The "transponder reader" is a flush-mounting device for British Standard wall boxes, designed to realize access control systems with a communication support based on KNX bus. It is equipped with one relay (4A @24 V AC/DC) and one input to be used for connecting external conventional card-holder (e.g. Zenit wiring accessories card-holder). The output can be programmed in three different ways: "Linked to access control", receiving in this case switching commands from the device itself (according to transponder card validation); being a standard KNX Switch actuator output, able to be controlled by every KNX standard devices; "linked to card-holder", that means that the relay is switched according to closing/opening internal input contact available on transponder reader. The bicolor (red-green) LED placed on the front of the device allow you to monitor device operation and can be also switched ON/OFF in the proper color according to KNX telegram (for example for DND/MUR purposes). The transponder reader can be configured with ABB Access control software in order to behave as transponder programming device. The transponder reader requires a 12...24 V AC/DC external power supply to ensure its operation even with bus voltage failure.