ID 442710.00 23WE KEEP THINGS MOVING
More about PROFINET?
6
Operation manual PROFINET
6 More about PROFINET?
The following chapter summarizes the important terms, services and
relationships concerning PROFINET.
6.1 PROFINET
PROFINET is the open standard for automation from Siemens that has been
developed in co-operation with the PROFIBUS user organization.
PROFINET is based on Ethernet TCP/IP – and is regarded as a further
development of PROFIBUS for applications where fast data communication via
Ethernet is essential in combination with industrial IT functions.
PROFINET is standardized to IEC 61158 and IEC 61784. PROFINET uses the
Ethernet protocol IEEE 802.3 for the lower transfer levels, special protocols for
real-time transfer as well as TCP/IP for network management and the transfer
of diagnostics data and alarms.
IT data such as statistics, programs and websites are transferred via HTTP and
FTP.
PROFINET IO
PROFINET IO is designed for the fast exchange of I/O data.
However PROFINET Ethernet communication is not capable of real-time
operation. For this reason, PROFINET offers special real-time extensions.
PROFINET IO – Real-Time (RT)
The RT protocol is the basis for data exchange for PROFINET IO, i.e.
PROFINET IO dispenses with the TCP/IP and UDP/IP transfer protocols
entirely.
RT uses the individual MAC addresses of the respective manufacturer for each
device for addressing subscribers. Received telegrams can be processed very
quickly; the response times are in the millisecond range.
Real-time data has a higher priority than standard TCP/IP data – it is assigned
priority 7 (Network Control). RT data is always preferentially handled by a
switch.
Cyclic data as well as event-controlled messages are generally transferred via
the RT protocol.
6.2 Device classes and device addressing
PROFINET distinguishes between various device classes and uses device
names for addressing the devices in the network.
6.2.1 Device classes
PROFIdrive distinguishes between the following device classes for PROFINET
IO.
IO supervisor
An IO supervisor is typically an engineering and diagnostics software that can
access all process and configuration data. A Supervisor is generally only
temporarily included in the network.
IO controller
An IO controller controls data communication, i.e. it receives process data and
event-controlled messages and processes them. A programmable logic
controller generally takes the role of the IO controller (PLC, e.g. SIMATIC S7-
1500).
IO device
An IO device is typically a decentrally arranged I/O field device (e.g. a SD6
drive controller) that is assigned to at least one IO controller. An IO device
transfers process and configuration data as well as alarms. It generally
consists of modules that include individual input and output signals of the
respective process.
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