S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
7-1
Addressing
7
7.1
Slot-specific addressing of modules
Introduction
In slot-specific addressing (default addressing if configuration data was not loaded to the
CPU yet), each slot number is assigned a module start address. This is a digital or analog
address, based on the type of module.
This section shows you which module start address is assigned to which slot number. You
need this information to determine the start addresses of the installed modules.
Maximum assembly and the corresponding module start addresses
The figure below shows you an S7-300 assembly on four racks, and the optional slots with
their modules.Start addresses
The input and output addresses for I/O modules begin at the same module start address.
Note
On a CPU 31xC system you cannot insert any modules into slot 11 of rack 3. The address
area is reserved for the integrated I/O.