Siemens SIMATIC S7-400H System Manual page 330

Differences between fault-tolerant systems and standard systems
Function
Information in the system status
list
Update monitoring
SSL ID W#16#0232 index
W#16#0004 byte 0 of the "index"
word in the data record
Restrictions of the fault-tolerant CPU compared to a standard CPU
Function
Warm restart
Multicomputing
Startup without configuration
loaded
Background OB
Multi-DP master mode
Direct communication between
DP slaves
Equidistance for DP slaves
Synchronization of DP slaves
Disabling and enabling DP slaves Disabling and enabling DP slaves is not possible. SFC 12
Insertion of DP modules in the
module slots for interface
modules
330
Additional programming
You can also obtain data records for the fault tolerance-specific
•
LEDs from the partial list using the SSL ID W#16#0019.
You can also obtain data records for the redundancy error OBs
•
from the partial list using the SSL ID W#16#0222.
You can obtain information on the current status of the
•
fault-tolerant system using the partial list with SSL ID W#16#xy71.
You can also obtain data records for the fault tolerance-specific
•
LEDs from the partial list using the SSL ID W#16#0174.
The partial list with the SSL-ID W#16#xy75 provides information
•
on the status of the communication between the fault-tolerant
system and switched DP slaves.
The operating system monitors the following four configurable
timers:
Maximum cycle time extension
•
Maximum communication delay
•
Maximum inhibit time for priority classes > 15
•
Minimum I/O retention time
•
No additional programming is required for this. For more detailed
information, refer to chapter 7.
Fault-tolerant CPU in stand-alone mode: W#16#F8
Fault-tolerant CPU in 1-of-1 mode: W#16#F8 or W#16#F9
Fault-tolerant CPU in redundant mode: W#16#F8 and W#16#F1
or W#16#F9 and W#16#F0
Restriction of the fault-tolerant CPU
A hot restart is not possible. OB 101 is not possible
Multicomputing is not possible. OB 60 and SFC 35 are not supported
Startup without loaded configuration is not possible.
OB 90 is not supported.
The fault-tolerant CPUs do not support multi-DP master mode in
REDUNDANT mode.
Can not be configured in STEP 7
No equidistance for DP slaves in the fault-tolerant system
Synchronization of DP slave groups is not supported. SFC 11
"DPSYC_FR" is not supported.
"D_ACT_DP" is not supported.
Not possible. The module slots are designed only for use by
synchronization modules.
System Manual, 09/2007, A5E00267695-03
S7-400H