
PS Engineering
PAC45J Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-045-2000
Page 2-10
November 2020
2.7.4
Logic Switch Details
SWITCH
NUMBER
FUNCTION
ON
OFF
1
FAILSAFE ALERTS TO
CREW
PILOT AND COPILOT HEAR
ALERTS IN FAILSAFE MODE
NO ALERT AUDIO IN
FAILSAFE (RADIOS
ONLY)
2
FAILSAFE ALERTS TO
OBSERVER
OBSERVER STATIONS HEAR
ALERTS IN FAILSAFE MODE
NO AUDIO IN FAILSAFE
3
ALERTS TO CREW
PILOT AND COPILOT HEAR
ALERT AUDIO
PILOT AND COPILOT
DO
NOT
HEAR ALERT
AUDIO
4
ALERTS TO OBSERVERS
OBSERVER STATIONS HEAR
ALERT AUDIO
OBSERVER STATIONS
DO NOT
HEAR ALERT
AUDIO
5, 7, 9, 11, 13,
15, 17, 19, 21
ALERT TRIGGER
EDGE TRIGGERED
LEVEL TRIGGERED
6, 8, 10, 12, 14,
16, 18, 20, 22
ALERT POLARITY
ACTIVE HI TRIGGER
(5 TO 28 VDC)
ACTIVE LOW TRIGGER
(GROUND)
23, 24
RESERVED
DO NOT TOUCH
MUST BE OFF
25
COPILOT CONTROL
HEAD INSTALLED
COPILOT CONTROL HEAD IN
USE
NO COPILOT CONTROL
HEAD
26
OBSVR 1 CONTROL
HEAD INSTALLED
OBSERVER 1 CONTROL HEAD
IN USE
NO OBSERVER
CONTROL HEAD
27
OBSVR 2 CONTROL
HEAD INSTALLED
OBSERVER 2 CONTROL HEAD
IN USE
NO OBSERVER 2
CONTROL HEAD
28
REVERSIONARY MODE
SEE §2.7.4.1
USER STATIONS “REVERT” TO
OTHER CONTROL HEADS
WHEN FAILED
USER STATIONS IN
FAILSAFE WHEN FAILED
29
TRANSMIT MUTE
COM RECEIVE AUDIO MUTES
FOR ALL HEADSETS
TRANSMITTING WHEN ANY
TX PTT IS PRESSED. COM TX
IS STILL HEARD (PREVENTS
SQUEALING ON CLOSE
FREQS)
SELECTED COM AUDIO
IS HEARD DURING
TRANSMIT
30
STUCK MIC ENABLE
IGNORES PTT IF GROUNDED
FOR MORE THAN 35 SEC.
NO STUCK MIC
TIMEOUT
31
MICROPHONE
SENSITIVITY
REDUCED MIC SENSITIVITY
FOR LOUD COCKPITS
NORMAL MIC
SENSITIVITY
32
PASSENGER 1, 2 OR
CREW OXYGEN MIC
P453-15 BECOMES PILOT O
2
MIC
P453-16 BECOMES COPILOT
O
2
MIC
P453-15 BECOMES PASS
1 MIC
P453-16 BECOMES PASS
2 MIC
33
PASSENGER 1, 2 OR
OBSERVER OXYGEN MIC
P453-17 BECOMES OBSVR 1
O
2
MIC
P453-18 BECOMES OBSVR 2
O
2
MIC
P453-17 BECOMES PASS
3 MIC
P453-18 BECOMES PASS
4 MIC
34
COM 7 & COM 8 AUDIO
OR COM 1 & COM 2
SIDETONE
J452-33 IS COM 1 SIDETONE
INPUT
J452-34 IS COM 2 SIDETONE
J452-33 IS COM 7
AUDIO INPUT