Siemens S5-135U/155U - Manual (Page 272)

6-10
System Manual
C79000-G8576-C199-06
Loading STEP 5 user programs in all CPUs:
S
Recommended precondition: The programs of the individual CPUs have
already been tested in single-processor operation.
For details of loading STEP 5 blocks and using the different types of
memory, please consult the relevant Programming Guides of the CPUs and
your PG Manual.
Prerequisites
What? Where?
Data block DB 1 must be present for I/O allocation. in all
CPUs 1)
Data block DX 0 must additionally be present at
CPU 948.
The mode for “Process interrupts via IB 0 = off” must
be set in DX 0.
only in
CPU 948
To start multiprocessor operation immediately with all
CPU programs, you must now load your programs into
the individual CPUs.
After completing these steps, however, you can load
individual programs into certain CPUs.
into the
desired
CPU 1)
1. You must only load the blocks for CPUs with RAM operations; for EPROM operation, the
inserted EPROMs must contain your user program with DB 1 (DX 0).
Data blocks which you have provided for dynamic data storage must be copied after a
RESET by program into the RAM.
Reaction
There is no change in the reactions of Step 4 (each CPU still emits the
output inhibit signal: the BASP LED is continuously lit).
Step 6
Multiprocessor Operation/Coordinators