Table 5- 4 Mode Switch Positions - Siemens SIMATIC S7-400H System Manual

The following table explains the positions of the mode switch. If an error or a startup problem
occurs, the CPU will either change to or stay in STOP mode regardless of the position of the
mode switch.
Table 5- 4 Mode switch positions
Position Explanations
RUN If there is no startup problem or error and the CPU was able to switch to RUN, the CPU either
executes the user program or remains idle. The I/O can be accessed.


STOP The CPU does not execute the user program. The digital signal modules are disabled. The output
modules are disabled.


MRES Momentary-on position of the toggle switch for CPU memory reset; see chapter Performing a memory
reset (Page 62).
(Memory reset;
Master Reset) Momentary-on position for the "Reset CPU to factory state" function; see chapter Resetting the CPU
to the factory state (Page 81)
S7-400H
System Manual, 03/2012, A5E00267695-11
You can upload programs from the CPU to the programming device (CPU -> Programming
device)
You can download programs from the programming device to the CPU (Programming device ->
CPU).
You can upload programs from the CPU to the programming device (CPU -> Programming
device)
You can download programs from the programming device to the CPU (Programming device ->
CPU).
Assembly of a CPU 41x–H
5.4 Mode switch
61