#314 B.39: improve definition of @MaxDelayTime

[Björn Andersen]

The definition has significant shortcomings, e.g. that it is unclear whether averaging period is included or not (should be conditional, not MAY). Seeing that we require this parameter for all MedX metrics in MPKP, the definition should provide as much guidance as possible.

[Simon]

Proposal for update

Maximum delay to real time.
For a measurement or calculation, the maximum delay to real time is the estimated or known maximum difference between the point in time when a physical variable value has been present and when the value has been computed and is ready for communication excluding communication delay.
For a setting, the maximum delay to real time is the estimated or known maximum difference between the point in time when a setting has been confirmed to be applicable and the time when the setting becomes effective on the actuator. This does not include any communication delay.

As this is a worst-case value right now, I would propose to include an optional @AverageDelayTime that contains the average delay time for >= N consecutive determinations. Proposal for N would be 10, but is negotiable.

[Björn Andersen]

Solved in PR#208.