0.1 s. These then are divded into single waveforms, time information are subtracted, a sort of loop to sprawl is used (I don't know how this exactly), the data are transferred to a XY Chart and saved to a .dat file. After all that's happened (I hope I understood correctly the flow of data within a while loop), the code in the while loop again then 1000 samples read and are processed.

  But if the treatment was too long the DAQmx.Read runs too late and cycle to cycle, reading buffer behind the generation of data on the card PCI-6221.

  This concern is reasonable? And how can I get around this? Does anyone know a way to average and save the data?

  I mean, the first thing that I would consider increasing the number of samples per channel, but this also increases the duration of the data processing.

  The other question is on the calendar. If I understand correctly, the timestamp is generated once when the task starts (with the DAQmxStartTask) and the time difference betweeen the datapoints is then computed by 1 divded by the sampling frequency. However, if the treatment takes considerable time, how can I make sure, that this error does not accumulate?

  I'm sorry for the long plain text!

  You can find my attached example-vi(only to show roughly what I was thinking, I know there are two averaging-functions and the rate are not correctly set now).

  Best wishes and thank you in advance,

  MR. KSE

  PS: I should add: imagine the acquisition of data running on a really old and slow PC, for example a Pentium III.

  PPS: I do not know why, but I can't reach my vi...

  
  

• My computer with two hard drives and 2 starting systems has the car crash in the solid state. When I got the new drive and tried to restore from time capsule, I lost some data. How can I see what backups are on the time capsule? My laptop is also backed u

  My computer with two hard drives and 2 starting systems has the car crash in the solid state. When I got the new drive and tried to restore from time capsule, I lost some data. How can I see what backups are on the time capsule? My laptop is also saved to the time capsule. Everything is in 'Data' when I look through the Airport utility. I think that the information that I've lost are still there since I was a Capsule 3 to.

  Time Machine backup to a sparsebundle.

  The sparsebundle will use the share name of computer. So, it should be obvious who is your Macbook and that is your Macpro.

  Open the sparsebundle in Finder and keep open the subfolders until you get to the backup of each separate hard drive...

  You has of course set the exclusion in Time Machine?

  By default, Time Machine will exclude your second drive unless you have included it. Did you?

  Once you get to this level during the backup, you can do a full restore manually whenever you want.

• Data acquisition tool NOR-DAQmx with Matlab R2012a

  Hello

  I'm trying to control NI USB-6211 of Matlab 2012 using NOR-DAQmx Data Acquisition tool:

  http://zone.NI.com/DevZone/CDA/tut/p/ID/3005

  I'm working on win7 64 bit. And I see the device AND Measurement & Automation Explorer.

  The tool does not work: DAQ_Demo_Browser do nothing. And I got the error "unexpected or unbalanced parenthesis or support" of AcqNUpdates_nonUI.m

  What is the problem?

  Thank you and best regards,

  Arthur Shulkin

  Hi Arthur,.

  Tools OR DAQmx for Acquisition of data with the Software Inc. MATLAB® from The Mathworks, supports up to the 2008 version of the MATLAB® software.  In order to use our products DAQ Multifunction with MATLAB® software, you could get back to 2008 or earlier, or instead use the Data Acquisition Toolbox provided by The Mathworks, Inc.

  Another option would be to import your ".m" files in a node MathScript in LabVIEW and use the functions of NOR-DAQmx everything in the LabVIEW development environment.  For more information on the Module LabVIEW MathScript, you can consult the information available on this link:

  Inside of the LabVIEW MathScript RT Module

  MATLAB® is a registered trademark of The MathWorks, Inc.

  Katie

• DAQmx data acquisition with persistent error of nyquist

  Hi, I created a multi channel data acquisition vi (accelerometer 2 and 1 sound pressure) using models for producer.   The vi is attached. Thanks to labview 2011.  I get the error of nyquist (2 enclosed) when you make a bandpass filter between 50 to 5000Hz.  This happens despite having put my sampling rate to 22050Hz.  When I checked the output of wave I noticed that the signal has a dt 1 s.  The text output to check the result.  I could not understand how this is so since I had set the sample rate to 22 k Hz.  Any help will be much appreciated.  Thank you.

  I would do something like that.  You must calculate the dt of the set (with the recipricol) sampling frequency and use to initialize the shift registers.  This way you only need to change 1 constant if you need to change your sample rate.

  

• How to find the time between two channels of entry in the data acquisition card or pci 6036

  Hello

  I read a lot-related posts on the simultaneous measurement of two input voltage of similar channels in map data acquisition. I know that the best material is "simultaneous measurments of the Series DAQ cards" but I only pci data acquisition card 6036 and I try to understand what is the time between the reading of the two channels . This period is always constant? (must it rely on a voltage (amplitude, frequency, waveform..). I send the sine wave (s) to the two channels and read the values of V, if they read the same value, the difference should always be zero but I get-0,002 to 0.002 Volt difference (I must find a way to convert it in time). A screenshot of my VI is attached. I wonder how I can accurately measure the time delay between the channel.

  I am open to any suggestion, my final goal to read exactly two channels at the same time ((ou connaître le délai exact donc je peux correspondre les données correspondantes étant donné le temps de retard))

  Hi spinup,

  better you should post your question in the forum of LabVIEW, LabWindows/CVI is used

  Good luck.

• do you need a power supply to the current entry with data acquisition or 9265

  Hello I just receive the NI 9265 Daq for research in my lab. I'm trying to present entry and display it on an oscilloscope. I don't get anything. I did some research on the internet, so my question is do you need a power supply to the current entry with data acquisition or 9265?

  Read the data sheet.  Clearly on the first page is a sentence which reads "the NI 9265 requires 9 V to 36 V external power.

• Portable data acquisition support ICP (IEPE) with external excitation source

  I work towards the acquisition of a force sensor data Peizoelectric (ICP) with 0 - 5v output and his own excitement of current constant.

  Please suggest materials DAQ recommended for these sensors. (We usually use PCI (6229) or the DAQ hardware (9215) compact for static load cells.)

  In addition, the LV point of view, is the process to acquire HAVE preamplificatrices such different force ICP sensor of the static load with 0 - 5v output cell?

  your thoughts?

  
  

• synchronize two loops for written tdms data acquisitions

  Hello

  I have two loops of different data acquisition. A slow acquisition of CAN (10 s/s) and an analog acquisition faster (30 samples taken at a frequency of 300 Hz), I need to synchronize these data for tdms writes for later analysis in DIAdem.

  My example and the result in the DIAdem channel list is attached.

  Thanks in advance!

  Magnus

  Magnus,

  for a professional solution, you do not want to synchronize the devices on a hardware level. Since the material CAN work differently to 'traditional' DAQ devices, there are important things to take care of.

  Please look in the viewfinder to LV example for the word "CAN". For example, you can choose the example 'several cards CAN and DAQmx map Wfm Input'.

  Norbert

• Measurement of low-cost input analog (4-20mA) with data acquisition

  Hello

  I would like to have a very low cost measurement system loop which I can plug in my laptop current:

  I have a load, which is connected to a circuit of air conditioning/signal booster, which output a 4-20mA. I want to measure this current loop signal.

  An idea for the lowest cost system? I think that the most NOR DAQ are too expensive and too exaggerated.

  I have LabVIEW.

  Use of remote sensing current low-value resistance, then measure the fall of voltage through it with the help of an acquisition of data 6008/6009?  They have about $150.

  You will probably need to amplify current-sense with a MAX4372 or similar resistance to achieve a result that allows you to use a reasonable scale on data acquisition.  I measure the current through our products in almost all of our equipment to test in this way.  The size of the resistance of meaning as a result.  The 6008 is accurate enough, but it is not the fastest nor well presented.  But starting at $ 150, they are hard to beat.

• How to create a new virtual machine with two warehouses of data through new-vm?

  Hi guys,.

  Can you please help or direct me to the right format? I'm new with vsphere powercli.

  How to create a virtual machine with two other data store by using the new-vm?

  $datastore1 = get-datastore. WHERE-object {$_.} Name - eq "lun1"}

  $datastore2 = get-datastore. WHERE-object {$_.} Name - eq "lun2"}

  new-vm-name vmtest01 - VMHost ESXserver - datastore $datastore1 diskmb - 8192 $datastore2 diskmb - 8192 - memorymb 4096 - numcpu 2 - ID winNetStandardGuest

  I got this error when I run vsphere powercli. I appreciate if you can help. Thank you

  New-VM: cannot bind parameter 'DiskMB '. Cannot convert the 'lun2"val

  EU to type 'VMware.VimAutomation.ViCore.Impl.V1.DatastoreManagement.DatastoreIm '.

  PL"type"System.Int64 ".

  At line: 1 char: 85

  + new-vm-name vmtest01 - VMHost ESXserver - $datastore1 data store

  diskmb - < < < < 8192, $datastore2 - diskmb 8192

  + CategoryInfo: InvalidArgument: ( , ParameterBindingE)

  Xception

  + FullyQualifiedErrorId: CannotConvertArgumentNoMessage, VMware.VimAutomat

  ion.ViCore.Cmdlets.Commands.NewVM

  Bryan

  The New-VM cmdlet takes a single value of the parameter - data store and all of the virtual disks will be located on this data store.

  If I understand your request, you create a virtual machine with 2 virtual disks, each on a different data store.

  You can use the cmdlet New - hard drive for it.

  $datastore1 = get-datastore | where-object {$_.Name -eq "lun1"}
  $datastore2 = get-datastore | where-object {$_.Name -eq "lun2"}
  
  $vm = new-vm -name vmtest01 -VMHost ESXserver -datastore $datastore1 -diskmb 8192 -memorymb 4096 -numcpu 2 -GuestId winNetStandardGuest
  new-harddisk -vm $vm -datastore $datastore2 CapacityKB (8192 * 1KB)
  

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