Troubleshooting - Siemens SINUMERIK 840D sl Function Manual

P3: Basic PLC program for SINUMERIK 840D sl
13.7 Starting up the PLC program
Identical numbers
If handling and basic program blocks have identical numbers, the block numbers of the basic
program must remain unchanged. The block numbers of the handling blocks must be renamed
to free numbers via STEP 7.
13.7.9

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 in‐
forma‐
tion
1
2
3
832
Errors Cause/description
No connec‐ The MPI cable is not plugged in
tion via MPI to or is defective. Possibly, the
PLC. STEP 7 software is also not cor‐
rectly configured for the MPI card.
PLC cannot A system data block SDB 0 has
be accessed been loaded with a modified MPI
in spite of PLC address. This has caused an MPI
general reset. bus conflict due to dual assign‐
ment of addresses.
All four LEDs A system error has occurred in
on the PLC the PLC.
flash (DI dis‐
Measures:
aster)
The diagnostic buffer on the PLC
must be read to analyze the sys‐
tem 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 re‐
quested after the hardware RE‐
SET. 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 con‐
nection "Direct_PLC". A number of
node addresses must be displayed
here. If they do not appear, the MPI ca‐
ble is defective/not plugged in.
Disconnect all MPI cables to other com‐
ponents. Create the link "Direct_PLC"
with the programmer. Correct the MPI
address.
Once the PLC program has been RE‐
SET or reloaded, the system may re‐
turn to normal operation. Even in this
case, the content of the diagnostic buf‐
fer should be sent to the Development
Office.
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions