COMPONENT MAINTENANCE MANUAL
AVIATION PRODUCTS
Model FA5000
Rev. 02 Page 41
July 21/17
Description and Operation
23–70
−
30
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the restrictions on the cover page of this document.
and Flash memory within the CSMU, that is used to store Data Link and audio data.
Each DSP has a total of 10k words of built
−
in RAM. Each DSP has access to 64k of
ROM for the executable program image. The system contains one NVRAM with a
minimum of 2k words being required.
(1) On
−
Board Maintenance System (OMS)
Interface
The CVR is identified as a
BITE Standard A
equipment so as to be portable to
other AIRBUS programs.
The CVR interfaces with the OMS through a system BITE such that the CVR
will pass fault information to the OMS (via SCI) and receive test request based
on two ARINC 429 buses (as per a
BITE Type 1
principle):
F
Use of one ARINC 429 High Speed (HS) output bus for continuous fault
reporting by means of the CVR output pins 50/51 (Data Link / OMS Out).
F
Use of one ARINC 429 Low Speed (LS) input bus for test request by
means of CVR input pins 39/40 (OMS IN).
(2) Fault Warning System (FWS) Interface
As per ARINC 757/A, the CVR transmits its status at a 1 Hz rate. The status is
transmitted on Label 350 per ARINC 429 in the format depicted in Attachment
19 of ARINC 757/A (CVR STATUS WORD).
The fault signal is indicated for any of the following (as per ED112 §2
−
1.4.2):
F
failure of the audio or digital interface and processing equipment.
F
failure of the recording medium and/or drive mechanism.
F
failure of the recorder to store the information in the storage medium as
shown by checks fo the recorded material including, if reasonably practi-
cable, correct correspondence with the inputs.
The following list explains system failures intended to be displayed with the
message: “CVR SYSTEM FAULT”
Table 2.
Software Fault Warning Failures
SSCVR label 350 bit 11
CVR CU label 350 bit 13
Datalink Recording label
350 bit 16
Failure of the audio circuit
Control Unit loads Its pow-
er supply below 15.5 Volts.
Failure of the recording
medium
Failure of the recording
medium
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