<s>
Profinet	B-Protocol
(	O
usually	O
styled	O
as	O
PROFINET	B-Protocol
,	O
as	O
a	O
portmanteau	O
for	O
Process	O
Field	O
Network	O
)	O
is	O
an	O
industry	O
technical	O
standard	O
for	O
data	O
communication	O
over	O
Industrial	B-Protocol
Ethernet	I-Protocol
,	O
designed	O
for	O
collecting	O
data	O
from	O
,	O
and	O
controlling	O
equipment	O
in	O
industrial	O
systems	O
,	O
with	O
a	O
particular	O
strength	O
in	O
delivering	O
data	O
under	O
tight	O
time	O
constraints	O
.	O
</s>
<s>
The	O
standard	O
is	O
maintained	O
and	O
supported	O
by	O
Profibus	O
and	O
Profinet	B-Protocol
International	O
,	O
an	O
umbrella	O
organization	O
headquartered	O
in	O
Karlsruhe	B-Algorithm
,	I-Algorithm
Germany	I-Algorithm
.	O
</s>
<s>
Profinet	B-Protocol
implements	O
the	O
interfacing	O
to	O
peripherals	B-Device
.	O
</s>
<s>
It	O
defines	O
the	O
communication	O
with	O
field	O
connected	O
peripheral	B-Device
devices	I-Device
.	O
</s>
<s>
Its	O
basis	O
is	O
a	O
cascading	O
real-time	B-General_Concept
concept	O
.	O
</s>
<s>
Profinet	B-Protocol
defines	O
the	O
entire	O
data	O
exchange	O
between	O
controllers	B-Architecture
(	O
called	O
"	O
IO-Controllers	O
"	O
)	O
and	O
the	O
devices	O
(	O
called	O
"	O
IO-Devices	O
"	O
)	O
,	O
as	O
well	O
as	O
parameter	O
setting	O
and	O
diagnosis	O
.	O
</s>
<s>
IO-Controllers	O
are	O
typically	O
a	O
PLC	B-Architecture
,	O
DCS	O
,	O
or	O
IPC	B-Device
;	O
whereas	O
IO-Devices	O
can	O
be	O
varied	O
:	O
I/O	B-General_Concept
blocks	O
,	O
drives	O
,	O
sensors	O
,	O
or	O
actuators	O
.	O
</s>
<s>
The	O
Profinet	B-Protocol
protocol	O
is	O
designed	O
for	O
the	O
fast	O
data	O
exchange	O
between	O
Ethernet-based	O
field	O
devices	O
and	O
follows	O
the	O
provider-consumer	O
model	O
.	O
</s>
<s>
Field	O
devices	O
in	O
a	O
subordinate	O
Profibus	O
line	O
can	O
be	O
integrated	O
in	O
the	O
Profinet	B-Protocol
system	O
seamlessly	O
via	O
an	O
IO-Proxy	O
(	O
representative	O
of	O
a	O
subordinate	O
bus	O
system	O
)	O
.	O
</s>
<s>
Applications	O
with	O
Profinet	B-Protocol
can	O
be	O
divided	O
according	O
to	O
the	O
international	O
standard	O
IEC	O
61784-2	O
into	O
four	O
conformance	O
classes	O
:	O
</s>
<s>
This	O
is	O
why	O
structured	O
cabling	O
or	O
a	B-Architecture
wireless	I-Architecture
local	I-Architecture
area	I-Architecture
network	I-Architecture
for	O
mobile	O
subscribers	O
can	O
also	O
be	O
used	O
.	O
</s>
<s>
Conformance	O
Class	O
B	O
(	O
CC-B	O
)	O
stipulates	O
that	O
the	O
network	O
infrastructure	O
also	O
includes	O
certified	O
products	O
and	O
is	O
structured	O
according	O
to	O
the	O
guidelines	O
of	O
Profinet	B-Protocol
.	O
</s>
<s>
Shielded	O
cables	O
increase	O
robustness	O
and	O
switches	B-Protocol
with	O
management	O
functions	O
facilitate	O
network	O
diagnostics	O
and	O
allow	O
the	O
network	O
topology	O
to	O
be	O
captured	O
as	O
desired	O
for	O
controlling	O
a	O
production	O
line	O
or	O
machine	O
.	O
</s>
<s>
For	O
a	O
device	O
to	O
adhere	O
to	O
Conformance	O
Class	O
B	O
,	O
it	O
must	O
communicate	O
successfully	O
via	O
Profinet	B-Protocol
,	O
have	O
two	O
ports	O
(	O
integrated	O
switch	B-Protocol
)	O
,	O
and	O
support	O
SNMP	B-Protocol
.	O
</s>
<s>
With	O
Conformance	O
Class	O
C	O
(	O
CC-C	O
)	O
,	O
positioning	B-Algorithm
systems	I-Algorithm
can	O
be	O
implemented	O
with	O
additional	O
bandwidth	O
reservation	O
and	O
application	O
synchronization	O
.	O
</s>
<s>
Conformance	O
Class	O
C	O
devices	O
additionally	O
communicate	O
via	O
Profinet	B-Protocol
IRT	O
.	O
</s>
<s>
For	O
Conformance	O
Class	O
D	O
(	O
CC-D	O
)	O
,	O
Profinet	B-Protocol
is	O
used	O
via	O
Time-Sensitive	B-Protocol
Networking	I-Protocol
(	O
TSN	B-Protocol
)	O
.	O
</s>
<s>
A	O
Profinet	B-Protocol
system	O
consists	O
of	O
the	O
following	O
devices	O
:	O
</s>
<s>
If	O
two	O
IO-Systems	O
are	O
in	O
the	O
same	O
IP	B-Protocol
network	I-Protocol
,	O
the	O
IO-Controllers	O
can	O
also	O
share	O
an	O
input	O
signal	O
as	O
shared	O
input	O
,	O
in	O
which	O
they	O
have	O
read	O
access	O
to	O
the	O
same	O
submodule	O
in	O
an	O
IO-Device	O
.	O
</s>
<s>
This	O
simplifies	O
the	O
combination	O
of	O
a	O
PLC	B-Architecture
with	O
a	O
separate	O
safety	O
controller	O
or	O
motion	B-Algorithm
control	I-Algorithm
.	O
</s>
<s>
Likewise	O
,	O
an	O
entire	O
IO-Device	O
can	O
be	O
shared	O
as	O
a	O
shared	O
device	O
,	O
in	O
which	O
individual	O
submodules	O
of	O
an	O
IO-Device	O
are	O
assigned	O
to	O
different	O
IO-Controllers	O
.	O
</s>
<s>
If	O
a	O
controller	O
for	O
a	O
partner	O
controller	O
acts	O
as	O
an	O
IO-Device	O
and	O
simultaneously	O
controls	O
its	O
periphery	O
as	O
an	O
IO-Controller	O
,	O
the	O
tasks	O
between	O
controllers	B-Architecture
can	O
be	O
coordinated	O
without	O
additional	O
devices	O
.	O
</s>
<s>
The	O
language	O
used	O
for	O
this	O
is	O
GSDML	O
(	O
GSD	O
Markup	O
Language	O
)	O
-	O
an	O
XML-based	O
language	O
.	O
</s>
<s>
The	O
GSD	O
file	O
serves	O
an	O
engineering	O
environment	O
as	O
a	O
basis	O
for	O
planning	O
the	O
configuration	O
of	O
a	O
Profinet	B-Protocol
IO	I-Protocol
system	O
.	O
</s>
<s>
All	O
Profinet	B-Protocol
field	O
devices	O
determine	O
their	O
neighbors	O
.	O
</s>
<s>
This	O
means	O
that	O
field	O
devices	O
can	O
be	O
exchanged	O
in	O
the	O
event	O
of	O
a	O
fault	B-General_Concept
without	O
additional	O
tools	O
and	O
prior	O
knowledge	O
.	O
</s>
<s>
The	O
engineering	O
can	O
be	O
supported	O
by	O
tools	O
such	O
as	O
PROFINET	B-Protocol
Commander	O
or	O
PRONETA	O
.	O
</s>
<s>
Profinet	B-Protocol
is	O
also	O
increasingly	O
being	O
used	O
in	O
critical	O
applications	O
.	O
</s>
<s>
This	O
risk	O
can	O
be	O
reduced	O
by	O
specific	O
measures	O
as	O
identified	O
by	O
a	O
dependability	B-Application
analyses	O
.	O
</s>
<s>
The	O
system	O
should	O
go	O
into	O
a	O
safe	O
state	O
in	O
the	O
event	O
of	O
a	O
fault	B-General_Concept
.	O
</s>
<s>
In	O
the	O
event	O
of	O
a	O
fault	B-General_Concept
,	O
the	O
system	O
should	O
still	O
be	O
able	O
to	O
perform	O
the	O
minimum	O
required	O
function	O
.	O
</s>
<s>
Profisafe	O
defines	O
how	O
safety-related	O
devices	O
(	O
emergency	O
stop	O
buttons	O
,	O
light	O
grids	O
,	O
overfill	O
prevention	O
devices	O
,	O
...	O
)	O
communicate	O
with	O
safety	O
controllers	B-Architecture
via	O
Profinet	B-Protocol
in	O
such	O
a	O
safe	O
way	O
that	O
they	O
can	O
be	O
used	O
in	O
safety-related	O
automation	O
tasks	O
up	O
to	O
Safety	O
Integrity	O
Level	O
3	O
(	O
SIL	O
)	O
according	O
to	O
IEC	O
61508	O
,	O
Performance	O
Level	O
"	O
e	O
"	O
(	O
PL	O
)	O
according	O
to	O
ISO	O
13849	O
,	O
or	O
Category	O
4	O
according	O
to	O
EN	O
954-1	O
.	O
</s>
<s>
It	O
is	O
designed	O
as	O
a	O
separate	O
layer	O
on	O
top	O
of	O
the	O
fieldbus	O
application	B-Application
layer	I-Application
to	O
reduce	O
the	O
probability	O
of	O
data	O
transmission	O
errors	O
.	O
</s>
<s>
They	O
do	O
not	O
depend	O
on	O
error	B-Error_Name
detection	I-Error_Name
mechanisms	O
of	O
underlying	O
transmission	O
channels	O
,	O
and	O
thus	O
supports	O
securing	O
of	O
whole	O
communication	O
paths	O
,	O
including	O
backplanes	B-Architecture
inside	O
controllers	B-Architecture
or	O
remote	O
I/O	B-General_Concept
.	O
</s>
<s>
The	O
Profisafe	O
protocol	O
uses	O
error	B-Error_Name
and	O
failure	O
detection	O
mechanisms	O
such	O
as	O
:	O
</s>
<s>
System	O
redundancy	O
can	O
also	O
be	O
implemented	O
with	O
Profinet	B-Protocol
to	O
increase	O
availability	O
.	O
</s>
<s>
In	O
this	O
case	O
,	O
two	O
IO-Controllers	O
that	O
control	O
the	O
same	O
IO-Device	O
are	O
configured	O
.	O
</s>
<s>
In	O
the	O
event	O
of	O
an	O
error	B-Error_Name
,	O
the	O
second	O
IO-Controller	O
can	O
therefore	O
take	O
control	O
of	O
all	O
IO-Devices	O
without	O
interruption	O
by	O
marking	O
its	O
output	O
data	O
as	O
primary	O
.	O
</s>
<s>
How	O
the	O
two	O
IO-Controllers	O
synchronize	O
their	O
tasks	O
is	O
not	O
defined	O
in	O
Profinet	B-Protocol
and	O
is	O
implemented	O
differently	O
by	O
the	O
various	O
manufacturers	O
offering	O
redundant	O
control	O
systems	O
.	O
</s>
<s>
Profinet	B-Protocol
offers	O
two	O
media	O
redundancy	O
solutions	O
.	O
</s>
<s>
The	O
Media	B-Protocol
Redundancy	I-Protocol
Protocol	I-Protocol
(	O
MRP	O
)	O
allows	O
the	O
creation	O
of	O
a	O
protocol-independent	O
ring	O
topology	O
with	O
a	O
switching	O
time	O
of	O
less	O
than	O
50	O
ms.	O
</s>
<s>
This	O
is	O
often	O
sufficient	O
for	O
standard	O
real-time	B-General_Concept
communication	O
with	O
Profinet	B-Protocol
.	O
</s>
<s>
To	O
switch	B-Protocol
over	O
the	O
redundancy	O
in	O
the	O
event	O
of	O
an	O
error	B-Error_Name
without	O
time	O
delay	O
,	O
the	O
"	O
Media	O
Redundancy	O
for	O
Planned	O
Duplication	O
"	O
(	O
MRPD	O
)	O
must	O
be	O
used	O
as	O
a	O
seamless	O
media	O
redundancy	O
concept	O
.	O
</s>
<s>
In	O
the	O
MRPD	O
,	O
the	O
cyclic	O
real-time	B-General_Concept
data	O
is	O
transmitted	O
in	O
both	O
directions	O
in	O
the	O
ring-shaped	O
topology	O
.	O
</s>
<s>
The	O
IT	O
security	O
concept	O
for	O
Profinet	B-Protocol
assumes	O
a	O
defense-in-depth	O
approach	O
.	O
</s>
<s>
In	O
this	O
approach	O
,	O
the	O
production	O
plant	O
is	O
protected	O
against	O
attacks	O
,	O
particularly	O
from	O
outside	O
,	O
by	O
a	O
multi-level	O
perimeter	O
,	O
including	O
firewalls	B-Application
.	O
</s>
<s>
In	O
addition	O
,	O
further	O
protection	O
is	O
possible	O
within	O
the	O
plant	O
by	O
dividing	O
it	O
into	O
zones	O
using	O
firewalls	B-Application
.	O
</s>
<s>
In	O
addition	O
,	O
a	O
security	O
component	O
test	O
ensures	O
that	O
the	O
Profinet	B-Protocol
components	O
are	O
resistant	O
to	O
overload	O
to	O
a	O
defined	O
extent	O
.	O
</s>
<s>
The	O
possible	O
functions	O
of	O
communication	O
with	O
Profinet	B-Protocol
are	O
restricted	O
and	O
additional	O
specifications	O
regarding	O
the	O
function	O
of	O
the	O
field	O
device	O
are	O
prescribed	O
.	O
</s>
<s>
It	O
was	O
jointly	O
developed	O
by	O
manufacturers	O
and	O
users	O
in	O
the	O
1990s	O
and	O
since	O
then	O
,	O
in	O
conjunction	O
with	O
Profibus	O
and	O
,	O
from	O
version	O
4.0	O
,	O
also	O
with	O
Profinet	B-Protocol
,	O
it	O
has	O
covered	O
the	O
entire	O
range	O
from	O
the	O
simplest	O
to	O
the	O
most	O
demanding	O
drive	O
solutions	O
.	O
</s>
<s>
Another	O
profile	O
is	O
PROFIenergy	B-Protocol
which	O
includes	O
services	O
for	O
real	O
time	O
monitoring	O
of	O
energy	O
demand	O
.	O
</s>
<s>
For	O
integration	O
into	O
a	O
Profinet	B-Protocol
system	O
,	O
a	O
two-wire	O
Ethernet	O
is	O
required	O
in	O
addition	O
to	O
increased	O
availability	O
.	O
</s>
<s>
Ethernet	O
Advanced	B-Protocol
Physical	I-Protocol
Layer	I-Protocol
(	O
Ethernet-APL	O
)	O
describes	O
a	O
physical	O
layer	O
for	O
the	O
Ethernet	O
communication	O
technology	O
which	O
is	O
especially	O
developed	O
for	O
the	O
requirements	O
of	O
the	O
process	O
industries	O
.	O
</s>
<s>
Ethernet	B-Protocol
APL	I-Protocol
opens	O
the	O
possibility	O
for	O
Profinet	B-Protocol
to	O
be	O
incorporated	O
into	O
process	O
instruments	O
.	O
</s>
<s>
Profinet	B-Protocol
uses	O
the	O
following	O
protocols	O
in	O
the	O
different	O
layers	O
of	O
the	O
OSI	O
model	O
:	O
</s>
<s>
Layers	O
1-2	O
:	O
Mainly	O
full-duplex	O
with	O
100	O
MBit/s	O
electrical	O
(	O
100BASE-TX	B-Protocol
)	O
or	O
optical	O
(	O
100BASE-FX	O
)	O
according	O
to	O
IEEE	O
802.3	O
are	O
recommended	O
as	O
device	O
connections	O
.	O
</s>
<s>
Autocrossover	O
is	O
mandatory	O
for	O
all	O
connections	O
so	O
that	O
the	O
use	O
of	O
crossover	B-Protocol
cables	I-Protocol
can	O
be	O
avoided	O
.	O
</s>
<s>
From	O
IEEE	O
802.1Q	O
the	O
VLAN	B-General_Concept
with	O
priority	O
tagging	O
is	O
used	O
.	O
</s>
<s>
All	O
real-time	B-General_Concept
data	O
are	O
thus	O
given	O
the	O
highest	O
possible	O
priority	O
6	O
and	O
are	O
therefore	O
forwarded	O
by	O
a	O
switch	B-Protocol
with	O
a	O
minimum	O
delay	O
.	O
</s>
<s>
The	O
Profinet	B-Protocol
protocol	O
can	O
be	O
recorded	O
and	O
displayed	O
with	O
any	O
Ethernet	O
analysis	O
tool	O
.	O
</s>
<s>
Wireshark	B-Language
is	O
capable	O
of	O
decoding	O
Profinet	B-Protocol
telegrams	O
.	O
</s>
<s>
The	O
Link	B-Protocol
Layer	I-Protocol
Discovery	I-Protocol
Protocol	I-Protocol
(	O
LLDP	B-Protocol
)	O
has	O
been	O
extended	O
with	O
additional	O
parameters	O
,	O
so	O
that	O
in	O
addition	O
to	O
the	O
detection	O
of	O
neighbors	O
,	O
the	O
propagation	O
time	O
of	O
the	O
signals	O
on	O
the	O
connection	O
lines	O
can	O
be	O
communicated	O
.	O
</s>
<s>
Layers	O
3-6	O
:	O
Either	O
the	O
Remote	O
Service	O
Interface	O
(	O
RSI	O
)	O
protocol	O
or	O
the	O
Remote	B-Operating_System
Procedure	I-Operating_System
Call	I-Operating_System
(	O
RPC	B-Operating_System
)	O
protocol	O
is	O
used	O
for	O
the	O
connection	O
setup	O
and	O
the	O
acyclic	O
services	O
.	O
</s>
<s>
The	O
RPC	B-Operating_System
protocol	O
is	O
used	O
via	O
User	B-Protocol
Datagram	I-Protocol
Protocol	I-Protocol
(	O
UDP	B-Protocol
)	O
and	O
Internet	B-Protocol
Protocol	I-Protocol
(	O
IP	B-Protocol
)	O
with	O
the	O
use	O
of	O
IP	B-Protocol
addresses	I-Protocol
.	O
</s>
<s>
The	O
Address	O
Resolution	O
Protocol	O
(	O
ARP	O
)	O
is	O
extended	O
for	O
this	O
purpose	O
with	O
the	O
detection	O
of	O
duplicate	O
IP	B-Protocol
addresses	I-Protocol
.	O
</s>
<s>
The	O
Discovery	O
and	O
basic	O
Configuration	O
Protocol	O
(	O
DCP	O
)	O
is	O
mandatory	O
for	O
the	O
assignment	O
of	O
IP	B-Protocol
addresses	I-Protocol
.	O
</s>
<s>
Optionally	O
,	O
the	O
Dynamic	B-Protocol
Host	I-Protocol
Configuration	I-Protocol
Protocol	I-Protocol
(	O
DHCP	B-Protocol
)	O
can	O
also	O
be	O
used	O
for	O
this	O
purpose	O
.	O
</s>
<s>
No	O
IP	B-Protocol
addresses	I-Protocol
are	O
used	O
with	O
the	O
RSI	O
protocol	O
.	O
</s>
<s>
Thus	O
,	O
IP	B-Protocol
can	O
be	O
used	O
in	O
the	O
operating	O
system	O
of	O
the	O
field	O
device	O
for	O
other	O
protocols	O
such	O
as	O
OPC	O
Unified	O
Architecture	O
(	O
OPC	O
UA	O
)	O
.	O
</s>
<s>
Layer	O
7	O
:	O
Various	O
protocols	O
are	O
defined	O
to	O
access	O
the	O
services	O
of	O
the	O
Fieldbus	O
Application	B-Application
Layer	I-Application
(	O
FAL	O
)	O
.	O
</s>
<s>
The	O
RT	O
(	O
Real-Time	B-General_Concept
)	O
protocol	O
for	O
class	O
A	O
&	O
B	O
applications	O
with	O
cycle	O
times	O
in	O
the	O
range	O
of	O
1	O
-	O
10	O
ms.	O
</s>
<s>
The	O
IRT	O
(	O
Isochronous	O
Real-Time	B-General_Concept
)	O
protocol	O
for	O
application	O
class	O
C	O
allows	O
cycle	O
times	O
below	O
1	O
ms	O
for	O
drive	O
technology	O
applications	O
.	O
</s>
<s>
This	O
can	O
also	O
be	O
achieved	O
with	O
the	O
same	O
services	O
via	O
Time-Sensitive	B-Protocol
Networking	I-Protocol
(	O
TSN	B-Protocol
)	O
.	O
</s>
<s>
The	O
functionalities	O
of	O
Profinet	B-Protocol
IO	I-Protocol
are	O
realized	O
with	O
different	O
technologies	O
and	O
protocols	O
:	O
</s>
<s>
The	O
basic	O
function	O
of	O
the	O
Profinet	B-Protocol
is	O
the	O
cyclic	O
data	O
exchange	O
between	O
the	O
IO-Controller	O
as	O
producer	O
and	O
several	O
IO-Devices	O
as	O
consumers	O
of	O
the	O
output	O
data	O
and	O
the	O
IO-Devices	O
as	O
producers	O
and	O
the	O
IO-Controller	O
as	O
consumer	O
of	O
the	O
input	B-General_Concept
data	I-General_Concept
.	O
</s>
<s>
In	O
addition	O
,	O
device	O
parameters	O
can	O
be	O
read	O
and	O
written	O
with	O
each	O
Profinet	B-Protocol
device	O
via	O
the	O
acyclic	O
communication	O
relation	O
Record	O
Data	O
CR	O
.	O
</s>
<s>
For	O
real-time	B-General_Concept
data	O
(	O
cyclic	O
data	O
and	O
alarms	O
)	O
,	O
the	O
Profinet	B-Protocol
Real-Time	B-General_Concept
(	O
RT	O
)	O
telegrams	O
are	O
transmitted	O
directly	O
via	O
Ethernet	O
.	O
</s>
<s>
UDP/IP	B-Protocol
is	O
used	O
for	O
the	O
transmission	O
of	O
acyclic	O
data	O
.	O
</s>
<s>
The	O
Profinet	B-Protocol
AR	O
life-cycle	O
consists	O
of	O
address	O
resolution	O
,	O
connection	O
establishment	O
,	O
parameterization	O
,	O
process	O
IO	O
data	O
exchange	O
/	O
alarm	O
handling	O
,	O
and	O
termination	O
.	O
</s>
<s>
Address	O
resolution	O
:	O
A	O
Profinet	B-Protocol
IO-Device	O
is	O
identified	O
on	O
the	O
Profinet	B-Protocol
network	O
by	O
its	O
station	O
name	O
.	O
</s>
<s>
Connection	O
establishment	O
,	O
parameterization	O
and	O
alarm	O
handling	O
are	O
implemented	O
with	O
User	B-Protocol
Datagram	I-Protocol
Protocol	I-Protocol
(	O
UDP	B-Protocol
)	O
,	O
which	O
requires	O
that	O
the	O
device	O
also	O
be	O
assigned	O
an	O
IP	B-Protocol
address	I-Protocol
.	O
</s>
<s>
After	O
identifying	O
the	O
device	O
by	O
its	O
station	O
name	O
,	O
the	O
IO-Controller	O
assigns	O
the	O
pre-configured	O
IP	B-Protocol
address	I-Protocol
to	O
the	O
device	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
AR	O
and	O
CRs	O
,	O
the	O
connect	O
request	O
specifies	O
the	O
modular	O
configuration	O
of	O
the	O
IO-Device	O
,	O
the	O
layout	O
of	O
the	O
process	O
IO	O
data	O
frames	O
,	O
the	O
cyclic	O
rate	O
of	O
IO	O
data	O
exchange	O
and	O
the	O
watchdog	B-Application
.	O
</s>
<s>
From	O
this	O
point	O
forward	O
,	O
both	O
the	O
IO-Device	O
and	O
IO-Controller	O
start	O
exchanging	O
cyclic	O
process	O
I/O	B-General_Concept
data	O
frames	O
.	O
</s>
<s>
The	O
process	O
I/O	B-General_Concept
data	O
frames	O
do	O
n't	O
contain	O
valid	O
data	O
at	O
this	O
point	O
,	O
but	O
they	O
start	O
serving	O
as	O
keep-alive	O
to	O
keep	O
the	O
watchdog	B-Application
from	O
expiring	O
.	O
</s>
<s>
Process	O
IO	O
data	O
exchange	O
/	O
alarm	O
handling	O
:	O
The	O
IO-Device	O
followed	O
by	O
the	O
IO-Controller	O
start	O
to	O
cyclically	O
refresh	O
valid	O
process	O
I/O	B-General_Concept
data	O
.	O
</s>
<s>
Termination	O
:	O
The	O
connection	O
between	O
the	O
IO-Device	O
and	O
IO-Controller	O
terminates	O
when	O
the	O
watchdog	B-Application
expires	O
.	O
</s>
<s>
Watchdog	B-Application
expiry	O
is	O
the	O
result	O
of	O
a	O
failure	O
to	O
refresh	O
cyclic	O
process	O
I/O	B-General_Concept
data	O
by	O
the	O
IO-Controller	O
or	O
the	O
IO-Device	O
.	O
</s>
<s>
Unless	O
the	O
connection	O
was	O
intentionally	O
terminated	O
at	O
the	O
IO-Controller	O
,	O
the	O
IO-Controller	O
will	O
try	O
to	O
restart	O
the	O
Profinet	B-Protocol
Application	O
Relation	O
.	O
</s>
<s>
These	O
functionalities	O
primarily	O
support	O
the	O
commissioning	O
,	O
operation	O
and	O
maintenance	O
of	O
a	O
Profinet	B-Protocol
IO	I-Protocol
system	O
and	O
are	O
intended	O
to	O
increase	O
the	O
availability	O
of	O
the	O
Profinet	B-Protocol
IO	I-Protocol
system	O
.	O
</s>
<s>
Support	O
of	O
network	O
diagnostics	O
with	O
the	O
Simple	B-Protocol
Network	I-Protocol
Management	I-Protocol
Protocol	I-Protocol
(	O
SNMP	B-Protocol
)	O
is	O
mandatory	O
.	O
</s>
<s>
Likewise	O
,	O
the	O
Link	B-Protocol
Layer	I-Protocol
Discovery	I-Protocol
Protocol	I-Protocol
(	O
LLDP	B-Protocol
)	O
for	O
neighborhood	O
detection	O
including	O
the	O
extensions	O
for	O
Profinet	B-Protocol
must	O
be	O
supported	O
by	O
all	O
Class	O
B	O
devices	O
.	O
</s>
<s>
With	O
these	O
mechanisms	O
,	O
the	O
topology	O
of	O
a	O
Profinet	B-Protocol
IO	I-Protocol
network	O
can	O
be	O
read	O
out	O
at	O
any	O
time	O
and	O
the	O
status	O
of	O
the	O
individual	O
connections	O
can	O
be	O
monitored	O
.	O
</s>
<s>
This	O
allows	O
system	O
redundancy	O
with	O
two	O
IO-Controllers	O
accessing	O
the	O
same	O
IO-Devices	O
simultaneously	O
.	O
</s>
<s>
For	O
the	O
functionalities	O
of	O
Conformance	O
Class	O
C	O
(	O
CC-C	O
)	O
the	O
Isochronous	O
Real-Time	B-General_Concept
(	O
IRT	O
)	O
protocol	O
is	O
mainly	O
used	O
.	O
</s>
<s>
With	O
the	O
bandwidth	O
reservation	O
,	O
a	O
part	O
of	O
the	O
available	O
transmission	O
bandwidth	O
of	O
100	O
MBit/s	O
is	O
reserved	O
exclusively	O
for	O
real-time	B-General_Concept
tasks	O
.	O
</s>
<s>
A	O
procedure	O
similar	O
to	O
a	O
time	B-Protocol
multiplexing	I-Protocol
method	O
is	O
used	O
.	O
</s>
<s>
The	O
red	O
phase	O
is	O
reserved	O
exclusively	O
for	O
class	O
C	O
real-time	B-General_Concept
data	O
,	O
in	O
the	O
orange	O
phase	O
the	O
time-critical	O
messages	O
are	O
transmitted	O
and	O
in	O
the	O
green	O
phase	O
the	O
other	O
Ethernet	O
messages	O
are	O
transparently	O
passed	O
through	O
.	O
</s>
<s>
In	O
order	O
to	O
implement	O
these	O
bus	O
cycles	O
for	O
bandwidth	O
reservation	O
,	O
precise	O
clock	O
synchronization	O
of	O
all	O
participating	O
devices	O
including	O
the	O
switches	B-Protocol
is	O
required	O
with	O
a	O
maximum	O
deviation	O
of	O
1	O
μs	O
.	O
</s>
<s>
This	O
clock	O
synchronization	O
is	O
implemented	O
with	O
the	O
Precision	B-Protocol
Time	I-Protocol
Protocol	I-Protocol
(	O
PTP	O
)	O
according	O
to	O
the	O
IEEE	B-Protocol
1588-2008	I-Protocol
(	O
1588	O
V2	O
)	O
standard	O
.	O
</s>
<s>
For	O
position	O
control	O
applications	O
for	O
several	O
axes	O
or	O
for	O
positioning	O
processes	O
according	O
to	O
the	O
PROFIdrive	O
drive	O
profile	O
of	O
application	O
classes	O
4	O
-	O
6	O
,	O
not	O
only	O
must	O
communication	O
be	O
timely	O
,	O
but	O
the	O
actions	O
of	O
the	O
various	O
drives	O
on	O
a	O
Profinet	B-Protocol
must	O
also	O
be	O
coordinated	O
and	O
synchronized	O
.	O
</s>
<s>
If	O
several	O
Profinet	B-Protocol
devices	O
are	O
connected	O
in	O
a	O
line	O
(	O
daisy	B-Application
chain	I-Application
)	O
,	O
it	O
is	O
possible	O
to	O
further	O
optimise	O
the	O
cyclic	O
data	O
exchange	O
with	O
Dynamic	O
Frame	O
Packing	O
(	O
DFP	O
)	O
.	O
</s>
<s>
Class	O
D	O
offers	O
the	O
same	O
services	O
to	O
the	O
user	O
as	O
Class	O
C	O
,	O
with	O
the	O
difference	O
that	O
these	O
services	O
are	O
provided	O
using	O
the	O
mechanisms	O
of	O
Time-Sensitive	B-Protocol
Networking	I-Protocol
(	O
TSN	B-Protocol
)	O
defined	O
by	O
IEEE	O
.	O
</s>
<s>
The	O
Remote	O
Service	O
Interface	O
(	O
RSI	O
)	O
is	O
used	O
as	O
a	O
replacement	O
for	O
the	O
Internet	B-Protocol
protocol	I-Protocol
suite	I-Protocol
.	O
</s>
<s>
Thus	O
,	O
this	O
application	O
class	O
D	O
is	O
implemented	O
independently	O
of	O
IP	B-Protocol
addresses	I-Protocol
.	O
</s>
<s>
The	O
protocol	O
stack	O
will	O
be	O
smaller	O
and	O
independent	O
of	O
future	O
Internet	O
versions	O
(	O
IPv6	B-Protocol
)	O
.	O
</s>
<s>
The	O
TSN	B-Protocol
is	O
not	O
a	O
consistent	O
,	O
self-contained	O
protocol	O
definition	O
,	O
but	O
a	O
collection	O
of	O
different	O
protocols	O
with	O
different	O
characteristics	O
that	O
can	O
be	O
combined	O
almost	O
arbitrarily	O
for	O
each	O
application	O
.	O
</s>
<s>
For	O
use	O
in	O
industrial	O
automation	O
,	O
a	O
subset	O
is	O
compiled	O
in	O
IEC/IEEE	O
standard	O
60802	O
"	O
Joint	O
Profile	O
TSN	B-Protocol
for	O
Industrial	O
Automation	O
"	O
.	O
</s>
<s>
A	O
subset	O
is	O
used	O
in	O
the	O
Profinet	B-Protocol
specification	O
version	O
2.4	O
for	O
implementing	O
class	O
D	O
.	O
</s>
<s>
For	O
this	O
purpose	O
,	O
the	O
specifications	O
of	O
the	O
Precision	B-Protocol
Time	I-Protocol
Protocol	I-Protocol
according	O
to	O
IEC	B-Protocol
61588	I-Protocol
for	O
time	O
synchronization	O
with	O
TSN	B-Protocol
are	O
adapted	O
accordingly	O
.	O
</s>
<s>
The	O
telegrams	O
are	O
arranged	O
in	O
queues	O
according	O
to	O
the	O
priorities	O
provided	O
in	O
the	O
VLAN	B-General_Concept
tag	O
.	O
</s>
<s>
The	O
Time-Aware	O
Shaper	O
(	O
TAS	O
)	O
now	O
specifies	O
a	O
clock	O
pulse	O
with	O
which	O
the	O
individual	O
queues	O
are	O
processed	O
in	O
a	O
switch	B-Protocol
.	O
</s>
<s>
For	O
the	O
realization	O
of	O
a	O
Profinet	B-Protocol
interface	O
as	O
controller	O
or	O
device	O
,	O
no	O
additional	O
hardware	O
requirements	O
are	O
required	O
for	O
Profinet	B-Protocol
(	O
CC-A	O
and	O
CC-B	O
)	O
that	O
cannot	O
be	O
met	O
by	O
a	O
common	O
Ethernet	O
interface	O
(	O
100BASE-TX	B-Protocol
or	O
100BASE-FX	O
)	O
.	O
</s>
<s>
To	O
enable	O
a	O
simpler	O
line	O
topology	O
,	O
the	O
installation	O
of	O
a	O
switch	B-Protocol
with	O
2	O
ports	O
in	O
a	O
device	O
is	O
recommended	O
.	O
</s>
<s>
For	O
the	O
realization	O
of	O
class	O
C	O
(	O
CC-C	O
)	O
devices	O
,	O
an	O
extension	O
of	O
the	O
hardware	O
with	O
time	O
synchronization	O
with	O
the	O
Precision	B-Protocol
Time	I-Protocol
Protocol	I-Protocol
(	O
PTP	O
)	O
and	O
the	O
functionalities	O
of	O
bandwidth	O
reservation	O
is	O
required	O
.	O
</s>
<s>
For	O
class	O
D	O
(	O
CC-D	O
)	O
devices	O
,	O
the	O
hardware	O
must	O
support	O
the	O
required	O
functionalities	O
of	O
Time-Sensitive	B-Protocol
Networking	I-Protocol
(	O
TSN	B-Protocol
)	O
according	O
to	O
IEEE	O
standards	O
.	O
</s>
<s>
Execution	O
in	O
fixed	O
design	O
ASIC	O
,	O
reconfigurable	O
in	O
FPGA	B-Architecture
technology	O
,	O
as	O
plug-in	O
module	O
or	O
as	O
software	O
component	O
.	O
</s>
<s>
In	O
2002	O
,	O
the	O
Profinet	B-Protocol
CBA	O
became	O
part	O
of	O
the	O
international	O
standard	O
IEC	O
61158	O
/	O
IEC	O
61784-1	O
.	O
</s>
<s>
A	O
Profinet	B-Protocol
CBA	O
system	O
consists	O
of	O
different	O
automation	O
components	O
.	O
</s>
<s>
To	O
describe	O
a	O
component	O
,	O
a	O
Profinet	B-Protocol
Component	O
Description	O
(	O
PCD	O
)	O
file	O
is	O
created	O
in	O
XML	B-Protocol
.	O
</s>
<s>
The	O
basic	O
idea	O
behind	O
Profinet	B-Protocol
CBA	O
was	O
that	O
in	O
many	O
cases	O
it	O
is	O
possible	O
to	O
divide	O
an	O
entire	O
automation	O
system	O
into	O
autonomously	O
operating	O
-	O
and	O
thus	O
manageable	O
-	O
subsystems	O
.	O
</s>
<s>
Such	O
so-called	O
Profinet	B-Protocol
components	O
are	O
normally	O
controlled	O
by	O
a	O
manageable	O
number	O
of	O
input	O
signals	O
.	O
</s>
<s>
Communication	O
with	O
Profinet	B-Protocol
CBA	O
was	O
suitable	O
for	O
bus	O
cycle	O
times	O
of	O
approx	O
.	O
</s>
<s>
However	O
,	O
Profinet	B-Protocol
CBA	O
does	O
not	O
find	O
the	O
expected	O
acceptance	O
in	O
the	O
market	O
and	O
will	O
no	O
longer	O
be	O
listed	O
in	O
the	O
IEC	O
61784-1	O
standard	O
from	O
the	O
4th	O
edition	O
of	O
2014	O
.	O
</s>
<s>
In	O
2003	O
the	O
first	O
specification	O
of	O
Profinet	B-Protocol
IO	I-Protocol
(	O
IO	O
=	O
Input	B-General_Concept
Output	I-General_Concept
)	O
was	O
published	O
.	O
</s>
<s>
In	O
the	O
following	O
year	O
,	O
the	O
extension	O
with	O
isochronous	O
transmission	O
follows	O
,	O
which	O
makes	O
Profinet	B-Protocol
IO	I-Protocol
suitable	O
for	O
motion	B-Algorithm
control	I-Algorithm
applications	O
.	O
</s>
<s>
Profisafe	O
is	O
adapted	O
so	O
that	O
it	O
can	O
also	O
be	O
used	O
via	O
Profinet	B-Protocol
.	O
</s>
<s>
With	O
the	O
clear	O
commitment	O
of	O
AIDA	O
to	O
Profinet	B-Protocol
in	O
2004	O
,	O
acceptance	O
in	O
the	O
market	O
is	O
given	O
.	O
</s>
<s>
In	O
2006	O
Profinet	B-Protocol
IO	I-Protocol
becomes	O
part	O
of	O
the	O
international	O
standard	O
IEC	O
61158	O
/	O
IEC	O
61784-2	O
.	O
</s>
<s>
In	O
2007	O
,	O
according	O
to	O
the	O
neutral	O
count	O
,	O
1	O
million	O
Profinet	B-Protocol
devices	O
have	O
already	O
been	O
installed	O
,	O
in	O
the	O
following	O
year	O
this	O
number	O
doubles	O
to	O
2	O
million	O
.	O
</s>
<s>
In	O
2019	O
,	O
the	O
specification	O
for	O
Profinet	B-Protocol
was	O
completed	O
with	O
Time-Sensitive	B-Protocol
Networking	I-Protocol
(	O
TSN	B-Protocol
)	O
,	O
thus	O
introducing	O
the	O
CC-D	O
conformance	O
class	O
.	O
</s>
