OPC Server in Python

[David Fraser]

F. GEIGER wrote:
> Hi all,
> 
> I consider writing a control application in Python (realtime stuff would run
> on hw, i.e. a PCI card). If I decide to do so, I'd like to provide access to
> the control app's data for OPC clients. This means writing an OPC Server
> (OPC DA).
> 
> Could I do this in Python too? At the core an OPC Server is a COM server,
> isn't it? Did anyone in this group do anything like that already? And if so,
> are you willing to share your experience?

I've tried to write an OPC server in Python, just for testing, I had a 
few bugs that I struggled to iron out but in the end I didn't need it so 
I never finished it, but it's definitely doable.
The nice thing is you could then write an OPC client in Python to test 
it as well...

> 
> Right now I'm trying to get more info about OPC, i.e. there are some
> additional issues like OPC Groups and OPC Items and Browsing etc.
> 
> Any books you would recommend? Other stuff to get me started quickly?

I would recommend looking at Lab43's LightOPC which is a C 
implementation of OPC code available under LGPL, you can use it as 
examples... Start with a simple server, look at the OPC 
groups/items/browsing later...

> 
> Any hint welcome!
> 
> Kind regards
> Franz GEIGER
> 

Would be good to hear how you progress...

David