Call Signal Connections For Other 4-Wire Communication Systems; 4-Wire Call Send And Call Enable/Inhibit; 4-Wire Call Receive; Figure 6. Typical Call Send And Call Enable/Inhibit Connections For A 4-Wire Intercom System - RTS SSA-424 User Instructions

2.5.2 Call Signal Connections for Other 4-Wire
Communication Systems

2.5.2.1 4-Wire Call Send and Call Enable/Inhibit

The SSA-424 accepts a switch-contact input from the
4-wire system and then generates a call signal output to
the 2-wire system. The SSA-424 also accepts an optional
switch contact input to enable or inhibit call signalling be-
tween the 4-wire and 2-wire systems. Figure
typical connections.
DB9F CONNECTOR PIN NUMBERS
(View from solder or crimp side)
1 2 3 4 5
6 7 8 9
CALL ENABLE/INHIBIT
4-WIRE CALL SEND
COMMON
Figure 6. Typical call send and call enable/inhibit con-
nections for a 4-wire intercom system.
6 shows the
CLEAR-COM APPLICATION NOTE:
IF A CALL ENABLE/INHIBIT
SWITCH IS NOT USED, A JUMPER
MUST BE INSTALLED TO ENABLE
CALL SIGNALING. THE JUMPER IS
NOT REQUIRED FOR ANY OTHER
APPLICATION.

2.5.2.2 4-Wire Call Receive

The SSA-424 receives call signals from the 2-wire sys-
tem, then converts this to relay contact closure for use as a
4-wire call receive indication. The SSA-424 also provides
+5VDC which can be connected to the relay contacts to
generate a DC output signal instead of a contact closure.
Connections for simple contact closure and DC output
signal are shown in Figure 7.
The SSA-424 power indicator flashes whenever a call
signal is received from either 2-wire line. This can be
used as an incoming call indication for the 4-wire
system if desired, and the level display should pro-
vide an indication of which line is calling.
5 VDC
DC COMMON
SSA-424 INTERNAL CIRCUIT FOR CALL SIGNAL
OUTPUT TO 4-WIRE INTERCOM SYSTEM
TO SSA-424 AUX CONNECTOR
DB9F CABLE CONNECTOR PIN NUMBERS
(View from solder or crimp side)
1 2
6 7
SIMPLE SWITCH CONTACT CLOSURE TO 4-WIRE
SYSTEM WHEN 2-WIRE SYSTEM CALLS
OPEN CIRCUIT FOR NO CALL
TO SSA-424
AUX CONNECTOR
(SYSTEM A OR B)
DB9F CABLE CONNECTOR PIN NUMBERS
(View from solder or crimp side)
1 2 3 4
6 7 8 9
+5VDC SIGNAL TO 4-WIRE
SYSTEM WHEN 2-WIRE SYSTEM CALLS
OUTPUT SHORTS TO COMMON FOR NO CALL
Figure 7. Call signal connections for 4-wire intercom
systems other than ADAM, ADAM CS, and Zeus.
User Instructions, SSA-424 Dual Digital Hybrid 13
AUX
CONNECTOR
(SYSTEM A OR B)
10 Ohm
PIN 9
PIN 3
PIN 4
PIN 8
PIN 5
3 4 5
9
8
TO 4-WIRE SYSTEM
5
TO 4-WIRE COMMON
TO 4-WIRE + INPUT