FUNGSION

The main purpose of an NTBA is to provide the NT1 function as per ITU-T I.411/I.412, i. e. detect the signals arriving on a two-wire line from an exchange, evaluate and convert them to the subscriber’s four-wire connection and vice versa. This involves: • Processing the line code 2B1Q or 4B3T • Access control via signaling channel D • Rapid fault detection through switching transparent loops • Flexible powering arrangements: – integ. power supply for 230 V – integ. power supply for 115 V – emergency operation via the remote power fed from an exchange • The NTBA supplies connected terminal equipment either directly from the integrated power supply (normal mode) or via the remote feed from the exchange in order to ensure that one terminal equipment maintains the basic telephony functions (emergency operation mode). Device Versions • For line code 4B3T: – NTBA for 230 V with integral power supply • For line code 2B1Q: – Euro-NTBA for 230 V with integral power supply – Euro-NTBA for 115 V with integral power supply Special device variants allow explicit use in different customer networks