TM 1-1510-218-10   3C-77 Table 3C-15.  CDU Annunciations and Scratchpad Messages  (Continued) ANNUNCIATION / SP MESSAGE INITIATING CONDITION RESET MECHANISM LOCATION BLINKING NOT CLEARABLE CDU MSG ALERT RTK IS ACTIVE Attempting    to    delete    or modify   the   racetrack   fix or delete MFP attribute or modify the flight plan course  or  insert  a  PPOS hold  or  insert  a  waypoint at    the    active    waypoint during pattern execution. Clear key. SP A safe keys GPS  SA/AS  keys  on  the GPS’s. Clear key. A N SELECT ALTN LOAD Access the Alternate Flight  Plan  Catalog  page from the Start 3 page. Clear key or select alternate. SP N SELECT SID/RWY Attempt    to    access    SID Transitions  page  without both SID and RWY selected. Clear key or selecting  a  SID or RWY. SP N SELECT STAR/RWY Attempt  to  access  STAR Transitions  page  without both     STAR     and     RWY selected. Clear key or selecting a STAR or RWY. SP N SET MASTER OFF Attempt   to   set   late   net entry    to    ON    when    the ARC-210 has been designated net master. Clear key. SP A sincgars cue V/UHF   R/T   indicates   to the     FMS     that     another user is on the cue frequency. Clear key. A B SINCGARS MODE Attempting    to    send    or receive     time     or     toggle squelch  while  tuned  to  a SINCGARS channel. Clear key. SP A TIME OP IN PROCESS Comm time operation being performed. Clear key. SP A UNUSED FUNCTION Attempt  to  select  IFF  or M3 key. Clear key. SP N update magvr Current magnetic variation     data     is     more than 6 months old. Clear key or load new magnetic variation data. A USER  WPT  LIST FULL Attempt    to    add    a    user waypoint  when  the  user waypoint     data     base     is full. Clear key. SP A