Value previous reading of measurement

Similar Questions

• How to read the measurements of the model eye?

  I'm new in LabView. I use an Agilent54855A to capture a model high-speed digital and want to read these measures of model of the eyes, eyes for example height, width & vice versa of the eyes. However, I couldn't find this VI in the palette.  I can read it on the screen, but do not know how to retrieve through LabView. What should I do?

  Steve,

  Thank you. There are commands to read the eye measures model. I'm changing the existing VI to add these new features and then I will check next week.

  Best regards

  KKNG

• usefulness of reading the measurement file express vi

  Hello

  I found reading file express vi measure in LV7.1 does not read from the beginning of the file when you run it the second time. Instead, it resume from where it left off last time. Usually, the user would read the entire file measure each time. So when you try to read the second time, it will show an error window saying that it has reached the end of the file (because he was reading the entire file first).

  I wonder how useful to resume from the last stopping point is? Is there a way to start over each time that the VI excute it?

  I'm sure that's how reading file measure works 90%. Whenever she is called in a single run of the application, it will start off the coast where it was stopped. You will need to work with the low level screw to get what you want to do.

  This Express VI works in a similar way the screws and the following functions:
  Open/create/replace file
  Read text file
  Read binary file
  Read the spreadsheet file
  File dialog box
  Scan to file

  And, you can always use the node to set the file Position to set the position at the beginning of the file.

• AF:inputComboboxListOfValues selected value indicates the previous value when read

  Hello
  
  I have a LOV as below.
  
  SELECT DISTINCT filter_prod_id, cis_cluster_config_hdr_dtl_vw WHERE cluster_type_id = prod_name: p_cluster_type_id
  AND type_criteria_id =: p_type_criteria_id order of prod_name
  
  Here prod_name is indicated in the attribute list and based on the selection, corresponding filter_prod_id is filled. I use af:inputComboboxListOfValues in the JSPX page. By default the the LOV is filled on the loading of the page. I have a valueChangeListener and AutoSubmit is set to true.
  
  Use case: tell the current selection in the drop-down list box is 'CHAIN '. Change the selection in the drop-down list of "3rd PARTY GIFT CARD" area. I have a productNodeSelectionChangeListener() method and here's the code.
  
  BindingContext bctx = BindingContext.getCurrent ();
  BindingContainer links = bctx.getCurrentBindingsEntry ();
  List JUCtrlListBinding = bindings.get ("ProdName") (JUCtrlListBinding);
  String prodName = (String) list.getAttributeValue ();
  System.out.println ("ProdName:" + prodName);
  FacesCtrlAttrsBinding list1 = bindings.get("FilterProdId") (FacesCtrlAttrsBinding);
  Number of filterProdId = (Number) list1.getAttributeValue ();
  System.out.println ("filterProdId:" + filterProdId);
  
  The code prints
  
  IN productNodeSelectionChangeListener CARD PART 3
  ProdName: STRING
  FilterProdId: 79
  
  Help, please.

  ValueChangeListener is _before shot phase UpdateModel.
  However, you can force the update of model the value change listener:

   public void your_VCL(ValueChangeEvent event)   {
          UIComponent c = event.getComponent();  
  
        //force update model phase for this component
        c.processUpdates(FacesContext.getCurrentInstance());
       // what happen when you try to get attribute value in this point ?
  
    }  
  

• Read file measure to XY Chart of waveform

  Something pretty simple that gives me a hell of a time right now.

  I have a .lvm here who was rescued from an acquisition of data and has a column of numbers from 0.0000 - 27.0000 to very small no. The next column is the amplitude of the signal at the point. Now this file LVM I'm starting a new vi and I want to read those values x and Y and get them on a waveform graph. Now, I tried hanging 'Reading a file measure' and tried to "Build the Table", but who do not want to connect on a chart. Rather the file directly on a chart causes two very different lines is displayed but is no where near what I'm looking for.

  Some tips on how to complete it?

  Tasty,.

  More often than otherwise, I find screw Express to be more trouble than they are worth. Here is an example of reading data tab delimited in a .txt and tracing the values of are against X a value on a chart. It will be useful.

  Andrew

• read from measure Makefile slow while loop

  Hello

  I'm using Labview for controlling a lower Member brace. What I did is to save in a spreadsheet, the values of two angles in a random walk. The control template is done well because I tested it by giving two sine waves with different frequencies and the system responds by following paths. The problems begin when instead of sine waves, I put the experimental values of the read angles and "the file of the measurement reading. I can't change the speed of the system by varying the time while loop. The speed is always the same.

  In the vi attached is possible to find this piece in the upper left corner of the while loop.

  I use windows 7, 2013 and cDaq-9178 labview.

  Thank you in advance for the answer.

  Best,

  Flavio

  
  

• Cannot read queue measurement - what is happening?

  Hi-

  I have problems reading data from a file of measures. 28 signals are merged and saved to a file text LVM. When this file is loaded into the program, all values appear as NaN. I looked at the properties of the File.VI of Measuement of reading and reading of the values, but there are other things mixed in there too - hour, day, things like that. Basically, I want to record a signal and to reproduce exactly later, the. Can I get help?

  Thanks in advance for any help.

  
  

• UTL_FILE get line previous reading of a file

  Hello
  
  I read a file with UTL_FILE
  
  I am writing a procedure that reads a file.
  Sometimes, I need to get back the previous line, is it possible to get it?
  
  I tried this but it does not work:
  ...
  fHandler UTL_FILE. TYPE_DE_FICHIER;
  fHandler2 UTL_FILE. TYPE_DE_FICHIER;
  ...
  1 < 2 while loop
  fHandler2: = fHandler;
  ...
  Chamois: = readbuffer (fHandler2); <-here I suppose that fHandler2 becomes different from fHandler but looks like I'm wrong and are always the same
  
  If (buff is false) then
  raise my_exception;
  end if;
  
  end loop;
  
  * Here fHandler must have the previous value of fHandler2 but are identical
  
  When my_exception then
  do something;
  end of procedure;
  
  
  
  
  
  Thank you

  A file descriptor is just a pointer to a memory area that contains details about the current state of the e/s access. To assign a file handle with the value of another it does not start from the beginning of the file again, but gives you just two pointers on the same thing.

  You can browse backwards in a file using the UTL_FILE. Procedure FSEEK, well I have have experienced some problems with this and generally easier to simply close and reopen the file.

  Also use external tables to read the file as a single VARCHAR2 lines and you can then access using SQL, as much as you like and that you specify the rownum to get the lines you want.

• Simultaneous digital writing and reading w. measurement interval

  Hi all

  For the last couple days, I've been trying my brain trying to get a program to run.

  I am trying to generate a camera digital 4 output bits then simulatanously count edges mounted on its LSB up to an arbitrary number set by the operator of the program, how the program should be a measure.

  I note, however, that, on a certain edge County number growing (~ 950 or almost), the program crashes. The problem persists even when I remove the function that reads the LSB, although, in this case, accidents occur to a much higher number. What could cause this? Is there a way I can work around this problem?

  Here is my code:

  arraySizeInBytes2 = 8
  
  bufferSize = 255
  
  ReDim readArray (arraySizeInBytes2)
  publicLifetime = 100' use this to control the duration of the task takes
  
  numSamplesToWrite = 10 * publicLifetime * numSample * 5
  
  numSamplesInArray = 5 * 10 * numSample
  "the code that sets the analog and digital output signals
  j = 0
  
    k = - 1
  
      <>
  
          If SampPerCycle Mod d = 0, then k = k + 1 other k = k
  
          For m = 0 to 3
  
          If ((k) and (2 ^ m)) = (2 ^ m) then writeArray (m, j) = 1 Else: writeArray (m, j) = 0
  
          Before m
  
          j = j + 1
  
          Loop
  publicStatus = DAQmxCreateTask ("", taskHandleDigitalOut)
  
      publicStatus = DAQmxCreateTask ("", taskHandleAnalog)
  
      publicStatus = DAQmxCreateTask ("", taskHandleDigitalIn)
  
      taskIsRunning = True
  publicStatus = DAQmxCreateDOChan (taskHandleDigitalOut, "Dev2/port0 / line0:3","", DAQmx_Val_ChanForAllLines ")
  
       publicStatus = DAQmxCfgSampClkTiming (taskHandleDigitalOut, "Ctr0InternalOutput", # 1000000, DAQmx_Val_Falling, DAQmx_Val_AcquisitionType_FiniteSamps, numSamplesToWrite)
  
       publicStatus = DAQmxCreateAOVoltageChan (taskHandleAnalog, "dev2/ao0","",-10, 10, DAQmx_Val_VoltageUnits2_Volts, "" "")
  
       publicStatus = DAQmxCfgSampClkTiming (taskHandleAnalog, "Ctr0InternalOutput", # 1000000, DAQmx_Val_Falling, DAQmx_Val_AcquisitionType_FiniteSamps, numSamplesToWrite)
  
       publicStatus = DAQmxCreateDIChan (taskHandleDigitalIn, "dev2/port0/line7", "", DAQmx_Val_ChanPerLine)
  
       publicStatus = DAQmxCfgChangeDetectionTiming (taskHandleDigitalIn, "dev2/port0/line7","", DAQmx_Val_AcquisitionType_ContSamps, 8 "')
  
       publicStatus = DAQmxWriteBinaryI16 (taskHandleAnalog, DACwaveFormSize, False,-1, DAQmx_Val_GroupByScanNumber, buffer (0), sampsPerChanWritten, ByVal 0 &)
  
       publicStatus = DAQmxWriteDigitalLines (taskHandleDigitalOut, numSamplesInArray, False,-1, DAQmx_Val_GroupByScanNumber, writeArray (0, 0), sampsPerChanWritten, ByVal 0 &)
  publicStatus = DAQmxStartTask (taskHandleDigitalIn)
  
       publicStatus = DAQmxStartTask (taskHandleAnalog)
  
       publicStatus = DAQmxStartTask (taskHandleDigitalOut)
  
       publicStatus = DAQmxStartTask (publicCounterHandle)
  r = 0
  
  < (publiclifetime="" *="">
  
  publicStatus = DAQmxReadDigitalLines (taskHandle, 1, 5, DAQmx_Val_GroupByScanNumber, readArray (0), arraySizeInBytes2, SampsPerChanRead, numBytesPerSamp, ByVal 0 &)
  
  If publicStatus = 0 then r = r + 1
  
  If r Mod publicMeasurementInterval = 0 Then ' measure Code here
  
  Loop
  publicStatus = DAQmxStopTask (taskHandleDigitalIn)
  publicStatus DAQmxWaitUntilTaskDone = (taskHandleDigitalOut - 1).
  
   publicStatus = DAQmxClearTask (taskHandleDigitalOut)
  
   publicStatus = DAQmxStopTask (taskHandleAnalog)
  
   publicStatus = DAQmxClearTask (taskHandleAnalog)
  
   publicStatus = DAQmxStopTask (publicCounterHandle)
  
   publicStatus = DAQmxStopTask (taskHandleDigitalIn)
  
   publicStatus = DAQmxClearTask (taskHandleDigitalIn)
  
   taskIsRunning = False
  

  Thank you.

  You were right: it was a buffer overrun. I was using integers when I should have used doubles.

  Thank you for your help.

• DAQmx read slowly measurement

  I am still fairly new to LabView, only it uses about 5 months, so bear with me.

  I'm trying to understand why the DAQmx playback function runs slower I expect.  I use a PCIe-6363 map connected to two BNC-2110 connector blocks.  I run the attached code (Position AOM control_prod_cons) and producer while the loop takes about 14 ms to execute.  Here's why this is a question:

  The Subvi belongs to a larger structure that we use in our research lab to run our system of construction craft nanofabrication.  You are using a computer-controlled turntable (wise move task), monitors of reading of the scene (spot monitor sensor) sensor and control a shutter that controls power to the sample (Subvi with lightning) laser.  Up to 4 outputs analog and three analog inputs.  The scene is being ordered to move in 5 steps of nanometer to a speed of 50 micrometers per second, a rate of analog output of 10,000 samples per second per channel (3 of them).  The shutter has a rate much more low yield, at most 5 samples per second.  Our goal is to synchronize the movement of the scene with the shutter, and so we must read the exact position of the scene using the analog inputs, one for each axis, x, y and z, vote as often as possible, even if in reality it didn't need to be more than one read each ms.

  AOM control_prod_cons position takes two points in space that we wish to move between two points where the shutter must open/close.  The first image in the flat sequence did some vector calculations to get the line that we write out the origin of the octant where x, y and z be positive by adding or subtracting, then making reflections around axes, if necessary.  The end of x, y and z values (which are now all positive) are summed and placed later in the sequence.  Coordinated sensor monitor are then read in (loop producer) and turn the same way coordinates the target have been transformed (consumer loop), then compared with the values of (x + y + z) end and start (0) and adjusted accordingly shutter. (For troubleshooting purposes, "off" is 2.5 and read the text file we entered to extract structure).

  All the tests I've done so now tell me that the loop of the producer is the rate limiting step.  For a line that is 30 microns long, with the displacement of scene I described above, I was 45 or 46 readings, that works on a read (on the three channels) once all the ~ 14 ms, or only 72 samples per second per channel, which is * very * slow for the card and is not acceptable for our application.  Am I missing something?  Why the producer loop takes 14 ms per iteration?  I tried to reduce the sampling frequency of writing to 1000 samples per second per channel, but that did not alter the reading rate, so I'm not sure I can cela pins on the map.

  I ran the DAQmx read function as a NChannel 1sample, read in a while loop like I do in more complicated VI, reading of the three analog inputs in a very simple VI who only reads the sensor monitors and nothing else and the reading rate was 2750 samples per channel (read 5000 samples through three channels in 1800 ms) , so I know that the card can read that fast.

  I've also attached the highest lying VI that sets up the physical channels for adding information.  I am also attaching a VI where the producer/consumer framework is not used.  Also, this while loop took ~ 14 ms to exploit.

  Sorry, that was so verbose, just try to do what I'm trying to erase.  If you have any other questions, please just ask.  Thanks in advance for your help.

  Well I'll be darn.  The "task AO is?" query seems to be the culprit.  I have no memory of being always aware that there was such an expensive application.  I don't know if I tried to make such a request in a tight loop before, but I'm a little surprised by the fact that I'm surprised.  I don't know if anything is changed, but in case it's a secondary-ish effect, I use the new DAQmx 16.0

  Another approach would be to use a property DAQmx writing node to query the Total number of the samples.  It seems quite a bit faster.

  -Kevin P

• How to use DAQmx Read to measure several analog channels

  I have two analog inputs using USB 6221 and I want to measure the voltage of each of them.  I use vi DAQmx-read and I select input analog, 1 sample, several channels, but I do not know how to connect several channels at the entrance of the physical channel.

  Hello, Bernadette.

  For reference - I would recommend ad DAQmx questions here:

  NEITHER Forums: Multifunction Data Acquisition

  http://forums.NI.com/T5/Multifunction-DAQ/BD-p/250

  There are several ways to add multiple channels for a fast task-ni.com look for "select multiple channels DAQmx" gives me this like the hit albums:

  2X8D7F5Z knowledge base: How can I select more than one channel of NOR-DAQmx LabVIEW?

  http://digital.NI.com/public.nsf/allkb/A3A05920BF915F1486256D210069BE49

  Hope that helps!

• DMM read IVI measure update

  Hello

  I use Teststand DMM IVI step to measure the voltage to ground via a pull-up 100K Ohms to 20V power resistance. Listening to this tension using DMM external it says 13.4V but after 'DMM IVI Read' step is ran the external voltage of DMM shows 19.7V! No idea why this is happening, I use:

  DMM OR 4070

  TestStand 4.1

  LabVIEW 2010

  and pass the Executive 3.0

  Thank you very much

  Mehran

  
  

• How to find the sampling frequency to read the measurement file

  Hello

  I would like to find/extract the sampling frequency of a .lvm file.

  Right now I am using the VI 'read file of measurement' and my data charge fine and all, but I need the frequency of sampling for certain calculations.

  I know the header of the file .lvm that the sampling frequency is 1613Hz, but I want to get this automatic information from the open file .lvm.

  Tried to find an express vi that could give me the answer, but I could not find a

  I'm sorry if this question already answered, but I could not just to find the answer.

  I hope you understand what I'm doing!

  Thank you

  Kind regards

  Tommy

  The timing is part of the production of signals information. Never use the functions of the Express, but you can use DDT to and convert to one of the data types of waveform. Waveform components then turns the dt.

• Read file measured (bad)

  I have a VI where I save data by using the "write to file measure utility". When I open the .lvm file in Notepad, I see all the data correctly, but when I use the 'Read of a file as' tool and try tho make a graph the data presented is not correct. Attached .lvm file and an image of the graph as labview using the file "read measurement. If you open the lvm in Notepad, you see that the duration column goes up to 22 sec. In the chart, the time axis will only up to 7.5 sec. What's not? Thank you

  PS: I changed the .lvm in .txt file to attach

  I have use Bundle.  I used Index and Bundle.

  My image is a code snippet.  Drag this image into your block diagram and use it!

• A value of reading either excel or a text file

  Hello

  We are students working on a schoolproject where we want to control some output engines. We want to create a set of input values are in red in our program either excel or a text file.

  For example, we want an entry to read the value '1' then the program runs its course and we get a result from the entry '1', after read the next value '2' and the program runs its course and so on.

  We looked for clues and answers, but I suppose were really wrong with that. Someone here who could help us?

  Less you can see one of our programs, its designed to control 3 fans depending on the input (ppm of CO). We want to replace the 'digital controller"(ppm of CO) in another 'thing' that gives us an entry in a list of values.

  

  Well cordially

  Tired students