Instruction manual

159
Power and Circuit Packs
Circuit Packs and Power Supplies List
May 2003
The X.25 protocol (Levels 1 and 2) is terminated and the data is reformatted into the ISDN
packet mode protocol for transport across the LAN bus. Supported adjuncts include AUDIX,
CMS, and Message Server Adjunct (MSA).
The TN577 also supports Distributed Communications System (DCS) by providing X.25
signaling through:
• One of the RS-423 physical ports
• Through the system using the TDM Bus to the appropriate DS1 or tie trunk circuit pack.
TN725B Speech Synthesizer
The TN725B speech synthesizer supports English and is used in the United States.
The TN725B speech synthesizer circuit pack has four ports that send voice message
information to telephones to activate leave word calling, automatic wake up, voice message
retrieval, and Do Not Disturb features. The ports can detect tones.
TN726B Data Line (8 ports)
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.
TN735 MET Line (4 ports)
The TN735 MET line circuit pack has four ports that connect to multi-button electronic
telephone (MET) sets. Each port has tip and ring (analog voice) and digital signals to control
terminals such as BT, BR, LT and LR.