Sequential Occupancy Detection System. B&C Transit completed office systems for 24 locations to detect occupancies from MUX inputs and shadow trains with pseudo occupancy (rear end protection) using dynamic logic within redundant system servers at each TCR location. SORS computers integrate with Allen-Bradley PLC’s and send all information to the Central mainframes at BART Central via BARTNET (Ethernet IP) for display on on all BART graphical mainline systems.