ReadProperty and WriteProperty are the most widely used BACnet services: they let a client (typically the BMS) read or write the value of a Property of a remote Object.

ReadProperty (Service Choice 12) and WriteProperty (Service Choice 15) are the foundation of traditional BMS polling. The supervisor periodically queries each Object on every controller to refresh its point database. The pattern is simple but verbose on the wire and is increasingly replaced by ReadPropertyMultiple for batched reads and SubscribeCOV for change-driven updates.

Avoid building a head-end supervisor that issues thousands of single ReadProperty requests per cycle: it works in lab conditions and collapses on MS/TP segments. Plan RPM and COV from the start.