The device is equipped with two bistable relays (8 A, 250 Vac), and three voltage-free, non-optically insulated inputs; the 5-Vdc scanning voltage is generated by the device itself. The transponder reader has on the front four LEDs for signaling indications. It requires a 10...32Vdc/12...24Vac auxiliary power supply to ensure its operation even in case of KNX voltage failure.