Procedure cpstas(pkt_sub: message_packet_sub_set;
                 var str: packed array [low..high:integer] of char);
   EXTERNAL;
{ Convert the Message Packet SUB type set elements to an alpha name.  STR
  can be a type0 or type1 string of any length.  Each element that is
  present in the set will be translated and placed in the target string.
  Commas will separate the translation, with no intervening spaces.  The
  string will be truncated if required.  A maximum of 100 characters will
  be used if the set contains all possible elements. }