Siemens SIMATIC S7-400H Manual page 196

Differences between Fault-Tolerant Systems and Standard Systems
Function
Information on the system
status list
Monitoring during update
Constraints with CPU 417-4 H compared to CPU 417-4
Function
Use of symbol-oriented
messages (SCAN)
Warm Restart
Multicomputing
Startup without configuration
loaded
Background OB
CPU hardware error
Global data communication
Basic communication
D-2
Additional Programming
You also obtain data records for the H-specific LEDs by
means of the partial list with the SSL ID W#16#0019.
You also obtain data records for the redundancy error
OBs by means of the partial list with the SSL ID
W#16#0222.
You obtain information on the current state of the
fault-tolerant system by means of the partial list with
SSL ID W#16#xy71.
You also obtain data records for the H-specific LEDs by
means of the partial list with the SSL ID W#16#0174.
The partial list with the SSL-ID W#16#xy75 provides
you with information on the status of the
communications between the fault-tolerant system and
switched DP slaves.
The operating system monitors the following four
configurable timers:
maximum scan-cycle time extension
maximum communication delay
maximum hold time for priority classes > 15
minimum I/O hold time
No additional programming is required for this. For more
details refer to Chapter 5.
Constraint with CPU 417-4 H
Use of symbol-oriented messages is not possible.
A warm restart is not possible. OB101 is not supported.
Multicomputing is not possible. OB60 and SFC35 are not
supported,
Startup without loaded configuration is not possible.
OB 90 is not supported.
OB 84 is not supported. Should a sporadic interface error
occur the CPU enters the error in the diagnostic buffer and
continues running.
GD communication is not possible (neither periodically nor
by calling system functions SFC60 "GD_SND" and SFC61
"GD_RCV")
Communication functions (system functions) for basic
communication are not supported.
S7-400H Programmable Controller Fault-Tolerant Systems
A5E00068197-04