Instruction manual

MERLIN LEGEND Communications System Release 5.0
Maintenance and Troubleshooting
555-650-140
Issue 1
June 1997
Glossary
Page GL-32
power supply
module
Device that directs electricity to modules and
telephones on the system. One power supply
module is needed for each carrier, and an auxiliary
power unit is added if the module exceeds capacity.
PRI (Primary Rate Interface) Standard interface that
specifies the protocol used between two or more
communications systems. As used in North America,
provides 23 64-kbps
B-channels for voice and/or
data and one 64-kbps D-channel, which carries
multiplexed signaling information for the other 23
channels.
primary system
operator position
First jack on the first MLX or analog multiline exten-
sion module in the control unit; that is, the extension
jack with the lowest logical ID in the system.
prime line Individual extension number assigned to a telephone
in a system operating in
Behind Switch mode. Each
telephone user has his or her own prime line and is
automatically connected to that line when he or she
lifts the handset.
processor module Module in the second slot of the control unit
(Slot 0,
to the right of the power supply module). Includes
the software and memory that runs the system.
programming port
reassignment
Reassignment of the system programming jack
position to any of the first five extension jacks on the
first MLX module in the control unit.
protocol Set of conventions governing the format and timing
of message exchanges between devices, such as an
MLX telephone and the control unit.
public network Network that is commonly accessible for local or
long-distance calling. Also called “public switched
telephone network.”