Assignment is carried out with respect to the input port.
Furthermore the CFDIU carries out correlation of this
fault (see Correlation Function below).
It detects intermittent operation of the system and adds (INTM) to the message so as to indicate that the system operates intermittently.
Example of message:
NO XXXX...X DATA (INTM) 9 char. max.
NOTE : The CFDIU does not monitor the non-refreshment of
____ the ECB bus when it is not supplied in flight.
-Acquires the fault messages and memorizes them:
* Type 1 or 2 systems
It checks the validity of the received frames (messages)
prior to their memorization.
The following checks are performed:
. Delta Block Word Count of first Start of Text (STX)
more than 0.
It checks that the number of words received between the
first STX and the End of Transmission (EOT) is equal to
the Block Word Count of the first STX.
R 1EFF : 106-149, 155-199, 208-299, 301-399, 1 31-32-00Page 51 1401-499, 1Aug 01/05 1 1 1CES 1 It checks that the Block Word Count associated with the STX(s) (except the first one in the frame) is at zero. It checks that an End of Text (ETX) is always followed by an STX. In these conditions the message(s) corresponding to the Block Word count increase is(are) acquired and memorized. Increase of the Block Word Count indicates that a first or a new fault has been detected by the system. The most recent fault message (the one that caused the modification of the Block Word Count) is the first message transmitted. . Delta Block Word Count of first STX less than or equal to 0. In this case the frame is immediately rejected and the following system is selected (polling). . Character check It checks that the characters composing the messages belong to the ASCII table of the MCDU characters. It detects the nature of the fault (internal or external to the system). It memorizes the new internal fault message and it also memorizes the identity of the systems that reacted to the internal fault by transmitting an external fault within the 30 seconds that preceded or followed (see Correlation Function below).
* Type 3 systems On each input discrete which is associated with the identification of a system fault, it scrutinizes discrete state so as to detect the state indicating the fault. It associates and memorizes a text enabling identification of the anomaly at each change in discrete state. Example : 240000 GCU EMERG (Ref. Fig. 012) Let us suppose that an angle of attack sensor fault has been detected and that systems A, B, C and D are affected by this fault. Systems A, B, C and D transmit EXTERNAL fault information on their bus. The air data system transmits the INTERNAL fault information; this is the message memorized by the CFDIU. The CFDIU also memorizes the identity of systems A, B, C and D which reacted to the air data system fault by transmitting an external fault message (correlation).
-Assigns the time to each event: For each new or the first fault occurrence memorized by the CFDIU, the latter associates the GMT (hour and minute) at which it occurred with it.
R 1EFF : 106-149, 155-199, 208-299, 301-399, 1 31-32-00Page 52 1401-499, 1Aug 01/05 1 1 1CES 1
b
_
c
_
GMT is memorized with the fault identity. Example: GMT : 0920 315000 FWC1 In the event of several non-refreshments being detected in a given flight, only the GMT associated with the first occurrence is memorized (capacity : 40 lines of 24 characters).
The CFDIU establishes the CURRENT/LAST LEG ECAM REPORT. The FWCs transmit the following information in real time on their output bus and on label 357:
-The characters making up the title of the fault message displayed on the display units (lower and upper). Example : ENG LOOP A FAULT
-ATA reference (4 digits) of the system affected by the fault (the first 5 characters of the warning message are always the ATA reference).
Example : 2 6 - 1 0
| | | | |
1st------- | | | ---------5th
2nd------------ | --------------4th
|
3rd
The informations above are sent only once, at the moment
of the FWC Warning computation (wathever the flight phase
display inhibition is). The warning message is limited to
24 characters.
Example of message sent by the FWC:
26-10 ENG LOOP A FAULT.
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