A receptacle block defines at least one socket at which a plug connector may be received. First contact members extend into each socket to receive a primary signal from a plug connector. Second contact members extend into one or more of the sockets to read physical layer information from any plug connector inserted into the socket. A sensing contact is positioned to electrically connect to one of the second contact members when a plug connector is inserted into the respective socket. At least a portion of the sensing contact is flexible to follow the movement of the one second contact member. In certain implementations, the second contact members have resilient sections that are identical to each other.