Writing an OPC client with Python ?

[pierlau]

Hello,

I use an OPC server for connection to DC Drive.
I would like to write a small OPC client.
I have the dll OPCDAAuto.dll which contains all class and method but I
wonder if its possible to instance in python the class that are in the dll ?

Thanks for your help .

Pierre

[Larry Bates]

pierlau wrote:

Hello,

I use an OPC server for connection to DC Drive.
I would like to write a small OPC client.
I have the dll OPCDAAuto.dll which contains all class and method but I
wonder if its possible to instance in python the class that are in the dll ?

Thanks for your help .

Pierre

You can call methods/functions in a .dll using ctypes.

http://starship.python.net/crew/theller/ctypes/

-Larry Bates

[pierlau]

Larry Bates a écrit :

pierlau wrote:

Hello,

I use an OPC server for connection to DC Drive.
I would like to write a small OPC client.
I have the dll OPCDAAuto.dll which contains all class and method but I
wonder if its possible to instance in python the class that are in the dll ?

Thanks for your help .

Pierre

You can call methods/functions in a .dll using ctypes.

http://starship.python.net/crew/theller/ctypes/

-Larry Bates

I have tried with ctypes.
I acheived to load the library
it works when I use following instructions :
print windll.OPCDAAuto or print cdll.OPCDAAuto
(i see an handle number)
But I can't run the functions?
I there a way to 'see' the inside of the dll
(i.e. to list the methods) ?

[Larry Bates]

pierlau wrote:

Larry Bates a écrit :

pierlau wrote:

Hello,

I use an OPC server for connection to DC Drive.
I would like to write a small OPC client.
I have the dll OPCDAAuto.dll which contains all class and method but
I wonder if its possible to instance in python the class that are in
the dll ?

Thanks for your help .

Pierre

You can call methods/functions in a .dll using ctypes.

http://starship.python.net/crew/theller/ctypes/

-Larry Bates

I have tried with ctypes.
I acheived to load the library
it works when I use following instructions :
print windll.OPCDAAuto or print cdll.OPCDAAuto
(i see an handle number)
But I can't run the functions?
I there a way to 'see' the inside of the dll
(i.e. to list the methods) ?

There may be but you really need to have the .DLLs API defined for
you somewhere. You aren't going to be able to determine the type
and geometry of arguments, return values, etc. without some docs
on what functions there are in the .DLL and what arguments they
take and what gets returned.

-Larry Bates

[Jarek Zgoda]

pierlau napisa³(a):

You can call methods/functions in a .dll using ctypes.

http://starship.python.net/crew/theller/ctypes/

I have tried with ctypes.
I acheived to load the library
it works when I use following instructions :
print windll.OPCDAAuto or print cdll.OPCDAAuto
(i see an handle number)
But I can't run the functions?
I there a way to 'see' the inside of the dll
(i.e. to list the methods) ?

Look for C header file (*.h) for this library or find docs.

--
Jarek Zgoda
http://jpa.berlios.de/

[F. GEIGER]

About a year ago I dev'ed a host app in Python (2.3 at that time) to control
a KUKA KR16 robot. Comm was over OPC. The OPC 2.0 server was inst'ed on the
KRC2. What I was needed to do, was to install the appropriate (i.e. delivere
together w/ the server) client software and to take Mark Hammonds COM Makepy
utility to to create the wrapper. The rest of the story was fun, pure fun,
as Python programming always is.

So, register the client software, fire up PythonWin, start the COM Makepy
utility and wrap that DLL. If you are completely new to this stuff, it might
help to look at all that from w/i MSVB 6.0 or something like that.

HTH
Franz GEIGER

"pierlau" <pi*****@free.fr> schrieb im Newsbeitrag
news:44***********************@news.free.fr...

Hello,

I use an OPC server for connection to DC Drive.
I would like to write a small OPC client.
I have the dll OPCDAAuto.dll which contains all class and method but I
wonder if its possible to instance in python the class that are in the dll
?

Thanks for your help .

Pierre