Avaya Definity 8-Port Data Line Circuit Module Card TN726B V3. The TN726B data line circuit pack has eight serial asynchronous EIA ports with modem interfaces that are connected through asynchronous data units (ADUs) to EIA ports (such as RS-232) on DTE. The TN726B circuit pack uses Mode 2 or Mode 3 data transfer protocol. The DTE can be adjuncts and peripheral equipment such as data terminals, printers, host computers, personal computers (PCs), graphics and facsimile systems, and call detail acquisition and processing systems (CDAPSs). With software-administered system access ports, a TN726B circuit pack connects through a cross-connect field to a TN553 packet data line circuit pack. The TN553 circuit pack then converts mode 2 protocol to mode 3 protocol that transfers the TN726B circuit pack from the packet bus to the TDM bus for EIA connections. Each port on a TN726B circuit pack has TXT (terminal, transmit, and tip), TXR (terminal, transmit, and ring), PXT (port, transmit, and tip), and PXR (port, transmit, and ring) signal leads.
Model Number: TN726B
Avaya Part Number: TN726B V3


