Siemens S5-155U System Manual page 294

The 304 and 314 Interface Modules
Setting the addresses
I/O Area Address
P area:F000 - F0FF
O area:F100 - F1FF
IM3 area:FC00 - FCFF
IM4 area:FD00 - FDFF
7 - 20
Switch Setting
0 = OFF, 1 = ON
*)
S1:0000
0001
1100
1101
*) Factory setting
The I/O area address is set on the IM 314. This setting applies only to
the digital and analog I/O modules.
Address areas P, O, IM3 and IM4 are available. To address the digital
and analog I/O modules in these areas, set the switches by depressing
the individual rockers.
In the STEP 5 standard operation set, you only address the P and O
areas.
Module addresses used in the CC cannot be used in the EU in the P
area, O area, IM3 area and IM4 area.
If you do not insert I/O modules in the central controller, an address
space of 256 bytes is available in each I/O area for input/output
addresses.
irrelevant
OFF
ON
System Manual
C79000-B8576-C199-03