Siemens S5-135U/155U System Manual page 527

Assignments of the CPU front connector (PG interface)
Pin No.
10
11
12
13
14
15
System Manual
C79000-G8576-C199-06
Designation
1 Housing/0 V/0V
2 R x D
3 VPG + 5 V DC
4 + 24 V from bus
5 0 V/0 V
int
6 TxD
7 TxD
8 Housing/0 V/0V
9 R x D
24 V ground
20 mA/transmitter
0 V/0 V
int
20 mA/receiver
VPG + 5 V DC
0 V/0 V
int
Connector Assignments
ext
ext
11-15