[4diac-dev] Support for OPC UA events

[Matthias Konnerth <matkonnerth@xxxxxxxxx>]

Hi,
we want forte connect to a opc ua statemachine and gather the
transition events of it. To interact with opc ua statemachines the
mechanisms of method calls (supported by forte) and events (currently
not supported by forte) are needed.

I've done a little prototype implementation and now able to get
notified when a event is triggered on an opc ua object. (I don't
filter the event type or any other member of the event type).

Now I'm thinking about the interface, how it could be used in the 4diac ide.

Currently I'm using a SUBSCRIBE_0 FB with ID:

opc_ua[SUBSCRIBE_STATEMACHINE;<endpointurl>;<browsePath to Object I
want to monitor>;<NodeId of EventType I'm interested in>]

Next step would be to map the opc ua TransitionIds to the RD_1 ...RD_n
outputs as boolean flags for signaling which transitionEvent has been
fired.

You see, the interface is quite narrowed for supporting statemachines.

Do you think, this can be done in a more generic way?

Best regards,
Matthias.