Another thing a came across, was that with subscriptions (at least for KNX) it makes sense to have field addresses that allow matching multiple values.
For example if I have an address */*/12, I get all the actual temperature values for all rooms in my house. The problem now is, that if I simply return a PlcValue (or multiple) ... we no longer know which address a value belongs to. So I was thinking: - We distinguish between pattern-fields and normal fields. Normal fields identify only one element, Pattern Fields can identify multiple values. - If a normal field is used, a normal PlcValue is returned - If a pattern field is used, a PlcStruct is returned (even if it's only one element) where the name of the property name is a stringified representation of the address and the value is the PlcValue Does this make sense? Chris Am 12.11.20, 23:15 schrieb "Łukasz Dywicki" <[email protected]>: Looking at subscription methods - I am not sure if there is one standard which can support all three kinds at the same time. Some kind of distinguish is necessary, but for an end user (counting myself) - multiple types of subscription happening at the same time are rather unlikely to happen. Looking from canopen perspective - there is possibility to subscribe to some messages happening directly on the bus if plc4x becomes a so-called master node (that's the way its implemented currently using EVENT subscription kind). There is also possibility to subscribe over coordinator node which is specified by yet another specification which number I don't remember right now. In theory - we could also subscribe to other node messages since canbus is still a bus system so everyone sees everything. Later two cases are currently left unimplemented. Best, Łukasz On 12.11.2020 18:33, Christofer Dutz wrote: > Hi all, > > I’m currently implementing the different subscription types in KNX4Go … and here I noticed something. > We create a SubscriptionRequestBuilder and here can add different types of fields and even combinations. > So we could create a subscription request with some on-value-change fields, some periodically pulled fields and some events/alarms. > > Now does it actually make sense to have this sort of combinations? I mean the program processing the results has to be very flexible in this case. > > Wouldn’t it make sense to have 3 different types of subscription requests? > > Chris >
