Siemens SIMATIC S7-400H System Manual page 448

Stand-alone operation
What you have to take into account for stand-alone operation of a fault-tolerant CPU
NOTICE
When operating a fault-tolerant CPU in stand-alone mode, no synchronization modules
may be connected. The rack number must be set to "0".
Although a fault-tolerant CPU has additional functions compared to a standard S7-400 CPU,
it does not support specific functions. So particularly when programming your automation
system, you need to know the CPU on which you are going to run the user program. A user
program written for a standard S7-400 CPU usually will not run on a fault-tolerant CPU in
stand-alone mode without adaptations.
The table below lists the differences between the operation of a fault-tolerant CPU in stand-
alone mode and in redundant mode.
Table B-1 Differences between stand-alone mode and redundant mode
Function
Connection of S5 modules via IM
or adapter casing
Redundancy error OBs (OB 70,
OB 72)
CPU hardware fault
(OB 84)
SSL ID W#16#0232 index
W#16#0004 byte 0 of the "index"
word in the data record
Multi-DP master mode
System modifications during
operation
448
Fault-tolerant CPU in stand-alone mode
via IM 463–2
Yes, but no calls
after the detection and elimination of
memory errors
W#16#F8
Yes
Yes, as described in the "System
Modification during Operation Using CIR"
manual.
Fault-tolerant CPU in redundant system
mode
No
Yes
after the detection and elimination of
memory errors
with reduced performance of the
redundant link between the two CPUs
Single mode: W#16#F8 or W#16#F9
Redundant:
W#16#F8 and W#16#F1 or
W#16#F9 and W#16#F0
No
Yes, as described in chapter Failure and
replacement of components during
operation (Page 265) for redundant
operation.
System Manual, 03/2012, A5E00267695-11
S7-400H