Technical data

Appendix
27.1 Operating Modes
Programming with STEP 7
560 Manual, 05/2010, A5E02789666-01
27.1.2 STOP Mode
The user program is not executed in STOP mode. All the outputs are set to substitute values so
that the controlled process is in a safe state. The CPU makes the following checks:
• Are there any hardware problems(for example, modules not available)?
• Should the default setting apply to the CPU or are there parameter sets?
• Are the conditions for the programmed startup behavior satisfied?
• Are there any system software problems?
In STOP mode, the CPU can also receive global data and passive one-way communication is
possible using communication SFBs for configured connections and communication SFCs for not
configured connections.
Memory Reset
The CPU memory can be reset in STOP mode. The memory can be reset manually using the key
switch (MRES) or from the programming device (for example, before downloading a user program).
Resetting the CPU memory returns the CPU to its initial status, as follows:
• The entire user program in the work memory and in the RAM load memory and all address
areas are cleared.
• The system parameters and the CPU and module parameters are reset to the default settings.
The MPI parameters set prior to the memory reset are retained.
• If a memory card (Flash EPROM) is plugged in, the CPU copies the user program from the
memory card to the work memory (including the CPU and module parameters if the appropriate
configuration data are also on the memory card).
The diagnostic buffer, the MPI parameters, the time, and the runtime meters are not reset.