The Abacus is a people counter, used to measure the use of meeting rooms. The unit needs to be permanently powered by 5V power supply. This unit is a standalone unit that communicates by itself, without the need for a relay unit.
High occupancy can indicate optimum space usage or crowding - which could mean your space needs expanding or reconfiguration. However, low occupancy could indicate underutilization of space, possibly indicating the need to make adjustments.