Siemens ET 200pro Operating Instructions Manual page 535

SELV
Safety Extra Low Voltage
Shared device
IO device which makes its data available to multiple IO controllers.
Slave
A slave may only exchange data with a → master when requested to do so. Slaves are all
DP slaves such as ET 200X, ET 200M, ET 200S.
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 in parallel with PROFINET applications on the
same network.
The scope of the supported functions varies depending on the device type. A switch, for
example, has more functions than a CP 1616.
SSI
The position data is transferred synchronously according to the SSI protocol (synchronous
serial interface). The SSI protocol is used with absolute value encoders.
Switch
PROFIBUS is based on a line topology. Communication devices are interconnected by
means of a passive line, namely the bus.
By contrast, Industrial Ethernet is made up of point-to-point connections: Each
communication device is connected directly with one other communication device.
A device is interconnected with several other communication device via the port of an active
network component (switch). Other communications devices (including switches) can then
be connected to the other ports of the switch. The connection between a communication
device 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 of other switches, and
forwards only the signals intended for the connected PROFINET device or switch.
A switch has a certain number of ports. Connect only one PROFINET device or a further
switch to any one of the ports.
ET 200pro distributed I/O system
Operating Instructions, 03/2013, A5E00335544-08
Glossary
535