TM 1-1510-224-10 NOTE Test   is   inhibited   during   glideslope capture. 3-19.  DISPLAY CONTROLLER (DC-811). a. Description.    The  display  controller  (fig.    3-8), enables each pilot to control formatting on his respective EHSI  and  EADI,  and  to  select  the  source  of  navigation, attitude, and heading information. b. Display     Controller     Controls,     Indicators,     and Functions: (1) Full/map pushbutton selector switch.  The FULL/MAP   pushbutton   selector   switch   is   a   multiple function  switch  that  allows  selecting  the  format  of  the EHSI.  When power is first applied to the EFIS, the EHSI will display a full 360 degree compass mode. Depressing the  FULL/MAP  switch  once  will  change  the display  to  a  90  degree  heading  arc  with  a  large  course pointer.      Depressing   the   switch   again   selects   a   90 degree    heading    arc    display    with    a    navigation    map display  that  is  dependant  upon  the  selected  navigation source. (2) Weather pushbutton selector switch.  The weather  pushbutton  selector  switch,  placarded   WX,   is used    to    select    weather    radar    and    lightning    sensor system data to be displayed on the partial compass heading arc display or the map display on the EHSI.  If the EHSI is in the full compass  mode,  depressing  the   WX  switch  will  change the   display   to   the   partial   compass   mode   and   display weather radar returns and lightning sensor system data. Depressing   the   switch   again   will   remove   the   weather radar  returns  and  lightning  sensor  system  data  from  the display. (3) Ground speed/time-to-go pushbutton selector switch. The groundspeed/time-to-go pushbutton   selector   switch,   placarded   GSPD/TITG,   is used to select whether groundspeed or time to go will be displayed    on    the    lower    right    corner    of    the    EHSI. GSPD/TTG   data    is    always    INS    data    if    the    INS    is functioning.  The   GSPD/TTG  field  will  be  blank  unless the  INS  is  the  selected  navigation  source.    If  the  INS  is not functioning, the GSPD/TTG field will be dashed. (4) Attitude  pushbutton  selector  switch.    The attitude   pushbutton   selector   switch,   placarded   ATT   is used to select whether attitude source 4# (vertical gyro # 1),   attitude   source   #   2   (vertical   gyro   #   2),   or   attitude source  #  3  (inertial  navigation  system)  will  provide  pitch and    roll    information    to    the    respective    EFIS.        Each depression   of   the   switch   changes   the   attitude   source and the respective EADI. 1. Full/Half Arc/Map Pushbutton Selector Switch 2. Weather Pushbutton Selector Switch 3. Groundspeed/Time-to-Go Pushbutton Selector Switch 4. Attitude Source Pushbutton Selector Switch 5. Heading Source Pushbutton Selector Switch 6. VOR/Localizer Pushbutton Selector Switch 7. INS/TACAN Pushbutton Selector Switch 8. Double-Needle Pointer Beoring Source Selector Switch 9. Weather Radar Dim Control 10.   EHSI Dim Control 11.   Decision Height Setting Control and EFIS Test Switch 12.   EADI Dim Control 13.   Single-Needle Pointer Beoring Source Selector Switch A9FE0D0I00 C Figure 3-8.  Display Controller 3-23