Private dll calling in Labview

Hi everyone, (refinement of my question)
I have two dlls. One contains public functions which I call from Labview. The functions in this dll call functions in the other (private) dll. However, how do I tell Labview where to find this private dll?
I have tried installing the dll in the system path directory. I have also put the dll in various different places relevant to Labview (e.g. in the directory of the Labview executable file). However, none seem to work (.
Is there an option in Labview where I can set paths to dlls?
Any help will be gratefully received.
Ciao,
Matthew Banham (colleague of Francois)

> I have two dlls. One contains public functions which I call from
> Labview. The functions in this dll call functions in the other
> (private) dll. However, how do I tell Labview where to find this
> private dll?
>
> Is there an option in Labview where I can set paths to dlls?
>
The problem is that the system loader is what handles the dependent
DLLs. Since LV knows about the primary DLL, we try multiple locations,
the path in the dialog, next to the VI, in the LV search paths, and
finally we ask the system to look in their places. LV doesn't know
about the dependent DLL, and it is up to the system to find it. I'd
recommend trying the system or windows folder again. That should be the
right solution.
An off the wall thought that might h
elp would be to add a dependency
directly into LV by making a DLL node that calls in the the "private"
DLL. You don't actually have to call it, you can place it in a case
structure with a constant set the other way. Anyway, this will cause LV
to look for the DLL, and I think it might help if nothing else works.
Greg McKaskle

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How to call a labview dll from excel-VBA?

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hello,
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MathITproblem.zip ‏1263 KB

Hi Srinivas,
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lvanlys.dll.txt ‏516 KB

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Thank you in advance.
#Date: Fr, 16. Sep 2011 16:25:25
#OSName: Microsoft Windows XP Service Pack 3
#OSVers: 5.1
#OSBuild: 2600
#AppName: PasTA
#Version: 11.0f2 32-bit
#AppKind: AppLib
#LabVIEW Base Address: 0x30000000
16.09.2011 16:25:26.181
Crash 0x0: Crash caught by NIER
File Unknown(0) : Crash: Crash caught by NIER
minidump id: 8a779b3f-51d7-4864-8e4d-6ab0195cd158
ExceptionCode: 0xC0000005
N
0x3072C804 - lvrt <unknown> + 0
0x3072CBB8 - lvrt <unknown> + 0
0x7C864191 - KERNEL32 <unknown> + 0
0x7C83AB50 - KERNEL32 <unknown> + 0
0x00000000 - PasTA <unknown> + 0
Attachments:
error.PNG ‏11 KB

On that note, you should be able to create DLLs in 2010 and run them with 2011, correct?? In my case, I have a 2010 built DLL (talking to sbRIO), most of the functions work when run in 2011, but a couple of them lock up LabVIEW on the desktop (but not the sbRIO), no lock ups happen with 2010 on the desktop.

Input parameter setting when calling a DLL(Built from LabVIEW and a kind of VISA communication driver) in Teststand.

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Attachments:
31.jpg ‏38 KB
11.jpg ‏36 KB
21.jpg ‏49 KB

Hi Srinivas,
Just another note, I noticed that the Math Interface Toolkit version (MIT) 1.0 is not compatible with LabVIEW 7.1. You’ll need version 1.0.1. of the MIT toolkit in order for it to work with LabVIEW 7.1.
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Attachments:
lvanlys.dll.txt ‏516 KB

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Hai,
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Examples:
I)
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void *p_device_config: How to access/pass these arguments in LabView and to which memory location it points in LabView.
II) #include <windows.h>
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With regards
Pavan Ramu Samu

"Somu" <[email protected]> wrote in message news:[email protected]...
Hai,
I am Pavan Ram Kumar Somu.
 
I am new to Labview, currently I am working on MVB Interface.
 
I need to access the API functions from *.dll file in Labview, as of now , I am doing this with Call function Library node in Labview but it does not support the following data types like
    1. Pointer Arguments(To which memory it points in Labview)
    2. function pointers Arguments
    3 .pointers in structures and pointer structures in structures and many other data types.
 
Please Answer the below queries also:
 
1. How to pass pointer arguments to API functions in DLL and how to collect pointer  
    return types from API functions in DLL
 
2. How to pass structure arguments to API functions in DLL and how to collect structure
    return types from API functions in DLL
 
3. How to use callback functions(nothing but function pointers) in Labview and how to
    collect callback fuctions return types from API functions in DLL
 
I need your help while passing these datatypes to API functions in DLL from labview.
 
Suggest me if there is any other alternative for implementing this task.
 
 
I am referencing some examples here:
Examples:
I)
Unsigned short int gf_open_device(void *p_device_config, unsigned long int client_life_sign_timeout, unsigned short int *device_error)
 
void *p_device_config: How to access/pass these arguments in LabView and to which memory location it points in LabView.
 
II) #include <windows.h>
     #include <process.h>
   
     HANDLE rcvEvent0, rcvEvent1;
 
/* Function call*/
CanGetReceiveEvent(handle[0], &rcvEvent0);
 
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Search the forum (forums.ni.com) for callback, pointer or handle, and you'll find that it is all possible, but not very easy.
e.g.: http://forums.ni.com/ni/board/message?board.id=170&message.id=88974&requireLogin=False
Regards,
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How do I call a LabView VI via dll to display its control panel in a tab of my uir in LabWindows

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When I run the VI, LabView 6.0.2 is crashing...
Here my export function prototype:
typedef struct
LVBoolean status;
long code;
LStrHandle source;
} TD1;
typedef struct
long dimSize;
unsigned char Numeric[1];
} TD2;
typedef TD2 **TD2Hdl;
void __cdecl driver(LVBoolean *SendCommand, unsigned char DataToSend[], long LenDataToSend, char RHICommandString[], TD1 *errorInNoError, LVBoolean *GetAnswer, LStrHandle *FrameReceivedID, long *Da
taLength, TD2Hdl *DataReceived, TD1 *errorOut);
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Thanks for your help,
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Hi Pascal,
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double Testdll(double B, double A);
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Feroz
Attachments:
SharedLib.dll ‏17 KB
SharedLib.h ‏1 KB
SharedLib.lib ‏3 KB

Labview 5.1 vs. 5.0 and dll calls

Hello!
I have Analogic cPCI-14-2 DAQ cards in the PXI box. Their driver is a dll
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I compiled executable from the DAQ module under 5.01 and 5.1. Executable
made under 5.1 would not even execute once, resulting in the crash. Then I
saved VI's using save as LV5.0 option, compiled executable under LV5.01 and
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because I needed to call Matlab. ActiveX server is actu
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DCOM in NT boxes, I can now run everything from my office super-duper
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Sincerely
Reinis Kanders

Mass compiled in 8.2.1
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines
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Keithly 8_2.zip ‏1231 KB

C++ Call to DLL made in LabVIEW Fails the second time it is called

I have an application where a C++ executive calls a LabVIEW DLL (a LabVIEW application built into a DLL).
The executive calls and operates the DLL fine the first time (NT, the applications task manager shows LabVIEW runtime runs, then stops when the DLL is done. However, when the executive calls the DLL a second time, it hangs, and the runtime engine never shows up in the applications task manager as running.
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Thanks a bunch

> Thanks for the information Greg. There is no documentation on this
> issue, except for the email that we got from NI Support. This is
> quite a new realm for us and NI alike. We would like to know what
> your experiences have been on this subject. If you have a bit of
> information, perhaps we should suggest a topic. As I said, this is a
> new frontier for LabVIEW, and there are a lot of things that NI
> doesn't know, and I'm sure a few of the programmers out there have
> figured out.
>
I often answer emails from home, but I work for NI on the LV development
team. So anything I know about, NI knows about. The info I was
describing about the DLL execution system is not well documented since
we were hoping that it would work we
ll with the way Windows Apps are
typically written. I suspect that we will need to write a Tech Note
to cover the nitty gritty. This sort of info gets lost in manuals,
and it is subject to change as we learn how people are expecting to
use it.
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Identify LabVIEW as DLL caller

I would like to be able to identify LabView as being the calling process of a C++ DLL (inside the DLL code). This way I can differentiate the behaviour of the DLL based on whether it is called from LabVIEW or from another programming environment. Does anyone have an idea how I could do this ?
Message Edited by Raistlin on 08-03-2006 09:13 AM

"Raistlin" <[email protected]> wrote in message news:[email protected]..
There are some interesting suggestions there. In fact, it should not only be able to identify if LabVIEW calls the DLL, it should also be impossible to act as if LabVIEW calls the DLL. It is in fact in the context of an SDK which we distribute to customers, which should be waterproof in terms of security. Only if it is called from LabVIEW certain possiblilities (such as a demo mode) should exist. We could off course work with two versions to make things easier.
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Settle for a mechanism that is waterproof enough. Removing it should cost (much) more than the official release. Spending one day to remove security mechanism from a 100$ toolkit would be kinda stupid. Also consider what public will use it. Big companies will usually not work with illegal software. The number of users is also important. If you're making something like Windows, or Word with millions of users, it will be cracked sooner that a LabVIEW SDK, with (hopefully for you) hundreds or max. thousends of users.
I'd use GetProcAddress, with NULL and any of LabVIEW.exe's export functions. LabVIEW will have them, the created executable won't. It will be very easy:
If (!tested)
If (GetProcAddress(NULL, "ASCIITime"))
labview=true;
tested==true;
Easy to make. Also easy to remove if you're making a c or c++ dll.
Let us know how it turns out.
Regards,
Wiebe.

DLL build by Labview App Builder doesn't work if Built-IN functions used!?

Hi All,
I hope somebody shed some light on this;
(All VIs are in the attached case1-2.zip)
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case1-2.zip ‏44 KB

Joel A wrote:
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and 7.1.
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Rolf Kalbermatter
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

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Hi
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m_ComboDevices.AddString(name);
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m_ComboDevices.SetCurSel(0);
OnCbnSelchangeDevices();
m_BtnConnect.EnableWindow(false);
m_BtnDisconnect.EnableWindow(true);
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Best regards

Hi
I have attached the help file describing the dll library (MTBApi.dll). My working program made on Visual C++ Dot Net is very big and therefore I can’t attach it.
In my header file I import at the beginning the dll library on this way:
#import "MTBApi.tlb" named_guids
using namespace MTBApi;
Than I have a class:
class CMTBClientUsingCOMDlg : public CDialogEx
public:
CMTBClientUsingCOMDlg(CWnd* pParent = NULL); // standard constructor
~CMTBClientUsingCOMDlg(); // standard destructor
enum { IDD = IDD_MTBCLIENTUSINGCOM_DIALOG };
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
protected:
HICON m_hIcon;
IMTBConnectionPtr m_MTBConnection;
IMTBRootPtr m_Root;
CComBSTR m_ID;
IMTBChangerPtr m_Changer;
IMTBDevicePtr m_Device;
DECLARE_MESSAGE_MAP()
public:
afx_msg void OnBnClickedConnect();
CButton m_BtnConnect;
In my .cpp file I have:
CMTBClientUsingCOMDlg::CMTBClientUsingCOMDlg(CWnd* pParent /*=NULL*/)
: CDialogEx(CMTBClientUsingCOMDlg::IDD, pParent)
m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
CoInitialize(NULL);
try
// create an instance of the connection class which can connect to the server
m_MTBConnection = IMTBConnectionPtr(CLSID_MTBConnection);
catch(_com_error e)
CMTBClientUsingCOMDlg::~CMTBClientUsingCOMDlg()
void CMTBClientUsingCOMDlg:isplayError(_com_error* e)
void CMTBClientUsingCOMDlg:oDataExchange(CDataExchange* pDX)
CDialogEx:oDataExchange(pDX);
DDX_Control(pDX, IDC_CONNECT, m_BtnConnect);
BEGIN_MESSAGE_MAP(CMTBClientUsingCOMDlg, CDialogEx)
ON_BN_CLICKED(IDC_CONNECT, &CMTBClientUsingCOMDlg:nBnClickedConnect)
END_MESSAGE_MAP()
BOOL CMTBClientUsingCOMDlg:nInitDialog()
CDialogEx:nInitDialog();
void CMTBClientUsingCOMDlg:nPaint()
void CMTBClientUsingCOMDlg:nBnClickedConnect()
try
// login to MTB, using english language
m_MTBConnection->Login(("en"), &m_ID);
// get MTB root (forcing an internal QueryInterface() on IMTBRoot!)
m_Root = (IUnknown*)(m_MTBConnection->GetRoot((BSTR)m_ID));
// ask root to return the number of devices
int count = m_Root->GetDeviceCount();
// list all devices
for (int i=0; i < count; i++)
_bstr_t name = ((IMTBIdentPtr)m_Root->GetDevice(i))->GetName();
catch(_com_error e)
// connection close
My question is how to start this code in labview. How to write the function in labview, par example this function:
m_MTBConnection->Login(("en"), &m_ID);
Best regards
Attachments:
MTBApi.zip ‏1935 KB

Error Code 1097 Coming in DLL Calling

Hi,
I am getting error code 1097 in DLL calling function. Please find the DLL calling function details for more information.
Function : GetControllerListTest(controller *ptrControllertest,char *max_controller);
Controllertest parameter details:
define NO_OF_CONTROLLER  100
#ifndef CONTROLLER_STRUCT
typedef struct
  CString name;
  char status;
  CString blocked_by;
  char group;
}controller;
Controllertest parameter data type is structure. In LabVIEW, I have configured parameter as a cluster.
name : String control
status : U8 Integer control
blocked_by : String control
group : U8 Integer control
Could you please confirm it, did I configured the datatype in correct way?
I am getting empty array output and Error Code from the DLL 1097. Can you please tell me where I am missing?
Thanks
Sivaramkumar.V
Solved!
Go to Solution.

Call Library Node problems without the VI in question attached AND the complete C prototype of the function provided, AND preferably some documentation about the C function in question can be not diagnosed. These informations are paramount to get the Call Library Node configured properly since there is no way a calling application can retrieve the necessary information from the DLL itself. The DLL interface was never intended to be a self configuring interface and it was designed with the understanding, that the user of such an interface is a fully knowledgeable C programmer knowing both, how to read a header file definition as well as various details about memory buffer handling.
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Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Private dll calling in Labview

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