Siemens SIMATIC S7-400H Manual page 188

Separate Operation
What you have to take into account with the separate operation of a CPU 417-4H
Note
Synchronization submodules must not be inserted when a CPU 417-4H is
operated separately.
Compared to a standard S7-400 CPU, a CPU 417-4H features additional functions,
but is does not support certain functions. You must therefore know on which CPU
your user program should run, especially when you are programming your
programmable logic controller. A user program that you have written for a standard
S7-400 CPU will therefore not normally run on a CPU 417-4H in separate
operation without adjustments.
The following table lists the differences between operation of a standard S7-400
CPU and separate operation of a CPU 417-4H.
Use of symbol-oriented
messages (SCAN)
Multicomputing (OB60, SFC35)
Startup without configuration
loaded
Insertion of DP modules in the
module slots for interface
modules
Connection of S5 modules via IM
or adapter casings
Self-test after POWER ON
Redundancy error OBs (OB70,
OB72)
Preset priority class for OBs 81 to
87
Response of the CPU upon
overflow of the start information
buffer in priority class 26
Response of the CPU upon
overflow of the startup
information buffer in priority
class 28
Background processing (OB90)
Restart (OB101)
B-2
Function Standard S7-400 CPU
Yes, if no IMs, no CPs
and FMs are plugged in
and no expansion units
are connected
This event cannot occur.
CPU 417-4H in Separate
Yes
Yes
Yes No. The module slots are
only intended for the
synchronization
submodules.
Yes
No
No
26
STOP (event Call OB80 in priority class
W#16#4541) 28. If OB not loaded,
STOP.
Entry in diagnostic buffer
Yes
Yes
S7-400H Programmable Controller Fault-Tolerant Systems
Operation
No
No
No
No
Yes
Yes, but no calls
25
No
No
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