1.4.3.6
Remote Extension Tie Line Interface Unit (Figure
FIGURE 14 REMOTE EXTENSION AND TIE LINE
INTERFACE UNIT BLOCK DIAGRAM
Ring and Tone Source
provide two oscillators, one for busy tone and ringing signal cadence. A
60V generator is provided for signalling.
Tie Line Interface
is always loop in, ring out from the main equipment. It can be either
Ring-in/Ring-out,
or Loop-in/Ring-out
from the tie line. The tie line interface uses
the
signal for ringing and sends ring back tone to the main equipment or tie line.
Remote Extension Interface
connected a 2 wire decadic telephone to the A-pair audio path. A
CPU interprets decadic signalling from the remote extension and controls ringing signals for the
remote extension.
System Interface
controls data transmission to the main equipment via the B-pair. The same
CPU is used as in a normal station. Keys are simulated by ROM under control of the Remote
Extension Interface CPU LED information is sent to the Remote Station Interface.
40
ISSUE 1
