Siemens Simatic S7-300 CPU 31xC and CPU 31x S7-300 - Manual (Page 23)

Operating and display elements
2.2 Operating and display elements: CPU 31x
CPU 31xC and CPU 31x, Technical data
Manual, Edition 08/2004, A5E00105475-05
2-7
2.2.2 Operating and display elements: CPU 317-2 DP
Operating and display elements
RUN
STOP
MRES
BF1
BF2
SF
DC5V
FRCE
RUN
STOP
X2 X1
MMC
1 2 3
4
5
6
7
The figures show the following CPU elements
(1) Bus error indicator
(2) Status and error displays
(3) Slot for the Micro Memory Card (MMC), incl. the ejector
(4) Mode selector switch
(5) Power supply connection
(6) 1. Interface X1 (MPI/DP)
(7) 2. Interface X2 (DP)