(UN) Managed Wrapper calling LabView-Dll

Similar Questions

• Problem calling LabVIEW DLL with c#

  Dear all,

  I compiled a few DLLs in LabVIEW and called these DLLs using c#.
  I'm having trouble passing in strings and arrays as input and output of the DLL.

  Whenever I try to view the string I have entered in a dialog box (this part is written in LabVIEW DLL), a LabVIEW message dialog box appears and the program just stuck there.

  Whenever I try to enter a string or an array to the dll, Microsoft Visual Studio would display "attempt read or write protected memory. It is often an indication that other memory has been corrupted. »

  I attached the vi and also the c# .sln file.

  Can you guys please advise where am I wrong?

  Thank you very much.

  You must allocate strings and arrays of output!

  private void button1_Click (object sender, EventArgs e)
  {
  output string;
  int [] value;
  StringOutput ("A", "B", exit, 3, value, 4);
  }
  }

  Your variable output and value must be preallocated to ensure storage of 3 items respectively. 4. and since you want to receive the C string that you need to increase this to 4 characters terminated by a NULL value.

  String in c# is also a not a C string of object pointer. You must declare the StringOutput() function as follows:

  [DllImport("SharedLib.dll",CallingConvention=CallingConvention.StdCall, Charset=CharSet.Ansi]internal static extern int StringOutput(StringBuilder A, StringBuilder B, out StringBuilder StringOutput, int sizeString, out int[] output, int sizeArray);
  

  Then call like this:

  StringBuilder output = new StringBuilder(4);int[4] array = new int[4];
  
  StringOutput("A", "B", output, output.Capacity, value, value.Length);
  

  Please note that I'm not a pro in c# and usually do not do much in it. Also that this code has not been tested or updated at all, so probably contains some errors. He however point you in the direction of where to look further.

  What you need to understand, is that the C DLL that you created in LabVIEW has a so-called unmanaged interface. This means c# is not able to know how to manage the memory for the parameters at all and you have to do everything yourself, where the obligation to explicitedly initialize variables output and table with a block of memory préallouée.

• Implement the Std::Vector < < Point2i > > Std::Vector in dll wrapper for LabVIEW

  Hi, I'm writing a wrapper dll that using OpenCV function. I had been sucessfully implement Std::Vector by referring to "An array of clusters to a dll C sending".

  And now, I want to implement the Std::Vector<>> who is a lot like table 2D but each line items may be different.

  In LabVIEW, I attribute a range of cluster of the dashboard cluster of 2 I32 elements, structure which is shown below:

  

  I think it has the same functionality as Std::Vector<>> in C++.

  So I plug this data on the "Call library function node" structure and generate C code that indicated below:

  /* Call Library source file */
  
  #include "extcode.h"
  
  /* lv_prolog.h and lv_epilog.h set up the correct alignment for LabVIEW data. */
  #include "lv_prolog.h"
  
  /* Typedefs */
  
  typedef struct {
      int32_t elt1;
      int32_t elt2;
      } TD4;
  
  typedef struct {
      int32_t dimSize;
      TD4 elt[1];
      } TD3;
  typedef TD3 **TD3Hdl;
  
  typedef struct {
      TD3Hdl elt1;
      } TD2;
  
  typedef struct {
      int32_t dimSize;
      TD2 elt[1];
      } TD1;
  typedef TD1 **TD1Hdl;
  
  #include "lv_epilog.h"
  
  void funcName(TD1Hdl arg1);
  
  void funcName(TD1Hdl arg1)
  {
  
      /* Insert code here */
  
  }
  

  Then, I write this code show below in dll wrapper:

  void funcName(TD1Hdl Blobs)
  {
      vector < vector > blobs;
  
      // Distribute contents of blobs to Blobs from LabVIEW
      MgErr err = mgNoErr;
      size_t arraySizeInBytes = Offset(TD1, elt1) + sizeof(TD2)*blobs.size();     // Determine row size
      err = DSSetHSzClr(Blobs, arraySizeInBytes);
  
      if (err != mgNoErr)
          return;
  
      (*Blobs)->dimSize = blobs.size();
  
      for (size_t i = 0; i < blobs.size(); i++) {
          arraySizeInBytes = Offset(TD3, elt) + sizeof(TD4)*blobs[i].size();  // Determine col size of each row
          err = DSSetHSzClr((*Blobs)->elt[i].elt1, arraySizeInBytes);
  
          if (err != mgNoErr)
              return;
  
                  /*......................*/
          }
  }
  

  When I call LabVIEW dll, the program get interuption(i.e shutdown) on line where I want to determine the size of each row.

  Could someone give me some suggestions on this subject or promote another application of this requirement?
  Thank you very much.

  MgErr funcName(TD1Hdl Blobs)
  {
      vector < vector > blobs;
  
          Labeling(image_binary, blobs);         // the prototype of this function is: Labeling(Mat &binary, Vector> &blobs)
  
      // Distribute contents of blobs to Blobs from LabVIEW
      MgErr err = mgNoErr;
      size_t arraySizeInBytes = Offset(TD1, elt) + sizeof(TD2)*blobs.size();      // Determine row size
  
          if (contours == NULL)        {                Blobs = (TD1Hdl)DSNewHClr(arraySizeInBytes);                if (Blobs == NULL)                         err = mFullErr;        }        else                err = DSSetHSzClr(Blobs, arraySizeInBytes);
          if (err != mgNoErr)                return err;    for (size_t i = 0; err == mgNoEerr && i < blobs.size(); i++) {
          arraySizeInBytes = Offset(TD3, elt) + sizeof(TD4)*blobs[i].size();  // Determine col size of each row
  
                  if ((*Blobs)->elt[i].elt1 == NULL)                {                        (*Blobs)->elt[i].elt1 = (TD3Hdl)DSNewHClr(arraySizeInBytes);                        if ((*Blobs)->elt[i].elt1 == NULL)                                    err = mFullErr;                }                else               err = DSSetHSzClr((*Blobs)->elt[i].elt1, arraySizeInBytes);
                  if (err == mgNoErr)                {                        (*((*Blobs)->elt[i].elt1))->dimSize = blobs[i].size();
  
                          /*......................*/
  
                  }
          }
          (*Blobs)->dimSize = i;        return err;}
  

  Personaally I've usually done like this. Already, the tar of DSSetHSzClr() indicates if there was something wrong and that the handle cannot really become NULL to call this function.

  To be entirely correct and safety integrated, you must do more than that. But as long as you assume that the incoming picture is always smaller that the outgoing Board will be (usually it be 0 items when you enter this function, but if you reuse sort table in the diagram, by storing it in a registry change for example, this may not be true more) this will be enough.

• TestStand do not call a Labview DLL copied to a new location.

  TestStand v4.2 & v8.6.1 LabVIEW: I have a problem with TestStand calling a Labview project DLL. It will call the DLL successfully if it points its record source (the directory where the DLL was built. However if the DLL is copied to the clients working directory and the appellant TestStand step points to the copied DLL, the problem occurs. The TestStand calls the DLL from the working directory of the client, but does not execute the DLL, simply set the status of the step to "Done" where he clearly didn't.

  The vi named in the DLL has correctly, all handles error clusters such that if there is an error in the vi running, the error would be forwarded to TestStand.

  Any ideas please?

  Update: the original problem was never solved, but another method was used successfully to generate an Excel results worksheet. This used controls Active-X to open a file, import a model, write the data, close the file, and then make the new file read-only. It now everything works fine.

• LabVIEW DLL called from C

  I would like to create a DLL in LabVIEW which can be called from a C program.

  The purpose of the DLL is to display a dialog box along side a C program user interface and view a picture is updated continuously in the program.

  The LabVIEW DLL would be

  1 would be considered to be a dialog box that opens up along the side of the user interface of the C program.

  2. the DLL would regularly be called with the parameters passed by the C program.

  3. the dialog box would contains a picture that is updated by the parameters of the permanence of program C.

  Is this feasible?  I assume that the DLL has to work like a demon, because the DLL is a dialog that must cover along the side of the user interface of C.  To run a DLL written in LabVIEW, is the needs of PC - the runtime?

  Everything was OK until 5. For 6, you do not get a reference to something C. You simply call the exported function that is the VI 'set params.

  I have included a sample project to give you an idea. The code LabVIEW is written in LV 8.2 and the project with a version of a DLL specification. I used c# for this example, but you can easily translate it c If you wish.

• Problem calling seconday DLLs in labview

  Hello

  I'm using Labview 8.6 for my application. The application calls a dll developed in vc ++ (main dll).  During execution of the application, the main dll(vc++) calls another (secondary dll) developed in vb 6.0 dll.

  During the process, the main dll sends data to secondary dll to display data in a pop-up window. After getting the user recognize the display, the vi application stops.

  When the application runs first time (the vi running first time after labview open), the data sent by the main dll are updated in view of the secondary DLLs. But, for the second time from new data of the main dll not are not updated in view of the secondary DLLs.

  Once again, after the closure of the vi and quit labview, if I open and run the vi, then the data of the main dll are updated in dll secodary display. But the maindll data must be updated in the secondary dll without leaving labview.

  I use "Function Call Library" to call the maindll.

  Can someone please give the remody to this problem...

  Thanks in advance.

  Swamy.

  Is - this two dll to reside in the same physical directory as your main vi? They are included in your project?

  -AK2DM

• do not call the dll of Labview in CVI

  I have a Labview dll should call for the CVI. but it always shows error.

  void __cdecl Idx_RW_Reg (uint16_t registry, int32_t RegLength,
  [LVBoolean Data_in], uint8_t OperationRd1Wr0, TD1Hdl * read_reg_table_in,.
  uint16_t PortAddress, TD1Hdl * Table_of_reg_out, LVBoolean ControlFrame [],.
  uint16_t * PortAddressOut, int32_t len2, int32_t len);

  TD1Hdl * read_reg_table_in: what is it, who can tell me

  typedef struct {}
  int32_t dimSizes [2];
  LVBoolean Boolean [1];
  } TD1;
  typedef TD1 * TD1Hdl;

  Any help is greatly appreciated.

  Thank you.

  Hello

  What is your calling code?

  I suggest you read: call a LabVIEW DLL in a CVI or other C/C++ project

  Kind regards

• File not found when you try to call a dll on LabVIEW Real Time machine

  I have a dll called "DLLRTTEST" that I wrote, and claim successfully on my host.  Now, I try to call this dll from a vi that is on my computer in real time.  Currently, I get a message 'error 7 occurred at the crux of library DLLRTTEST.vi. call function' when running

  In the attached screenshot, I try to ensure that the vi that I am running is indeed on the system in real time.  I then use a 'check if file or folder Exists.vi' to confirm that the dll that I'm about to call exists on the system in real time as well.  However, I always get an error "error 7 file not found" from the node call library feature.

  Any help is appreciated.

  Thanks again for all the responses.  As I said earlier, I had already met and solved the problem identified in the link provided by Nathand.  I had to go down to Visual Studio 2008 to go beyond this particular error, after which the app of auditor of the dll in real-time reported my dll needs to run successfully.

  I just got the phone with Jack in charge NEITHER well, and it turns out that I simply had to compile my dll in release mode.  Decommissioning of VS 2008 I got the correct version of dll (msvcr90.dll), but since I am compiling in debug mode, I found myself using msvcr90d.dll (d for debug) who doesn't have my computer in real time.

• How does the library function call Labview? Can I emulate using C++?

  Hi all. I recently finished writing a dll CUDA for LabView, and now I'm in the steps of optimization of code, memory management, etc. BUT since my code depends on the entries of Labview (lots of data under types of specific data as table manages and Clusters labview) I can't use the CUDA Profiler or the Profiler VC ++ on the DLL. What I intend to do runs labview and then out of all data entry for the DLL in a binary file and then add an additional function in my code that will read in the binary file, allocate and assign variables to their respective positions, and then call the specific DLL function in Labview. In the end, this miniature function will act as the library function call to my specific group of data entries.

  In any case, I started to make this purchase all my data entry of cluster and it comes out in a binary file. And then I started the initialization of the handles of labview, allocating memory and begins to write the binary data in the memory and it works for integers (ints), floats, etc., but I'm confused on how it works with table handles!

  Some examples of code:

  Sets the Handle for table 1 d for INT
  
  typedef struct {}
  
  	int length;
  
  	int val [1];
  
  		to access the value in a row-online val [Online]
  
  } Array1dInt, * Array1dIntHandle;
  
  int main()
  
  {
  
  	Array1dIntHandle x = new Array1dInt *;
  
  	(* x) = new Array1dInt;
  ifstream file ('TESTDATAIN.dat', ios: in | ios::binary);
  If (file.is_open ())
  
  	{
  
  		file ((char *) &(*x)-> length, sizeof;)
  
  		file ((char *) &(*x)-> val [0], sizeof (int) *(*x)-> length);
  LabviewSpecificFunction (x);
  
  		leader. Close();
  
  	} else
  
  	{
  
  		< "file="" did="" not="" open!"=""><>
  
  	}
  
  	return 0;
  
  }
  __declspec(dllexport) LabviewSpecificFunction (Array1dIntHandle x)
  
  {
  
  ...
  
  }

  However, my program crashes when the table is nominally big, and it is expected, because if we look at the Array1dHandle, it has allocated only enough memory to 1 item of value! YET, somehow, in its magical and mysterious labview is capable of making val [1] be val [HOWEVERMANYYOUWANT], even if C++ 101 says that val [1] is a constant pointer, and even if I dynamically allocated memory another somwhere, I would never be able to put these data in this round!

  Can you explain, or maybe even write example on how I can fool my program into thinking that the binary code comes from labview, so I can then run my program independent of allowing me to profile the functions inside labview?

  I hope that this question is clear and my sample code is also clear, but I'm happy to answer any questions that relate to this.

  Thank you all!

  I think that I thought about it.

  Array1dIntHandle x = new Array1dInt *;
  int tempsize;
  
  file ((char *) & tempsize, sizeof;)
  
  (* x) = (Array1dInt *) malloc (sizeof (int) + sizeof (int) * tempsize);
  
  (* x)-> length = tempsize;
  
  file ((char *) &(*x)-> val [0], sizeof (int) *(*x)-> length);

  Well enough, you will need to make the handle, and then make a new Array1dInt * for him, then read in the length of the array in a temporary variable. Then use this information to then malloc memoery quantity you need for the table and pass this place on the handle. Now the handle will point to the size of the memory and you will be able to access the memory in the format, you've done the handle. Badabing badaboom

• Loading of a DLL on RT: Missing Export "DecodePointer" "Kernel32.dll" and 7 error when calling the DLL

  Hi, I recently changed to Visual Studio 2010 and Windows 7 64-bit.

  I have an existing Office RT system running RT 2009.  This system calls a DLL that I already built using Visual Studio .net 2003 and Windows XP.

  Since I've recompiled the DLL I get an error 7 file not found error when I call the RT DLL, even if I simply replaced the old DLL with a new one in the file system so the path has not changed.

  I also noticed that the message on the screen connected to the RT system during startup:

  "achieveworldpeace.dll" load error: lack of export 'DecodePointer' of ' Kernel32.dll'.

  Any ideas on this problem?  It is perhaps as simple as a switch in the compiler?

  Thank you.

  I'm not sure it's a simple switch in the project settings in Visual C. The problem is clearly in the standard C runtime library that gets linked to your DLL and refers to exports of Windows which are not available on the RT system. Don't forget that the RT system is a limited Win32 API emulation.

  I usually avoid these problems using Visual C 6 to create DLLs for LabVIEW projects. The standard library of the C runtimes will not know what Windows API reference more recent exports because they have supported even under Win95. So unless your explicitedly reference code not supported RT APIs you wouldn't have problems. If you do not use the standard C file i/o functions and management of memory in your DLL functions, you can also try to link statically C runtime libraries in your DLL, or vice versa depending on what you have now. It may or may not work. Otherwise there is not much else but by using an earlier version of Visual Studio.

• Loop timed in LabVIEW DLL does not close

  Hello!  I have what I think, it is a simple loop timed in LabVIEW that stops after 100 iterations by throwing an error and letting the loop 'stop on error.  It works fine when it is executed in the ordinary LabVIEW environment, however, when compiled as a Dynamic Linked Library (DLL) and called from LabWindows it requires me to put an end to execution, rather than going out nicely.  As well, it seems to leave the real appeal of virtual Instrument very well and go to the next line of code, but when my function main() in LabWindows is completed it must always be something not cleaned which is the cause not come out well.  Any ideas?   I tried to add only a call to QuitLabVIEW and that doesn't seem to do it.

  Thanks in advance - hoping you will notice an error really easy. )

  A photo of the timed loop is attached.

  An excerpt from the code of LabWindows:

  int main)
  {
  CallMyLabVIEWDLL();  This line launches successfully and closed the window for my virtual instrument LabVIEW
  MessagePopup ("' My Title:", "That occurs after the call to your LabVIEW DLL" ");    This popup appears - indicating the call to the DLL has finished

  But after the code has completed LabWindows always shows "running", rather than close.

  return 0;
  }

  Why do you use a loop timed in the windows environment?  They are best used for real-time environments (not windows) and tend to have more support than the time.

  Is there a particular reason, a while loop will not work?

• call LabVIEW screws in Visual Studio Express

  Hi, I have LabVIEW 2013 and I create a Vi in which I control some signals input and output for a NI PCIe. This VI must be integrated into a larger program developed in C++ in Visual Studio community 2015. Searching the net I found a lot of topics on the use of Visual Studio DLLs in LabVIEW, but I think in this case, I do the reverse process, because the main program runs in Visual Studio and I should call the LabVIEW VI from there. So my question is: which are the steps to do this? Any suggestions would be very helpful!

  If you have the Application Builder or professional development system you can not only create LabVIEW code executables but also dll. Turn your VI in a DLL and call your application Visual Studio. Alternatively you can also select to create a .net assembly and call it as such. For C++ but I would choose the path of the DLL.

  A few notes: a DLL LabVIEW requires the LabVIEW runtime to be installed on each computer that you want to use this DLL on. Also of course all drivers additional as DAQmx etc. If you use them in your screws. You can create an installer too when you have the Application Builder that includes all the dependencies, if you want.

  Last but not least LabVIEW dll (and executable files) are compiled for the target architecture CPU on which they are created, so if you use a LabVIEW 32 Bit in a 32-bit Windows process, the resulting DLL will be only executable. It is not a WinRT component which you can go from one platform to another platform.

• repeatedly calling a dll that contains a loop

  I would like to call a dll function that contains a while loop. This copy of the data to a buffer loop a signal command "on" is true:

  void Get (double * x, double * y, double z *, double *, double * P, double * R, int on)
  {
  int index is Index - 1;.

  while(on == 1)
  {
  If (index > = buffersize)
  {
  index = 0;
  }
  * x = buffer [index]. Position [0];
  * y = buffer [index]. Position [1];
  * z = buffer [index]. Position [2];
  * Y = buffer [index]. Angles [0];
  * P = buffer [index]. Angles [1];
  * R = buffer [index]. Angles [2];
  index ++;
  }
  }

  I want to call this function from dll once 'on' is set to true and it ends once it becomes false. I also want to be able to 'on' on and outside, so that it can copy data from the buffer when I want to. I could not find a way to do it, and whenever I walk through the program it does not 'stick' when the Get function is called (i.e. the while loop inside the GET is running), as I would expect.

  Thank you for any assistance.

  I guess 'Index', 'buffersize', etc., is static variables?

  In any case, once you called the function expected of LabVIEW for the function to fill. You can not dynamically pass a new value for "on" during the execution of the function. Note that this is not a question of LabVIEW. The same would be true when using this DLL from any other programming language. What you need to do is to have the function use static 'on' and then provide a separate function to set this value. Note that you must also configure the COLD LAKE to be "incoming".

• Set the string for LabView dll parameter

  Hello

  I created a simple vi LV 2010 (departure vi), which reads the identification of an oscilloscope. Then I take this vi and incorporate it into a dll of LabView. I have test the dll calling LabView (RunFrom dll). Basically, it seems to work, but len and ReadBuffer back empty. It must be in the way I'm configuration configuring the setting for Readbuffer (settings) in the configuration of the dll. I tried several different configurations, but nothing seems to work. Any help is appreciated!

  What is the parameter len?  Normally, you should only set the length of the string, but it seems that you did not do this.  Also, you're passing len by value, and not by reference, so the function is expecting her to be a starter and you will never get return a different value to any value that you provide.

  Do not use a local variable of the ReadBuffer for entry "readbuffer".  You must pass a string initialized long enough to contain the expected quantity of data.  The best way to proceed is to use the array to initialize to create a table of U8, then use the array of bytes to a string.  Set the parameter 'minimum size' to 'len' then run through the length of the string initialized (this is not mandatory but is recommended).  If you need the length obtained output, add another indicator and another parameter to this value.  There might be a way to do it with one by len parameter passing by reference, you need to experiment (it is certainly feasible in C but I don't know if allows him to LabVIEW).

• Generation of C++ with LabVIEW DLL error

  Hi, I am a student at the UC Irvine, learn how to use LabVIEW.  I'm working on a practice project for which I use a PID system to control the temperature of an object.  Things are starting to be a little awkward with the control statements nested, loops, etc., so I thought I have exported a LabVIEW DLL with all the difficult to encode things like interfacing with my instruments and tracing of data or something else and do the calculation and follow-up of the commands in C++.

  The DLL file I made in LabVIEW exploded without a hitch, as far as I can tell, but when it a link to my C++ test program (which at this point is just including the .h file of the LabVIEW for the DLL and an empty main() function), I get a lot of build errors.  I'm using Dev - C++ that uses g ++ to compile the code.

  Here is a picture of my build errors:

  Normal windows applications are not so forgiving on where you can put your DLL under LabVIEW. You must have a DLL or in the Active Directory where the executable file itself (this is your build directory, not the source directory), windows or directory system or any what directory defined in the PATH environment variable. Anythin else probably won't work, or at least not reliably.

  No need to add the cintools directory to your include paths or paths of the library file. You must only that if you decided to leave native LabVIEW DLL export data types, in which case you would need Manager of LabVIEW to prepare the correct data buffers.

  Rolf Kalbermatter