Specifications

X723-300151 2-10 Issue 2
The RS terminal is used to indicate when ringing voltage is required to
switch on an external ringer, it is an open collector O/P. When RS = 0V
(battery +ve) then ringing voltage should be present on RV and RR. The
RS terminal does not have to be connected, ringing voltage may be present
continuously across the RV and RR terminals.
Section Backplane Link
RV RS
PORT 1 - PORT 3C LK5 LK6
PORT 3D - PORT 3G LK1 LK2
PORT 4A - PORT 4C LK3 LK4
PORT 4D - PORT 4F - -
Table 2-4 Ringing Voltage Isolation Links
The section of the backplane, port 4D to port 4F, is always connected to
the terminal block. If an internal ringer is used, no connection should be
made to the terminal block at the rear of the equipment.
The perspex cover on the terminal block must be fitted when an internal
ringer is fitted as ringing voltage will always be present across the
terminals. Note that ringing voltage will also be present on Pin 25a of the
DIN 41612 I/O connector for each port.
The backplane sections are as shown below.
RV
RR
RS
PORT4D
TO
PORT4F
PORT4A
TO
PORT4C
PORT3D
TO
PORT3G
PORT1
TO
PORT3C
LINKED
LK3
SEPARATE
LK1
SEPARATE
LK5
SEPARATE
LINKED LINKED
LK4
SEPARATE
LINKED
LK2
SEPARATE
LINKED
LK6
SEPARATE
LINKED
Figure 2-2 Ringing Voltage Backplane Links