Multiprocessor Mode - Siemens SIMATIC S5 Manual

9.8.2

Multiprocessor mode

Definition Multiprocessor mode means that two, three or four CPUs access one or more
IM 308-C master interfaces.
Figure 9-6
Rules
The following rules apply to multiprocessor mode:
S5-135U and
Note that the following rules apply if you operate a series S5-135U CPU in
S5-155U
multiprocessor mode in conjunction with a series S5-155U CPU:
ET 200 Distributed I/O System
EWA 4NEB 780 6000-02a
IM 308-C – addressing, diagnostics and use of the FB IM308C
Host system 1
IM 308-C No. 1
Slave No. 9 Slave No. 10
Multiprocessor mode
Multiprocessor mode is permissible only in conjunction with linear
addressing (P- and Q-areas) or addressing through the FB IM308C.
If you want to use page addressing nevertheless, the CPU accesses to the
IM 308-C master interfaces must be coordinated with semaphores. This
means that at any one time, only one CPU can access a page.
Digital inputs/outputs can be processed by multiple CPUs.
Word consistency can be ensured only if you use load/transfer commands
with word access (e.g. L PW x, TNW, ...).
The FB IM308C can be called in multiprocessor mode. The maximum
data consistency ensured is byte-by-byte.
If you address an IM 308-C master interface from multiple CPUs via the
FB IM308C, you must implement semaphore interlocks to ensure that
only one CPU can address the FB IM308C at any given time.
Select the S5-135U as the host type in COM ET 200 Windows.
Make sure that there are no entries in the DB1 (digital inputs, digital
outputs) for the series S5-155U. You must use direct load/transfer
commands to enable the S5-155U CPU to access the process image.
The process image may contain addresses in the case of S5-135U.
Master system 1
Slave No. 11 Slave No. 12
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