Release Level	5.4
Release Date	2008 10
Revision Level	1.0

RTXPS ACTIONS: built-in FUNCTIONs

The built-in generic FUNCTIONs include triggers for simulation models, the backward chaining expert system, or external communication tasks such as data acquisition from monitoring systems or tasks such as automatic dialing for phone connections, or sending automatically generated eMail, fax or SMS messages.

Other ACTION functions trigger special interactive editors to obtain information on more complex risk objects (such as trains, plants, etc.) which require specific dialogue windows for consistent editing of the attributes of the the risk objects and provide additional functionality such as links to on-line databases.

From an implementation perspective there are two groups of functions:

• those defined in the library (and thus available in all applications)

• and the application specific FUNCTIONs only implemented for a specific application such as CourseWare.

FUNCTIONs implemented in the expert system library:

• set_descriptor_value(<descriptor name>,<value>)
  Initialises the DESCRIPTOR <descriptor name> with the specified value.
  Should the DESCRIPTOR already have a value set it will be overwritten with the new one.
   
  

• clear_descriptor_value(<descriptor name>)
  The value of the DESCRIPTOR <descriptor name> is cleared.
  The previous value (if present) is saved in the default value of the DESCRIPTOR.
   
  

• execute_rule(<rule#>[,<rule#>,...])
  The backward chaining rules with the specified rule numbers (<rule#>) are fired in the given sequence until one of them has been sucessfully completed.
  At least one rule number must be specified.
   
  

• execute_rt_rule(<rule#>[,<rule#>,...])
  All forward chaining rules with the specified rule numbers (<rule#>) are fired in the given sequence.
  Whenever an ACTION is set to ready the ACTION is automatically started and afterwards set to done.
  At least one rule number must be specified.
   
  

• export(<descriptor name>)
  The value of the DESCRIPTOR <descriptor name> is written to a file. The file is put into the subdirectory defined by the default "rtxps.fax.dir" in the directory specified by the log-files-path (defined in the CONFIG file of the application). The name of the file is the name of the DESCRIPTOR cut to its first 14 characters.
  If the DESCRIPTOR does not have a value the string *unknown* is written to the file.
   
  

• system(<descriptor name>)
  The value of the DESCRIPTOR <descriptor name> is run as a UNIX shell command in the directory specified by the default "rtxps.bin.dir".
  If the DESCRIPTOR value is emplty no command is executed.
   
  

• shell(<cmd>)
  The string <cmd> is run as a UNIX shell command in the directory specified by the default "rtxps.bin.dir".

Interactive RTXPS sessions

• update_descriptor(<descriptor name>[,ask])
  The value for the DESCRIPTOR <descriptor name> is set most commonly triggering the backward chaining inference engine, but more generally using the resources specified in its DESCRIPTOR definition (eg., backward chaining rules, data base access,...).

  Please note: depending on the parameters and current status of the dynamic knowledge base, the function update_descriptor() may also be applicable in an automatic, autonomous RTXPS sessions, see above.

  The user is prompted only in case of missing information.
  If the value of the DESCRIPTOR has already been set before the function is called the value is not modified unless the update parameter is specifed. Then the DESCRIPTOR AskBox is displayed showing the current value and the user can decide if he wants to keep the value, modify it, or re-run the deduction.
   
  

• display_html(<filename>)
  The content of the file <filename> is displayed in HTML format over the map display of the RTXPS screen.
  Position and extent are taken from the defaults also defining the position of the map display, ie., "rtxps.map.x", "rtxps.map.y", "rtxps.map.w", and "rtxps.map.h".
   
  

• close_html()
  The HTML display previously opened with the FUNCTION display_html(<filename>) is closed.<