Technical data

TIME INTERRUPTS Program execution in fixed time bases
In the CPU 928B, you can execute up to 9 different time-driven
programs, each program being called at a different time interval.
Triggering A time interrupt is triggered automatically at a fixed time interval if
the corresponding OB is programmed.
User interfaces When a particular time interrupt occurs, the corresponding
organization block is activated as the user interface at the next block
boundary (or operation boundary).
Assignment of the time interrupt time to the OBs:
Time base Organization block called
10 ms
20 ms
50 ms
100 ms
200 ms
500 ms
1 sec
2 sec
5 sec
OB 10
OB 11
OB 12
OB 13
OB 14
OB 15
OB 16
OB 17
OB 18
Falling priority
For example, program the program section to be inserted into the
cyclic program every 100 ms in OB 13.
Note
OBs with shorter time bases have a higher priority and can
interrupt OBs with longer time bases.
Time since last interrupt
processed
Whenever a time interrupt OB is called (OB 10 to OB 18) ACCU 1
contains the number of time units that have occurred since the last
time interrupt OB call, as follows:
ACCU 1 := number of time units - 1
If, for example, ACCU 1 contains the number "5" when OB 11 is
called, this means that 120 ms (6 time units) have elapsed since
OB 11 was last called. As long as there is no collision of time
interrupts, a "0" is transferred in ACCU 1.
Table 4-3 Assignment "Time interrupt time - called OB"
4
RUN Mode
CPU 928B Programming Guide
C79000-B8576-C898-01
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