EFJohnson 3000 SERIES - Manual (Page 116)

TELEPHONE INTERFACE MODULE (TIM)
14-6
14.2.4 TYPE I AND V
A straight interconnect between the trunk circuit
and signaling circuit. Two conductors are signaling
and four are balanced audio (see Figure 14-4
).
Figure 14-4 TYPE I AND V
14.2.5 TYPE II AND III
A straight interconnect between the trunk circuit
and signaling circuit. Two conductors are signaling,
four are balanced audio and two are System Battery
and System Ground (see Figure 14-5).
Figure 14-5 TYPE II AND III
14.2.6 TYPE IV
This interface is a cross-connect between the
trunk circuit and signaling circuit. Two conductors are
signaling, four are balanced audio and two are System
Battery and System Ground. This type of interface has
the M-Lead and System Battery cross-connected (see
Figure 14-6).
Figure 14-6 TYPE IV
14.2.7 TYPE II TRUNK-TO-TRUNK
Some applications may require an interface to
another trunk circuit (e.g. PBX). This interface is a
cross-connect between trunk circuits. Two conductors
are signaling, four are balanced audio and two are
System Battery (SB) and System Ground (SG). The
System Battery and System Ground are cross-
connected with the E-Lead and M-Lead (see 14-
7Figure 14-6).
Table 14-2 E&M LEAD STATES
M-Lead States for Type I through V
Type Idle Active
I Ground -48V
II Open -48V
III Ground -48V
IV Open -48V
V Open Ground
E-Lead State for all Types
7 (Off), 8 (On) Open Ground
7 (On), 8 (Off) Ground Open
TRUNK
CIRCUIT
E-LEAD
M-LEAD
RX AUDIO
TX AUDIO
TR1
RR1
T1
R1
E-LEAD
M-LEAD
RNT
SIGNALING
CIRCUIT
TRUNK
CIRCUIT
E-LEAD
M-LEAD
RX AUDIO
TX AUDIO
TR1
RR1
T1
R1
E-LEAD
M-LEAD
RNT
SIGNALING
CIRCUIT
SB
SG
SB
SG
TRUNK
CIRCUIT
E-LEAD
M-LEAD
RX AUDIO
TX AUDIO
TR1
RR1
T1
R1
E-LEAD
M-LEAD
RNT
SIGNALING
CIRCUIT
SB
SG
SB
SG