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PRESENT
TRACK 
HEADING
ANNUNCIATOR
TRUE 
WIND SPEED DISTANCE
AND DIRECTION 
COMPASS 
ROSE
ROUTE 
DATA 
NORTH-UP POINTER 
SOURCE 
ANNUNCIATOR
Plan Mode 
Figure 17
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B74 R-RADIO ALTIMETER (E9) 
Radio Altimeter Interface Figure 18 
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 (4)  The digital data from the IRUs is sent to the EIU on ARINC 429 high speed data bus. If there is an IRU fault, an analog discrete IRS FAULT message is sent to the EIU.
 C. Air Data Computer (ADC) Interface (Fig. 20)
 (1)  
The air data computers transmit both analog and digital signals to the EIUs. Digital data such as airspeed, angle of attack, baro correction and Mach is transmitted on an ARINC 429 low speed bus. The overspeed information is transmitted as an analog discrete and a digital discrete signal.
 (2)  
Normally, the left EIU receives information from the left ADC, and the right EIU receives data from the right ADC. However, the CAPT's ADC source select switch can enable the left EIU to receive data from the center or right ADC. Similarly, the F/O's ADC source select switch can enable the right EIU to receive data from the left or center ADC.
 (3)  
When the F/O's ADC source select switch is in the center position, the pitot and static source select valves will switch to alternate positions. The IDS receives the altitude alert and altitude advisory from the MAWEA.
 D. Flight Control Computer (FCC) Interface (Fig. 21)
 (1)  
The flight control computers provide inputs to the EIUs on ARINC 429 low speed digital data buses.
 (2)  
Each EIU receives the following information from the FCC:
 (a)  
Selected heading or selected course.
 (b)  
Flight director pitch/roll commands.
 (c)  
Localizer deviation warning, glideslope deviation warning and localizer not captured.
 (d)  
Automatic Flight Director System (AFDS) mode status.
 (e)  
Selected altitude, airspeed, Mach, runway heading and vertical speed.
 (f)  
Autopilot battery warning.
 (3)  
The flight director source select switches enable the EIU to receive data from any FCC source (FCC L,C,R).
 E. Control Display Unit (CDU) Interface (Fig. 22)
 (1)  The CDUs may be used to initiate IDS test. This places the IDS test display format on all six of the display units.
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-TRACK-E-W, N-S
 HORIZONTAL VELOCITY 
ACCEL
-FLIGHT PATH
-BODY ACCEL, ANGLE, ACCEL 
RATE
-INERTIAL
-DRIFT ANGLE ALTITUDE
-GROUND SPEED
-INERTIAL
-MAG, TRUE
VERTICAL 
HEADING
 SPEED
-IRMP BITE
 POSITION
-PRESENT DISPLAY 
-IRS DISCRETE-TRACK ANGLE 
-IRS MAINT
 DIRECTION
-WIND SPEED, DISCRETE 
-IRS TEST 
ACCELERATION
-VERTICAL 
-PLATFORM 
-PITCH, ROLL