Nortel Enterprise 1000 Reference Manual page 82

Page 82 of 236 Analog Trunk Cards - NT8D14 Universal Trunk Card
553-3023-211 Standard 1.00 June 2001
Continuous operation mode
In the continuous operation mode (sometimes called the Audichron mode), a
message is constantly played, over and over again. Callers "barge in" on a
playing message or are provided with a ringback tone until the message plays
again. The start line (ST+) is hardwired as always active. See Figure 31 on
page 80. At the end of each message, a pulse is issued on the "C" line that is
used by the trunk unit to cut through to the waiting call.
Note: The "B" (busy) signal line is used to indicate availability of an
announcement machine message to the trunk unit when configured for
the continuous operation mode. This signal is made active (ground) by
the announcement machine if the channel contains a recorded message
and is in an online condition. The "B" line is not connected to a trunk unit
when configured for start mode operation.
Start modes (minimum vintage BA)
In a start mode (sometimes called the Code-a-Phone or start-stop mode),
playback of a message does not begin until a start pulse is received by the
announcement machine. Two subcategories of the start mode exist: pulse
start and level start.
In the pulse start mode, a start pulse activates playback of a message that
continues until completion. The announcement machine ignores all other start
pulses that might occur until the message is complete.
In the level start mode, the start signal is a "level" rather than a pulse. The
leading edge of the start signal initiates message playback that continues until
either the trailing edge of the start signal occurs or the end of the message is
reached. A message that is terminated by the trailing edge of a level start
signal is immediately reset and ready for playback again.
Call routing to RAN trunks
Software in the Succession CSE 1000 controls recorded announcement
machines. These programs detect the calls to be intercepted, determine the
type of intercept treatment required (for example, overflow, attendant,
announcement), queue the intercept, and provide ringback tone to the calling