Differences Between Fault-Tolerant Systems and Standard Systems
D-2
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
Function Additional Programming
Information on the system
status list
• You also obtain data records for the fault
tolerant-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 fault
tolerant-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.
Monitoring during update The operating system monitors the following four
configurable timers:
• maximum scan-cycle time extension
• Maximum communication delay
• Maximum retention time for priority classes > 15
• minimum I/O retention time
No additional programming is required for this. For more
details refer to Chapter 6.
Restrictions for the Fault-Tolerant CPU Compared to a Standard CPU
Function Restriction for the Fault-Tolerant CPU
Use of symbol-oriented
messages (SCAN)
Use of symbol-oriented messages is not possible.
Warm Restart A warm restart is not possible. OB 101 is not supported
Multicomputing Multicomputing is not possible. OB 60 and SFC 35 are not
supported
Startup without configuration
loaded
Startup without loaded configuration is not possible.
Background OB OB 90 is not supported.
CPU hardware error OB 84 is not supported. Should a sporadic interface error
occur, the CPU enters the error in the diagnostics buffer
and continues running.
Global data communication GD communication is not possible (neither cyclically nor by
calling system functions SFC 60 “GD_SND” and SFC 61
“GD_RCV”)
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