Communication Via S7 Connections - One-Sided Mode - Siemens SIMATIC CPU 410 System Manual

Supplementary information
18.10 Communication via S7 connections
Note
The START and STOP communication functions act on exactly one CPU or on all CPUs of
the fault-tolerant system. More detailed information is available in Reference Manual
Software for S7-300/400 System and Standard Functions
Note
Downloading the connection configuration during operation
If you download a connection configuration during operation, established connections may
be terminated.
18.10.1

Communication via S7 connections - one-sided mode

Availability
Availability for communication between a fault-tolerant system and a standard system is also
increased by using a redundant plant bus instead of a single bus (see figure below).
Figure 18-8
With this configuration and redundant operation, the fault-tolerant system is connected to the
standard system via bus1. This applies no matter which CPU is the master CPU.
For linked fault-tolerant and standard systems, the availability of communication cannot be
improved by means of a dual electrical bus system. To be able to use the second bus
system as redundancy, a second S7 connection must be used and managed accordingly in
the user program (see next figure).
326
Example of linking standard and fault-tolerant systems in a simple bus system
.
CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC
System