Technical data

7.4 Examples of Parameter Assignment
7.4.1
STEP 5 Programming
Example A:
In multiprocessor operation, you want to use three CPUs: CPU A, B and C.
CPU A and B operate closely together, often exchange data and process a
complex restart program. CPU C is largely independent and has a short,
time-critical program.
As standard, all CPUs in multiprocessor operation start cyclic program
execution together, i.e. the CPUs wait until all CPUs have completed
their restart procedures and then start cyclic program execution at the
same time.
Since CPU C runs a
very short restart program independent of the other
CPUs, its restart procedure does not need to be synchronized. By
assigning parameters in DX 0, you can arrange for CPU C to start cyclic
program execution immediately after its restart, without waiting for CPU
A and B.
Programming DX 0 for CPU C:
DX 0 start ID "MASKX0" DW 0: KH= 4D41
DW 1: KH= 534B
DW 2: KH= 5830
1st field ID/length DW 3: KH= 0201
parameter 1 DW 4: KH= 2001
end delimiter DW 5: KH= EEEE
Once you have loaded this DX 0 in the program memory, it becomes
effective after the next COLD RESTART. Since CPU C processes a very
short restart program and does not wait for A and B, its green LED is
lit immediately following the restart. The BASP signal (disable command
output) is, however, only cancelled when all three CPUs have completed
their restart. This means that CPU C cannot access the digital
peripherals.
7
Examples of Parameter Assignment
CPU 928B Programming Guide
C79000-B8576-C898-01
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