33 30 24 2I I5 I2 6 3 CMP 1 GS 148 K HDG 315 NAV 2 3.7 NM CRS 300 Selected course Heading data source Heading select bug Forward lubber line Navigation data source Distance Course select pointer To/from indicator Selected heading Aircraft symbol Aft lubber line Reciprocal course pointer Groundspeed Glideslope scale Glideslope pointer Lateral deviation bar Pilot’s display system Copilot’s display system Display controller Display controller EADI EHIS EADI EHIS Pilot’s symbol generator Center symbol generator Copilot’s symbol generator Data buses Display drive signals Figure 10-118.  A simplified diagram of an EFIS system. The EADI and EHSI displays are CRT units in earlier systems. Modern systems  use digital displays, sometimes with only one multifunctional display unit replacing the two shown. Independent digital processors can  also be located in a single unit to replace the three separate symbol generators.  Figure 10-117.  Approach and VOR mode presentation of an electronic horizontal situation indicator.  EFIS systems display an altitude and vertical speed scale.  Since most EFIS EADI depictions include the inclinometer,  normally part of the turn coordinator, all of the basic flight  instruments are depicted by the EFIS display.  [Figure 10-119] category aircraft, this can mean monitoring numerous gauges  in addition to maneuvering the aircraft. The electronic  centralized aircraft monitoring (ECAM) system is designed  to assist with this duty.  The basic concept behind ECAM (and other monitoring  systems) is automatic performance of monitoring duties for  the pilot. When a problem is detected, or a failure occurs, the  primary display, along with an aural and visual cue, alerts the  pilot. Corrective action that needs to be taken is displayed,  The pilot’s workload on all aircraft includes continuous  monitoring of the flight instruments and the sky outside  of the aircraft. It also includes vigilant scrutiny for proper  operation of the engine and airframe systems. On transport  Electronic Centralized Aircraft Monitor (ECAM) 10-71