Siemens SIMATIC S7-400H System Manual page 322

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 adaptation.
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 in
operation
Fault tolerance-specific LEDs
The REDF, IFM1F, IFM2F, MSTR, RACK0 and RACK1 LEDs show the reaction specified in
the table below in stand-alone mode.
322
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.
LED
REDF
IFM1F
IFM2F
MSTR
RACK0
RACK1
Fault-tolerant CPU in redundant 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 185) for redundant operation.
Reaction
Unlit
Unlit
Unlit
Lit
Lit
Unlit
System Manual, 09/2007, A5E00267695-03
S7-400H