Addressing; Slot-Defined Addressing Of Modules; Introduction - Siemens SIMATIC S7-300 Hardware And Installation Manual

Addressing

8.1 Addressing
In this chapter
shows you the options for addressing specific module channels.
Slot-based addressing
Slot-based addressing is the default setting, that is, STEP 7 assigns each slot
number a defined module start address.
User-defined addressing
With user-defined addressing, you can assign any module address from the
address area managed by the CPU. Free addressing for the S7-300 is only
possible with the CPUs 312, 314 (6ES7314-1AF10-0AB0) 315, 315-2 DP, 316-
2 DP and 318-2 DP, and with the CPUs 31xC.
8.2

Slot-defined addressing of modules

8.3

Introduction

In slot-based addressing (default addressing), a module start address is allocated
to each slot number This is a digital or analog address, depending 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 module start addresses.
The input and output addresses for I/O modules start from the same module start
address.
S7-300 Programmable Controller Hardware and Installation
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