Ethernet in Automation

Ethernet in
Automation
Seite 1
Ethernet in Automation: Technical environment
Embedded
Systems
Communications
technology
EiA
Automationtechnology
Seite 2
Distributed controls
IoT (Internet of things): e.g.:
devices (Sensor, Actor, HMI)
Ninja Blocks, Sensaris, Xively , ….
+ Netzwork (Bluetooth, WLAN, Ethernet)
+ contol logic (Cloud)
= IoT
⇒ distributed Automation typical criteria:
• distance
• Bandwidth
• Integration capability
• availability, robustness
• costs
Seite 3
Vertical Communication in Automation
IoT
Industry 4.0
ERP
Enterprise Resource Planning
MES
Manufacturing Execution System
System Control level
Process control on cell level
Input/ output and dezentralized controls
Seite 4
Requirements in automation:
Trends:
• more optimization in the processes
• more safety & security
• Bigger facilities
• higher complexity
• Cost reduction
Seite 5
Requirements in automation:
Trends @ customer:
• more optimization in the processes
• more safety & security
• Bigger facilities
• higher complexity
• Cost reduction
Evolution process
Relay based
Software
Fieldbus
?
Seite 6
1.st Evolution in Automation: introduction of software
Programmable Logic Control
Relay based controls
Read
Readinputs
inputs
Hardware
Compute
Computeoutput
output
Software
Activate
Activateoutput
output
( (wait
waitfor
fornext
nextcycle)
cycle)
Seite 7
Evolution in Automation: introduction of software – Part II
SPS
Relais-based controls
Embedded µC
Software
Soft PLC
PC with control software:
Matlab, National Instruments, Agilent Vee, embedded systems
Seite 8
Soft-PLC and PC-based controls gain momentum
•
•
Graphical User interface
-
Development
-
Debugging
-
Diagnose
Hardware
-
performance
-
Cost
-
Availability and robustness
Hardware development is driven by consumer market
File-System
Connectivity
Powerful CPU
Large memory … all built in
Hardwareadaption via field busses
(bus adapters)
Ethernet: Profinet, Ethercat, Ethernet IP, Ethernet Powerlink, Varan, Sercos III, …
Profibus, CAN, DeviceNet, Interbus-S, ASI, …
Seite 9
Software fosters larger facilities => wiring bottleneck
conventional wiring
All signals are wired to the central control
• any information actual & centrally available
• high wiring costs
• bad shielding of sensitive signals
• no signal check
• large steps in extension effort
Fieldbus communication
• serialized process image via serial digital channel
• local wiring
• Bus monitoring
• Redundancy (partially)
• Extendability
• intelligent Components
• Reaction at failure in communication
⇒ Failure of subsystems
⇒ precautions in component behaviour
x
Seite 10
2.nd Evolution in Automation: fieldbus introduction
Architecture: central control + field bus
- Hardware:
- high performant, robust PC’s
- Industry, standard-PC or PLC
- performace / cost ration good
- PC-I/O-cards for bus extension
- flexible, slightly more expensive – more functionality
- decentralized IO via network
- benefits from trend towards decentral peripherals
- high flexibility
- Software:
- operating system: Windows / Linux / special Realitime-OS
IEC 6-1131-3:
- supports many coding languages and qualifications:
Technicians / Engineers / computer science
- coding Language:
AWL, ST, AS, KoP, FBS
- Methods for large scale systems are established
C, C++, Java, …
Perl, Python, Ruby, …
- Funktions:
- GUI integrated
- easy communication
- high capacity data storage
- GUI covers development, test , diagnosis, Service
- Runtime-System = Development system
- Functionality & performance skaleable
- Compatibility and legacy solution
Seite 11
Design of automation systems:
Optimizing potentials using field busses
Technical Benefits of fieldbusses prevail:
Wiring
- Clear design structure
- Functionality
- Hardware
- Software
- Local: transparency, robustness
- Central: monitoring, diagnosis
- Extendability
- Smaller cost
Functions using decentralized components
- Configuration / Consistency check
- Addresses
Seite 12
Improvement:
- Qualität
- cost
- Functionality
- Securing your
investment
task:
- adress configuration
Design of automation systems:
Optimisation potential fieldbus + decentralized peripherals
Technical Benefits of fieldbusses prevail:
Wiring
- Clear design structure :functionality, hardware, software
- Local: transparency, robustness
- Central: Monitoring, Diagnosis
- Extendability & Smaller cost
Intelligent components
- distribution / Scaleability of computing power
- local failure strategies
Functions using decentralized components
- Configuration / Consistency check
- Addresses & Parameters
-
Softwaredownload for intelligent components
- Error handling in the field
- Application download
Improvement:
- Qualität
- cost
- Functionality
- Securing your
investment
Task:
- adress configuration
- parameter configuration
- software download
Seite 13
Future use : Industry 4.0
Man-Machine-Interaction
Servicereport
Shiftplan
Quelle: Fraunhofer IAO, 2013
Seite 14
Technology evaluation
IMS RESEARCH World Market for Industrial Ethernet
2012: 31.3 mio Feldbusknoten, 23.2% mit Ethernet
2015: 45.1 mio Feldbusknoten, 26.2% mit Ethernet
Quelle Quest Technomarketing
=> Other fieldbusses lose market share
Quelle: Elektroniknet 05-2013
Seite 15
Quelle Markt & Technik 2013
Outdated:
Token Ring, ARCNET, FDDI
Frames Ethernet Version I
28.Dez. 2012
30. Sept. 2010
10 Base 5 (thick Ethernet)
Energy eefficient Ethernet
10 Base 2 (thin Ethernet = Cheapernet)
17. Jun. 2010
40 Gb/s and 100 Gb/s Ethernet
22. März 2007
Backplane Ethernet
6. Apr. 2005
Power overEthernet
12. Jun. 2003
10 Gb/s Ethernet
13. Jun. 2002
Link Aggregation
25. Jun. 1998
1 Gb/s Ethernet
20. März 1997
Full Duplex Ethernet
14. Jun. 1995
100 Mb/s Ethernet
28. Sept. 1990
10 Base-T
10. Dez. 1987
10 Mb/s Fiber-Repeater
12. Dez. 1985
10 Mb/s Repeater
23. Jun. 1983
10 Mb/s Ethernet
1973
Seite 16
2012 Revision of the Ethernet Standard
Ethernet development starts
10BASE FB (Fibre Backbone)
10 Base FP (Fibre passive)
Vertical communication in present automation
Effizienz @
Batch size 1
Customer-integrated
business processes
»Industrie 4.0« addresses the use of information- and communication
technology to form an Internet of things out of distributed controls, services
and production data, capable to operate in realtime.
Autonomeous objects, mobile communication und event processing in realtime
enable new paradigms for decentralized control and Ad-hoc-input in the
production workflow.
Quelle: Fraunhofer IAO, 2013
Seite 17
Ethernet in Automation
Key facts:
• Ethernet is an established technology in automation and will be further improved
• decentralized automation is the key to handle complexity in large Systems
• this requires a change in the control design paradigm
• controls systems with decentralized components thus are a keystone:
• matured base technology with large application areas
• growing importance of decentralized automation with local „intelligence“
• transparency using master/slave control schemes
• central functions (netzwork, communication, events, real-time)
in Master /Slave can be designed easily
Seite 18
USE CASES ??
Seite 19
examples from science:
Atlas (A Toroidal LHC ApparatuS)
CMS (compact muon solenoid)
ELBE (Elektronen Linearbeschleuniger mit
hoher Brillianz und geringer Emittanz)
Seite 20
examples from science: (Steinbach, TU DD)
Seite 21
Beispiele aus der Wissenschaft: (Prof. Steinbach, TU DD)
Datenübertragung with IP – UDP in a topology without collisions
Seite 22
ESRF: Beamline for radionuclides in low concentration
Seite 23
automation and data akquisition
Funktion data akquisition:
Data processing:
- specialised frontend
- Powerful preprocessing
- Network & modularity
- Standard-PC
- Perfomance/Price +++
- Flexibility ++
DAQ- &
Control Computer
Ethernet
Seite 25
Commercial control systems :
Functionality e.g. @ Profinet
-System control and engineering
- Man machine interface
- Parameter handling
- Data base connectivity
- History / Logging
- Security & Safety
- communikation (OPC)
- Scripting language for user apps
Seite 27
04|2010
Fokus: Automatisierung und Datenerfassung
Target architecture automation: criteria
System criteria:
- performance
- Open interfaces
- Scaleability
- conventional & safe systems (SIL3)
Performance example :
- Plant uptime:
* Redundancy in communication
* Multi – Master
* Hot Swap capability
- Availability:
* > 20 years of experience
* large range of
components
available
40 Achsen (je 20 Byte Eingangs- und Ausgangs-Daten)
50 E/A Stationen mit insgesamt 560 EtherCAT Busklemmen
2000 Digitale + 200 Analoge I/O, Buslänge 500 m
Performance EtherCAT: Update-Zeit = 276µs
bei 44% Buslast, Telegrammlänge =122µs
Zum Vergleich: Sercos III 479 µs, Profinet IRT 763 µs,
Powerlink V2 2347µs†, Profinet RT 6355 µs
56% Bandbreite übrig,
z.B. für TCP/IP
276 µs
EtherCAT
479 µs
SERCOS III
763 µs
Profinet IRT
2347 µs
Pow erlink
6355 µs
Prof inet I/O
0
Seite 28
1000
2000
3000
4000
5000
6000
7000
Network Components :
UDP @ <1ms
TCP
HTML
8 digitale Inputs galvanisch getrennt
8 digitale Outputs galvanisch getrennt
4 analog Inputs 12 Bit
4 analog Outputs 12 Bit
Ethernet protokol (TCP/UDP)
2 x serial RS485 (1x optisch)
Webserver
24 V power supply
Seite 29
04|2010
Ethernet in automation
Ethernet in Automation:
- Transmission of small datapakets
- transmission time in mikroseconds
- high availability, ggf. redundant
- Network payload balanced
- synchroneous in most cases
- isochroneous cykles in most cases
- individual installation of each facility
- Fixed participants prevail
- industrial standard
- cabinet or dragchain
- tree - topologie
- Supply with 24 V oder PoE
- wiring individually with grounding concept
- fanless computers are typical
- Robust design
- temperatures
- humidity
- dust
- EMC
- mechanical stress
- UV + chemical resistance
- operation modes
- Initialization
- Parameterization
- cylic operation
Seite 30
Ethernet in the office :
- Transmission of large files
- transmission time: seconds
- medium availability
- Large fluctuations in network traffic
- Asynchroneous transmission
- No isochroneous cykles
- Standardized installation
- participants changing
- Standard working environment
- Tree - topology
- Supply 230 V AC
- Wiring in conduits / floor installation
Price sensitive design
for moderate environmental conditions
Ethernet in automation
Adaption of Ethernet to automation is linked to the demand for realtime response:
Computation results have to be available within a given time span (DIN 44 300).
colloquially:
- deterministic time response
- garanteed response time
"hard" Realtime: 100% guaranteed response time
e.g. system failure at larger response times
„soft" Realtime : tolerable consequences -> degradation of performance
=> Communication without collisions is required
Seite 31
Ethernet in automation
Collisions
Access to the Ethernet network happens with a peer to peer scheme where collisions may happen.
These will be resolved on the cost of additional latency, depending on the individual network topology.
⇒Collision zone
- Repeater and Hubs extend the collision zone
- Bridges, Switches and Gateways limit the collision zone
Collision zone
Switch
Rep.
Seite 32
HUB
HUB
Ethernet in automation
Different solutions to avoid network collisions:
Restrictions to the topology
Dedicated Hardware to avoid collisions
Communication schemes
…
Rule of thumb for a conservative estimate of a topology using switched Ethernet:
• no use of hubs
• use different level of Switches to achieve direct connection to all devices
⇒ worst case response time may be estimated in case of a well defined network
traffic
⇒ may lead to built-up of message queues in the message buffers of switch-ports
Worst case estimation:
- n participants & packets
- n switch ports
- tp max. message length
- tgap message gap
- tL Latency to resolve collisions
tmax = tp + tL + n * tp + (n-1)*tgap Estimate for max. time to send all messages
Seite 33
Ethernet in automation
Different solutions for collision-free operation :
Restrictions to the Topologie
Special Hardware to avoid collisions: Switches and devices
Communication schemes: avoidance of collisions using predefined communication schemes
…
Master/Slave communikation – and user organisations:
Communication in the subsystems of automation equipment providers is handled in most cases with the use of master-slave
communication. The bus master performs network channel arbitration and thus avoids collisions. Some systems employ dedicated IC‘s in
order to address the MAC-layer.
Die option to use commercial switches in an industrial automation network and the use of standard telegrams is liable to a number of
restrictions. The recommendation thus is, to stay with the switches of the equipment provider.
There are numerous user-organisations to coordinate…. and spread the use of the particular automation system. *
• Jetter
• Allen Bradley(Rockwell)
EtherNet IP *
• UEI
• Beckhoff
EtherCAT *
• Oregano Systems
• B&R
Ethernet Powerlink *
• RealtimeSystemsGropup
• IEEE
IEEE 1588 *
• Pilz
SafetyNET p *
• Yokogawa
• Schneider Electric Modbus-IDA RTPS *
• Toshiba
• Sercos
SERCOS III *
• Zhejang Supcon Instr.
• Siemens
Profinet *
• ETAS
• Sigmatek
Varan *
• MEI
SynqNet *
• Panasonic
•…
• Bachmann, Phoenix, Wago, … kooperieren
Seite 34
JetSync
Power DANN
SyncUTC
RTnet
Vnet/IP
Ontime Networks
EPA
DART-EC
RTEX
Ethernet in automation
Devices or Switches:
predominantly with learning routers (dynamic source address table)
⇒ Store and forward Switches – buffering and checking on the basis of complete ingoing messages
⇒ Cut through Switches
• Fast-Forward-Switching (forwarding after receiving the destination-MAC-adress: 14 byte latency)
• Fragment free Switches (messages >64 Byte will be forwarded without CRC => faster than Store
and Forward
• diverse dedicated solutions (messages of lower priority will be discontinued, if a high-priority
realtime message is detected)
⇒ Error-Free-Cut-Through/Adaptive Switching
• Flexible switching between different arbitration algorithms to maximize throughput
Seite 35
Ethernet in automation
Categories of solutions with real-time Ethernet (several may apply)
Ethernet-basiert: Use of pakets, which do not comply to TCP/IP
(dedicated Ethertypes, z.B. EtherCAT, Profinet, Ethernet POWERLINK, SERCOS III)
Ethernet fieldbus:
use of dedicated Ethernet-IC‘s (z.B. EtherCAT)
restriction to Topologie (e.g. SERCOS-III with linie-structure)
Incompatible with Standard-Ethernet (e.g. EtherCAT)
Master Slave-communication or time slots:
Arbitration by Busmasters (e.g. EtherCAT, SERCOS-III,)
internal time synchronisation (e.g. Profinet IRT or SafetyNET p, Ethernet Powerlink)
⇒There is no generic approach besides the standard
⇒ Basic principles to avoid collisions remain identical
⇒ for didactical reasons we‘ll focus on the standard
Seite 36