Data Exchange With Higher-Level Dp Master - Siemens SIMATIC ET 200AL System Manual

5.5.2

Data exchange with higher-level DP master

Introduction
The following section describes the data exchange between the I-slave and the higher-level
DP master.
Transfer areas
Transfer areas are an interface to the user program of the I-slave CPU. Inputs are processed
in the user program and outputs are the result of the processing in the user program.
The data for communication between DP master and I-slave is made available in the transfer
areas. A transfer area contains an information unit that is exchanged consistently, in terms of
bytes, words or overall, between DP master and I-slave. You can find more information on
configuration and use of transfer areas in the section Configuring transfer areas (Page 84).
The following figure shows the data exchange between the I-slave and the higher-level DP
master. The individual communication relations are explained below based on the numbers.
Figure 5-14
PROFIBUS with STEP 7 V13
Function Manual, 12/2014, A5E03775446-AC
Data exchange with the DP master
5.5 Intelligent DP slaves (I-slaves)
Functions
81