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 Rajanb.rajan@beckhoff.com