COMPONENT MAINTENANCE MANUAL
AVIATION RECORDERS
FA2100CVR
Rev. 15 Page 12
Apr. 14/16
Description and Operation
23–70–04
Use or disclosure of information on this sheet is subject
to the restrictions on the cover page of this document.
E.
Data Recording Storage
Refer to Figure 5 for a diagram of the FA2100CVR recording schemes used in the
30-minute and 120-minute recorders and Table 1 for a breakdown of the recording
durations for each of the High Quality and Standard Quality combined channels.
The audio received from the cockpit area microphone (CAM) is applied to the CAM
input channel (CH4). The recorded CAM audio has a bandwidth of 150 to 6000
Hertz. The other three channels receive audio from the pilot audio selectors and
have a bandwidth of 150 to 3500 Hertz. The spare audio input applied to Channel 1
may be from a third crew member or PA system.
The four audio input signals are applied to separate input circuits located on the Au-
dio Compressor PWA for amplification and shaping with equalization performed as
necessary. These four streams are then converted to a digital pulse code modula-
tion (PCM) 16-Bit word format on the Audio Compressor PWA and then routed to the
Acquisition Processor PWA. The PCM data for each channel is then encoded for
storage using an adaptive differential pulse code modulation (ADPCM) processor.
These four streams are recorded as high quality (HQ) audio for a 30-minute dura-
tion. In the case of P/N: 2100
−
1X25/1X26/1X27
−
XX and 2100
−
1X20
−
XX MOD
−
DOT #7, these HQ Channels are recorded for 120
−
minutes. The rate of the data
stream recorded varies with the type of audio as follows:
F
24 kbps for CH 1, 2, and 3 HQV
F
48 kbps for CH 4 HQC
In the 120
−
minute FA2100CVR (2100
−
1020
−
XX pre MOD
−
DOT #7), three of these
audio streams (pilot, co-pilot, and spare CH1, 2, and 3) are combined to provide a
fifth audio stream, designated Standard Quality Voice (SQV), to be recorded in stan-
dard quality audio. In the 120-minute FA2100CVR version (2100
−
1020
−
XX pre
MOD
−
DOT #7), a sixth audio stream is formed using using the Standard Quality
Cockpit Area Microphone (SQC) input. All six digital-encoded ADPCM signals are
applied to the CSMU for storage in the solid-state flash memory. In this case, the
rate of the data stream recorded varies with the type of audio as follows:
F
24 kbps for CH 1, 2, and 3 HQV
F
48 kbps for CH 4 HQC (CAM)
F
16 kbps for SQV and SQC (CAM)
In both versions of the Model FA2100CVR, the four primary audio streams are al-
ways recorded as high quality audio (HQV) for 30 minutes. In the 120-minute Model
(2100
−
1020
−
XX pre MOD
−
DOT #7), the Standard Quality Voice (SQV) and Cockpit
Area Microphone channels (SQC) are recorded for a minimum of 120 minutes.
The document reference is online, please check the correspondence between the online documentation and the printed version.
