Siemens SIMATIC S7-400H - Page 47

Installation of a CPU 41x-H
4-7
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
Type of
Fault/Error
Error LED
Response of the Operating
System
Cause of Error
Priority class
error
• Priority class is called, but the
corresponding OB is not available.
• In the case of an SFB call: The
instance DB is missing or defective.
OB 85 call
If the OB is not loaded: The CPU
goes into STOP mode.
INTF
• Error during the updating of the
process image
EXTF
Failure of a
rack/station
• Power failure in an expansion rack
• Failure of a DP line
• Failure of a coupling line: missing or
defective IM, interrupted line)
OB 86 call
If the OB is not loaded: The CPU
goes into STOP mode.
EXTF
Communication
error
• Status information cannot be entered in
DB
• Incorrect frame identifier
• Frame length error
• Impermissible global identifier number
• DB access error
OB 87 call
If the OB is not loaded: The CPU
goes into STOP mode.
INTF
Cancel
processing
The processing of a program block is
cancelled. Possible reasons for the
cancellation are:
• Too much nesting depth of a
bracket level
• Too much nesting depth of a
master control relay
• Too much nesting depth for
synchronization errors
• Too much nesting depth from
block calls (i stack)
• Too much nesting depth from
block calls (b stack)
• Error allocating local data
• Unknown instruction
• Branch instruction with destination
outside of the block
OB 88 call
If the OB is not loaded: The CPU
goes into STOP mode.
INTF
Programming
error
Error in the machine code or in the user
program:
• BCD conversion error
• Range length error
• Range error
• Alignment error
• Write error
• Timer number error
• Counter number error
• Block number error
• Block not loaded
OB 121 call
If the OB is not loaded: The CPU
goes into STOP mode.
INTF
MC7 code error Error in the compiled user program (e.g.
impermissible OP code or jump over the
end of the block)
The CPU goes into STOP mode.
Reboot or memory reset required.
INTF