Evaluation Of The Sf Led (Hardware Error) - Siemens SIMATIC S7-300 Hardware And Installation Manual

Possible Errors
number
•
Read/write access to
wrong area
•
Etc.
I/O access error
An error has occurred when
module data was accessed
Global data communication
error, e.g. insufficient length
of the DB for global data
communication.
Table 11-4
Possible Errors
A module was removed or
inserted during operation.
A diagnosable module
reports a diagnostic
interrupt.
Attempt to access a missing
or faulty module. Loose
connector (Software or
hardware error).
Faulty Memory Card.
Tip: You can use SFC 39 to disable all interrupts and asynchronous error events.
Tip on OB 32 and OB 35: You can set the times in watchdog OB 32 and OB 35,
starting from 1 ms.
Note
The shorter the selected watchdog interrupt period, the more likely is it that
watchdog interrupt errors will occur. You must take into account the operating
system times of the CPU in question, the user program runtime and extension of
the cycle time by active PG functions, for example.
S7-300 Programmable Controller Hardware and Installation
A5E00105492-02
Testing functions, Diagnostics and Fault Elimination
response of the CPU Remedies
Calls OB 122. CPU
does not STOP if
OB 122 is loaded.
Calls OB 87. CPU
does not STOP if
OB 87 is loaded.

Evaluation of the SF LED (hardware error)

response of the CPU
CPU goes into STOP
Calls OB 82. CPU
does not STOP if
OB 82 is loaded.
Call of OB 85, if
access was attempted
during update of the
process image (here,
the OB85 call must be
enabled accordingly in
the parameters). Call
of OB122 with direct
I/O access. CPU
switches to STOP if
the OB is not loaded.
The CPU goes into
STOP mode and
requests memory
reset.
Check module addressing in HW
Config or whether a module/DP
slave has failed.
Check global data communication
in STEP 7. If required, correct the
DB size.
Remedies
Screw-tighten the modules and
restart the CPU.
response to the diagnostic event,
depending on the module's
configuration.
Generate OB 85, the start
information of the OB contains the
address of the relevant module.
Replace the relevant module,
tighten the plug or eliminate the
program error.
Replace the Memory Card, reset
CPU memory, transfer the program
again and set the CPU to RUN
mode.
11-9