E&M SIGNALING
Most signaling systems, other than loop signaling, are
separate from the trunk equipment. They are normally
located between the trunk equipment and the line facility.
E&M signaling systems derive their name from the
historical designations of the signaling leads on
schematics covering these systems. By convention, the
"E" stands for ear and the "M" stands for mouth (rEceive
and transMit). The E&M lead signaling interface consists
of two leads between the switching equipment (central
office) and the signaling equipment (PBX). The “M lead
carries signals from the switching equipment to the
signaling equipment. The “E” lead carries return signals
from the signaling equipment to the switching equipment.
The E&M interface is designated as TL31M, and the 50-
pin connector is designated as RJ2GX. At the RJ2GX
interface, the PBX is the switching equipment side, and
the network side (toward the central office) is the
signaling equipment side. An example of E&M signaling
is shown in Figure 1-11.
Theory of Operation 1-45
Содержание administration and
Страница 1: ...AT T 518 600 016 MERLIN II COMMUNICATIONS SYSTEM Installation Administration and Maintenance Manual ...
Страница 40: ...FIGURE 1 9 System architecture Theory of Operation 1 37 ...
Страница 175: ...Top cover Front cover FIGURE 2 27 Control unit covers Testing the System 2 107 ...
Страница 177: ...Top cover E m p t y m o d u l e FIGURE 2 28 Installing the control unit top cover Testing the System 2 109 ...
Страница 179: ...Front cover E m p t y module FIGURE 2 29 Installing the control unit front cover Testing the System 2 111 ...
Страница 211: ...FIGURE 3 I A MERLIN II System Display Console The Administrator Attendant Console 3 3 ...
Страница 213: ... FIGURE 3 2 A BIS 34D Console The Administrator Attendant Console 3 5 ...
Страница 217: ...1 1 FIGURE 3 3 Administration Menu for MERLIN II System Release 3 The Administrator Attendant Console 3 9 ...
Страница 218: ...t FIGURE 3 4 Administration Menu for MERIJN II System with Feature Module 2 3 10 The Administrator Attendant Console ...
Страница 331: ...General Tests 4 55 Reaming the Control Unit 4 55 Testing Outside Lines 4 56 ...
Страница 389: ...Section 5 Ordering Information Ordering Information 5 1 Product Listing 5 1 Ordering Information 5 1 ...