Siemens Simatic S7-1500 Function Manual page 76

Parameters, static
Static parameters of modules cannot be changed by the user program but only by the
configuration in STEP 7, e.g. input delay of a digital input module.
Primary CPU
If the R/H system is in RUN-Redundant system state, the primary CPU guides the process.
The backup CPU processes the user program synchronously and can take over the process
management if the primary CPU fails.
Process image (I/O)
The CPU transfers the values from the input and output modules to this memory area. At the
start of the cyclic program, the CPU transfers the process image output as a signal state to
the output modules. The CPU then transfers the signal states of the input modules into the
process image input. The CPU then executes the user program.
PROFINET
PROcess FIeld NETwork, open Industrial Ethernet standard which further develops
PROFIBUS and Industrial Ethernet. A cross-manufacturer communication, automation, and
engineering model defined by PROFIBUS International e.V. as an automation standard.
PROFINET IO
Communication concept for the realization of modular, distributed applications within the
scope of PROFINET.
PROFINET IO controller
Device used to address connected I/O devices (e.g. distributed I/O systems). The IO
controller exchanges input and output signals with assigned I/O devices. The IO controller
often corresponds to the CPU in which the automation program is running.
PROFINET IO device
Distributed field device that can be assigned to one or more IO controllers (e.g. distributed
I/O system, valve terminals, frequency converters, switches).
Redundancy connection
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 to synchronize
the CPUs, which means the bandwidth is not available for PROFINET IO communication.
Contrary to S7-1500R, PROFINET ring and redundancy connection are separate in an S7-
1500H. The two redundancy connections are fiber-optic cables which directly connect the
CPUs to each other via synchronization modules. The bandwidth on the PROFINET cable is
available for PROFINET IO communication.
Cycle and response times
Function Manual, 10/2018, A5E03461504-AD
Glossary
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