W3C

– DRAFT –
WoT-WG - TD-TF - Slot 1

06 November 2024

Attendees

Present
Cristiano_Aguzzi, Ege_Korkan, Jan_Romann, Josh_Thomas, Kaz_Ashimura, Klaus_Hartke, Kunihiko_Toumura, Luca_Barbato, Mahda_Noura, Michael_Koster, Tomoaki_Mizushima
Regrets
-
Chair
Ege
Scribe
Ege, EgeKorkan, cris

Meeting minutes

Minutes

https://www.w3.org/2024/10/30-wot-td-minutes.html

Ege: any concerns?
… hearing none, minutes are approved

Quick Schedule

Ege: first BACnet, and then initial conenction. then registry if time left

BACnet

PR 381

<kaz> wot-binding-templates PR 381 - fix: add day of week to BACnet protocol binding's Date and DateTime types

Ege: BACnet datetime extends ISO 8601
… so Dogan has adapted the regex

Ege: klaus do you want to summirize your contribution?

<kaz> ISO 8601 (Wikipedia)

Klaus: we need a way to express the intervals when clients can do a certain action
… the solution that I'm proposing is to re-use part of ISO8601
… with some minor extensions
… however, we should explain this choice better in the future

Ege: I think this feature might be applied to other use cases too
… for now we can limit this to bacnet

Koster: changes are fine

PR 379

<kaz> wot-binding-templates PR 379 - BACnet support for events

Ege: this is interesting for everyone not just bacnet
… actions are required to correctly model events in BACnet
… the actions are application logic relevant not low level protocol
… in practice we have a sort of state machine here
… the example td cannot be easily adapted to other protocols
… this example shows that we have also events as manageable afforndaces

Cristiano: ok with the concerns, but I'm not sure we should display this workaround in the specification

Klaus: Event word is confusing, in BACnet the right word is Alarm
… it is a long running process
… and it requires somebody (from the application level) to acknowledge it.
… a generic TD consumer does not know about this little protocol
… this is a fundamental question about WoT
… some people say that this consumer might be particularly aware about the low level protocol
… we could make this state machine writable in a standard way
… we need a short term solution for now

Luca: this is very protocol specific and it is perfectly fine
… I'm ok for the proposed solution for BACnet
… for the future it would be interesting to further explorer

Ege: there might be interesting cases on other bindings

Klaus: alarms might not BACnet specific

Luca: some protocol do have the concept of acknowledgment

Klaus: in HTTP you could poll a resource to get an alarm

Luca: which is the layer that have this kind of interaction

Ege: in this specific case is more application level

Luca: to me it is just a detail
… if you want to translate protocol to protocol
… you still need a markup
… I agree it is not just something specific to BACnet
… profile could deal with specific constraint of the protocol
… we can try even ensuring that the compatible client won't do wrongdoings.
… we also have the problem this kind of behaviours might change a lot from different use cases

Ege: we will get there when we have more examples

Luca: this is an event that need to trigger an action, we have the situation in which an action can be canceled through another action or a property may trigger events depending on its state, e.g. turning on an oven triggers events about cooking status
… but the combinations might be a lot
… getting a container to have some sort relationship
… it is better than ad hoc solutions

Cristiano: ok to publish this, however I would add similar examples to http binding for the managiable actions use case or pagination
… plus we could consider to extend the affordances and add alarm as an affordance type

Koster: we are not extending events or actions, but rather we are creating an application state machine
… thanks for bringing this up

Luca: we could try to write an example of a possible markup to bind together some affordances... but when ? we still have to close other topics
… I would first close the connection feature

Ege: I agree

Cristiano: +1

Ege: I am not sure about the proposed solutions but for sure this is something we could work on

Klaus: how BACnet consumer can use this example?

Ege: for me it can search inside forms you have bacnet specific key words

Koster: can we introduce a BACnet vocabulary term

Cristiano: I agree

Kaz: I would like to suggest to clarify these points as Editor Notes

[adjourned]

Minutes manually created (not a transcript), formatted by scribe.perl version 238 (Fri Oct 18 20:51:13 2024 UTC).