Secutron MMX Series

104
Addressable Loop Interference on Phone Handset Lines
• For class B wiring, leave the shield unconnected at the end of the line.
Figure 64 Telephones and addressable modules showing shielded wiring (Class
A)
Figure 65 Telephones and addressable modules showing shielded wiring (Class
B)
MIX-M500FP(A)
MIX-M500FP(A)
+
-
FIRST
Firephone
Module
LAST
Firephone
Module
TNC-5000
-
+
-
+
Shield
twist-on connector
Shield
Shield
to S terminal
near the RS-485
on main fire
alarm board
twist-on connector
-
+
-
+
Main
Board
Shield
twist-on connector
-
+
-
+
twist-on connector
twist-on connector
twist-on connector
Shield
Shield
Shield
-
+
-
+
-
+
-
+
Shield
twist-on connector
MIX-M500FP(A)
MIX-M500FP(A)
+
-
FIRST
Firephone
Module
LAST
Firephone
Module
TNC-5000
-
+
-
+
twist-on connector
Shield
to S terminal
near the RS-485
on main fire
alarm board
-
+
E.O.L.
3.9 kΩ
twist-on connector
E.O.L.
3.9 kΩ
-
+
-
+
Main
Board
twist-on connector
twist-on connector
twist-on connector
twist-on connector
Shield
Shield
Shield
Shield
Shield
Shield
-
+
-
+
-
+
twist-on connector
Shield