The cascadable ADN PS Power Supply allows the extension of the conference and discussion system to up to 400 conference units. It also increases the failure-safety of the system by allowing redundant ring-cabling (redundancy rings) on its two double conference ports. Up to 40 units can be connected in two rings and up to 70 units in alternative branch cabling (daisy-chain branches). Status LEDs at the front of the 19″ rack-mount unit indicate the type of cabling to easily monitor the system.