Operating Principle Of The S7-1500R/H Redundant System - Siemens SIMATIC S7-1500 System Manual

System overview
5.1 What is the S7-1500R/H redundant system?
Reference
You can find an example for SIMATIC Safety Integrated with the 1518HF-4 PN CPUs in the
section Safety (Page 106).
5.1.2

Operating principle of the S7-1500R/H redundant system

Introduction
S7-1500R/H redundant systems tolerate the failure of one of the two CPUs.
The S7-1500R and S7-1500H systems differ in structure, configuration limits and
performance.
S7-1500R systems tolerate an interruption of a ring topology.
S7-1500H systems can also tolerate an interruption of a line topology and the failure of an
interface module in an R1 device.
Note
Each PROFINET ring may only contain one R-system or one H-system at a time.
A combined setup with one R-system and one H-system in the same PROFINET ring is not
supported.
S7-1500 design and operating principle
The S7-1500R redundant system consists of:
• Two S7-1500R CPUs ①
• A PROFINET ring with Media Redundancy Protocol ②
• IO devices ③
• Possibly switches ④
A PROFINET ring is required for the S7-1500R redundant system. The two CPUs must be
directly connected to each other with a PROFINET cable. All devices can still communicate
with each other in the event of an interruption in the ring. All PROFINET devices in the
PROFINET ring must support media redundancy (MRP).
You can decouple further devices from the PROFINET ring via a ④ switch, e.g.:
• PROFINET devices with one port
• Non MRP-capable PROFINET devices
• PROFINET devices that do not support H-Sync forwarding, such as standard IO devices
The redundancy connections in an S7-1500R system are the PROFINET ring with MRP ②.
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S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF