Siemens SIMATIC ET 200AL System Manual page 113

Glossary
PROFINET IO controller
Device used to address connected I/O devices (e.g. distributed I/O systems). This means
that: The IO controller exchanges input and output signals with assigned I/O devices. The IO
controller often corresponds with 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).
PROFINET IO
Communication concept for the realization of modular, distributed applications in the
framework of PROFINET.
Reference potential
Potential from which the voltages of the circuits involved are observed and/or measured.
SELV
Safety Extra Low Voltage = Safety extra-low voltage
TIA Portal
Totally Integrated Automation Portal
The TIA Portal is the key to the full performance capability of Totally Integrated Automation.
The software optimizes operating, machine and process sequences.
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Distributed I/O system
System Manual, 08/2019, A5E31861578-AG