Siemens SIMATIC S7-1500 System Manual page 514

Redundancy connection/redundancy connections
The redundancy connection in an S7-1500R system is the PROFINET ring with MRP. The
redundancy connection uses part of the bandwidth on the PROFINET cable for the
synchronization of the CPUs. This bandwidth is therefore not available for PROFINET IO
communication.
Unlike in S7-1500R, the PROFINET ring and redundancy connections in S7-1500H are
separate. The two redundancy connections are fiber-optic cables that connect the CPUs
directly over synchronization modules. The bandwidth on the PROFINET cable is available for
PROFINET IO communication.
Redundancy ID
The load memory of both CPUs contains the project data of one as well as the other CPU. By
assigning the redundancy IDs, you define which project data a CPU uses for itself.
Redundant systems
Redundant systems have multiple (redundant) instances of key automation components.
Process control is maintained if a redundant component fails.
Reference potential
Potential from which the voltages of the circuits involved are observed and/or measured.
Restart
A warm restart deletes all non-retentive bit memory and resets non-retentive DB contents to
the initial values from load memory. Retentive bit memory and retentive DB contents are
retained. Program execution begins at the call of the first startup OB. A restart is triggered
with POWER OFF/POWER ON of the CPU supply voltage.
Retentivity
A memory area whose content is retained after power failure and after a STOP to RUN
transition is retentive. The non-retentive area bit memory area, timers and counters are reset
after a power failure and after a STOP to RUN transition. The non-retentive content of data
blocks is reset to the initial values.
Row
All the modules attached to a rail.
Runtime error
Error that occurs during execution of the user program in the automation system (thus not in
the process).
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF
Glossary
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