Media Redundancy In The Redundant S7-1500R/H System; H-Sync Forwarding - Siemens SIMATIC ET 200AL System Manual

6.1

Media redundancy in the redundant S7-1500R/H system

The two CPUs of the redundant system must be located in a PROFINET ring that uses the
media redundancy method MRP. All PROFINET devices in the PROFINET ring are connected to
the S7-1500R/H in a media-redundant manner. If the PROFINET ring is interrupted,
reconfiguration may occur. After a short reconfiguration time, the PROFINET devices can be
accessed again via an alternative path.
6.2

H-Sync Forwarding

Introduction
H-Sync Forwarding enables a PROFINET device with MRP to forward synchronization data
(synchronization frames) of a S7-1500R redundant system only within the PROFINET ring.
In addition, H-Sync Forwarding forwards the synchronization data even during
reconfiguration of the PROFINET ring. H-Sync Forwarding avoids a cycle time increase if the
PROFINET ring is interrupted.
Note
Support of H-Sync Forwarding
The technical specifications typically state whether a PROFINET device supports
H-Sync Forwarding.
The GSD file will also indicate whether the device supports H-Sync Forwarding. The device
supports H-Sync Forwarding when the "AdditionalForwardingRulesSupported" attribute in the
"MediaRedundancy" element is set to "true".
PROFINET with STEP 7
Function Manual, 05/2021, A5E03444486-AL
PROFINET with the redundant S7-1500R/H system
6.1 Media redundancy in the redundant S7-1500R/H system
293