LabVIEW
how to accesss Dll's Related to the display card
No, you can't simply convert an exe into a DLL without the source code for the executable, which I doubt you have. What you usually do is invoking the executable with the LabVIEW "System Exec.vi" function and passing the command line parameters to the executable in that way. This assumes that the executable supports command line parameters to do what you want to control with it, of course.
Rolf Kalbermatter
Rolf Kalbermatter
command line means the actual DOS command you would enter on the Command Prompt otherwise, to start that application. It typically looks like this:
C:\WinNT\System32\yourapp.exe /I /F C:\somedatfile.dat
The first part is the executable program to start up, then follow some switches or flags to tell the application to behave in a certain way and last is a command line parameter consisting of a file path, which the program might read to further execute specific things. The path for your executable is obvious, the rest you will have to find in the documentation for your executable program you want to invoke in such a way and it may be in many cases not officially documented, which would mean you can't execute it in such a way.
The standard input is optional and won't work with most Windows applications, which have some sort of graphical user interface. For simple command line applications only, it would allow to pass in the characters you want the application to see during its execution as if they would have been entered over the keyboard.
Rolf Kalbermatter
C:\WinNT\System32\yourapp.exe /I /F C:\somedatfile.dat
The first part is the executable program to start up, then follow some switches or flags to tell the application to behave in a certain way and last is a command line parameter consisting of a file path, which the program might read to further execute specific things. The path for your executable is obvious, the rest you will have to find in the documentation for your executable program you want to invoke in such a way and it may be in many cases not officially documented, which would mean you can't execute it in such a way.
The standard input is optional and won't work with most Windows applications, which have some sort of graphical user interface. For simple command line applications only, it would allow to pass in the characters you want the application to see during its execution as if they would have been entered over the keyboard.
Rolf Kalbermatter
@tanisha_lv wrote:
hello ,
Facing a bit of a problem while working with DLL's .
An image application vendor has provided with the dll and using this i m creating i own user interface .but after passing the parameters to the "call library function node" and when i run my VI ,it completely closes LabView 7.1
what can be the possilble reasons ?
i find the user manual a bit confusing because it also talks of building library functions.
regards
tanisha
Well, DLL interfacing is really something completely different than what you are used in LabVIEW. The fact that LabVIEW has a possibility to access DLLs does not mean that using that feature is as simple and painless as the rest in LabVIEW. DLL interfaces are based on classical programming languages and here mostly C. This means that in order to interface them you really should understand some basics about C programming. Without this knowledge it gets messy and painful very fast. No manual about Call Library Node usage can possbly replace a fundamental introduction into C programming, which in my case was acquired over years from sources like C programmer manuals, ANSI C standard manuals, LabWindows CVI programmers reference manual, Microsoft Developer Network, studying many Open source projects and examples and last but not least weeks and weeks of programming with the trial and error method. There exist no simple shortcuts to this other than hiring someone who knows all these things already.
Especially interfacing something like an image acquisition library over the Call Library Node in an efficient manner is something I would estimates more in weeks than hours of work for myself. Without some fundamental C programming knowledge this is most likely going to be an exercise in vain with lots of crashes and no working code in the end. I'm sorry for the bad news but I don't think it makes any sense to claim interfacing DLLs is even remotely as easy as most other things in LabVIEW.
Rolf Kalbermatter
