Interrupt Processing
S5-95F
Interrupt Priority
OB3 can interrupt the cyclic or time-controlled program after each STEP 5 statement. If OB3 has
not been programmed, the cyclic or time-controlled program scan is resumed immediately after the
interrupt has been triggered.
The OB3 interrupt processing routine can be interrupted by an OB2 interrupt, but not by another
OB3 interrupt or an OB13 call. If OB3 interrupts are generated while the OB3 service routine is
executing, they are stored so that OB3 can be reinvoked once it has terminated.
Interrupt processing can be disabled with IA and re-enabled with RA. The default is RA. Interrupts
are stored while "IA" is in force (see Interrupt priority).
Note
The block nesting depth of 16 may never be exceeded, even during interrupt
processing.
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EWA 4NEB 812 6210-02