RTS SSA-424A - Manual (Page 16)

Installation
12
2-Wire Call Signal
Call Signal Connections for Audiocom, RTS TW
and Clear-Com
The call signals are superimposed on the audio signal, so no
separate call signal connections are required. However,
make sure that a call enable switch or jumper is installed for
Clear-Com applications as shown in Figure 6 on page 11 and
Figure 7.
Call Signal Connections for Other 2-Wire
Communication Systems
Any other 2-wire device must be able to generate and
receive a 20 kHz signal superimposed on the audio as
follows:
SSA-424A Signal Specifications for balanced configuration:
SSA-424A Receive: 20 kHz ±100 Hz, 100 mV
RMS
SSA-424A Send: 20 kHz ±800 Hz, 500 mV
RMS
, ±10%
SSA-424A Signal Specifications for unbalanced
configuration:
SSA-424A Receive: 20 kHz ±100 Hz, 100 mV
RMS
SSA-424A Send: 20 kHz ±800 Hz, 350 mV
RMS,
±10%
FIGURE 7. Call signal connections for a 4-wire intercom system
other than ADAM, ADAM CS and Zeus.
Balanced Audio Configuration
Pin 1 No Connection
Pin 2 Balanced 20 kHz + Input/Output
Pin 3 Balanced 20 kHz - Input/Output
Unbalanced Configuration 1
Pin 1 20 kHz Common
Pin 2 20 kHz Input/Output
Pin 3 No Connection
Unbalanced Configuration 2
Pin 1 20 kHz Common
Pin 2 No Connection
Pin 3 20 kHz Input/Output