Siemens SINUMERIK 840Di Function Manual page 1211

General reset
A description of how to perform a general PLC reset appears in the Installation and Start-Up
Guide. However, a general reset does not delete the contents of the diagnostic buffer nor the
node address on the MPI bus. Another possible general reset method is described below.
This method must be used when the normal general reset process does not work.
Proceed as follows:
No.
1
2
3
4
NC tags
The latest NC VAR selector can be used for each NCU software version (even earlier
versions). The variables can also be selected from the latest list for earlier NC software
versions. The data content in DB 120 (default DB for variables) does not depend on the
software version, i.e., selected variables in an older software version must not be reselected
when the software is upgraded.
2.4.8 I/O modules (FM, CP modules)
Special packages for STEP7 are generally required for more complex I/O modules. Some of
these special packages include support blocks (FC, FB) stored in a STEP7 library. The
blocks contain functions for operating the relevant module which are parameterized and
called by the user program. In many cases, the FC numbers for the CP and FM module
handling blocks are also included in the number range of the basic program for the 840D.
What action can be taken if such a conflict occurs?
The block numbers of the basic program must remain unchanged. The block numbers of
handling blocks can be assigned new, free numbers using STEP7. These new blocks (with
new FC numbers) are then called in the user program with the parameter assignments
required by the function.
PLC Basic Program Solution Line (P3 sl)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Action
Control system is switched off
PLC switch setting 3 (MRES) and switch control on
again or perform hardware reset.
Set PLC start-up switch to position 2 (STOP) and
back to position 3 (MRES).
Set PLC start-up switch to setting 2 or 0.
Detailed Description
2.4 Starting up the PLC program
Activation
LED labeled PS flashes slowly.
The LED labeled PS starts to flash
faster.
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