Siemens Simatic S7-400 - Manual (Page 520)

Interface Submodules
13-24
S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
13.6.1 Pin Assignments
X1 Socket
There is a 25-pin sub D socket connector on the frontside of the submodule for
plugging in the connecting cable.
Figure 13-6 shows the pin assignments of the submodule.
13 5M
12 5L+
11 DO0
10 DO1
9 DO2
8 DO3
7 6M
6 6L+
5 DO4
4 DO5
3 DO6
2 DO7
1 NC
DI7 25
DI6 24
4M 23
DI5 22
DI4 21
3M 20
DI3 19
DI2 18
2M 17
DI1 16
DI0 15
1M 14
Figure 13-6 X1 Socket Assignments, IF 961-DIO (25-Pin Sub D Connector)