Many-to-many publish/subscribe

[Eccles]

I have been looking for evidence that IEC 61499 pub/sub might support
many publishers and many subscribers for any given "topic", but as far
as I can tell it is a one-to-many model. Depending on the way the
Standard is worded, this could be defined behaviour or implementation-
dependent behaviour.

In any case, I am looking for "message bus"-like functionality, in
which instances of an event type of common interest (and some
associated data) may be generated by multiple parties in the system,
and multiple interested parties may wish to react.

How would this be rendered in IEC 61499 function blocks?

Cheers,
Neil

[Jim Christensen]

The PUBLISH/SUBSCRIBE function blocks in the Compliance Profile at
http://www.holobloc.com/doc/ita/index.htm already use UDP multicast.
Other profiles may use other implementations of PUBLISH/SUBSCRIBE, but
so far there aren't any.

For a "local message bus" you can use the "Local Multicast" pattern at
http://www.holobloc.com/doc/despats/. To link it seamlessly to a
"distributed message bus" you can use the "Tagged Data" design pattern
supported by the FBDK .

- Jim C