RFC: Clarification and Update of Occupancy-related Points.

[jbkoh]

Based on the discussion at #32.

Motivation

Current usage of Occupancy, Occupied, Command and Status are not standardized and it's unclear when to use what. This RFC is unifying such clutter into using Occupancy and Command in general.

Introduce following TagSets:

• Occupancy_Command: Command informing Occupancy to target Points or Equipment.
  • Reasoning: "Occupied" in previous Occupied_Command misreads as it's only for true/false value.
• Scheduled_Occupancy_Command: Occupancy Command related to some Equipment, which is scheduled by a system in advance. For example, it may be on weekdays 7am-5pm.command used by the system at the moment.
• Override_Occupancy_Command: A type of Occupancy_Command that overrides other Occupancy_Value types such as Scheduled_Occupancy_Command. Usually a point of thermostats. Replace previous Temporary_Occupancy_Status to make the meaning clearer.
• Effective_Occupancy_Command: Occupancy_Command effective at the moment. It is usually calculated from other Occupancy_Command such as Scheduled_ and Override_Occupancy_Commands.

Remove following TagSets:

• Temporary_Occupancy_Status
  • Reasoning: The term is ambiguous and Override_Occupancy_Command
• Occupied_Command
  • Reasoning: It causes confusion with Occupancy_Command
  • Alternative: Keep both of them and make them sameAs. I however argue to avoid sameAs as much as possible as users will get confused. We have heard such complaints from users (which one to use between this and that?).
• Occupancy_Status
  • Reasoning: It was only subclassed by Temporary_Occupancy_Status. If it is removed, this has little usage. Occupancy_Sensor can easily substitute this.

[jbkoh]

Resolved by #42