Siemens Simatic S7-300 Technical Data Manual page 18

Operating and display elements
2.1 Operating and display elements: CPU 31xC
The figure below illustrates the integrated digital and analog I/Os of the CPU with open front
covers.
SF
BF
DC5V
FRCE
RUN
STOP
Figure 2-1
The figure shows
(1)
(2)
(3)
Slot for the SIMATIC Micro Memory Card (MMC)
A SIMATIC micro memory card (MMC) is used as memory module. You can use MMCs as
load memory and as portable storage medium.
Note
These CPUs do not have an integrated load memory and thus require an MMC for
operation.
2-2
X11
1 2
RUN
STOP
MRES
1
Integrated I/Os of CPU 31xC (CPU 314C-2 PtP, for example)
the following integrated I/Os
Analog I/Os
each with 8 digital inputs
each with 8 digital outputs
X12
2
3
2 3
CPU 31xC and CPU 31x, Technical data
Manual, Edition 08/2004, A5E00105475-05