TM 1-1510-225-10 3B-40 configuration settings and entered data are maintained through    each    power    cycle    to    maintain    continuity between    aircraft    sorties.        Also,    a    lot    of    data    is maintained in the event of a bus controller swap. (a)  Valid    Data    Ranges    and    Units    for Entry and Display.  Data entry valid ranges for a given field are generally limited by the display resolution with assumption   of   a   fixed   decimal   point   and   positive entries (i.e., a four-digit numerical field with no decimal point   will   accept   entries   from   0   to   9999).      Some entered  data  is  limited  by  operational  considerations, e.g., VNAV angle of 6.0° or 3500 fpm maximum.  For values  which  cannot  be  computed  due  to  insufficient data,  the  CDU  will  display  dashes  (–  –  –  –);  e.g.,  if gross    weight    cannot    be    computed    by    the    FMS because  total  fuel  has  not  been  specified.    Asterisks (****)   are   displayed   if   the   value   is   too   large   for   its respective display field. (b)  Entry     and     Display     of     Waypoints.   Flight  plan  waypoints  and  other  locations  are  entered in three basic formats: 1   Position    Coordinates.        Latitude- longitude waypoint pair. 2   Waypoint   Identifier.      Up    to    five character alphanumeric string.  The appropriate data is extracted  from  an  on-board  ICAO  waypoint  database or    user    defined    waypoint    list    of    navigation    aids, airports, intersections, etc. 3   Identifier    /    Bearing    /    Distance.    Position defined at the specified bearing and distance from a database waypoint with the indicated identifier. (c)  Entry and Display of Latitude- Longitude   Waypoints.      Latitude-longitude   waypoints are   entered   in   the   form   of   degrees   and   minutes followed  by  optional  decimal  minutes  or  seconds  and decimal  seconds.    The  required  format  is  an  N  or  S followed by four or six digits, with a decimal point and up to three additional digits optional.  Then followed by E  or  W  with  five  or  seven  digits,  with  a  decimal  point and up to three additional digits optional. Latitude-longitude   waypoints   are   displayed   as whole    minutes    on    all    CDU    pages   except   in   the scratchpad   when   the   value   is   copied   and   on   the Position, Integrated Navigation, Start 1, or Data pages where thousandths of minutes are displayed. (d)  Entry and Display of Identifier Waypoints.      Identifiers   are   entered   as   up   to   five alphanumeric.    Identifier  waypoints  are  displayed  left justified,  with  alphabetic  characters  always  written  as capital  letters.    Crew-entered  identifiers  are  limited  to between  two  and  five  characters.    Single  character identifiers cannot be entered by the crew and are only accessed  by  inserting  a  SID,  STAR,  or  approach  that includes such a waypoint in the procedure. (e)  Entry and Display of Identifier/ Bearing/Distance Waypoints. Identifier/bearing/ distance    waypoints    are    entered    as    an    identifier followed by a / , followed by the bearing, followed by a / , followed by distance.  Bearings are entered as three digits  optionally  followed  by  a  decimal  point  and  an additional  digit.    Bearing  is  displayed  as  three  digits rounded to the nearest degree.  An entry of 145.3° will be  displayed  as  145°.    In  the  case  of  a  number  such as  145.5°,  the  CDU  always  rounds  up  to  the  nearest whole  number.    Distances  are  entered  as  up  to  four digits  optionally  followed  by  a  decimal  point  and  one additional digit. When     a     bearing/distance     is    applied     to     a waypoint,   the   waypoint   will   appear   as   one   of   the following: 1.   If the waypoint is an ICAO identifier and the distance is 999 nm  or  less,  the  waypoint  will be  displayed  as  identifier/bearing/ distance (e.g. EDW/350/45). 2.   If  the  waypoint  is  not  a  way point identifier or the distance is greater than  999  nm,  the  waypoint  will  be displayed as latitude/longitude. (f)   Use of Magnetic Variation and Declination.    Magnetic  variation  is  used  in  converting most azimuth angles from true to magnetic reference.   Courses     into     navaid     waypoints     and     any     offset waypoints  described  relative  to  these  waypoints  use stored station declination rather than magnetic variation in the computations, so that they match those on published Instrument Flight Rules (IFR) charts. (g)  Entry and  Display  of  Time  and  Date.   Time  is  entered  with  no  delineators  between  hours, minutes,  and  seconds.    Seconds  are  optional,  so  that three to six digits are acceptable.  If no time or date is available  for  a  given  field,  blanks  are  displayed.    All times   are    entered    and    displayed    as    Coordinated Universal Time (UTC).  Dates are entered and written using  the  military  convention  of  day,  month,  year  (six digits  total).    Example  would  be  16/12/97  (December 16, 1997). The   FMS-800   system   has   been   designed   to avoid  date  and  time  rollover  problems.    The  operator will  not  see  problems  if  a  current  date  and  time  are entered into the CDU prior to initializing GPS modules.