Function “a” (alternate intercom mode), Function “b” (monitor mode), Unction – PS Engineering PMA8000MP3 Installation Manual User Manual
Page 29: Lternate, Ntercom, Onitor

PS Engineering
PMA8000B-MP3 Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-890-0600
Page 3-8
Rev. 6, Oct. 2010
Figure 3-2 Smart Function Keys
Function A
AUX
Function B
MUTE
Function C
SPR
Alternate Intercom
mode
Monitor Mode
Music Distribution
State 1
State 2
State 1
State 2
State 1
State 2
State 3
“Alternate
intercom
function”
“Standard
Intercom
Function”
“Monitor
on”
“Monitor
off.”
“
Standard
music
distribution”
“Alternate
music
distribution”
“Music 1 all
headsets”
These functions are non-essential and non-required and as such are only an accessory capability. They
don’t affect the audio panel’s primary function as a selector panel, aircraft intercom, or marker beacon
receiver. You can’t do anything with these buttons to prevent the PMA8000B-MP3 from doing its main
job.
Looking at the front panel you’ll notice that the TEL, Aux, Mute and SPR buttons have “Function” a s-
signments.
To use these function keys A, B, C – press and hold “F” and then press the desired key, “A” “B” or “C”.
There are three special functions. Function Button “A” allows the front panel jack to be distributed to all
headsets..
Function Buttons “B” controls a monitor function (S/N E10251 and up) or B and “C” control how music
is distributed in your airplane (S/N E10250 and below).
There are two music sources available to the PMA8000B-MP3. Music 1 input can be either on the front
jack, OR the Music 1 input at the rear connector (Pins 23 and 24 J2). Music 2 is wired into the rear con-
nector, only (Pins 26 and 27, J2)
3.10.5 Function “A” (Alternate Intercom Mode)
Function “A” controls the distribution of aircraft radio within the intercom, as well as passenger intercom
muting. In the “standard intercom function” mode, aircraft radios are distributed to all, when the intercom
is in the ALL mode. In CREW mode, only the pilot and copilot positions will hear aircraft radios.
When Function A is toggled into “Alternate Intercom Function,” the passengers will NOT hear aircraft
radios, even in the all mode. They will be able to converse with the crew. However, when the aircraft radio
becomes active, the intercom audio from the passengers is muted, allowing the crew to focus on the radio.
The passengers will still be able to talk to each oth er.
3.10.6 Function “B” (Monitor Mode)
Pressing Function “B” will activate or deactivate the COM radio monitor function. When the Monitor is
on, the audio from the COM that is selected for reception only (only top LED illuminated) will be muted
when the radio that is selected to transmit becomes active.