function crc16(s:string):Word;
var i,j:byte;
begin
  Result:=0;
  for i:=1 to Length(s)do
  begin
      Result := Result xor Ord(s[i]) shl 8;
      j := 8;
      while j<>0 do
      begin
        if (Result and $8000 = $8000) then //( BYTE1(v2) & 0x80 )
          Result := 2 * Result xor $8005
        else
          Result := Result * 2;
        Dec(j);
      end;
end;
end;

////////////////////////////////////
///////////////////////////////////
//...
  tmp:=(len+lenID) div 2;
  p1:=format('%0.4x',[crc16(Copy(szName+szID,1, tmp))]);
  p2:=format('%0.4x',[crc16(Copy(szName+szID,tmp+1, len+lenID-tmp))]);
  serial:='HT-'+p1+'-'+p2;
//...