Essential quality criteria for planning and validation of PROFINET networks For PROFINET devices the quality criteria that are checked within the scope of the device certification are described in published specifications, standards and test specifications. Interoperability is protected by both the specification and the test procedures in the cooperation of the devices. From practical experience in the realization of network arrangements it appears that beside the device qualities also the planning quality and the quality of the validation of a whole arrangement can have an influence on the functionality. In the task force CB / PG3 "Installation Guidelines" the suitable planning directives and introduction directives are now integrated into the quality criteria for the planning and validation of the PROFINET networks. The methods, measuring procedures and also the background will be fully explained.

1. PROFINET
System Validation
Quality Criteria for Planning
and Technical Acceptance Testing
Updated Planning
and
Commissioning
Guidelines for
PROFINET
Xaver Schmidt

2. Current situation
PROFINET is an internationally standardized bus protocol.
The specified behavior of the devices is documented and is
tested and documented in device tests(certification testing).
 Device Certification
The planning and structuring of PROFINET networks is
documented in the PROFINET Design Guideline.
Nevertheless, the question arises with users as to how the
configuration and quality of the network can be evaluated
during the acceptance testing
 System Validation
The WG CB/PG3 Installation Guide PB & PN therefore
revised and expanded the PROFINET Design and
Commissioning Guidelines in the past year.
3
Xaver Schmidt / PROFINET System Validation

3. New Guidelines Design / Commissioning
PROFINET Design Guideline
Version 1.14, December 2014
Order No.: 8.062
PROFINET Commissioning Guideline
Version 1.36, December 2014
Order No: 8.082
4
Download:
http://www.profibus.com/nc/download/installation-
guide/downloads/profinet-installation-guide/display/

4. Technical
Background

5. Folie 6
© AIT Solutions GmbH
 cyclic update (I/O cycle)
 device run in ‘autonomous‘ mode
 devices may have individual I/O cycle
PROFINET Communication

6. Response time depends on
PLC cycle time
Update interval (I/O cycle of PROFINET devices)
Communication monitoring (watch dog)
Line depth
Switching Technology
NRT Netload
Delay
ConfigurationInfrastructure
Response Time

7. Response time depends on
PLC cycle time
Update interval (I/O cycle of PROFINET devices)
Communication monitoring (watch dog)
Line depth
Switching Technology
NRT Netload
Delay
ConfigurationInfrastructure
Response Time

8. Response time depends on
PLC cycle time
Update interval (I/O cycle of PROFINET devices)
Communication monitoring (watch dog)
Line depth
Switching Technology
NRT Netload
Delay
ConfigurationInfrastructure
Response Time

9. Consequences
Response
Time
Netload
PLC cycle time
I/O cycle time
Watchdog
Line depth

10. Response Time / Worst Case
12
TD1
TC
TD2
TPN1
TPN2
ΔTPN1
ΔTPN2
Event
ΔTC
Reaction
Tc : Cycle Time Controller
ΔTC: Processing Time Controller
TD1, TD2: Cycle Time I/O Devices
TPN1, TPN2: Transmission Time Network

11. … some Figures
… some figures based on 100 Mbit/s
64 Byte= 512 Bit = approx. 5 microseconds
 approx. 150 PROFINET packets/ms
 approx. 0,5% netload per device
at an IO cycle of 2 ms
1500 Byte: approx. 125 microseconds
 approx. 8 IP packets/ms

12. Netload … some aspects
no uniform load
Different in each cable segment
Full Duplex
Load distribution to/from controller (up-/downstream)
…
PLC  Devices
Devices  PLC
Reference: Klasen, F. / Whitepaper PROFINET Validation

13. Non-uniform netload
16
Video
camera
Video
display

14. Additions
for planning

15. Hints for Planning Reliability
The defined recommen-
dations and values should
assure a secure and reliable
operation as well as a good
diagnostics of the network.
This does not mean that
higher values are not
permitted or not necessarily
lead to malfunction.
The specified values
consider reserves for
extensions of the plant over
the life time.
E.g., extension of an
existing plant by additional
functions
18
Time
Utili-
zation
Commissio-
ning
Extension End of
Operation

16. Uniform
Firmware
versions

17. Definition of uniform firmware versions
During planning, it is
recommended that uniform
firmware versions be defined
and that this definition be
documented.
PROFINET nodes
Network components
This is checked during
commissioning.
If there are any different
firmware versions, they are to
be aligned during
commissioning through
updating.
20
V1.3
V1.3
V1.1
V1.3

18. Line
topologies

19. The long line …
22
Devices with integrated switches facilitate a simple and
economical creation of line topologies.
However, very long lines lead to restrictions with respect
to:
Availability
Diagnostics
Throughput delay
Two measures should lead to an improvement here:
Definition of a primary infrastructure
Specification of a maximum line depth

20. Primary
infrastructure
consisting of
switches.
Primary infrastructure for lines
23
Lines branching
from this.
Tree structure
building on this

21. Line depth
24
1 2 3 4
5
6
7 8
9
→ Line depth: 9 (cut-through switches)

22. Maximum Line Depths
25
Store and Forward Switches
Maximum Line Depths with Update Time of
1 ms 2 ms 4 ms 8 ms
7 14 28 58
Cut through Switches
Maximum Line Depths with Update Time of
1 ms 2 ms 4 ms 8 ms
64 100 100 100

23. Cycle times
and Timeouts

24. Cycles at Data Transfer
27
Task PROFINET Task TaskPROFINET

25. Processing Chain, Shortest Reaction Time
28
ΔTC
TD1
TC
TD2
TPN1
TPN2
ΔTPN1
ΔTPN2
Event
Reaction
Tc : Cycle Time Controller
ΔTC: Processing Time Controller
TD1, TD2: Cycle Time I/O Devices
TPN1, TPN2: Transmission Time Network

26. Processing Chain, Longest Reaction Time
29
TD1
TC
TD2
TPN1
TPN2
ΔTPN1
ΔTPN2
Event
ΔTC
Reaction
Tc : Cycle Time Controller
ΔTC: Processing Time Controller
TD1, TD2: Cycle Time I/O Devices
TPN1, TPN2: Transmission Time NetworkProf. Dr. Frithjof Klasen / PROFINET System Validation

27. Recommendation for Cycle Time
Recommendation:
The shorter the update time is the more bandwith is
consumed by the cyclic real time communication
Longer update times cause longer reaction times
Therefore, for each PROFINET Device you should choose
update time as short as necessary and as long as possible
The following slide gives you a hint on how the I/O Cycle
Time influences the Netload
30

28. Cyclic PROFINET Netload
31
0
10
20
30
40
50
60
70
80
90
100
0 20 40 60 80 100 120 140 160 180 200
Netzlastin%
Anzahl Netzwerkteilnehmer
2 ms Aktualisierungszeit 4 ms Aktualisierungszeit 8 ms Aktualisierungszeit
PROFINET Paket Size of 108 Byte
(60 Byte User Data)

29. Error Counter (1)
32
0
0
1
2
0
0
1
2
t t
CounterStatus
CounterStatus
EMI
EMI
EMI
EMI
EMI
EMI

30. Watchdog / Error counter (3)
A higher threshold increases the error tolerance in the
event of a malfunction, but extends the time until an error
is detected.
It is recommended that the default setting of 3 be used. If
a value other than this default is used, a check must be
performed to determine whether the reaction time is
sufficiently short in the event of a malfunction.
33

31. Netload

32. Netload, Multi Controller
36
1%
1% 1%
3%
1% 1%
3%
1%
2%
1%1% 1% 1%
1%
1%

33. Cyclic Real Time Load
37
Update time Generated cyclic real time netload per
PROFINET Device
1 ms 0,86 %
2 ms 0,43 %
4 ms 0,22 %
8 ms 0,11 %
Generated cyclic real time netload (typ. PROFINET Packet Size
60 Byte PROFINET User data, 100 Mbit/s)
Prof. Dr. Frithjof Klasen / PROFINET System Validation

34. Cyclic Real Time Communication
38
Netload Recommendation
< 20%: No action neccessary
20…50%: It is recommended to check the designed netload
> 50%: There is a necessity to take measures to reduce the netload
Recommended threshold values for
netload of cyclic real time communication

35. Standard Ethernet Participant (1)
39
Video
camera
Video
display

36. Standard Ethernet Participant (2)
40
Video
camera
Video
display

37. 41
User Interface Netload Calculation Tool
Minimaler Sendetakt ms
Gerätegruppe Gruppe 1 Gruppe 2 Gruppe 3 Gruppe 4 Gruppe 5 Gruppe 6
Anzahl Geräte 1 0 0
Nutzung von IRT
Anzahl der Module
Input 40 10
Output 30 10
Nettodaten je Gerät
Input Daten 30 20 Bytes 100 Bytes
Output Daten 40 20 Bytes 100 Bytes
Sendetakt je Gerätegruppe
Input 4 1 ms 1 ms
Output 8 1 ms 1 ms
Taktinformationen
SendClock Factor 32 32 32 32 32 32
Reduction Ratio Output 4 1 0 1 0 0
Reduction Ratio Input 8 1 0 1 0 0
Netzlast je Gerät
Resultirende PROFINET-Netzlast Input 0,296 0,704 MBit/s Input 1,200 MBit/s
Output 0,158 0,704 MBit/s Output 1,200 MBit/s
Netzlast je Gerätegruppe
Resultirende PROFINET-Netzlast Input 0,296 0,000 MBit/s Input 0,000 MBit/s
Output 0,158 0,000 MBit/s Output 0,000 MBit/s
A
u
s
g
a
b
e
f
e
l
d
e
r
MBit/s Input MBit/s
E
i
n
g
a
b
e
f
e
l
d
e
r
1
Gemeinsame Netzlast auf einer Leitung
0,296Output 0,158
Netzlast-Berechnung
1
Remote IO Antriebe
Download:
http://www.profibus.com/nc/
download/installation-
guide/downloads/profinet-
installation-
guide/download/18580/

38. Additions to
commissioning

39. Network parameters and anomalies
DCP Multicast
ARP Broadcast
MRP Multicast
CRC Errors
discarded
packets
43

40. Check list
44

41. New Guidelines Design / Commissioning
PROFINET Design Guideline
Version 1.14, December 2014
Order No.: 8.062
PROFINET Commissioning Guideline
Version 1.36, December 2014
Order No: 8.082
45
Download:
http://www.profibus.com/nc/download/installation-
guide/downloads/profinet-installation-guide/display/

42. Thank You! Xaver Schmidt