Function that allows the rule file execution frequency($RULE) to be imposed from the program.

Management of execution frequency rules.

There are three ways to impose the execution frequency (interrupt) of the RULES task:

•If CANbus and/or EtherCAT networks are being managed, the rules execution frequency is set equal to the PDO exchange frequency set in the respective fieldbus configuration editors. If both networks are being managed, the frequency must be the same in both editors.

•If no fieldbuses are being managed, the frequency is imposed from project configurator (see SYS_FREQ). If the "System frequency cannot be changed" flag is also present, a frequency change from program via the rule_freq instruction will not be possible and an attempt to use this instruction will generate an alarm.

Note: If the rules frequency set in the configurator is different from the PDO exchange frequency of the canbus and/or EtherCAT networks, the setting from the project configurator is ignored and a warning is given in the report.

•If no fieldbuses are handled and the "System frequency not changeable" flag is not entered in the project configurator, the rule_freq instruction can be used to change the frequency.