Total occupancy but larger spaces can be segmented however they might want (order line, dining, bathrooms, bar area, etc.) Just need to separate two sections with a sensor.
1 sensor... ingress = movement into one area out of an adjacent area. Simultaneously, that counts as an egress (that person having moved out of that adjacent area into the next).
but what he's made of is two infrared distance sensors. measures ingress and egress.