Siemens SIMATIC ET 200AL System Manual page 1213

Glossary
PROFINET IO Device
A distributed field device that is assigned to one of the IO controllers (e.g. remote IO, valve
terminals, frequency converters, switches)
PROFINET IO System
PROFINET IO controller with assigned PROFINET IO devices.
Programmable logic controller
Programmable logic controllers (PLCs) are electronic controllers whose function is stored as
a program in the control unit. The structure and wiring of the device does not therefore
depend on the controller's function. A programmable logic controller is structured like a
computer. It consists of a CPU with memory, input/output modules and an internal bus
system. The IOs and the programming language are oriented to the requirements of the
control technology.
Programming device
Programming devices are essentially compact and portable PCs which are suitable for
industrial applications. They are identified by a special hardware and software configuration
for programmable logic controllers.
Proxy
The PROFINET device with proxy functionality is the substitute for a PROFIBUS device on
Ethernet. The proxy functionality allows a PROFIBUS device to communicate not only with
its master but also with all devices on PROFINET.
With PROFINET, existing PROFIBUS systems can be integrated into the PROFINET
communication with the aid of an IE/PB link, for example. The IE/PB Link PN IO then
handles communication via PROFINET on behalf of the PROFIBUS components.
In this way, you can link both DPV0 and DPV1 slaves to PROFINET.
Real-time
Real-time means that a system processes external events within a defined time.
Real-time communication
Group error for RT and IRT.
PROFINET uses its own real-time channel (RT) rather than TCP/IP for communication of
time-critical IO user data.
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PROFINET with STEP 7 V15
Function Manual, 12/2017, A5E03444486-AH