Technical data

A process interrupt is also recognized and processed when the
interrupt signal is no longer active when the block boundary is
reached.
When it is called, OB 2 is processed completely. If the interrupt signal
is still active or active once again at the end of OB 2, a block is
processed in the cyclic program and OB 2 is then called again. If the
level is no longer active, OB 2 is only called again at the next change
of signal state (from inactive to active).
Active interrupt signal states
before processing the block end
operation (BE) of OB 2 are irrelevant.
Process interrupt signal:
edge-triggered
You can select this setting by assigning parameters to DX 0. After
OB 2 has been processed, a new process interrupt can only be
triggered by a signal state change (from inactive to active).
After
processing the block end command (BE) of OB 2 an "inactive-active
signal change"
of the interrupt signal must follow to generate a
process interrupt.
A process interrupt is also recognized and processed when the
interrupt is no longer active at the block boundary.
OB 2 OB 2 OB 2
Cycle
(at block boundaries)
Process interrupt
Interrupt
OB 2
active
inactive
= block boundaries
line
Fig. 4-7 Process interrupt, level triggered
OB 2
OB 2
Cycle
(at block boundaries)
Process interrupts
Interrupt
inactive
active
= block boundaries
OB 2
line
Fig. 4-8 Process interrupt, edge-triggered
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RUN Mode
CPU 928B Programming Guide
C79000-B8576-C898-01
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