Station topology

Referential separates timetable geography from station operations.

There is deliberately no Station-to-Bay relation. A station is a timetable calling place. A bay is where Allocation sends a dated departure.

Destination and station

A Destination answers “which town?” A Station answers “which physical calling place inside it?” Stations retire rather than delete so historical itineraries keep resolving.

One deployment may manage several stations. managed is data on the station record, not a separate entity or hardcoded constant.

Station areas

Controlled kinds are FORECOURT, REGULATION, and PLATFORM. Areas support correction, retirement, and reactivation.

Retirement is refused while any active bay or checkpoint references the area. The conflict names every blocking reference.

Bays

A bay carries unique code, area, position, positive dimensions, and lifecycle. Temporary unavailability, reservation, occupation, and vehicle eligibility belong to Allocation or Rules.

Checkpoints and installed functions

A checkpoint is a directed edge from one area to another. Installed functions are RFID_READER, BARRIER, INTERCOM, and KEYPAD.

Each function has at most one active device. Replacement retires the previous installation in the same transaction and preserves history. Referential stores wiring references, never vendor protocols, addresses, or credentials.

Guarantees

• Codes are unique within each catalog.
• Bays and checkpoints cannot reference unknown or retired areas.
• A checkpoint cannot connect an area to itself.
• Corrections never change durable codes.
• Lifecycle changes record reasons where required.
• Retired records still resolve by ID and code.