Troubleshooting - Siemens SINUMERIK 828D Function Manual

P3: Basic PLC Program for SINUMERIK 840D sl
13.5 Starting up the PLC program
13.5.9

Troubleshooting

This section describes problems which may occur, their causes and remedies and should be read carefully
before hardware is replaced.
Errors, cause/description and remedy
Serial
no.
error Errors
informati
on
1 No
connection
via MPI to
PLC.
2 PLC cannot
be accessed
in spite of
PLC general
reset.
3 All four LEDs
on the PLC
flash (DI
disaster)
858
Cause/description
The MPI cable is not plugged in
or is defective. Possibly, the
STEP 7 software is also not
correctly configured for the MPI
card.
A system data block SDB 0 has
been loaded with a modified MPI
address. This has caused an
MPI bus conflict due to dual
assignment of addresses.
A system error has occurred in
the PLC.
Measures:
The diagnostic buffer on the PLC
must be read to analyze the
system error in detail. To access
the buffer, the PLC must be
stopped (e.g. set "PLC" switch to
position 2). A hardware reset
must then be performed. The
diagnostic buffer can then be
read out with STEP 7. Relay the
information from the diagnostic
buffer to the Hotline /
Development Service. A general
reset must be carried out if
requested after the hardware
RESET. The diagnostic buffer
can then be read with the PLC in
the Stop state.
To correct or avoid errors
Test: Create a link with the
programmer in the STEP 7 editor by
means of connection "Direct_PLC". A
number of node addresses must be
displayed here. If they do not appear,
the MPI cable is defective/not plugged
in.
Disconnect all MPI cables to other
components. Create the link
"Direct_PLC" with the programmer.
Correct the MPI address.
Once the PLC program has been
RESET or reloaded, the system may
return to normal operation. Even in this
case, the content of the diagnostic
buffer should be sent to the
Development Office.
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions