Shared Tools: Reference Manual

Release Level	5.4
Release Date	2008 10
Revision Level	1.0

Last modified on: Monday, 29-Sep-08 13:57 CEST

RTXPS: TIMERS

There are 3 predefined descriptors and several buil-in functions relating to time:

START_TIME: start time of the current RTXPS cycle, mainly used in interactive applications such as CourseWare or the RiskWare real-time emergency management applications.
CURRENT_TIME: system (local) time for the system defined time zone, including day saving time shifts, HH:MM:SS
CURRENT_UTC: global standard time (Zulu, UTC, GMT), HH:MM:SS
ELAPSED_TIME, difference between CURRENT_TIME and START_TIME.
MINUTE(number): : TRUE if the current minute from HH:MM:SS matches;
HOUR(number): TRUE if the current hour from HH:MM:SS matches;
DAY(number), DAYN(string):
- TRUE if DAY(number) argument matches the number of the day (1-31) within the current monthy.
- TRUE if the string argument of DAY matches the three-character abbreviation for the current days name (system date function) as in SUN, MON, TUE, WED, THU, FRI, SAT, case insensitive;
- MONTH(), MONTHM();
- YEAR() TRUE if the argumenrt matches the currenr year from date (YYYY).

The Descriptor definitions (in the respective application's KnowledgeBase) are shown below, with the TIMERS being of the TYPE: variable.

RTXPS first creates dynamic knowledge base, then sets predefined descriptors to their current values.

Implementation: CourseWare

START_TIME and ELAPSED_TIME rely on the fact that the first action of every course calls function init(). These descriptors can be used for computation as well as display. The behaviour of value(ELAPSED_TIME) is equivalent to header in-text function \elapsed_time and behaviour of value(CURRENT_TIME) is equivalent to header in-text function \time.

Besides user can define application specific time descriptors and set their value using rtxps function set_time(descriptor_name).

All time descriptors can be displayed with rtxps in-text function

\value whose format is hh:mm:ss or with rtxps in-text function
\valuef which displays an integer number in seconds.

There are two operations defined for time descriptors:

addition: add_time(result,operand1,operand2)
substraction: subst_time(result,operand1,operand2)