-
ARINC 453 buses from the weather radar,
-
RS 232 buses for shop test.
-
RS 422 in block mode for FWC messages
(2)
Processing (outputs) The processing channel enables the DMCs to perform validity check and to convert signals into suitable format (output signals) such as:
-discrete signals,
-ARINC 429 output buses,
-A629 for transmission of information to the DUs,
-A453 bus for weather radar output to the DUs.
C. DMC/DU Interface (Ref. Fig. 013)
(1) DU inputs/outputs
(a)
A629, radar buses, discrete signals (INPUTS): Each DU has 3 inputs (PFDs and NDs) or 2 inputs (EWD and SD) from the DMCs:
(b)
Return A629 (feedback) (OUTPUT): Each DU has 1 output to the onside DMC:
1_ for the weather radar image (PFDs and NDs) there is one
dedicated input linked to the related output of the ONSIDE DMC
2_ One A629 (Normal), linked to the ONSIDE DMC
3_ One A629 (Master), linked to the OFFSIDE DMC
NOTE : It also receives discrete signals such as ON/OFF signal____
and analog signals for brightness control.
-The feedback bus A629 (Return),
NOTE : In addition, the DU provides voltage supply for its
____ brightness parameters.
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DMC/DU Interface
Figure 013
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1CES 1
(2) DMC inputs/outputs
(a)
Return A629 Each DMC has 6 inputs A629 from the DUs: one per working DU.
(b)
Master A629, radar buses (OUTPUTS):
Each DMC has 4 outputs to the DUs:
-
2 A629, one for the PFD, one for the ND,
-
2 weather radar buses both linked to the ONSIDE PFD and ND.
5. Eis Operation
_____________
A. Operation
(1)
Normal operation In normal operation the DMC drives the following display units:
-
the DMC 1 drives the CAPT PFD DU, the CAPT ND DU, the EWD DU and the SD DU.
-
the DMC 2 drives the F/O PFD DU and the F/O ND DU,
-
the DMC 3 is a hot spare awaiting the failure of the DMC1 or 2 and able to take over the DUs linked to the failed DMC.
(2)
Acquisition With respect to sensor and computer connections as inputs, each DMC uses its onside sources for display:
-
the DMC 1 uses the ADC 1, IRS 1, FMGC 1,... buses,
-
the DMC 2 uses the ADC 2, IRS 2, FMGC 2,... buses.
In case of failure of a given ONSIDE source, the DMC switches over to
the related OFFSIDE source or the THIRD source if any.
The switching is manual (ADC, IRS or FMGC for example).
The DMC switches back to the ONSIDE sensor/computer if it works
properly again (under certain conditions).
Concerning the radio navigation sensors (ILS, VOR, DME and ADF) the
two sides are processed in parallel by each DMC.
No switching is set in the basic display.
B. Switching Due to the highly integrated design of the EIS system, the schematics and certain switching cases concern both the ECAM and the EFIS parts.
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(1)
Normal operation The information displayed for the Captain and First Officer must be as independent from each other as possible (split concept). So, they are computed by independent computers from distinct sources using their onside sources (E.G.) ADIRU1 for DMC1 and ADIRU2 for DMC2:
-DMC1 supplies data to the CAPT EFIS DUs (PFD and ND), the upper ECAM DU and the lower ECAM DU.
-DMC2 supplies data to the F/O EFIS DUs (PFD and ND) only.
-DMC3 is then in standby, (HOT SPARE) and does not control any display, but nevertheless computes all data necessary for display on the Captain's EFIS DUs and upper ECAM DU. Thus it is prepared to replace DMC1. DMC3 receives data from sides 1 and 2 sensors but in this case, it only uses data from side 1 sensors.
(2)
Source reconfiguration The following table shows which sensors and computers are connected to each DMC and indicates those DMC inputs used in normal operation
(N) or after source reconfiguration (A), according to the validity of these sensors/computers and the switching possibly made by the crew (ATT/ HDG, AIR DATA and EIS DMC). The table gives an exhaustive list of all the DMC input buses. Bus "processed" by a DMC means: the parameters of the bus are acquired by the DMC and stored in its memory for possible use by the EFIS or ECAM processors. The sensors/computers I/P buses fall into different classes according to the nature of the possible reconfigurations, manual or automatic:
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