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Tie Two-way Dial Repeating operation
In an incoming call configuration, the far end initiates a call by placing a low
resistance loop across the Tip and Ring leads. This causes a current to flow
through the battery feed resistors in the trunk circuit. Address signaling is
then applied by the far end in the form of DTMF tones or dial pulses. When
the called party answers, an answer supervision signal is sent by software,
causing the trunk to reverse battery and ground signals to the far end. The far
end then removes the low resistance loop and normal battery and ground are
restored at the system.
In an outgoing call configuration, the trunk is connected to another PBX by a
Tie trunk. An outgoing call from the system seizes the trunk facility by
placing a low resistance loop across the Tip and Ring leads. Outward
addressing is then applied from the system in the form of DTMF tones or dial
pulses (battery/ground pulsing). If answer supervision is provided by the far
end, reverse battery is received, which provides a disconnect supervision
signal.
Tie Outgoing Automatic Incoming Dial operation
When the trunk is seized by the far end on an incoming call, a low resistance
loop is placed across the Tip and Ring leads. Dial pulses are sent by the far
end by interrupting the loop current. The trunk is released at the far end when
the loop is opened. When it detects an open loop, the near end reverts to a
normal state.
When seized as a dial-selected outgoing trunk, the NTMW07 Trunk/Line
Card places battery on the Tip and ground on the Ring. This alerts the far end
of the seizure. The far end responds with a low resistance across the Tip and
Ring leads.
Recorded Announcement operation
In this mode of operation, the trunk is connected to a digital announcement
machine. The announcer provides a number of channels and operates in a
continuous mode, generating 150-300 ms common control pulses every 7 or
14 seconds (at the start of the announcement period). A number of trunks can
be connected to one announcement machine.
The NTMW07 Trunk/Line Card does not support the Code-A-Phone 210DC
announcement recorder.
Chapter 11 — NTMW07 Trunk/Line Card
Meridian 1 Option 11C Compact
Page 113 of 136
Technical Reference Guide
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