Siemens SINUMERIK 840Di Function Manual page 1212

Detailed Description
2.4 Starting up the PLC program
2.4.9 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
infor-
mation
1
2
3
2-18
Error Cause/description
No The MPI cable is not
connection connected or is defective.
via MPI to
PLC. The STEP 7 software for
the MPI card may not be
configured correctly.
PLC cannot A system data block SDB 0
be accessed has been loaded with a
in spite of modified MPI address. This
PLC general has caused an MPI bus
reset. conflict due to dual
assignment of addresses.
All four LEDs A system error has
on the PLC occurred in the PLC.
flash (DI Actions: The diagnostic
disaster) 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 STEP7.
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.
Remedy
Test: Create a link with the programmer in the
STEP7 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 faulty/has not been
connected.
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.
PLC Basic Program Solution Line (P3 sl)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0