EtherCAT, the fastest automation fieldbus in the world
2005-2009: B.Tech - Applied Electronics & Instrumentation, University of Kerala, India.
2015-2016: M.Sc – Industrial Automation & Communication, The Manchester Metropolitan University, UK.
Since 2018: Technical Sales Specialist, Beckhoff Automation FZE, UAE.
Speaker Introduction
Berley Rajan
Agenda
1. Basic PLC operation
2. Challenges of Ethernet for Real time communication
3. EtherCAT : Performance breakthrough
Functional Principle
4. Advantages and benefits of EtherCAT
5. Redundancy in EtherCAT
6. ETG: EtherCAT Technology Group
Agenda
1. Basic PLC operation
2. Challenges of Ethernet for Real time communication
3. EtherCAT : Performance breakthrough
Functional Principle
4. Advantages and benefits of EtherCAT
5. Redundancy in EtherCAT
6. ETG: EtherCAT Technology Group
PLC working principle
Input Logic Output
Sensorsswitches
Motors,Indicators
Detect Information Output resultsExecute programs
PLC
EtherCAT – The Ethernet Fieldbus
Ethernet is a great technology –But it is challenging to use it on the fieldbus level:
Switch + Router Configuration (+ Costs)
MAC + IP-Address Handling
Star Topology
Complex Protocols
Diagnostics
Performance
Comprehensive IT Know-HowRequired
Router
Agenda
1. Basic PLC operation
2. Challenges of Ethernet for Real time communication
3. EtherCAT : Performance breakthrough
Functional Principle
4. Advantages and benefits of EtherCAT
5. Redundancy in EtherCAT
6. ETG: EtherCAT Technology Group
Ethernet for Real-Time Communication?
3 Main Performance Problems:
1. Bandwidth Utilization
2. Stack Delays
3. Switch Delays
1. Industrial Ethernet Bandwidth Utilization
Minimum Ethernet Frame: 84 Bytes
Example: with 4 Bytes Process Data (32 I/O): 4/84 = 4.75 % Application Data Ratio
Ethernet Frame Payload: min. 46 BytesEthernet HDR
14 Bytes
Process
Data
Process Data, e.g. 1..4 Bytes
FCS CRC
4 Bytes
Interpacket Gap
12 Bytes
≥ 84 Bytes, regardless which Protocol
Preamble+ SOF
8 Bytes
1. Industrial Ethernet Bandwidth Utilization
2. Industrial Ethernet Stack Delays
Industrial Ethernet Protocol Stacks are
BIG
Processing them needs
TIMEEthernet MAC
IP
TCP UDP
Encapsulation
CIP Message Encapsulation
Implicit Msg
Explicit Msg
CIP Network & Transport
Device Profile Application Objects (e.g. I/O)
I/O Ports
Ethernet MAC
IP
UDP
Checker
Socket
RPC
Context Management
IOD Control Program
Device Profile Application Objects(e.g. I/O)
EthernetDeviceDriver EDD
DCP ACPIOPC
I/O Ports
3. Industrial Ethernet Switch Delays
Switch Buffer Delay: Unpredictable “by Nature”
Buffer delay dependson buffer load @ framearrival. QoS (Quality ofService) eases thepain by introducingmultiple priorities (and buffers), but does not resolve the issue.
Fast Controls with slow Bus System
Super Fast Controls (such as PC-based controls) requires a super fast bus technology!
Picture courtesy of Technews Publishing (Pty) Ltd.
EtherCAT: highest Performance
The fastest Industrial
Ethernet Technology
1000 distributed digital I/O in 30 µs
100 Servo-Axis every 100 µs
EtherCAT directly to the I/O Slice, no Sub-Bus
Optimal Usage of the Standard Ethernet Port in the Controls, no extra hardware
Reason for this Unique Performance:
The EtherCAT Functional Principle
(Ethernet on the Fly)
Agenda
1. Basic PLC operation
2. Challenges of Ethernet for Real time communication
3. EtherCAT : Performance breakthrough
Functional Principle
4. Advantages and benefits of EtherCAT
5. Redundancy in EtherCAT
6. ETG: EtherCAT Technology Group
Functional Principle: Ethernet “on the fly”
Efficient: Typically only one Ethernet Frame per Cycle
Ideal Bandwidth Utilization for maximum Performance
Functional Principle: Ethernet “on the fly”
Minimal protocol overhead via implicit addressing Optimized telegram structure for decentralized I/O Communication completely in hardware: maximum
(+ predictable!) performance No switches needed if only EtherCAT devices in the network Outstanding diagnostic features Ethernet-compatibility maintained
Ethernet Header ECAT HDR CRCPLC Data 1
HD
R 1
NC Data
HD
R 2
PLC Data 2
HD
R 3
EtherCAT resolves the Performance Problems
3 Main Performance Problems:
1. Bandwidth Utilization
2. Stack Delays
3. Switch Delays
Resolved!
Resolved!
Resolved!
Agenda
1. Basic PLC operation
2. Challenges of Ethernet for Real time communication
3. EtherCAT : Performance breakthrough
Functional Principle
4. Advantages and benefits of EtherCAT
5. Redundancy in EtherCAT
6. ETG: EtherCAT Technology Group
EtherCAT wiring is more flexible
Standard Ethernet Topology: Star
EtherCAT wiring is more flexible
Flexible tree structures – arbitrarily extendable Topology variants like Line, Star, Tree, Daisy Chain
+ Drop Lines possible; can be used in any combination! Up to 65,535 nodes for each EtherCAT segment Standard Ethernet cabling Line
Star/Tree Drop Line
EtherCAT Extra Large System Test
10,056
EtherCAT Nodes
EtherCAT is easier to configure
1. Select + plan topology according to system limitations2. Configure Node Address at Slave Device3. Select and configure Bitrate, depending on:
Network Length + Topology EMI-Environment Application requirements
4. Select Device Description Files (GSD, EDS) in Configuration Tool5. Select and configure communication parameters,
such as: cyclic polling event driven communication synchronized or free running
6. Allocate physical to logical process image (Mapping)7. Optimize (“tune”) the communication parameters for best network
performance
Configuration: Classical Fieldbus Systems
EtherCAT is easier to configure
Configuration: EtherCAT
1. Select + plan topology according to system limitations2. Configure Node Address at Slave Device3. Select and configure Bitrate, depending on:
Network Length + Topology EMI-Environment Application requirements
4. Select Device Description Files (ESI) in Configuration Tool5. Select and configure communication parameters,
such as: cyclic polling event driven communication synchronized or free running
6. Allocate physical to logical process image (Mapping)7. Optimize (“tune”) the communication parameters for best
network performance
EtherCAT is lower costs (1): Engineering
Less effort for Network planning: Simplified configuration Default settings will work, no network tuning
Improved Diagnosis: Faster error handling leads to less downtime
Faster Setup: No address setting required
Implementation / Tools: Standard Network Monitor Tools, e.g. MS Network Monitor or Wireshark:
free of charge Parser Software: free of charge
EtherCAT is lower costs (2): Hardware
Infrastructure:
no Switches/Hubs required Standard Ethernet Cabling + Connectors
Master:
no dedicated plug in card (co-processor) on-board Ethernet Port is fine
Slave:
low cost Slave Controller FPGA or ASIC
for simple devices: no µC needed at all no powerful µC + lots of memory needed
32 Bit
µC
EtherCAT Versioning
There is only one
EtherCAT Version,
not one every year…
Agenda
1. Basic PLC operation
2. Challenges of Ethernet for Real time communication
3. EtherCAT : Performance breakthrough
Functional Principle
4. Advantages and benefits of EtherCAT
5. Redundancy in EtherCAT
6. ETG: EtherCAT Technology Group
Without Redundancy: Normal Operation
……
Slave 1
RX TX
RXTX
Slave 2
RX TX
RXTX
Slave N
RX TX
RXTX
EtherCAT Master
MAC 1
RX TX
RX Unit TX Unit
TXRX
Without Redundancy: Cable Failure
……
Slave 1
RX TX
RXTX
Slave 2
RX TX
RXTX
Slave N-1
RX TX
RXTX
Slave N
RX TX
RXTX
EtherCAT Master
MAC 1
RX TX
RX Unit TX Unit
TXRX
Without Redundancy: Node or Cable Failure
……
Slave 1
RX TX
RXTX
Slave 2
RX TX
RXTX
Slave N-2
RX TX
RXTX
Slave N-1
RX TX
RXTX
Slave N
RX TX
RXTX
EtherCAT Master
MAC 1
RX TX
RX Unit TX Unit
TXRX
With Redundancy: Normal Operation
……
Slave 1
RX TX
RXTX
Slave 2
RX TX
RXTX
Slave N
RX TX
RXTX
EtherCAT Master
MAC 1 MAC 2
RX TX RX TX
RX Unit TX Unit
TXRX
Only 2nd EthernetPort required – no special Interface Card
With Redundancy: Cable Failure
……
Slave 1
RX TX
RXTX
Slave 2
RX TX
RXTX
Slave N-1
RX TX
RXTX
Slave N
RX TX
RXTX
EtherCAT Master
MAC 1 MAC 2
RX TX RX TX
RX Unit TX Unit
TXRX
With Redundancy: Node or Cable Failure
……
Slave 1
RX TX
RXTX
Slave 2
RX TX
RXTX
Slave N-2
RX TX
RXTX
Slave N-1
RX TX
RXTX
Slave N
RX TX
RXTX
EtherCAT Master
MAC 1 MAC 2
RX TX RX TX
RX Unit TX Unit
TXRX
Safety over EtherCAT: Features
Safety over EtherCAT (FSoE) defines a safety communication layerfor the transportation of safety process data between Safety over EtherCAT devices.
FSoE is an open technology within the EtherCAT Technology Group (ETG).
The protocol is developed according to IEC 61508 It meets the Safety Integrity Level (SIL) 3
Residual Error Probability R(p) < 10-9 The protocol is approved by an independent Notified Body (TÜV)
Agenda
1. Basic PLC operation
2. Challenges of Ethernet for Real time communication
3. EtherCAT : Performance breakthrough
Functional Principle
4. Advantages and benefits of EtherCAT
5. Redundancy in EtherCAT
6. ETG: EtherCAT Technology Group
EtherCAT is an open technology
Foundation: November 2003 Tasks: Support, Advancement and Promotion of EtherCAT The worlds largest fieldbus organization More than 5400 member companies from 65 countries in 6 continents:
Device Manufacturers End Users Technology Providers
As of June 11, 2019
ETG Membership Distribution
EtherCAT Technology Group: a
truly Global Organization!
Germany
Europew/o Germany
America
Asia
33 members>5400 members
ROW
EtherCAT – The Ethernet Fieldbus
Why go for something slower, just because it is more expensive?
Visit us at the Beckhoff standHall 3, Booth E12
Berley [email protected]