QUESTION:
What are the functions of the Operating Mode Switch of new CPUs
(as of Firmware Version 4.0)?
ANSWER:
New CPUs (Truncated Order No.: 6ES741x-xxx04-0AB0) are
fitted with a toggle switch that has already been successfully in
use with the S7-300 for some time. This toggle switch has three
positions to select the current operating mode. The old key switch
is void.
| Old |
New |
| RUN-P |
RUN |
| RUN |
RUN + Protection Level 2 |
| STOP |
STOP |
| MRES |
MRES |
Tab. 1: Comparison of old and new functions of the Operating
Mode Switch
Positions of the Operating Mode Switch
- RUN (previously RUN-P)
The CPU processes the application program. In this case access to
the periphery is possible. Programs can be retrieved with the PG
from the CPU (CPU –> PG) as well as transferred into the CPU (PG
–> CPU). Via protection level 2 (CPU configuration via HW
Config) the operating mode can be locked: merely read-only
with blocks (previously RUN).
- STOP
The CPU does not process an application program. Access to the
peripherie is not possible. Programs can be retrieved with the PG
from the CPU (CPU –> PG) as well as transferred into the CPU (PG
–> CPU).
- MRES (Master Reset)
Position of the switch for the master reset of the CPU.
Note:
Cold start is further possible via STEP 7, but
no longer via the operating mode switch.
| 
german
