(a)
If the EIS DMC selector switch is in the NORM position, this signal is a ground when the PFD image is to be displayed on the ND and the ND image on the PFD. In this case, the ALTERNATE inputs are selected for both DUs. This signal is an open circuit if the PFD and ND images are to be displayed at their normal location, the PFD image on the PFD, and the ND image on the ND.
(b)
If the EIS DMC selector switch is in CAPT/3 (or F/O/3) position, the ground and open circuit states of the discrete signal are inverted with respect to the previous case (EIS DMC selector switch in NORM position), because of the cross-wiring of the PFD and ND DSDLs.
The CAPT and the F/O relay boxes perform all the above functions by controlling the state of their A-Y2 contact. Note that the output state of each relay box can always be changed by means the PFD ND XFR P/BSW, which enables each pilot to restore the desired display configuration.
NOTE : When setting on the electrical power, a given relay box
____ immediately controls the A-Y2 contact output state which corresponds to that required by the PFD ON-OFF/brightness potentiometer, the NORM PFD INV signal and the EIS DMC selector switch, indepently of the last state before de-energizing the A/C electrical network and assuming that the PFD/ND XFR P/BSW has not yet been pressed.
The relay boxes keep their present output state whatever it is, in case of 28VDC electrical power supply transient of less than 200ms. But, in case of loss of the 28VDC electrical power supply, the output of the affected relay box has the open circuit state after 300ms.
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EIS Relay Boxes - PFD/ND XFR Circuitry
Figure 007
R 1EFF : 001-049, 051-099, 101-105, 151-199, 1 31-68-00Page 13/14 1201-299, 301-302, 1Config-1 May 01/05 1 1 1CES The relay boxes perform the switching of discrete signals concerning the selection for the DME audio signals: the DME audio outputs are associated with the audio outputs of the VOR or ILS receivers (ILS if the ROSE-ILS mode is selected or if the ILS P/BSW has been pressed). This configuration is sent by the DMCs in use (1 or 3 and 2 or 3) to the Audio Management Unit. (Ref. Fig. 008)
C. Switching of the ECAM DUs (Upper ECAM DU - Lower ECAM DU and ECAM/ND Transfer)
(1)
Transfer from the upper ECAM DU to the lower ECAM DU In the event of upper ECAM DU failure, the Engine/Warning image is displayed on the lower ECAM DU instead of the system page or status message. This switching is automatic : on reception of the upper DU anomaly signal, through the feedback DSDL bus, the DMC 2 ECAM channel processor switches by software to an ECAM single display configuration which privileges the E/W processing. The lower ECAM DU receives the E/W image from the DMC 2, still through its NORMAL input. The same applies when turning the UPPER DISPLAY potentiometer to OFF.
In case of lower ECAM DU failure, the Engine/Warning image remains displayed on the upper ECAM DU, but it is also a single display configuration. The single display configuration is called MONO display configuration (M). More generally, it corresponds to any situation with only one DU for all the ECAM information. The image which is displayed is pratically the same as an Engine/Warning image (minor difference concerning the Advisories, as explained). In case of single display configuration, the E/W image can be temporarily replaced by any A/C system page or by the status page, as long as the corresponding key is maintained pressed on the ECAM control panel. When the pilot releases the key, the E/W image appears again.
(2)
ECAM-ND transfer By means of the ECAM/ND XFR selector switch, each pilot can call on his ND an ECAM image (normally A/C system or status image, or Engine/Warning image if both ECAM DUs are inoperative) instead of the ND image. Obviously, the pilots can at any time get their ND image back by setting the selector switch back to NORM.
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(3) Survey of the various ECAM display configurations The following table gives the various possible ECAM display configurations according to the availability of the ECAM processing channels in the DMCs and the ECAM DUs. The list is not exhaustive.
-------------------------------------------------------------------------------NR DMC1,2,3 CREW XFR DISPATCHING OF ECAM IMAGES
COND SELECTION CAPT ND UPPER DU LOWER DU F/O ND -------------------------------------------------------------------------------1 NORM NORM ND E/W (N) S (N) ND
DMC1 IN E/W DMC2 IN S 2 NORM ECAM/ND F/O ND E/W (N) NIL S (N) DMC1 IN E/W DMC2 IN S 3 NORM ECAM/ND CAPT S (N) NIL E/W (N) ND DMC1 IN S DMC2 IN E/W 4 DMC1 NORM NIL NIL E/W (N) ND FAILED DMC2 IN M 5 DMC2 NORM ND E/W (N) NIL NIL FAILED DMC1 IN M 6 NORM NORM ND DU E/W (N) ND FAILED DMC2 IN M 7 NORM ECAM/ND F/O ND DU E/W (A) S (N) FAILED DMC1 IN E/W DMC2 IN S 8 NORM ECAM/ND CAPT S (N) DU E/W (N) ND FAILED DMC2 IN E/W 9 NORM NORM ND E/W (N) DU ND DMC1 IN M FAILED 10 NORM ECAM/ND F/O ND E/W (N) DU S (N) DMC1 IN E/W FAILED DMC2 IN S 11 NORM ECAM/ND CAPT S (N) E/W (A) DU ND DMC2 IN E/W FAILED 12 NORM ECAM/ND F/O ND DU DU E/W (N) FAILED FAILED DMC2 IN M 13 NORM ECAM/ND CAPT E/W (N) DU DU ND FAILED FAILED
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