Mitel SX-2000 EL Information Manual page 252

SX-200 General Information Guide
Loop Tie Trunk
A tie trunk between PBXs which is seized by the application of a loop condition on the trunk.
Subsequent supervisory conditions can be determined by the presence/absence of the loop or
by battery-reversal conditions.
MCC
Main Control Card.
MDF
See Main Distribution Frame, page 238.
MODEM
A MOdulator-DEModulator is a piece of Data Communications Equipment (DCE) that accepts
data signals from a piece of Data Terminal Equipment (DTE) and converts them into modulated
tone signals suitable for transmission over telephone lines. The DCE at the far end converts
the tone signals back into data signals and sends them to its DTE. The data circuit is commonly
a duplex circuit; it is capable of operation in both directions simultaneously.
MPU
Main processing unit. In the SX-200 EL/ML system, this refers to the 68000 CPU on the main
control card.
Main Distribution Frame
The main distribution frame (MDF) forms the interconnection point between the in-house PBX
(for example the SX-200 EL/ML system, and the internal and external cabling to the PBX. The
MDF provides a convenient and flexible means of interfacing the cabling to the system.The
MDF is also known as the cross-connect field.
Message Subsystem
The message subsystem is one of the subsystem blocks of the SX-200 EL/ML system. Its
function is to act as the main message collection and distribution facility for the system, and
links the main controller with the intelligent entities at the peripheral level or below. In effect it
is the "nervous system" of the SX-200 EL/ML system, in that it passes messages and commands
between the lowest and highest levels of the system.
Mixed Station Dialing
The SX-200 EL/ML system caters to the use of both rotary dial and DTMF types of
industry-standard telephones installed on the system.
Multiple Consoles
More than one attendant console can be installed on an SX-200 EL/ML system. The trunk
groups can be arranged to terminate such that they can be accessed from all of the consoles,
and any call can be answered from any console.
238 Revision A 50003510