Technical data

Table Of Contents
Organization Blocks
System Software for S7-300/400 System and Standard Functions - Volume 1/2
1-40
A5E00709327-01
1.20 CPU Hardware Fault Organization Block (OB84)
Description
The OS in the CPU calls OB84 in the following cases:
After memory errors have been detected and corrected
For S7-400H: if there is reduced performance of the redundant link between the
two CPUs
For WinAC RTX: Error in operating system (e.g. "blue screen")
You can use SFCs 39 to 42 to disable or delay the CPU hardware error OB and
then enable it again.
Local Data for the Hardware Fault OB
The following table includes the temporary (TEMP) variables of the CPU hardware
fault. The variable names are the default names of OB84.
Variable Type Description
OB84_EV_CLASS BYTE Event class and identifiers:
B#16#38: outgoing event
B#16#35, B#16#39: incoming event
OB84_FLT_ID BYTE Error code (B#16#81, B#16#82, B#16#83, B#16#85,
B#16#86, B#16#87)
OB84_PRIORITY BYTE Priority class; can be assigned via STEP 7 (hardware
configuration)
OB84_OB_NUMBR BYTE OB number (84)
OB84_RESERVED_1 BYTE Reserved
OB84_RESERVED_2 BYTE Reserved
OB84_RESERVED_3 WORD Reserved
OB84_RESERVED_4 DWORD Reserved
OB84_DATE_TIME DATE_AND_TIME DATE_AND_TIME of day when the OB was called
The following table shows the event that started OB84:
OB84_EV_CLASS OB84_FLT_ID Start Event of OB 84
B#16#39 B#16#81 Interface error, incoming
B#16#38 B#16#81 Interface error, outgoing
B#16#35 B#16#82 Memory error in operating system detected and corrected
B#16#35 B#16#83 Accumulation of detected and corrected memory errors
B#16#35 B#16#85 Error in PC operating system
B#16#39 B#16#86 Performance of an H-Sync link negatively affected
B#16#35 B#16#87 Multi-bit memory error detected and corrected