PASSENGER ADDRESS SYSTEM DESCRIPTION
GENERAL
The Cabin Intercommunication Data System (CIDS) directors (DIRs) accept audio signals from the various Passenger Address (PA) sources in the aircraft. The active DIR assigns priorities to each
source. It transmits the signal in digital form via the four top-line data buses to the type A Decoder/Encoder Units (DEUs) and, optionally via the Passenger Entertainment System Main MUltipleXer (PESMMUX), to each Passenger Control Unit (PCU). The type A DEUs send the signal to the cabin loudspeakers for broadcasting. The announcements can be heard, at each passenger seat, with a headset.
The Cabin Intercommunication Data System (CIDS) directors (DIRs) accept audio signals from the various Passenger Address (PA) sources in the aircraft. The active DIR assigns priorities to each
source. It transmits the signal in digital form via the four top-line data buses to the type A Decoder/Encoder Units (DEUs) and, optionally via the Passenger Entertainment System Main MUltipleXer (PESMMUX), to each Passenger Control Unit (PCU). The type A DEUs send the signal to the cabin loudspeakers for broadcasting. The announcements can be heard, at each passenger seat, with a headset.
SOURCES
A PA announcement can be manually initiated from the cockpit and from the cabin. The announcement from the cockpit can be initiated with:
– the cockpit handset,
– other equipment: handmic, boomset mic, oxygen-mask mic in conjunction with the Audio Control Panels (ACPs),
– the NO SMOKING and SEAT BELTS switches set to ON. The announcement from the cabin can be initiated with:
– the attendant handsets,
– the Forward Attendant Panel (FAP): from which the prerecorded announcements, stored in the PRerecorded Announcement and Music (PRAM), can be selected and initiated, as the BoardinG Music (BGM),
– if a video system is installed, PA announcements can be initiated from the Video Control Unit (VCU) (optional).
A PA announcement can be automatically initiated from the PRAM when:
– the NO SMOKING and SEAT BELTS cockpit switches are set to AUTO and according to the airline definition,
– a cabin decompression occurs.
A PA announcement can be manually initiated from the cockpit and from the cabin. The announcement from the cockpit can be initiated with:
– the cockpit handset,
– other equipment: handmic, boomset mic, oxygen-mask mic in conjunction with the Audio Control Panels (ACPs),
– the NO SMOKING and SEAT BELTS switches set to ON. The announcement from the cabin can be initiated with:
– the attendant handsets,
– the Forward Attendant Panel (FAP): from which the prerecorded announcements, stored in the PRerecorded Announcement and Music (PRAM), can be selected and initiated, as the BoardinG Music (BGM),
– if a video system is installed, PA announcements can be initiated from the Video Control Unit (VCU) (optional).
A PA announcement can be automatically initiated from the PRAM when:
– the NO SMOKING and SEAT BELTS cockpit switches are set to AUTO and according to the airline definition,
– a cabin decompression occurs.
PRIORITY
The basic levels of priority are:
– 1st priority: Flight compartment,
– 2nd priority: Cabin attendant stations,
– 3rd priority: Prerecorded announcement (if installed),
– 4th priority: Boarding music and/or entertainment system (if installed).
As an option the FWD attendant station could have the 2nd level of priority, in this case the other attendant stations will have the 3rd level of priority. The levels of priority and the defined options are programmed in the Cabin Assignment Module (CAM).
The basic levels of priority are:
– 1st priority: Flight compartment,
– 2nd priority: Cabin attendant stations,
– 3rd priority: Prerecorded announcement (if installed),
– 4th priority: Boarding music and/or entertainment system (if installed).
As an option the FWD attendant station could have the 2nd level of priority, in this case the other attendant stations will have the 3rd level of priority. The levels of priority and the defined options are programmed in the Cabin Assignment Module (CAM).
PA LEVEL
The volume of PA announcements can be automatically adjusted if several conditions are met. It is the active DIR which establishes the level according to the software, sending the level setting to each individual type A DEU. Then the type A DEUs do the required amplification. When an engine is running, the PA volume is increased automatically by + 6 dB. The PA volume is also increased by + 4 dB in the event of cabin depressurization. Depending on software, PA level may be adjustable via Programming and Test Panel (PTP) menu screens.
The volume of PA announcements can be automatically adjusted if several conditions are met. It is the active DIR which establishes the level according to the software, sending the level setting to each individual type A DEU. Then the type A DEUs do the required amplification. When an engine is running, the PA volume is increased automatically by + 6 dB. The PA volume is also increased by + 4 dB in the event of cabin depressurization. Depending on software, PA level may be adjustable via Programming and Test Panel (PTP) menu screens.
Credit : Renu Kumari
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