Display PDM

Similar Questions

• PDM Viewer do not display data with time stamp

  Need help with the timestamp of the data in a PDM file generated by the DAQ Assistant.

  When I use the PDM Viewer, with x the value absolute time scale, the date starts in 1903. If I use Excel to look at the file that the start time is correct (i.e. 2013).

  Bo_Xie, I simplified my VI and now able to display the correct time stamp. Thanks for your time!

• PDM - the page cannot be displayed

  I was able to access the MDP without problem before. Now, I can get through logging in the PIX, but the window PDM says "cannot display page". I think I would have changed my browser settings. Any ideas?

  Thank you.

  It happens a lot. That remedy is, go to my settings and erase cookies, files, Internet and everything else here. Restart your browser, it should work again.

  I hope this helps...

  Eduardo

• Saving data using Write to PDM

  Hello

  I am writing a program where I connect the values I measure and send to a host VI as network published variable shared

  I am looking for the following final result
  -The first column shows the time
  -The second column displays measurement signal No. 1
  -The third column displays measurement signal No. 2
  Fourth column displays measurement signal nr 3
  -Etc.

  I'm a little confused as to how to work with the the PDM write the function, and I am currently getting a little all the measures and the timestamp in a single column

  Also, I'm trying to understand how to name each log file automatically by date; for example: 01/14-data, 01/15-Data, etc and have a feature that auomtiatcally creates a new file every time that the program is run, for example:

  01/14-Data1

  01/14-Data2

  01/14-Data3, etc.

  Any advice?

  Screenshot of the code and the VI are attached

  Thank you

  Yes, open it with "open or create.

• Displays the absolute time of a waveform channel

  Hello

  I would like to display the absolute timestamps on the x axis of a 2D graph in the DISPLAY of the waveform channels in a PDM file. The timestamp of the first sample is stored in the wf_start_time property.

  I found this article , but I don't want to generate a weather channel because the benefit of waveforms is to avoid storing the part x of the signal in the files.

  Is there another solution since 2007?

  I use DIAdem 2011 and LV 2011.

  Thanks in advance

  Hi Yohanna,

  The only way to display the datetime values on the x-axis of the graph in SIGHT and the only standard way to do the graphics in the REPORT, is to create a DateTime String.  DIAdem in 2011 it is much easier to do, since you can use the standard ANALYSIS function "Generate digital channel", by selecting the option buttons 'values of x-part of a waveform channel' and 'Create channel time (with absolute time reference).  You can also use the standard ANALYSIS function "digital channels <==>waveform.

  Brad Turpin

  Tiara Product Support Engineer

  National Instruments

• Channel import from time to tiara from a PDM file

  I have a generated Labview tdms data file has the timestamp clock computer written in the file as a string. When I add this tdms file to the portal in DIAdem data it is important this time string channel, and I can't trace this as the x-axis data. I would like to import this time string of the tdms as a weather channel file easily. Is this possible?

  The work around I have found is to import the tdms file in excel, and then save as an excel file. I can then import this channel since the Excel using the Excel Import Wizard and specifying the time stamp column is a weather channel. Surely, there must be a better way.

  Thank you.

  Hi PRinOR,

  Here is a VBScript script that converts each text string "Time Stamp" in the data portal to a 'Time Stamp' datetime string.  You can run this VBScript manually whenever you load one of these TDMS files in the data portal, or we could implement to run automatically on your computer as an event of BROWSER loading custom.

  If you can convince the controller LV for a Brown wire entry datetime to the PDM file, then this new channel of data will appear as a column of values datetime correctly recognized in Excel, even if the display in Excel will be different from the datetime string in your TDMS file because Excel does not this default format (I think it's possible with a custom display Excel datetime type) display type.

  Brad Turpin
  Tiara Product Support Engineer
  National Instruments

• New Labview user. Need help with PDM

  I'm reading the data of 30 thermocouples, he discovered in real time on my interface and keep it for further analysis. Sales guy suggested I use TDMS it display the information in the same way if I had to do a right click on a wave form, then click 'export Excel' (30 columns representing each thermocouples and a column for the moment). The test would go for an hour or two, and each channel could save data to one sample per second. I tried to make this parameter adjustable on the interface as well as adding a clock that could be adjusted to set the duration of the tests, but too late for me because I've only been using labview for a week or two.

  I have a code that worked fine, until what I put in what I thought was acceptable code to store a PDM. Now, the code will run, but seems as if no data is read. Is there an easier way to accompish this task or I am just on something very simple? Thanks for the help!

  I took the liberty of cleaning of your VI some.  You had a lot on your front too.  He was also thrown everywhere.  Group together things that are similar, so you can easily find what you are looking for.  You have also had a lot of indicators it the only reason for them is debugging.  This is what the probes are for.  I also condensed your block diagram.

  I hope this helps.

• Acquisition using waveforms info incorrect when time gives the writings in PDM

  Hi all, in most of my daq applications, I am interested in phenomena rather slow (temperature and static pressure) more than 30 to 60 channels as well as two or three instruments series for a very long time (for example: a few days or weeks). In general, I also calculate values based on the acquired data. I had used 2D charts to achieve, but the discovery that defines metadata inherent with the type of waveform data extremely useful for organizing my data. I've attached a screenshot of my typical acquisition using waveforms code.

  The problem that I notice, is that the time stamp at the end of the data set is never correct. By example, if I start a test at 08:00 Monday and you complete it at 16:00 Tuesday, when I remove the PDM file data and he draw on a waveform chart the final stamp displayed could be from 19:00 Wednesday 15:00 or Monday or some other time nowhere share near real-time the trial was stopped. I suspect it has something to do with the parameter "dt" waveforms, but so far I have not been able to understand. What I am doing wrong? Thank you.

  It seems that the lu daqmx VI indeed default dt = 1 when the instance of "N chan Samp wfm 1" is selected.  Switching to continuous sampling and parallel loops with a queue has solved the problem.

  Thanks for your help!

• Memory insufficient error when opening file of 1 GB of PDM, no possible split

  Hi all

  the file in question contains about 1.4 million channels, each has entire 295 points. The channel name is the timestamp when its action has been taken.

  Tiara impossible to completely load and displays only the first 65,000 channels.

  LabVIEW (PDM read) may not even read smaller blocks of data. I tried to separate the file using Split TDMS file independent memory LV2009.vi (https://decibel.ni.com/content/docs/DOC-20054) , but nothing is done - the error I get is Code 2 (memory is full).

  I use Win7 and Labview 2012 32-bit SP1.

  Thanks in advance for any help.

  Best regards, Markus

  markhors wrote:

  [...] Do you know if LabVIEW can handle extremely large channels (> 1 GB) data?

  Regards, Markus

  64 bit LV, Yes. But according to the RAM installed, it would have the impression that the process is blocked.

  Looks like you create the configuration of the TDMS exactly the other way around such as recommended.

  Looks like you got some 295 transducers and read a value of each cycle of each. These values must be written in 295 channels consecutively, including an additional channel, you use the timestamp.

  Norbert

• Reading of custom in PDM properties

  Hello

  I'm trying to read custom properties in the root of a file of PDM using Matlab with nilibddc.dll. I found two problems.

  (1) I can't read the names of the properties of file only up to 643. They are the ones on the first two lines of the first page when opened in Excel. nilibddc cannot read the rest of the properties posted 4th and 5th rows tdms open Excel file.

  (2) I can read the names of the properties of file with DDC_GETFILEPROPERTYNAMES, but how to read the values of the properties of file?

  Thank you very much!

  Hi Nathalie

  «(1) I can read the names of the properties of file only up to 643.» They are the ones on the first two lines of the first page when opened in Excel. nilibddc cannot read the rest of the properties posted 4th and 5th rows tdms open Excel file. »

  The properties displayed in the 4th and 5th rows are those of 31 groups of your file.

  I guess that those who are no longer available in the group named "user properties.

  You can call DDC_GetChannelGroups to retrieve the file channel groups.

  So DDC_GetNumChannelGroupProperties like DDC_GetNumFileProperties will return the number of properties.

  "(2) I can read the names of the properties of file with DDC_GETFILEPROPERTYNAMES, but how to read the values of the properties of file?

  To retrieve a propertyyou values need to call DDC_GetFilePropertyType (DDC_GetChannelGroupPropertyType) to determine the type of the property, and then call the function of reading according to:

  DDC_GetFilePropertyUInt8
  DDC_GetFilePropertyInt16
  DDC_GetFilePropertyInt32
  DDC_GetFilePropertyFloat
  DDC_GetFilePropertyDouble
  DDC_GetFilePropertyString

  For properties of type string, be sure, you resereved a buffer of size (DDC_GetFileStringPropertyLength).

  For DateTime (DDC_Timestamp), call the DDC_GetFilePropertyTimestampComponents.

  Please refer to the help named 'nilibddc.chm' file in the '. '. \DOC"folder for more details.

  See you soon

  Stefan

• Continuous recording 6008 to PDM

  I need to record data over long periods of time, using NIDAQmx and WinXP with a USB NIDAQ 6008.  Record to the TDMS format is probably very effective since the data is stored in binary format, 2 bytes per channel. I made some changes to one of the files example in order to obtain continuous to a PDM file. Allow me to include the source code hacked and the display of error message. Note that the size of the buffers have been adjusted in sector size (4096) on the Windows XP computer. Two problems:

  (1) data reading takes place approximately 3.5 times more slowly than anticipated, judging by the screen updates every 1000 measures.

  (2) after approximately 3300 samples, the program crashes with the error attached screen, indicating the saturation of data in the data buffer.

  If I change the data rate for example 500 samples/s instead of 1000 samples/s, there is no difference in behavior, so is probably not because of scheduling problems.

  Change the ConfigureLogging parameter of Val_LogAndRead to Val_Log (naturally!) produced an early error message, which indicates that data reads may occur while recording takes place. I strongly suspect a coding error.

  Any advice will be highly appreciated. Best regards, Willem

  Hello. I'll try to answer some of your questions.

  The value of No.Samples / channel in affected ReadAnalog64F64 work and product of errors when certain values were used. I finally got him to the system default value. What does this parameter actually mean if you samples at a frequency of 1 Hz?

   

  When you're constantly sampling, the number of samples per channel setting indicates overall how many values to withdraw from the buffer each time. By default, you put in (DAQmx_Val_Auto) is - 1, which means that each time, he grabs all available in the buffer. If the table you are dumping is too small for this (according to the parameter ArraySize), based on the values you were here before, you might not have been attracting enough data at the same time to avoid that the buffer overflows.

  Is the parameter ArraySize in ReadAnalogF64 must exactly match the size of the array [] data?

  I think this technically isn't "need." It basically puts forward for how the points table is great. If you put a value smaller than the actual size of the table, then you'll be sure mistakes. If you put a number larger than the actual size of the table, and then the program attempts to write on the Board with more values it can hold, you will probably get an index of table by mistake. Don't forget, as I said in the question above, when the function DAQmx entering values in the buffer zone, it examines the ArraySize parameter to check its limit, not in the table itself (it's how that points to a table usually works, and is a common point of frustration in C code).

  Should it be the same as the last parameter in CfgSampClkTiming?

  N ° the last parameter in this function in continuous mode, actually used to determine the buffer size (Note: this does not set the size of the buffer, it helps to determine what size of buffer).

  In addition, how sampsPerChannelToAquire is bound to the values of the parameters in RegisterEveryNSamples?

  You are right that they do not relate. The settings in RegisterEveryNSamplesEvent set the number of samples waiting to happen in the buffer (or leave the buffer in case of output) before firing an event.

  You can find much more information on this topic in LabWindows help. If you go to LabWindows > help > contents > choose the Index tab and scroll to the bottom in alphabetical order for «DAQmx»... ", then you will find the list of all these functions DAQmx. If you double-click on one, you get a description of the function and each of the parameters. This might help clear things for you. All these names sound very similar settings and can be confusing, so it is a reference tool handy to clarify things.

• How to read the two columns of data in a file of PDM.

  Hi all

  I am reading two data columns for the 2nd of a PDM file two sheets, as shown below.

  

  Two columns of data must then be shared so they can be displayed in a xy chart and also apply a linear adjustment VI. I implemented the graph xy and linear adjustment using a txt file (see below), therefore all the outputs work, however this application with a tdms file turns a little more tax.

  

  

  

  So, essentially, that I don't know how read the correct leaf and therefore the columns in the PDM file and then how to produce the graph xy and linear adjustment of the data types produce. Here's my current attempt, which produces several errors of the type of terminal, as well as not being able to select the exact data in the PDM.

  

  Any help/suggestions/example vi on this asap would be greatly appreciated.

  Thanks in advance,

  Pete

  Also the PDM file viewer. VI helps you easily understand the structure of data files.

• Write the spectrum of power + other tables to PDM

  Hello world!

  I am building a project of data acquisition, using compactDAQ to measure and record data from an accelerometer.

  The main objective is to save the data of acceleration, speed, displacement and frequency in a PDM spectrum, but I'm having some trouble it.

  As you can see in the attached file I had coveted, data of the wizard Express in a waveform to unbundle + build using waveform, after that I wired this waveform of a generation a table with data ACC, of speed and movement.

  The problem arises with the viewer TDMS data reading because the plot of the frequency band is not the x-axis with the right values, instead display the data of frequency it indicates the date and time that does not correspond with the PC, but the fact is that I need the frequency values.

  Is it possible to change and enter the correct values in the TMDS file?

  Thanks in advance,

  Omar

  The TDMS Viewer included with LabVIEW is not going to meet the needs of each.  And this is a case where it is inadequate.  Your data is stored correctly (at least the image looks right.  Also next time code postal no pictures.  Attach a VI or a code snippet.

  When you read your data PDM Regularisez using a DDHN reading him indicate you the type of data to expect, and there you can provide an analog waveform.  Then when you read back you will have the same dT and T0 he wrote with.  The problem with the Viewer is probably does not know it is a waveform and is simply read data from amplitude and then confuse around the X axis.

  You can write your own code to read the file, make a copy of the existing Viewer, then change it. Or my favorite is try Scout by Signal.X.  They took the standard TDMS Viewer and gave it an overhaul.  You might get lucky and open the data normally here.

  http://sine.NI.com/NIPs/CDs/view/p/lang/en/NID/211879

• The most effective way to log data and read simultaneously (DAQmx, PDM) high data rates

  Hello
   
  I want to acquire the data of several Modules cDAQ using several chassis to
  high data rates (100 k samples per second if possible). Let's say the measurement time is 10 minutes and we got a large number of channels (40 for example). The measured data is written to a PDM file. I guess, the memory or the HARD disk speed is the limits. For the user, there must be a possibility to view the selection of channels in a graph during the measurement.

  My question: what is the best and most effective way to save and read data at the same time?

  First of all, I use an architecture of producer-consumer and I don't want to write and display the data in the same loop. I expect two possibilities:

  [1] to use the 'DAQmx configure logging.vi' with the operation 'journal and read' to write the data to a PDM file. To display the data in a second loop, I would create a DVR samples documented and 'sent' the DVR for the second loop, where the data will be displayed in a graph (data value reference). This method has the disadvantage that the data of all channels is copied into memory. Correct me if I'm wrong.

  [2] use 'DAQmx configure logging.vi', but only with the "journal" operation to write the data to a PDM file. To view the selected data, I had read a number of samples of the TDMS file in the second loop (I'm currently writing the TDMS file). In this case, I have only one copy data from the selected channels (not), but there will be more HARD drive accesses necessary.

  What is the most effective and efficient solution in this case?

  Are there ways to connect and read data with high frequencies of sampling?

  Thank you for your help.

  You say that the measurement time is 10 minutes. If you have 40 channels and you enjoy all CHs at 100 kHz, it is quite a number of values.

  In this case, I always try to approach under the conditions of use. If a measure is only 10 minutes, I just connect all PDM data and create a graphic module that could be in the same loop of consumers where connect you the data. You can always work on the raw data files big offline afterwards, the extraction of all the information you need (have a look at the product called NI DIAdem: http://www.ni.com/diadem/)

  The main issue is that the user needs to see in the graph (or perhaps a chart can be useful too). Lets say that the graph is 1024 pixels wide. It makes no sense to show multiple data to 1024 points, Yes? Every second will produce you 100 data points k per channel. What is the useful information, which should see your username? It depends on the application. In similar cases, I usually use some kind of data reduction method: I use a moving average (Point by point Mean.VI for example) with a size of the interval of 100. This way you get 100 data points of 1000 per channel every second. If you feed your graph every second with these average values, it will be able to data points in 1024 of the store (as a default) by channel (curve), which is a little more than 10 minutes, so that the user will see the entire measurement.

  So it depends on the frequency at which you send data to the consumer. For example, collect you values 1024 by iteration of the producer and send it to the consumer. Here you can make a normal means calc or a bearing (according to your needs) and he draw a graphic. This way your chart will display only the values of the last 10 seconds...

  Once I programmed some kind of module where I use a chart and not a graph, and the user can specify the interval of the absolute timestamp that is traced. If the data size is larger than the size of the chart in pixels, the module performs an average calculation in order to reduce the number of data points. Of course, if you need to see the raw data, you can specify an interval that is small. It all depends on how you program zoom functions, etc... In my case I hade a rate of 1 Hz, so I just kept all data in RAM limiting the berries to keep 24 hours of data, so that technicians could monitor the system. In your case, given the enormous amount of data, only a file read/write approach can work, if you really need access to all of the RAW data on the fly. But I hope that the values of working capital means will be enough?

• record data continuously using PDM

  Hello

  I'm new to LabView and sought some means of recording of analog data using PDM. I tried to implement in my code but found that when I open files created with excellent I get gibberish and no data value. I enclose a photo of part of my code that is responsible for this.

  DAQ Assistant called the values of two analog voltage inputs (two Photodetectors). The signals are displayed just fine and continuous via waveform graph, but I want to record these values as well. I tried to use Write to Spreedsheet but only a certain value (100 samples) were recorded at the time. I want that all THE values from these two analog inputs at that time, I click START on time I click STOP.

  Thank you!

  Alfredo

  So, I guess that it is placed in a loop. Well, you are always 'creation' a TDMS file on each iteration of the loop instead of using "open and create" TDMS open and add the data. Yet once again, take a look at my instructions to search in the Finder of the example. After the back if you have additional questions.