beckhoff-ethercat beckhoff course (en)

7/26/2019 BECKHOFF-EtherCAT Beckhoff Course (en)

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Beckhoff EtherCAT Training


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Content

EtherCAT Training

Hardware Function principle

Topology

Advantages and efficiency

In praxis: Driver installation in System

Manager

EtherCAT data exchange

Protocol

Performance

The Fieldbus EtherCAT

Configuration in System Manager

In praxis: Parameterization and

commissioning in System Manager

Sync Units

In praxis: Hot Connect

Diagnosis In praxis: Cable redundancy

XFC eXtreme Fast Control Technology

In praxis: Timestamp terminal

In praxis: Oversampling terminal

15.03.2012 2EtherCAT Training 2


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Hardware

EtherCAT Fieldbus master

IPC / Control Panel

Intel chipset based network card

with special TwinCAT real-time

Ethernet driver:

FC9001/9002/9004/9011

Supported network adapter in

Information System(online:http://infosys.beckhoff.com/c

ontent/1033/tcsystemmanager/refer

ence/ethercat/html/ethercat_supnet

workcontroller.htm?id=10257)

Embedded PC / Control Panel

CX90xx CX10xx

CX50xx

etc.15.03.2012 3EtherCAT Training 3


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Hardware

Overview standard components EL (IP20)

Bus Coupler

EK1100 / EK1101

EL or ES terminal with E-bus

Busen

dcap:EL9011


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Hardware

Overview standard components KL (IP20)

Bus Coupler

BK1120

KL or KS Terminal with K-bus

En

dterminal:KL9010

(BK1250: EtherCATK-bus)


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Hardware

Overview standard components EP (IP67)

EP1111 EtherCAT BoxEP1122 EtherCAT 2-port junction

The EtherCAT connection is done via screwable, shielded M8 plug. The

plug shows the link and activity state.


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Hardware

Further EtherCAT components

15.03.2012 7EtherCAT Training

EK1501 EK1521 EK1122 EK 1132

EK1110 EL6692


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Functional princ ipleEtherCAT Ultra high-speed for Automation



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Functional principle

Highlights

Ethernet up to the terminal complete continuity

Ethernet process interface scalable from 1 bit to 64 kbyte

First true Ethernet solution for the field level

exact timing and adapted to synchronisation

Different approaches that try to provid real-time capability for classical

Ethernet:

Suspend collision detection (CSMA/CD)

Special switches that distribute Ethernet telegrams in a precisely

controlled timely manner

ProblemEven for very small data quantities a complete Ethernet frame has to

be sent

An underlying bus system adds small delays (e.g. K-bus)



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EtherCAT

Ethernet down to the I/O terminals!

Direct access of EtherCAT slave controller (ESC) to process data inEtherCAT frame

ESC differs by command header between process data and other

commands

Ring bus system with software based ending

Ethernet view: EtherCAT bus is one Ethernet node

Process data e.g. from the PLC are no longer received and

interpreted in devices. Process data is taken from the telegram by

the EtherCAT Slave Controller (ESC) or copied into it.

The EtherCAT frame is delayed [ns] by passing through the

EtherCAT slaves.

The last node in the segment returns the frame to EtherCAT-master.



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EtherCAT

ESC

EtherCAT Slave Controller (ESC) handles the EtherCATcommunication in an EtherCAT slave.

Each EtherCAT slave has such an ESC to ensure that cyclical and

acyclical process data can be exchanged between mater and slave

via the EtherCAT fieldbus.

This ESC can handle simple functions such as digital inputs and

outputs directly, or it can be connected to a further processor in the

EtherCAT slave via serial/parallel interfaces for handling more

complex tasks such as drive control.


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EtherCAT

Scheme of EtherCAT slave


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EtherCAT

typical embedding of ESC

From the RJ45 socket electrical signals are transferred to the PHY(PHYsical interface) via the transformer.

It extracts the user data from the coded Ethernet signal and

transfers them to the ESC for processing.

The EtherCAT telegram is then relayed with minimum delay (due todynamic processing) to the next EtherCAT slave via the PHY and

the socket.

The ESC automatically parameterises itself with configuration data

from an EEPROM.when the salve starts up. If a further CPU exists

in the slave, the slave can communicate with it via interfaces.


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TopologyEtherCAT Ultra high-speed for Automation



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Topology

line, tree or star topology

up to 65,535 devices

network size: almost unlimited (> 500 km)

operation with or without switches

cost-effecitve cabling: Industrial-Ethernet- patch cable (CAT5)

twisted pair physical layer

Ethernet 100BASE-TX, up to 100 m between 2 devices

alternative: fibre-optic variants 50 up to 2,000 m

hot connect/disconnect of bus segments

extension to GBit Ethernet possible

Transfer physics is converted in the coupler to the E-bus signalLVDS (Low Voltage Differential Signaling)

If necessary reconversion of the signal at the end of the bus

segment for transfer to the next Anschaltgruppe resp. Coupler.15.03.2012 15EtherCAT Training


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Topology variant

line: any number of nodes lined up

DVI

IPC

....

up

65,535

nodesCable: standard CAT5 cable

without crossover


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Topology variant

Daisy Chain

DVI

IPC

....

Cable: standard CAT5 cable

without crossover

Up to

65,535

nodes


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Topology variant

Daisy Chain + drop lines

DVI

IPC

....

Cable: standard CAT5 cable,

without crossover

Up to

65,535

nodes


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Topology variant

mixed structures

Cable: standard CAT5 cable

without crossover

DVI

IPC

....

Up to

65,535

nodes


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Advantage and eff iciency

EtherCAT Ultra high-speed for Automation



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Advantage and efficiency

no more network tuning: lower engineering costs

Hard real-time with software master: no plug-in card required

no active infrastructure components (switches, etc.) required

Ethernet cable and connector costs : lower than for traditional

fieldbus

EtherCAT right down to the I/O terminal: no complex Bus Couplers

required

Low interface costs due to the highly integrated EtherCAT Slave

Controller

EtherCAT as alone fieldbus

integration fieldbus in fieldbus to connect further fieldbusses likeCAN, PROFIBUS, ETHERNET, etc.

No further fieldbus master e.g. as PCI card in PC necessary!



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Advantages and efficiency

EtherCAT instead of PCI

Seamless integration

of exisiting fieldbus devices Process image update-time

via EtherCAT (1500

bytes input and output data):

150s

Until now: Process image update-time

via PCI ( 500 byte input and

output data): 400s


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Topology with Ethernet over EtherCAT

Ethernet over EtherCAT (EoE) enables direct connection of

Ethernet devices in EtherCAT fieldbus

Free patency of all Ethernet technologies!

Performance: > 5MBit/s outgoing

Performance: > 2MBit/s incoming

DVI

IPC

....

virtual Ethernet Switch

Functionality

EoE

Switchport

e.g.

connection ofLabel

printer/Scann

er

Programming/

Parameterizationdirectly in I/O

range


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Topology with vertical integration

DVI

IPC

....

...via 2. Ethernet Port

+ any Ethernet protocol can be used

+ EtherCAT performance

is not limi ted

+ No switchport terminal necessary

- Requires second Ethernet port (at IPC/controller)


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Driver installation in System Manager



In practise


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Real-time Ethernet driver

real-time communication via the network card requires a Y driver

transparent connection in the operating system (conform for theoperating system, at the same time TwinCAT fieldbus card driver)

On the control side an internal prioritization and buffer ensure that

real-time frames alwasy find a free transmission channel

Ethernet frames for the operation system are sent inside the

intervals

At the receiving end, all the Ethernet frames received are examined

by the TwinCAT I/O system, and those with real-time relevance are

filtered out.

all other frames are sent back to the operating system

EtherCAT frames have always the hightest priori ty!

It is recommended to use a separate network card for high-performance data communication from the operating system!



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embedded to operating system


1 2

Network card operating systemOther

fieldbus


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In praxis


The installation of the real-time Ethernet driver can be done easily

via the TwinCAT System Manager

To use the cable redundancy, the driver has to be istalled on two

network cards



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A range of components are available for implementing direct

synchonous data exchange between two EtherCAT systems.

Depending on the application requirements, the appropriate method

can be selected based on the following criteria.

The characteristic features are:

Synchronous data exchange with predefined data that arespecifiedin the configuration

Asynchronous data exchange

Support for ADS over EtherCAT (AoE)

Support for synchronization of the distributed clocks (DC) in the

two systems



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Overview

EL6692 Publisher/

Subscriber

EL6601 FC1100 CX50x0-

B110Maximum

synchronous

Data quantity

480 bytes,

bidirectional

variable 1024 bytes,

bidirectional

(publisher/

subscribermethod)

1024 bytes,

bidirectional

Maximumasynchronous

data quantity

- - Optional -

AoE support Yes Yes - Yes Yes

DC support Yes - - - -

notice - recommended for

synchronization of

EtherCAT systems

- TwinCAT 2.11

required

- use of an

Ethernet port in

both systems as

real-time device

- recommended

for synchronousdata exchange

- transfer of RT

devices into

EtherCAT

terminal

- recommended

for synchronousdata exchange

- Requires free

PCI slot in the

IPC

- TwinCAT 2.11

R2 required

- CX5000 as

subordinate

autonomous

controller with its

own IO is

integrated in thehigher level

system as an

EtherCAT slave

- option B110

required

- TwinCAT 2.11

R2 required15.03.2012 31EtherCAT Training


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Topologiy


TwinCAT

Ec MasterEc Slave

(CX/IPC)

TwinCAT

Ec Master

TwinCAT

Ec Master


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Protocol




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Protocol

optimised protocol directy within the Ethernet frame

fully hardware-implemented

for routing and socket interface: UDP datagram

processing while passing

distributed clock for accurate synchronisation

Time stamp data types for resolution in nanosecond range

Oversampling data types for hight-resolution measurements



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Protocol in detail

description

The EtherCAT protocol is an Ethernet protocol optimized for process

data. It is sent consistently in one (ore further) Ehternet frames or

via UDP/IP.

The Ethernet frame has a size of 1514 byte. EtherCAT datagramms

(process data, etc.) with a user size of 1486 byte can be sent.

Larger process images are distributed over several Ethernet frames.

With the EtherCAT process data in the Ethernet frame a processimage up to 4 gigabytes can be served.

The data sequence is independent of the physical order of the

EtherCAT slaves in the network, addressing can be in any order.

Device profile according to CANopen (CoE) or Sercos (SoE)



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EtherCAT uses standard frames according to IEEE 802.3

no shortened frames

alternatively via UDP/IP (if IP routing is needed)

Protocol in detail

Structure of frames

MTU: max. 1514 Byte

SourceDestination Header EtherType CRC

16 Bit16 Bit48 Bit48 Bit 32 Bit

Embedded in Standard Ethernet

Frame, EtherType 0x88A4

Ethernet H. IP Header UDP H. Header

Or: via UDP/IP

UDP Port 0x88A4

TypeRes.Length

CRC

1 Bit 4 Bit11 Bit

160 Bit 64 Bit

0 11 12 15

1..n EtherCATtelegrams

MTU=Maximum

Transmission Unit,

in computer

network the

maximum non

fragmented

transferable datavolume.

TCP /IP

UDP /IP


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EtherCAT Device

Protocol in detail

Continuity for technologies

fully transparent for TCP/IP

all internet technologies available: HTTP, FTP,

Without restricing the real-time capabilities of the bussystem!

Ethernet PHY

EtherCAT MAC / DLL

Process DataMailbox

Ethernet PHY

IP

TCP UDP

Ethernet

Application

Acyclic

Data

Real Time

Application

StandardTCP/IP

Stack


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Performance




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Performance

256 digital I/Os in 12 s

1,000 digital I/Os in 30 s

200 analog I/Os (16 Bit) in 50 s, that is equivalent to 20 kHz

sampling rate

100 servo axis each 100 s

12,000 digital I/Os in 350 s

The EtherCAT bus system is so fast that between two (PLC) control

cycles internal EhterCAT eradication can be done (compare XFC)

EtherCAT is not limited to 100MBaud

The bus system is no longer the bottle neck of the control!



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Performance

Function pr inciple Ethernet on the Fly


Wagen

27

Example ICE:

Train (Ethernet Frame) doesnt stop

Somebody who sees the train through a narrow window, sees

the whole train

railway car (Sub telegramms) have variable lengthSingle people (bits) or tour groups (x kbyte) can be removed

and/or inserted.


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Performance

Processing on the fly


vom Master

to Master

From Master

Data is modified

and/or added while

telegram passes

through

Without buffering,

storing the telegram

minimal

telegram delay

per node

Optimal

performance


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Performance

processing times

Runtimes by the cable length are nearly irrelavant,

100 m Ethernet cable need approx. 550 ns.

Processing time of one or more Ethernet frame through all real

slaves on the foreward path and return path. As order of magnitute

for each slave can be taken:

For an Ethernet device: approx.1 s

For an Ebus device: approx. 300 ns

Processing t ime delayed hub and switches (ISO Layer 2) arenot part of an EtherCAT network. A segementation by router

(ISO layer 3) does not take place.



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Der Feldbus EtherCAT




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The fieldbus EtherCAT

Mapping of several process images

Traditional fieldbus systemes generate physical process image

This has to be mapped to logical process image(s)


Control, e.g. IPCFieldbus Scanner/

Master

Logicalprocessimages

PLC Data

Data n

NC Data

DPRAM

node 1

node 2

node 3

node 4

node 1

node 2

node 3

node 4

Mapping


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Mapping of process image bisher

The same applies to control systems with just one process image

Resorting of process data (mapping) is required, too.


Control e.g. PLCFieldbus Scanner/

Master

Logicalprocessimages

Process

Data

DPRAM

node 1

node 2

node 3

node 4

node 1

node 2

node 3

node 4

Mapping


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Mapping moved into the slave devices


Logicalprocessimageupto4GByte

0

232 Telegram structu re

Ethernet HDR HDR 1 PLC Data HDR 2 NC Data HDR n Data n CRC

PLC Data

Data n

NC Data

Sub

Telegram 1Sub

Telegram 2

Sub

Telegram n

DVI

IPC

..

..

Control system in unburdened, master becomes

very simple

Data is transmitted according to the application

requirements: extremely fast, flexible and efficient


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Direct Memory Access saves time

Fieldbus cards: up to 30% of CPU

time data copying

EtherCAT: NIC is PCI bus master,

is provided by DMA,

directly to PC RAM:

CPU relieved

More performance


PC RAMPC Control with fieldbus cards

PCI

bus

Scanner card, DP RAM Control task

memcopyCPU

PC RAM

CPU

PC Control with EtherCAT

NIC card, DMA transferControl task

DMA

PCI

bus


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Reaction time with legacy fieldbus


Bus Cycle Bus Cycle Bus Cycle Bus Cycle Bus CycleBus CycleBus Cycle

Tmpd

TI/O

TI/O

TI/O

TI/O

TI/O

TI/O

TI/O

TI/O

TI/O

TI/O TI/O TI/O TI/O TI/O TI/O

PLC Task OI PLC Task OI PLC TaskOI PLC TaskOI PLC TaskI

Input Output

(Worst case)

best case Reaction Time

Tmpd: Master Processing Delay

TI/O: Local I/O Update Time

(local Extension Bus + Firmware)

worst case Reaction Time

Input

(best case)


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EtherCAT System


Tmpd

TI/O TI/O TI/O TI/O TI/O TI/O TI/O TI/O TI/O TI/O TI/O TI/O TI/O TI/O TI/O

PLC task OI PLC task OI PLC task OI PLC task OI PLC taskI

No underlying extension bus any more

No dedicated master device any more

bus cycle bus cycle bus cycle bus cycle bus cyclebus cyclebus cycle


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Processing between two control cycles



TDMA (NIC)

TEtherCAT Cycle

TDMA (Time for data transferfrom/to Ethernet controller via

direct memory access):

neglectible


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Reaction time with EtherCAT



Input(Worst case)

Output

worst case

Reaction Time

Input(best case)

best case

reaction time reduced significantly with the same

controller performance

no underlying local I/O cycles and extension bus delays

any more due to the very simple protocol no dedicated master

systems (e.g. plug in cards) required

beckhoff-ethercat beckhoff course (en)

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