PS Engineering
PAC45 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-045-0100
Page 2-7
January 2020
2.4.6 Unswitched inputs
These inputs are presented to the pilot and copilot regardless of the audio configuration, and
will always mute the crew entertainment inputs. These 510Ω inputs can be used for altimeter
DH audio, GPS waypoint audio, autopilot disconnect tones, or any other critical audio signal.
Unswitched #1 is always presented to the crew headphones, and is available to the pilot in fail-
safe (off) mode.
Unswitched
Input
Input Pins
Hear in
Fail Safe
Hear in
Crew Headset
Adjustable at
installation
1
P452 - 13
WRT
32
Yes
Yes
Yes
2
P452 - 1
WRT
20
No
Yes
Yes
3
P454 - 14
WRT
23
No
Yes
Yes
4
P454 - 13
WRT
22
No
Yes
Yes
Table 2-2 Unswitched inputs
2.4.7 Cockpit Voice Recorder
The PAC45D audio controller contains a Cockpit Voice Recorder output for the pilot and copilot
(PAC45D, -0005 and HUB45R -0101 only).
Pilot CVR output is P454-12; Copilot CVR output is P454-2, both with respect to CVR low, P454
21
A single pilot CVR output is available on PAC45D with a cockpit speaker output (PAC45D, -0006
and HUB45R -0103 only).
The CVR output is consistent with RTCA DO-214A §1.5.7,
2.4.8 Audio Alerts
The PAC45D contains an independent audio alerting system that will play up to three alert audio
messages.
These messages are spoken words “ALERT”
,
“MASTER CAUTION” and a
n audio chime.
The alert system has a power input (P451-16) that will keep the systems operable if the PAC45D
systems power source is removed. Alert audio is provided in Fail-safe when power is on P451-
16.
Alert Trigger Input
Audio
Input Pins
1
“ALERT”
P451
–
11
2
“MASTER
CAUTION”
P451
–
12
3
CHIME
P451
–
13
Alert Power
P451
–
16
Remote
Acknowledge
P454-9
The alert triggers can be configured to be Active High (>4.5 VDC) or Active Low (<0.5 VDC), and
trigger at the leading-edge transition or by the voltage level. See §
tions.
Alerts with edge triggers will play three times or until the front panel Acknowledge button (ACK)
is pressed (or the remote ACK P454-9 grounded).
Alerts with level trigger will play three times or until the front panel Acknowledge button (ACK)
is pressed (or the remote ACK P454-9 grounded), or the input level reverts.
When power is applied to the alerts and not the PAC45D audio controller, it will play the mes-
sage three times or until the remote acknowledge is selected.
Audio alerts are inhibited for the first 30 seconds after power up to reduce nuisance triggers.
PRELIMINARY
