Call an external function?

Similar Questions

• Problem call Matlab external function under Labview 7.1

  Hello

  I have the problem when I want to call my m.file function in the script Matlab under Labview 7.1, that labview does not seem to be able to find this external Matlab function. I searched this forum, someone talked about setting search path in the tool-> option-> Matlab search path, but it seems that it does not exist in the version 7.1.

  Is it possible to solve this problem in version 7.1 or update to the latest version, the only solution?

  Thank you

  Hello

  I think you're confusing the LabVIEW MathScript nodes and the MATLAB® script.  The MathScript node is introduced in LabVIEW 8.0 and the setting of path search that you speak to MathScript, reason why it does not exist in LabVIEW 7.1.  Look at the example of differential equation Lorenz for the MATLAB script node.  It shows how to set the path of research to be compared to the VI.  The example is found in the node of script examples\scriptnode\MATLAB - Lorenz Diff Eq.vi.

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

  Grant M.
  Staff software engineer | LabVIEW Math & Signal Processing | National Instruments

• Calling the external functions (DLL)

  Hello world!
  I know maybe it's an issue, but I have found no solution (whycih I could understand) to my problem:
  Is it possible to call functions of a (in written C++) DLL, or any other way to access the C++ functions?
  
  It would really help me, because I want to use Flash to create desktop applications and use C++ for system integration.
  Any sujestions are welcome!

  The third-party tools "wrap" or "Home" activex control and provide a api extended - consider a well improved version of the standard flash projector, which is quite limited. I know not what is possible, I can't speak from experience - but I know that others here on the forums have used them.

  There is a type of open source implementation called haxe and screenweaver... or something like that... but I don't know if it will do what you want.

  I know that zinc will be because I did a quick search and it says - so I guess it must! Other names that come to mind are Jugglor and Swf Studio. I haven't checked to see if they can use external libraries.

• How to call external functions without one. DLL (just using a.) H and. LIB file)?

  Hi all

  in fact, I am facing difficulties on how to get an external function is called in CVI (Version 2009).

  I was delivered with a. H file and a. LIB file to call an external function of my project CVI. The. H file looks like this:

  void exportedFunction(double *parameter);
  

  As far as I know, the external function was written with MS Visual C++ 6.

  So, I tried to link statically to the al extern like this function:

  -Add the. H file and the. LIB file to the CVI project

  -#include the. Folder H when I needed to call the external function

  -do the external function call

  During construction I get unresolved CVI external function call error, so this seems not work.

  I did some research autour and stood up with two possible problems. Maybe one of you can help me get a bit further and do work things out.

  (1) of the code of the 'real' function inside the DLL file that was not delivered to me. Or y at - it a way to get concrete results (calling external functions) with just one. H and a. LIB file (with none. Included DLL file)?

  (2) the external function does not export according to the rules of Style 'C '. The signature of the function in the. H file shows some things don't like

  extern "C" __declspec(dllexport) void __stdcall ...
  

  Or maybe it's a combination of these two issues (missing. DLL + bad export style function)?

  I guess I could get around the incorrect service export style when I managed to write a wrapper around the original function that actually uses Style C exporters. But I guess I need to the. DLL file for this test as well.

  Thank you very much for your answers.

  Best regards

  Bernd

  There is no need for the stuff of dllexport. There is also the option of a static library without any DLL.  But the "extern"C"' is essential, because it forces the C++ compiler, which was probably used to compile the library to use the C calling convention.

  If you are unable to ask the library vendor to provide a version that was compiled using C calling convention is the way to write a wrapper with VC ++ 6 around this library that functions using C calling convertion reexports. Something like

  extern 'C' myfunc1 type0 (type1 arg1,...) {

  Back to func1 (arg1,...);

  }

  for each function, you must use.

  BTW. "unresolved symbol" is the error message from the linker, you can expect if you try to bind the C code against a generation of library with the C++ calling convention.

• Flash cannot call the javascript function in the local html file

  Hello!

  Us is to develop our first application on Playbook. It is an html file including a flash file and javascript code. Everything is packed in. in the file bar, a config.xml file and has been correctly loaded into the Playbook. Everything works locally (no web access)

  Everything works well except when we use an ExternalInterface.call("saveglobalscore",score) in flash that calls a javascript function in the .html file.

  In the actionscript3, we selected the "authorized local file access" and put the 'Security.allowDomain("*) '.

  Any ideas? Thank you!

  External interface tries to access the files packaged locally is currently a known issue.  I have not really of a calendar when or if this can be resolved.  It may be in the code base of flash.

• How to call the javascript function in ADF

  I have the javascript function stored in a .js file external (try to reuse in another application). How can call the javascript function for an event of ADF faces component. I need to I am a newbie to ADF, all ideas are appreciated.
  
  Kind regards
  Surya
  
  Published by: sgodavar on Sep 24, 2010 11:44

  Include JavaScript to the jsff/jspx as page:

  Call it like:
  
  Type = "dblClick" / >
  Amit

• receive the following error code when searching for a piece of music I did several times without a music problem but have recently updated Firefax: Fatal error: Call to undefined function AmazonData() in/home/boss/public_html/mc on line 13

  I am in the page web http://www.songarea.com/ and after searching a piece of music, I get the following error message:
  "Fatal error: Call to undefined function AmazonData() in/home/boss/public_html/mc on line 13.
  I did this several times before without a problem, but have recently updated Firefox with the Skype add-on and wonder if the two things are related.

  URL of affected sites

  http://www.songarea.com/

  Hi John,.

  It is an error message from the web server providing this site. Specifically, it is something wrong with their PHP code.

  It is not browser specific and would go into another browser besides Firefox.

  You will need to contact the webmaster of this site to report this problem. A quick test does not show this problem, but you do not specify what search query, you tried:

  http://www.songarea.com/music-codes/test.html

• Two parallel executions, calling a DLL function

  Hello

  Since this test takes about 6 hours to test my USE, I plan to use the parallel model to test 2 UUT at the same time in parallel.

  I implement the test code as a DLL of CVI.

  However, to my surprise, it seems that the steps that call a DLL function actually traveled in one series, not in parallel:

  Test 2 power outlets if one enters and executes a DLL works, the other waits for the first to complete its operation and return. While the other runs on the same copy of the DLL, so that the DLL global variables are actually shared between executions.

  So if a DLL will take 5 minutes to complete, two executions in the running at the same time take 10 minutes. This isn't a running in parallel in every way.

  What I want and expect also TestStand, was to completely isolate the copies of these two executions DLL such as test two casings could run at the same time the same DLL function by arbitrary executiong their copy of the function, completely isolated from one another.

  So they separated globals, discussions, etc., and two parallel jacks take 5 minutes to run a step, instead of 10.

  Such a scenario is possible?

  If not, how can I use my test in parallel (in truly parallel) when the use of 2-socket test?

  (1) Yes, he'll call the multiple executions in TestStand calling into the same dll in memory the same copy of this DLL. Thus dll called in this way must be thread-safe (that is written in a way that is safe for multiple threads running the code at the same time). This means usually avoiding the use of global variables among other things. Instead, you can store the thread shows in local variables within your sequence and pass it in the dll as a parameter as needed. Keep in mind all the DLLs your dll calls must also be thread-safe or you need to synchronize calls in other DLLs with locks or other synchronization primitives.

  1 (b) even if your dll are not thread-safe, you might still be able to get some benefits from parallel execution using the type of automatic planning step and split your sequence in independent sections, which can be performed in an order any. What it will do is allow you to run Test a socket A and B Test to another socket in parallel, and then once they are then perhaps test B will take place on one and test one run on the other. In this way, as long as each test is independent of the other you can safely run them in parallel at the same time even if it is not possible to run the same test in parallel at the same time (that is, if you can not run test on two Sockets at the same time, you might still be able to get an advantage of parallelism by running the Test B in one take during the tests in the other. See the online help for the type of step in autoscheduling for more details).

  (2) taken executions (and all executions of TestStand really) are threads separated within the same process. Since they are in the same process, the global variables in the dll are essentially shared between them. TestStand Station globals are also shared between them. TestStand Globals file, however, are not shared between runs (each run gets its own copy) unless you enable the setting in the movie file properties dialog box.

  (3) course, using index as a way to distinguish data access are perfectly valid. Just be careful that what each thread does not affect data that other threads have access. For example, if you have a global network with 2 elements, one for each grip test, you can use safely the decision-making of index in the table and in this way are not sharing data between threads even if you use a global variable, but the table should be made from the outset before start running threads , or it must be synchronized in some way, otherwise it is possible to have a thread tries to access the data, while the other thread is created. Basically, you need to make sure that if you use global data which the creation/deletion, modification and access in a thread does not affect the global data that the other thread use anyway in or we must protect these creation/deletion, modification and access to global data with locks, mutex or critical sections.

  Hope this helps,

  -Doug

• Lack of external function DAQ channel read

  Hello

  I did a few installers to share on the network variables, one is based at DAQmx readings of analog channels use modules of simulations and the second donkey receives variables shared these radings... I thought it was pretty good, because I have the main application (channels read and share variables) in my main PC (which has istalled LabVIEW 2012) and the other track in a regular PC (no software OR installed until my Installer Act) and it worked fine. However, I installed the main application in the regular PC and I got an error stating: lack of external function DAQmx read single sample DLB... I guess I should include in my Installer features on DAQmx but I Don t know which ones to avoid this error and be able to install my apps in any PC... Thanks I await your advice!

  Well, I found the solution...

  I've just included confiuration NI DAQmx MAX support to my app Installer and I solved the problem...

• Error when you try to call the Javascript function in the ActiveX Web browser

  I have a requirement to call a Javascript function in a web page that is displayed in the browser's ActiveX control.  I have the control on the front panel, and I use the Navigate method to call to the top of the appropriate page.  Based on an example, I found, I'm trying to get a reference to the HTML Document so that I can then get a reference to the Fenetreparent.  There is a method of the HTML Window object called execScript who I'm calling.  See the attached image of the code (reference close calls do not appear, but when I run it, they are there).

  I can't the node property that returns the parentWindow reference.  The error I get is the following.

  Error-2147467262 LabVIEW: (Hex 0 x 80004002) No. taken such interface supported.

  Any ideas on where to go from here?

  

  Hello

  I have reproduced the issue and the error you are seen and tried to understand what is the solution.

  It seems that the problem is with getting the pointer to the parentWindow.  From what I read on MSDN, it's maybe a limitation in the use of an ActiveX control in LabVIEW. It seems like Internet Explorer creates the object of the window, and so opening in one ActiveX control you free access to this top-level object.

  Here could be workaround for javascript execution in your program:

  

  I would like to know if it works for you and if it will work in your program.

• How to use the node to call a library function to convert C++ source codes

  Hi all

  There are two dll name 'QMSL_WLAN_Transport.dll' and 'QCAMSL_MSVC10R.dll' and some codes c ++ to connect to the DUT. The two DLLs work together for communicaite with the DUT.

  I am confused as how to use the node to call a library function to load the 'QCAMSL_MSVC10R.dll' function as

  g_hResourceContext = QLIB_ConnectServer_UserDefinedTransport((HANDLE) USER_HANDLE,
  UserDefinedSend,
  UserDefinedReceive,
  UserDefinedFlushTxRx,
  true,
  true);
  

  It seems that 'UserDefinedReceive, UserDefinedSend, UserDefinedFlushTxRx' Processaddress?  And "UserDefinedReceive, UserDefinedSend, UserDefinedFlushTxRx"'s functions in 'QMSL_WLAN_Transport.dll '.

  UserDefinedReceive = (_UserDefinedReceive)GetProcAddress(hUDT,"UserDefinedReceive");
  UserDefinedSend = (_UserDefinedSend)GetProcAddress(hUDT,"UserDefinedSend");
  UserDefinedFlushTxRx = (_UserDefinedFlushTxRx)GetProcAddress(hUDT,"UserDefinedFlushTxRx");
  

  Attached DLLs and C++ code snippets.

  Need help.

  Thank you.

  These parameters are reminders - pointers to functions that are called by the DLL - and there is no way to duplicate this purely in LabVIEW. Search this forum for the word "recall" and you will find similar questions (for other DLLs). You will need to write your own DLL (in C, C++, etc.) that implements these functions and provides a way to transfer data to LabVIEW.

• How to call a DLL function that has need of an array initialized structures which can be written in by the DLL?

  I need to call the following function in a C DLL:

  __declspec (dllexport) int MSIL_EnumSpectrometers (SPECTROMETER_ID * spectrometers);

  where the only parameter is a pointer to:

  typedef struct
  {
  tank model [32];
  series char [32];
  Channel int;
  } SPECTROMETER_ID;

  Before LabVIEW 2011 I would use a CIN allocate the memory and call the function, but in LabVIEW 2011, the INC has been deleted and I have to use a library function node call instead. When I go to set the parameter, it seems that I need to set the type to "Adapt to the Type" and data for 'Pointer to data in table' Format, then pass an initialized array of SPECTROMETER_ID with the many elements he so the DLL can fill the table with data. (See the attached picture.) When I do that, however, it blocks LabVIEW desktop.  I guess it is because the DLL is corrupting the memory space of LabVIEW, but I don't see why, because I'm basically passing in a void pointer to an array initialized in the right size. Note that the first node of NSI returns the number of elements required in the table.  Anyone have any idea what I'm doing wrong here?

  In LabVIEW, when a table is in a cluster - cluster don't detain actually table but sort of a pointer that points to the table. If you need the cluster to contain 32 to 32 Add to the cluster. See the VI attached to how it's supposed to be done.

• Call the library function does not find the DLL in the directory where are my LLBs

  I'm using LabVIEW 8.6.  I have a set of screws in several LLBs.  All LLBs located in a directory.  Most of my screws is wrappers for the functions in a DLL.  I was told to put my DLL in the directory where are the LLBs, and apparently this is how the previous programmer has worked (using an earlier version of LabView).

  In the configuration of the library call, I've specified .dll without path.  (This is how we want our screws are an API that will integrate other programmers, so I don't know where they put things and I can't use absolute paths).

  When I insert the VIs in LabVIEW, LabVIEW can not find the DLL and wonder of spotted.  It's just that here in the directory with the LLBs and when I double click on it, everything works fine.  However my absolute path to the DLL now appears in the library to call configuration, and we don't want that.

  Does anyone know how to make this work?  I guess the location of the screw (or LLBs, in this case) should be the current directory and thus Windows search there for the DLL.  However, it seems that this is not the case (in the least, in the latest version of LabVIEW).

  Thank you.

  Batya

  Well someone using your library should not have to dig into your screws and do it all on his own. Instead your library must wrap that and hide disorders it altogether.

  The cluster of error has been added when the dynamic path option has been added. It is not useful hide this error output, so it's always there. As well as the dynamic path, there was the improved error handling added the CLN. One of them is that the level of verification when calling function errors (exception handling) can be specified. I guess that some of these options may generate an error code instead of bring up a dialog box, as they did before and that the output of error code can be useful even in the case of static calls.

  As to what you want to do, I would have long managed that with a DLL that has essentially the same functions as your other wrapper DLLs and an initiliasation function that returns a pointer to a structure of functional distribution based on the actual DLL you want to call. Quite like what an object-oriented function dispatch table is. Then, when your interface initilising you call initialize function and specify the device interface/type that you want to use and after that all other functions take a pointer extra function parameter expedition as the first parameter, in addition to the parameters of the real function. This dispatch function pointer would be just a pointer to a structure that contains the table of function for this interface pointers and the sake of LabVIEW would simply be an integer of size pointer.

  The wrapper function then checks the pointer structure validity send feature and call the actual function with the remaining parameters. It is a C programming and may require a planning and desigining the different interfaces to facilitate this kind of technique of the expedition, but it will certainly pay to long-term and make your library even can be used in previous versions of LabVIEW, so that VB etc. without delicate dynamic loading in the level high, programming environment.

  Rolf Kalbermatter

• How to read / write to a HID device with call a library function?

  I had tons of problems to read from a device USB HID in VISA. I had no problem make a driver for him and write it in LabVIEW. However, whenever I try to read using Read Visa, Visa USB Control In or interrupt USB event get different types of error messages.

  I decided to give up this route and talk to the device through hid.dll, setupapi.dll and any other .dll that I need to use. The problem is that I'm not sure I correctly use the nodes to call a library function... I've seen several KB articles that explain how to set up the nodes call library feature, but I need more information. I can configure stuff and sometimes get things to work, but I don't always know what each specific selections in Settings tab is doing. Can someone give me more detailed information on what do the settings tab and all of its components?

  Thank you

  Matt

  Have you looked HERE?

  Shane.

• External function with a pointer to a callback within a DLL function

  Hello.

  I am loading a DLL and try to call a function with the following prototype:

  Func1(HANDLE, hHandle, LPVOID (*pCallback)(UINT, UINT LPVOID), CHAR* sPath)
  

  Now, I have no problem with the types of variables, because CVI 9.0.1 recognizes each of them and I have no problem with LoadLibrary() and GetProcAddress().

  But, how to pass a pointer to a callback function that is inside the DLL, I am trying to use.

  I tried to declare the callback like this:

  LPVOID (CALLBACK Callback)(UINT iDevNo, UINT evEvent, LPVOID pData);
  

  and call the Func1 function like this:

  (Func1)(hHandle, &Callback, NULL);
  

  but it irritates me:

  Symbol not defined "_Callback@12" referenced in "source.c.

  Hopefully I can help.

  I appreciate your time on this issue.

  Kind regards.

  Hi Daniel,.

  He must first make sure that the callback function is exported by the DLL, so the program that uses the DLL can access the identifier of the function name. Then you must make sure that you call GetProcAddress not only on Func1, but also on the exported callback function. You must store the two address function values in their respective function pointers. You can then pass the pointer to callback in the form of argument to the call to Func1.

  It's probably cleaner if you set of typedefs for all your function pointers, in the calling program:

  typedef LPVOID (__stdcall * CallbackType) (UINT, UINT, LPVOID);
  typedef? (__stdcall * Func1Type) (HANDLE, hHandle CallbackType, CHAR *);

  ...

  CallbackType CallbackPtr;
  Func1Type Func1Ptr;

  ...

  dllHandle = LoadLibrary ("... ») ;
  CallbackPtr = (CallbackType) GetProcAddress (dllHandle, 'Callback');
  Func1Ptr = (Func1Type) GetProcAddress (dllHandle, "Func1");

  ...

  Func1Ptr (..., hHandle, CallbackPtr, NULL);

  Boa kind!

  Luis