An elevator control mode that collects and serves all hall and car calls only in the downward direction of travel, used mainly in residential buildings.
Full Definition
Down collective control (DCC) is a dispatching mode where, during the upward trip, the car answers only registered car calls; when travelling down it stops at all landing calls in sequence. This means passengers wanting to go up must first ride to the top with the car, then descend stopping at each intermediate floor that has called. DCC is suited for residential buildings where the dominant traffic pattern is tenants returning home — descending from the lobby. It requires minimal control complexity compared to full-selective collective and reduces the number of floor stops when the building is occupied mainly by people leaving. EN 81-20 does not mandate a control mode but various national codes and fire-service regulations interact with collective control logic.
