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Converting User Programs of the CPU 928B for the CPU 948
Timer processing
FB 0 as cycle block
Default priorities
Data block DB 0
(block address list)
1 - 20
CPU 928B
The timers are updated during
start-up.
CPU 928B
If no cycle block OB 1 exists, the
system program calls FB 0
cyclically, provided it is loaded.
CPU 928B
Process interrupts have higher
priority than timed interrupts.
CPU 928B
The block address list contains
the direct start addresses of the
blocks.
CPU 948
The timers are only updated in
the RUN mode
(Reason: compatibility with
CPU 946/947)
CPU 948
Only OB 1 can be used for cyclic
processing. If you have
programmed FB 0, create an
OB 1 in which FB 0 is called.
CPU 948
Timed interrupts have priority
over process interrupts via IB 0
or system interrupts. You can
change the priority with the
parameters in DX 0.
CPU 948
The block address list contains
the segment addresses of the
blocks. To obtain the start
address of a block, its segment
address must be shifted 4 bits to
the left.
CPU 948 Programming Guide
C79000-G8576-C848-04
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