SET(MAX_LINES)

  Specifies the maximum number of lines the buffer can contain.  If this
  number is exceeded, TPU deletes lines from the beginning of the buffer
  to make room for new lines.

  Syntax

     SET (MAX_LINES, buffer, integer)

  Parameters

     buffer     The buffer for which you want to set or change the maximum
                lines.

     integer    The maximum number of lines for the buffer.  If you
                specify 0, the feature is turned off; that is, TPU does
                not check for the maximum number of lines.

  Example

     SET (MAX_LINES, message_buffer, 20);

  Sets the maximum number of lines in the message buffer to 20, so that only
  recent messages are kept in the buffer.