Siemens SIMATIC ET 200SP System Manual page 314

Glossary
Service life
Period of time for which the switching device will work properly under normal operating
conditions. This is specified as the number of operating cycles, the electrical durability (e.g.
contact erosion), and the mechanical durability (e.g. operating cycles without load).
SIL (Safety Integrity Level)
Discrete level (one of three possibilities) for defining safety integrity specifications of safety-
related control functions. Safety integrity level 3 is the highest possible level, level 1 the
lowest.
Slave station
A slave can only exchange data after being requested to do so by the master.
SNMP
SNMP (Simple Network Management Protocol) is the standardized protocol for diagnosing
and also configuring the Ethernet infrastructure.
In the office area and in automation technology, devices support a wide range of
manufacturers on the Ethernet SNMP.
SNMP-based applications can be operated on the same network in parallel to applications
with PROFINET.
Standard mode
Operating mode of F-I/O in which standard communication is possible by means of → safety
frames, but not → safety-related communication.
Fail-safe ET 200SP modules can only be operated in safety mode.
Switch
PROFIBUS is a linear network. The communication nodes are linked by means of a passive
cable - the bus.
By contrast, Industrial Ethernet consists of point-to-point connections: each communication
node is interconnected directly with precisely one other communication node.
If a communication node is linked to several communication nodes, this communication node
is connected to the port of an active network component - the switch. Other communications
devices (including switches) can then be connected to the other ports of the switch. The
connection between a communication node and the switch remains a point-to-point
connection.
The task of a switch is thus to regenerate and distribute received signals. The switch "learns"
the Ethernet address(es) of a connected PROFINET device or additional switches and only
forwards those signals that are intended for the connected PROFINET device or switch.
A switch has a specific number of connections (ports). You connect at most one PROFINET
device or additional switch to each port.
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Distributed I/O system
System Manual, 09/2019, A5E03576849-AJ