Debugging functions, diagnostics and troubleshooting
10.6 Diagnostics using status and error LEDs
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
10-13
10.6.4
Evaluating the SF LED in case of hardware errors
Table 10-4 Evaluation of the SF LED (Hardware error)
Possible errors
Response of the CPU
Remedies
A module was removed or
inserted while the system was
in RUN.
CPU goes into STOP.
Screw-tighten the modules and
restart the CPU.
A distributed module was
removed or inserted on
PROFIBUS DP while the
system was in RUN.
Calls OB86. CPU does not
STOP if OB86 is loaded.
When the module is integrated
by means of GSD file:
Call of OB82. CPU goes into
STOP when OB82 is not loaded.
Load OB86 or OB82.
A distributed module was
removed or inserted on
PROFINET IO while the
system was in RUN.
Call of OB 83. CPU goes not
STOP if OB 83 is not loaded.
OB 86 is also called when one or
several modules of an ET 200S
(IO device) are removed or
inserted while the system is in
RUN. CPU switches to STOP if
OB86 is not loaded.
Load OB 83 and OB 86.
A diagnosable module reports
a diagnostic interrupt.
Calls OB82. CPU goes into
STOP if OB 82 is not loaded.
Reaction to the diagnostic event,
based on the module
configuration.
Attempt to access a missing
or faulty module. Loose
connector (software or
hardware error).
Call of OB85, if access was
attempted during update of the
process image (OB 85 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.
Load 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.
MMC is defective.
The CPU goes into STOP mode
and requests memory reset.
Replace MMC, reset CPU
memory, transfer the program
again, then set the CPU to RUN
mode.
Reference
Details on the OBs and on SFCs required for their evaluation can be found in the
STEP 7
Online Help and in the Manual System Software for S7-300/400 - System and Standard
Functions.