Siemens S5-155U System Manual page 414

The 463 Analog Input Module
9 - 42
If one of the inputs or outputs (Channel 0 to 3) of a module is to be
addressed, the relevant subaddress must be specified in the program.
The subaddress of the input or output, based on the start address of the
module, is given by:
Start address + 2 x channel no. = subaddress
Example:
Analog input module with 4 inputs
The address is the sum of the significances set with the individual
coding switches.
7
160 = 128 + 32 = 2 + 2
On Setting
(Switch Pressed)
A module with 4 inputs (Channel 0 to 3) and start address 160
reserves the address range from
160 to address 160 + 3 x 2 = 166
In this example, the next free address for another module is 168.
Addresses already assigned must not be set again.
5
IB 160
System Manual
C79000-B8576-C109-03