TM 1-1510-225-10 3C-57 Table 3C-6.  Navigation Data Items   (Continued) USER SELECTIONS ABBR Estimated Time Enroute ETE Groundspeed GS Latitude Lat Longitude LONG Magnetic Variation at Present Position MVar Minimum Safe Altitude MSA Minimum En route Safe Altitude MESA Range to Active Waypoint Rng Stormscope System Stopwatch Time Track Trk Waypoint Identifier WPT Figure 3C-29.  Navaid Setup – Select To place the item into one of the six positions on the screen, press the  PLACE button.  This places the data item in the upper left position in the legend area.   To move the item to another position, press the  MOVE button.    Each  additional  press  of  the   MOVE  button advances the item counterclockwise.  Refer to Figure 3C-30. Figure 3C-30.  Navaid Setup - Move To set the display position of a highlighted item, press the SET button.  This establishes the position of the  data  item  display  on  the  weather  screens.    After pressing the SET button, the highlight will return to the next data item on the grid.  To return the data item to the grid without setting it, press the   CANCEL button.   This   will   return   the   data   item   highlight   to   the   grid.   Since  the  data  item  was  not  set  to  the  legend  area, any  data  item  previously  occupying  the  position  will remain  there.    To  select  additional  data  items,  repeat the sequence of  NEXT  to highlight the item,  PLACE it from   the   grid   to   the   legend   area,   MOVE  it  to  the desired  position  on  the  legend  area,  and   SET  it.    To replace  a  data  item  previously  set  in  position,  follow the same sequence. Pressing the  SET  button when a highlighted data item is in an occupied legend position causes the new item to replace the previous item. To  erase  an  item  from  the  legend  area,  press NEXT to highlight the blank space on the grid, PLACE it to the legend area, MOVE it in the legend area to the position to be erased, and SET it. (8)   Error   Messages.    Most  common  errors and malfunctions are indicated on the display screen.   These messages enable service personnel to diagnose    and    correct    the    problem.        If    continued operation  is  possible,  a  message  to  press  any  key  to continue operation will be displayed.  When the Loran or GPS receiver fails to acquire a consistent signal and is not certain of its position, the message NAV FLAG will display in place of the CDI.  Navigational data will not    be    displayed    if    the    receiver    indicates    a    flag condition.    In  conditions  where  the  LORAN  or  GPS receiver   determines   its   position   error   to   be   greater than  1.7  nm,  a  warning  (W)  will  display  next  to  the affected data items.