Siemens SIMATIC ET 200AL, System Manual

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Glossary
PROFINET with STEP 7
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Function Manual, 05/2021, A5E03444486-AL
Subnet
All the devices interconnected by switches are nodes of the same network or subnet. All the
devices in a subnet can communicate directly with each other.
All devices in the same subnet have the same subnet mask.
A subnet is physically restricted by a router.
Subnet mask
The bits set in the subnet mask decide the part of the IP address that contains the address of
the network.
In general, the following applies:
•
The network address is obtained from the AND operation of the IP address and subnet
mask.
• The device address is obtained from the AND NOT operation of the IP address and subnet
mask.
Switch
Network components used to connect several terminal devices or network segments in a
local network (LAN).
Switched S1 device
The "Switched S1 device" function of the CPU enables operation of standard IO devices on the
S7-1500R/H redundant system.
PROFINET communication runs on an AR between the primary CPU and the standard IO
device. When replacing the primary CPU, the standard IO device is briefly disconnected from
the S7-1500R/H redundant system until the new primary CPU has set up an AR to the
standard IO device.
Sync domain
All PROFINET devices to be synchronized with IRT via PROFINET IO must belong to a sync
domain.
The sync domain consists of exactly one sync master and at least one sync slave. An IO
controller or switch generally handles the role of the sync master.
Non-synchronized PROFINET devices are not part of a sync domain.
System diagnostics
System diagnostics refers to the detection, evaluation, and signaling of errors that occur
within the automation system, for example, programming errors or module failures. System
errors can be indicated by LEDs or in STEP 7.