Relay module for video door intercom system VT200, for connecting an electric door opener (ET100A or other door openers with at least 50 ohm internal resistance can alternatively be connected directly to the door intercom) and for tamper-proof door opening. Reverse polarity-proof 2-wire bus connection (looped through) to a VT200 system power supply unit. Responds to switching commands from the indoor stations: either first door opener, second door opener or light as well as to RFID transponders. Door opening time: adjustable 5 - 30 seconds. Light switching time: adjustable 30 seconds - 15 minutes (in 30 second increments). Connection for external button. Door opener supply via bus: 12 V DC, max. 450mA. Potential-free changeover contact for controlling external power supply up to 230V AC, max. 6A. Power supply: 24-29V DC, max. 0.55W from system power supply. In REG housing for DIN rail mounting (4TE). Incl. wall bracket. Dimensions: 72 x 89 x 45mm.