variant data

Similar Questions

• Connection (or not) the entrance to 'type' of function 'variant data?

  I noticed (again i) assumed that when I connect an output "Data Variant" connector of a VI or a known type indicator, the thread automatically adopt the correct type. Exports means that I don't have to connect a wire to the 'Type' of the 'variant data?

  There are many similar situations where this shortcut does not work. For example, the variant of wiring data function for a bundle by node Name will automatically select the target type of the conversion. I suppose that the index case is a very specific optimization, and this isn't a generally available shortcut.

• Variant data vs Flattened to string

  Hi all

  I haven't worked a lot with the type of a variant in LabVIEW and after having read about a few items, I wonder what is the fundamental difference between a flattened chain and a variant data type.

  I read somewhere that the variant data types also contain metadata that includes the data type there and again we need to wire the data type to the function 'variant data. Why?

  What is the case of the use of the variant data type? I think essentially to a use case where flattened string cannot do a job which variant data type can do.

  Thank you

  Ritesh

  Use the Set attribute varying function.

  

  

• How to create a Subscriber variable to the network & OnDataUpdate for Variant data type?

  Looking at the example C:\Documents and Settings\All Users\Documents\National Instruments\MStudioVS2008\DotNET\Examples\NetworkVariable\Basic\cs\Subcriber.2008, how can I create a subscriber to the network variable and OnDataUpdate for Variant data types?

  All tracks will be useful. Thank you.

  I solved it by using the correct data type in .NET, for example an sbyte to CVIInt8.

• Problem reading video image from the camera IP Axis - confusion of variant data buffer.

  Hi there;

  I am writing a VI for an Axis IP camera.  He went to work, but I need to extract individual video stream images so I can overlay text using the functions of text IMAQ overlay.

  The thing is when I take a picture using the axis dll library (GetCurrentFrame), it returns a buffer size and a Variant representing the raster data.  The data is = 921 640 bytes representing a 40 byte header, and then the 640 x 480 x 3 raster data.  When I run the vi, I get a correct value for the size of the buffer (921 640) so I know it works.

  What don't understand me, it's the video image is placed in a buffer of type variant.   I don't quite know how to extract the raster data of the data type of "buffer" which is a type variant.  My apologies, I'm a bit ignorant in how to handle the types of "Variant".

  Does anyone have a suggestion?

  This is the VI

  Hi Peter,.

  Just to confirm, what IMAQdx version do you use?  You want to get the version 2010.3 since it is the latest version: http://joule.ni.com/nidu/cds/view/p/id/1641/lang/en

  The next issue would be that the Ethernet cameras discover is not necessary and that it is only used for GigE Vision cameras. The VI was named before IP camera support has been added and the name is unfortunately confusing now. In any case, the discovery of cameras takes place in the background and is automatic. The VI list must list your camera. It may be worth trying just to see if the camera appears in first MAX. Note that the IP camera must be installed on your local subnet, so it can be discovered.

  Regarding the examples, virtually none of the IMAQdx examples included in help-> find examples should work.

  Eric

• Variant data type conversion

  Hi all

  I use VI Scripting in LabVIEW 2010. I need to know the data type of the wire connected to a Terminal. Terminal wire reference gives a property called "Datatype". I thought that this will help me. But he is a variant and how do I actually convert the data to find out the data type. Specifically, I want to make use of data type of cluster. How do I know if the wire is of type cluster?

  Thanks for any help.

  You want to use the 'GetTypeInfo.vi' VI "LabVIEW 20xx\vi.lib\Utility\VariantDataType\" folder for this!

  I would recommend installation of this Package of VI because it adds these features to pallets:

  https://decibel.NI.com/content/groups/hidden-gems-in-vilib

  Here's what it looks like:

  

• Strict Variant data

  What I get as output is

  

  The problem is that I simply quoted text. Most of the ways I tried to do (flatten chain) or enter the properity nodes does not work.

  Any suggestions?

  (The goal is to automatically to load/unload the clusters without carring what they store in their own country).

  What you need is the data type of the control, and not on his label. This vi is probably what you need: vi.lib-> utility GetTypeInfo.vi-> VariantDataType folder.

  

  ben64

• Shared data varying variable published network write error

  In my project in real time, on the VI host running on my Windows PC, I try to write in a number of published network shared variables.  All these write operations are successful (which means that I can read them on the RT target, then a cRIO-9012), except for these shared variables network-published with data type defined as Variant.  I'm not sure what is causing the problem.

  I take the table of clusters shown here...

  

  .. .and going through one "in Variant' VI and then subsequently in writing to the shared variable (data type: Variant).  Diagnosis of the failure of the VI in real-time to read the data, I found that variable writing shared on the host VI produced the following error:

  Error - 2147467259 appeared to Variable shared in the PC host TTS CTRL.vi

  Possible reasons:

  LabVIEW: Unspecified error (Hex 0x80004005).
  =========================
  System OR Configuration: Various operating default (Hex 0x80004005).

  This error or warning occurred when writing the following shared Variable:
  Shared \\My Computer\Network Variables\TC trust Array Group - network
  Shared \\128.144.90.143\Network Variables\TC trust Array Group - network

  .. where 128.144.90.143 is the IP address of the PC.

  Any thoughts?

  Sean

  I saw this post, and when I found myself with no other option, I have redefined the variables in question to the string data type and replaced all the "to variant" and "given Variant of ' functions with functions 'Flatten channel' and"The string Unflatten"respectively.  Initially, it did not work - functions "Chain Unflatten" would produce error 74, until I realized that the "data includes array or string of size? (T)"input on each 'string Unflatten" function must be set to FALSE. Wiring a constant false for each instance of "Unflatten to the string" seems to have corrected the problem.

  I have still no idea why wouldn t Variant.  Shared variables Editor allows to define a variant data type, so I guess it's supposed to?

  Sean

• Reliability of the data in the conversion to & from a Variant...

  It is possible to convert any data type to a variant, and then turn it back on.  In doing so, are there data types who will lose information during the conversion process?  If so, why?

  Yes, you can convert any type to a variable ranging and back. There is a VI called "Variant data" which will have a type as input. He continued to convert the variant the correct data. The side variant must know what type of data to expect. He can pull of the Variant. However, you can use a cluster of generic data that consists of a username and a Variant. Then you can have different types of data which can handle the side reception. It is a two-step process. One of conversion the variant of general type (data type and Variant cluster). The second would be a case statement uses the type then covert the internal variant to the specified type. This approach is used for generic messaging systems. The upper levels of the code will know what to do with the data. The lower levels are just generic data passing around.

  I'm not aware of any information that get lost during the conversion of the data to and from a variant. Of course, I not had no problem using them.

• Variant of data with Null void management / vi

  Hi all

  I create an application that uses a DataSocket to generate Variant data.  I then transform variant in its form 'real data' (Boolean, U8, DBL) by using the 'Variant' to Data.vi, it works very well when there are data from the DataSocket however if no data is present, an error is received (error code 91).  I added a check to see if there is no current using the code below, data however as there are more than a dozen cases of this code throughout my program of conversion of the variants for a mixture of; Boolean values, U8 and DBL, I want to put this code in a Sub VI, I believe this would be more careful and do real programmers.

  My problem is that the "output data" must be able to adapt to the "Type" of entry before execution (as does "Variant of Data.vi"), but I could not find a way to do it.  Does anyone have any suggestions on what I need to do to get there?

  Thanks in advance,

  Mark

  With the help of LabVIEW 2010 Full Development System

  Wrap the function in a case structure and use empty String/path? with the cable Variant function to determine if the variant is empty.  Run the variant to the data if it is not empty.

  Edit: Looks like you added a picture I posted and do what I was proposing.  Anyway, I don't know that you can really conclude it in a Subvi with different types.  If you have a limited number of different types, you could maybe do a polymorphic VI.

• Error 91 - try to use the variant of the function of data

  I'm running a problem when you try to use variations in my application. I have a setup of State machine that a State creates a list of tasks (cluster of tables), and then converts it to the Variant. The variant is fed into a shift register that allows me to access the list of tasks of a different State.

  The problem comes when I try to use the variant of the function Data. I right click on the task cluster to create a constant and then wire to the TYPE of the variant of the function Data. I wire the variant of cluster of task to the terminal of the VARIANT. When I run the VI, I get error 91: or the possible reasons: LabVIEW: the variant data type is not compatible with the data type of wired for the input type. ».

  How can I get this error if the type that I have connected to a Terminal TYPE of the Variant Data terminal is a constant created from the exact type created a variant of?

  Section of the machine of the State where I wire the cluster variant:

  

  Section of the machine of the State where I use the data out of the cluster variant:

  

  The constant wire to the terminal of data TYPE variant was created from the cluster that is connected to the Variant type data. I don't understand how there is a type mismatch?

  Is there another State between these two?  I notice you have some tunnels 'Use default if unwired' coming out of the structure of your business.  First of all, clear on the tunnels.  Second, in cases where you do not only affect the data, the data directly from the tunnel entrance in the tunnel exit of the wire.  I recommend using the tunnels linked to make it even easier on yourself.

  With the default tunnels being output, your variant coming could really be empty, so the conversion fails.

• Gets the data type variant for the selection of cases

  I don't ' know much about alternative, so I'll ask as many questions as possible on this subject.  If I have a table of varying, and each of these variations has been converted to a different data type.  This table will be the clue to a for loop and each item will be handled in a case inside the loop structure for.

  The issue is that I would like to take the variant data type, convert enum and use it to select the box on the structure of the case.  How do I do that?  Or what is the best way to do it?

  Yik

  www.Openg.org

  VI 'Get TDEnum of data' of the data tools package.

  There is also the "GetTypeInfo" VI which is located in the \vi.lib\Utility\VariantDataType folder.

• Variant of data object class

  The 'variant data' has 'Type' is a required entry, according to the help documentation.

  However, I can make a Variant to the data without the help of the type when the variant is an object and a class method is fixed. Is this expected behavior?

  A screenshot is also attached. The top loop to have a "blue wire" method, which is then become a child of the «Brown wire» method Since there is no type, blue seems to have kept his last colors. By duplicating the code, the new instance has the right color. The two loops to provide the same performance.

  Richard_Ha wrote:

  The 'variant data' has 'Type' is a required entry, according to the help documentation.

  The documentation is no longer correct. I guess at some point, that someone thought it was a good idea to let the function of being able to deduce the data from the output if nothing is connected to the entry type, but then I forgot to update the image of the assistance.

  I do not remember to do with classes (or to all the less, I almost never rely on this behavior, because I prefer explicitly the type of wiring), but I could certainly imagine where it would work unexpectedly. Unlike other types, the classes have a dynamic element to the data type, which is certainly more an incentive to make sure you wire in the class.

• Variant to Boolean conversion

  Hello

  Also, we get a very unfortunate mistake of Boolean variable reading of a PLC register that is automatically converted to a Variant. And therefore, when wire us a Boolean indicator (led) it gives me the error 91: "the variant data type is not compatible with the data type of wired for the input type.

  Some people have had the same problem but I'm not a little to get around / solution !

  The intervening variable is down, "F3 BLOKKAGE SCHROEF 2 OK.

  Thanks for help

  In addition, you really should provide the data type during the conversion of a variant.  There is an entry on the top of the variant data Type node.

  

• Scripting-Terminal of a "Data Type creation.

  I have a script function that is supposed to create a constant (think melting or Variant data type) a receiver provided. He then connects this constant to a designated terminal.

  I get this error when I try to catch the terminal of the object that I just created. (just before the error dialog box that I placed)

  

  I tried a handful of things, and I have a hypothesis for now. LabVIEW handed me a constant with a command reference.

  More specific error when I try to make a constant. Guess it makes sense because it does not move to the top or to the bottom of the tree.

  Has used the 'create data type' incorrectly? Is there a way to force the referral to continue to point to the object but to be recognized as a constant?

  Thank you

  This is a known bug with the creation of the method of Data Type. The workaround prescribed, it is exactly what you've done... convert the order for GObject reference, then convert this constant reference.