Siemens Simatic S7-1500R - Technical Specifications; Configuration; Programming; Know-how Protection

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".
Conditions:
•
H-Sync forwarding is not relevant for redundant S7-1500H systems. With the redundant
S7-1500H system, the H-Sync frames are transmitted exclusively via the fiber-optic cables.
•
When you use PROFINET devices with more than two ports (e.g. switch) in the
PROFINET ring of an R-system, then H-Sync Forwarding is mandatory for these
devices.
H-Sync frames leave the PROFINET ring with a switch without H-Syncforwarding. This
results in an additional load on the network. Another serious result is that the redundancy
of other R-systems in the network can fail or startup can be prevented.
•
H-Syncforwarding is recommended for all devices in the PROFINET ring if you are
using PROFINET devices with only 2 ports in the PROFINET ring of an R-system.
When you operate PROFINET devices without H-Syncforwarding in the PROFINET ring of
the redundant S7-1500R system, the following scenario will result in an additional cycle
time increase:
48
S7-1500R/H redundant system
System Manual, 11/2022, A5E41814787-AD
System overview
4.3 S7-1500 R/H-CPUs