(2)
 Marker system There are three marker transmitters positioned on the ground at known distances from the runway threshold :

 -
the outer marker at approx. 4 N miles

 -
the middle marker at 0.6 N miles

 -
the inner marker at the runway threshold.
 The markers transmit a modulated 75 MHz signal to provide a marker
 position.
 When the aircraft passes through the beam of a marker, the modulating
 frequency is detected. Then, the system provides aural and visual
 indications to the flight crew.

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 B. System Architecture (Ref. Fig. 002A)
 (1)
 VOR system The VOR comprises two independent systems. Each system consists of : - one VOR/MKR receiver 1(2) 3RS1 (3RS2) - one VOR 1/2 antenna 4RS - one VOR/ADF/DME Radio Magnetic Indicator (VOR/ADF/DME RMI) 21FN. The components given after control the VOR system : (Ref. Fig. 003A)

 -
the CAPT (F/O) Audio Control Panel (ACP) 2RN1 (2RN2) and the Audio Management Unit (AMU) 1RN for audio control

 -
the Multipurpose Control and Display Unit 1(2) (MCDU) 3CA1 (3CA2), the Radio Management Panel 1(2) (RMP) 1RG1 (1RG2) and the Flight Management and Guidance Computer 1(2) (FMGC) 1CA1 (1CA2) for frequency/course selection

 -
the MCDU 1(2) and the Centralized Fault-Display Interface-Unit (CFDIU) 1TW for test purposes.

 (2)
 Marker system The marker system consists of one system only. The receiver is part of the VOR/MKR receiver 1. The system comprises : - one VOR/MKR receiver 1 3RS1 - one marker antenna 1RS. All the data are shown on the CAPT and F/O Primary Flight Displays (PFD).

 C. Utilization Technical Data
 (1) Data display
 (Ref. Fig. 004A)

 (a) VOR system
 1 On the Navigation Display (ND)
_ In ROSE and ARC modes. If you set the ADF/VOR/OFF switch on the EFIS control section of the Flight Control Unit (FCU) to VOR, this causes : display of the characteristics of the VOR 1 and/or VOR 2 stations in the L and/or R lower corner of the ND (item 7) :
 -type of station (VOR 1, VOR 2)
 -shape of the associated bearing display
 -station identification
 -mode of tuning: nothing : automatically tuned by the FMGC
 M : manually tuned through the MCDU
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 VOR/Marker - Data and Warning Displays
 Figure 004A

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 R : tuned through the RMP.
 A single pointer on the heading dial shows the bearing of
 the VOR 1 (item 5), a double pointer that of the VOR 2 (item
 1).
 All these data are shown in white.
 in case of VOR system fault, all the corresponding data go
 out of view and the VOR indication turns to red.
 In ROSE VOR mode, the data below are shown:

 -a dagger-shaped pointer points to the selected VOR course (cyan) (item 6)
 -the lateral deviation bar which represents the VOR deviation is shown with an arrow for the TO FROM indication (cyan) (item 2)
 -in the R top corner, the VOR characteristics come into view: VOR 1 or 2, frequency, selected course (item 4), identification (cyan).
 In case of VOR system fault, all these data go out of view and the VOR 1 or 2 indication turns to red. If the VOR approach is selected, the VOR APP message comes into view in the center top section of the ND (item 3). In ROSE NAV and ARC modes, the characteristics and location of the VOR stations which are not already included in the flight plan, can be shown when you push the VOR-D pushbutton switch on the EFIS control section of the FCU :
 -cross symbol for the VOR station (item 8)
 -circle plus cross symbol for the VOR/DME station (item 9).
 2 On the VOR/ADF/DME RMI
_
 Set the VOR/ADF selector switches to ADF.
 The RMI indicates the VOR bearings :

 -
a single pointer indicates the VOR 1 bearing (item 11)

 -
a double pointer indicates the VOR 2 bearing. A warning flag comes into view to indicate system malfunction (item 12). In this case, the corresponding pointer is in the 3 o'clock position (item 13). If No Computed Data (NCD), the warning flag comes into view and the related pointer stays at the position corresponding to the last correct data.

 (b) Marker system The MKR data are shown on the PFD, in approach at the intersection of the G/S and LOC scales (item 14). When the aircraft overflies the corresponding marker, the data given after come into view on the PFD :
　
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