Master Classes

Document:

ETG.1500 D (R) 1.0.2

Nomenclature:
ETG-Number
Type
State
VersionETG.1500
D (Directive)
R (Release)
1.0.2

Created by:Contact:
Filename:
Date:

ETG
info@ethercat.org
ETG1500_D_MasterClasses.docx
19.05.16

LEGAL NOTICE

Trademarks and Patents
EtherCAT® is a registered trademark and patented technology, licensed by Beckhoff Automation
GmbH, Germany. Other designations used in this publication may be trademarks whose use by third
parties for their own purposes could violate the rights of the owners.
Disclaimer
The documentation has been prepared with care. The technology described is, however, constantly
under development. For that reason the documentation is not in every case checked for consistency
with performance data, standards or other characteristics. In the event that it contains technical or
editorial errors, we retain the right to make alterations at any time and without warning. No claims forthe modification of products that have already been supplied may be made on the basis of the data,
diagrams and descriptions in this documentation.
Copyright© EtherCAT Technology Group 10/2015.
The reproduction, distribution and utilization of this document as well as the communication of its
contents to others without express authorization is prohibited. Offenders will be held liable for thepayment of damages. All rights reserved in the event of the grant of a patent, utility model or design.

ETG.1500, EtherCAT Master Classes

II

DOCUMENT HISTORY
Version
1.0.0
1.0.1
1.0.2

Comment
First outline
Removed ETG.1400 reference and update ETG.8000 Name
Replaced ETG.1400 by ETG.8000 throughout the document

ETG.1500, EtherCAT Master Classes

III

CONTENTS
1
2
3

4

5

Scope .............................................................................................................................................2
References .....................................................................................................................................3
Terms, Definitions and Word Usage ..............................................................................................4
3.1 Terms and Definitions ................................................................................................4
3.2 Word usage: shall, should, may, can .........................................................................4
Master Classes ...............................................................................................................................5
4.1 Introduction ................................................................................................................5
4.2 Master Class A ..........................................................................................................5
4.3 Master Class B ..........................................................................................................5
4.4 Feature Packs ............................................................................................................6
4.5 Validity of Master Classes and Feature Packs ..........................................................6
Master Classes Requirement Specification ...................................................................................7
5.1 Version history Master Classes specification ............................................................7
5.2 Overview ....................................................................................................................7
5.3 Basic Functions .........................................................................................................95.3.1Service Commands ....................................................................................9
5.3.2
IRQ Field in datagram ................................................................................9
5.3.3
Slaves with Device Emulation ................................................................. 10
5.3.4
EtherCAT State Machine (ESM) ............................................................. 10
5.3.5
Error Handling ......................................................................................... 10
5.3.6
VLAN ....................................................................................................... 10
5.3.7
Ethernet Frame Types ............................................................................. 11
5.4 Process Data Exchange ......................................................................................... 11
5.4.1
Cyclic PDO .............................................................................................. 11
5.4.2
Multiple Tasks ......................................................................................... 11
5.4.3
Frame repetition ...................................................................................... 11
5.5 Network Configuration ............................................................................................ 12
5.5.1
Getting Network Configuration ................................................................ 12
5.5.2
Compare network configuration during boot-up ...................................... 125.5.3
Explicit Station Identification.................................................................... 12
5.5.4
Station Alias Addressing ......................................................................... 12
5.5.5
Access to EEPROM ................................................................................ 13
5.6 Mailbox Support ...................................................................................................... 13
5.6.1
Support Mailbox ...................................................................................... 13
5.6.2
Mailbox Resilient Layer ........................................................................... 13
5.6.3
Simultaneous Mailbox protocol transfer to one device ........................... 13
5.6.4
Mailbox polling ......................................................................................... 14
5.7 CAN application layer over EtherCAT (CoE) .......................................................... 14
5.7.1
SDO Up-/Download ................................................................................. 14
5.7.2
Segmented Transfer ................................................................................ 14
5.7.3
Complete Access .................................................................................... 14
5.7.4
SDO Information Service ......................................................................... 14
5.7.5
Emergency Message ............................................................................... 15
5.7.6
PDO transmission with CoE .................................................................... 15
5.8 Ethernet over EtherCAT (EoE) ............................................................................... 15
5.8.1
EoE Protocol............................................................................................ 15
5.8.2
Virtual Switch ........................................................................................... 15

ETG.1500, EtherCAT Master ClassesIV5.8.3
EoE Endpoint to Operating Systems ....................................................... 15
File Access over EtherCAT (FoE) .......................................................................... 16
5.9.1
FoE Protocol ............................................................................................ 16
5.9.2
Boot State ................................................................................................ 16
5.10 Servo drive profile over EtherCAT (SoE) ................................................................ 16
5.10.1 SoE Services ........................................................................................... 16
5.11 ADS over EtherCAT (AoE) ..................................................................................... 16
5.11.1 AoE Protocol............................................................................................ 16
5.12 Vendor-specific over EtherCAT (VoE) .................................................................... 17
5.12.1 VoE Protocol............................................................................................ 17
5.13 Synchronization with Distributed Clocks (DC) ........................................................ 17
5.13.1 DC support .............................................................................................. 17
5.13.2 Continuous Propagation delay measurement ......................................... 17
5.13.3 Sync window monitoring .......................................................................... 18
5.14 Slave-to-Slave Communication .............................................................................. 18
5.15 Master information .................................................................................................. 18
5.15.1 Master Object Dictionary ......................................................................... 18
Feature Packs ............................................................................................................................. 19
6.1 FP Cable Redundancy............................................................................................ 19
6.1.1
Version history FP Cable Redundancy ................................................... 19
6.1.2
FP Cable Redundancy description .......................................................... 19
6.1.3
Basic Functions ....................................................................................... 20
6.1.4
Diagnosis Functions ................................................................................ 20
6.1.5
Redundancy with Hot Connect ................................................................ 20
6.1.6
Redundancy with DC ............................................................................... 21
6.2 FP Motion Control ................................................................................................... 21
6.2.1
Version history FP Motion Control .......................................................... 21
6.2.2
FP Motion Control description ................................................................. 21
6.2.3
Drive Profile CiA402 ................................................................................ 21
6.2.4
Drive Profile SERCOS ............................................................................. 21
6.2.5
Synchronization with DC ......................................................................... 22
6.3 FP Hot Connect ...................................................................................................... 22
6.3.1
Version history FP Hot Connect .............................................................. 22
6.3.2
FP Hot Connect description .................................................................... 22
6.4 FP External Synchronization .................................................................................. 22
6.4.1
Version history FP External Synchronization .......................................... 22
6.4.2
FP External Synchronization description ................................................ 22
6.5 FP EtherCAT Automation Protocol ......................................................................... 22
6.5.1
Version history FP EtherCAT Automation Protocol ................................ 22
6.5.2
FP EtherCAT Automation Protocol description ....................................... 22
6.6 FP Device Replacement ......................................................................................... 23
6.6.1
Version history FP Device Replacement ................................................. 23
6.6.2
FP Device Replacement description ....................................................... 23
6.7 FP Mailbox Gateway............................................................................................... 23
6.7.1
Version history FP Mailbox Gateway ...................................................... 23
6.7.2
FP Mailbox Gateway description ............................................................. 23
5.9

6

ETG.1500, EtherCAT Master Classes

VTABLES
Table 1: Master classes requirement specification ................................................................................. 7
Table 2: FP Cable Redundancy specification ....................................................................................... 20
Table 3: FP Motion control specification ............................................................................................... 21

ETG.1500, EtherCAT Master Classes

VI

FIGURES
Figure 1: EtherCAT Master and Configuration Tool Structure ................................................................ 5
Figure 2: The cable redundancy principle ............................................................................................ 19

ETG.1500, EtherCAT Master Classes

VII

ABBREVIATIONS
µC
C
CMD
CoE
DC
DPRAM
ENI
EoE
ESC
ESI
ESM
ETG
FMMU
FoE
FPMR
FPRD
FPRW
FPWR
I/O
IDN
IEC
INT
IRQ
LRD
LRW
LSB
LWR
M
MAC
MI
MII
MSB
NIC
NOP
ns
O
OD
OS
PDO
DLPDU
PreOp
RD
SDO
SII
SM
SoE
SOF
SPI
SU
WD
WKC
WR
XML

Microcontroller
Conditional
Command
CANopen over EtherCATDistributed Clock
Dual-Ported RAM
EtherCAT Network Information (EtherCAT XML Master Configuration)
Ethernet over EtherCAT
EtherCAT Slave Controller
EtherCAT Slave Information (EtherCAT Devices Description)
EtherCAT State Machine
EtherCAT Technology Group
Fieldbus Memory Management Unit
File Access over EtherCAT
Configured Address Physical Read Multiple Write
Configured Address Physical Read
Configured Address Physical ReadWrite
Configured Address Physical Write
Input/Output
Identification Number (Servo Profile Identifier)International Electrotechnical Commission
IntegerInterrupt Request
Logical Read
Logical ReadWrite
Least Significant Bit
Logical Write
MandatoryMedia Access Controller(PHY) Management Interface
Media Independent Interface
Most Significant Bit
Network Interface Card
No Operation
nanoseconds (10-9 seconds)
Optional
Object Dictionary
Oversampling
Process Data Object
Data-Link Layer Process Data Unit
Pre-Operational
Read
Service Data Object
Slave Information Interface (EEPROM content)
SyncManager
Servo Profile over EtherCATStart of Frame
Serial Peripheral Interface
Sync Unit
Watchdog
Working Counter
Write
eXtensible Markup Language

ETG.1500, EtherCAT Master Classes

VIII

ScopeGLOSSARY
configurator

configuration tool or configuration logic

ETG.1500, EtherCAT Master Classes

1

Scope1

Scope

End users and/ or System integrators expect a defined minimum functionality and interoperability
when selecting an EtherCAT Master device. But not every master has to support all features of the
EtherCAT Technology.
This specification defines Master Classes with a well-defined set of Master functionalities. In order tokeep things simple only 2 Master Classes are defined:Class A: Standard EtherCAT Master Device

Class B: Minimum EtherCAT Master Device

The principle idea is that each implementation should aim to meet Class A requirements. Only if
resources prohibit, e.g. on embedded systems, at least Class B shall be met.
Additional Functionality, which can be considered to be optional, is described by Feature Packs. The
Feature Pack describes all mandatory master functionality for a specific feature, e.g. Redundancy.

ETG.1500, EtherCAT Master Classes

2

References2

References

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ETG Standards[1] ETG.1000.2: Physical Layer service definition and protocol specification[2] ETG.1000.3: Data Link Layer service definition[3] ETG.1000.4: Data Link Layer protocol specification[4] ETG.1000.5: Application Layer service definition[5] ETG.1000.6: Application Layer protocol specification[6] ETG.1005: EtherCAT Automation Protocol[7] ETG.1020: EtherCAT Guidelines and Protocol Enhancements[8] ETG.2000: EtherCAT Slave Information[9] ETG.2100: EtherCAT Network Information[10] ETG.5001: EtherCAT Modular Device Profiles[11] ETG.6010: EtherCAT Implementation Guideline for CiA402 Drive Profile[12] ETG.8000: EtherCAT Knowledge Base
Other References[13] IEC 61158-x-12 (all parts for type 12): Industrial communication networks – Fieldbus
specifications[14] IEC 61784-2: Industrial communication networks – Profiles – Part 2: Additional fieldbus
profiles for real-time networks based on ISO/IEC 8802-3[15] IEC 61800-7: Adjustable speed electrical power drives systems – Part 7: Generic interface
and use of profiles for power drive systems

ETG.1500, EtherCAT Master Classes

3

Terms, Definitions and Word Usage3
3.1

Terms, Definitions and Word Usage
Terms and Definitions

The terms and definitions of ETG.1000 series shall be fully valid, unless otherwise stated.
3.2

Word usage: shall, should, may, can

The word shall is used to indicate mandatory requirements to be followed in order to conform to thedirective and from which no deviation is permitted (shall equals is required to).
The word should is used to indicate that among several possibilities one is recommended as
particularly suitable, without mentioning or excluding others; or that a certain course of action ispreferred but not necessarily required; or that (in the negative form) a certain course of action isdeprecated but not prohibited (should equals is recommended that).
The support of this possibility increases performance of the system or broadens the support of devices
or functionalities which are used in a relatively small number of implementations.
The word may is used to indicate a course of action permissible within the limits of the standard (mayequals is permitted to).
The support of this possibility is used for optimization and mainly implemented for concrete use cases
only.
The word can is used for statements of possibility and capability, whether material, physical, or causal(can equals is able to).

ETG.1500, EtherCAT Master Classes

4

Master Classes

4

Master Classes

4.1

Introduction

The main tasks of an EtherCAT master are the network initialization and the handling of the statemachines of all devices, the process data communication and providing acyclic access for parameterdata exchange between master application and slave.
However, the master itself does not collect the information for the list of initialization and cycliccommands. This is done by a network configuration logic. In many cases this is an EtherCAT network
configuration software.
The configuration logic collects the necessary information from the ESI or the SII, ESC registers andobject dictionary or IDN list and generates the EtherCAT Network Information (ENI). This is provided
to the EtherCAT master.

Application

EtherCAT Network Information

EtherCAT Master

EtherCAT Slave Information(ESI)

NeworkConfiguration Logic

Device Profile

Process Data
Image

MailboxServicesreq.

cycliccommands

resp.

acyclic
commands

EtherCAT Network

Slave

OD/
IDN LIst
ESC
Registers

SII

Figure 1: EtherCAT Master and Configuration Tool Structure

Configuration Functionality: Either Configuration Tool or Configuration functionality in MasterIn the following this is referred to as configuration tool. This represents both versions.
Master application may be a PLC or Motion Control function, or online diagnosis application.
4.2

Master Class A

A Master Class A device shall support all functions that are described by the ETG specification
ETG.1000 series as well as many functions of the ETG.1020. Additional functions are listed in therequirement specification, see Table 1.
Master devices should support the Master Class A requirements.
4.3

Master Class B

The Master Class B has reduced functionality compared to Class A. The main functions that areneeded to run most of the EtherCAT devices (e.g. support of CoE, cyclic process data exchange) are
required for this master.
ETG.1500, EtherCAT Master Classes

5Master Classes
Only master devices those are not able to fulfill Master Class A requirements shall fulfill Master ClassB requirements.
4.4

Feature Packs

Feature Packs (FP) defines sets of optional functionality. If a FP is supported than all functions of thelisted requirements shall be fulfilled.
4.5

Validity of Master Classes and Feature Packs

The definition of Master Classes and Feature Packs is an ongoing process due to enhancements ofthe technology and additional features needed to satisfy upcoming requirements from customers andapplications.
The Master Classes are meant to take those enhancements into account to the end-user’s benefit.
Therefore, the range of functionalities of the basic feature set and each individual Feature Pack is
identified by a version number.
The Master vendor must not classify his Master Classes implementation (basic feature set as well as
each Feature Packs) without the corresponding version numbers.

ETG.1500, EtherCAT Master Classes

6

Master Classes Requirement Specification

5

Master Classes Requirement Specification

5.1

Version history Master Classes specification

Version history Master Class A
VersionComment

1.0.0First release

Version history Master Class B
VersionComment

1.0.0First release

5.2

Overview

Table 1 lists features for the Master Classes and the assignment to Master Class A and MasterClass B. The following chapters give a detailed specification of each function.
Table 1: Master classes requirement specification
Feature name

Short description

MasterClass A

MasterClass B

FeatureID

see

Basic Features
ServiceCommands

Support of all commands

shall if
ENI importsupportshall if
ENI importsupport

101

5.3.1

IRQ field in
datagram

Use IRQ information from Slave in datagram header

shouldshould102

5.3.2

Slaves with Device
Emulation

Support Slaves with and without application
controller

shall

shall

103

5.3.3

EtherCAT State
MachineSupport of ESM special behaviour

shall

shall

104

5.3.4

Error Handling

Checking of network or slave errors, e.g. Working
Counter

shall

shall

105

5.3.5

VLAN

Support VLAN Tagging

may

may

106

5.3.6

EtherCAT Frame
Types

Support EtherCAT Frames

shall

shall

107

5.3.7

UDP Frame Types

Support UDP Frames

may

may

108

5.3.7

Process Data Exchange
Cyclic PDO

Cyclic process data exchange

shall

shall

201

5.4.1

Multiple Tasks

Different cycle tasks

may

may

202

5.4.2

may

may

203

5.4.3

at least oneof them

at least oneof them

301

5.5.1

Multiple update rates for PDO
Frame repetition

Send cyclic frames multiple times to increase
immunity

Network Configuration
Online scanning

Network configuration functionality included in
EtherCAT Master

Reading ENI

Network Configuration taken from ENI file

Compare Network
configuration

Compare configured and existing network
configuration during boot-up

shall

shall

302

5.5.2

Explicit Device
Identification

Identification used for Hot Connect and prevention
against cable swapping

shouldshould303

5.5.3

Station Alias
Addressing

Support configured station alias in slave,

may

may

304

5.5.4

5.5.1

i.e. enable 2nd Address and use it

ETG.1500, EtherCAT Master Classes

7

Master Classes Requirement Specification
MasterClass A

MasterClass B

FeatureID

see

Support routines to access EEPROM via ESC
register

Read shall

Read shallWrite may

305

5.5.5

Write may

Support Mailbox

Main functionality for mailbox transfer

shall

shall

401

5.6.1

Mailbox Resilient
Layer

Support underlying resilient layer

shall

shall

402

5.6.2

may

may

403

5.6.3

shall

shall

404

5.6.4

Feature name

Short description

Access to
EEPROM
Mailbox Support

Multiple Mailbox
channels
Mailbox polling

Polling Mailbox state in slaves

CAN application layer over EtherCAT (CoE)SDO Up/Download

Normal and expedited transfer

shall

shall

501

5.7.1

Segmented
Transfer

Segmented transfer

shallshould502

5.7.2

Complete AccessTransfer the entire object (with all sub-indices) at
once

shall

should503

5.7.3

SDO Info service

Services to read object dictionary

shall

should504

5.7.4

Emergency
Message

Receive Emergency messages

shall

shall

505

5.7.5

PDO in CoE

PDO services transmitted via CoE

may

may

506

5.7.6

EoE protocol

Services for tunneling Ethernet frames. includes all
specified EoE services

shallshall if EoE
support

601

5.8.1

Virtual Switch

Virtual Switch functionality

shall

shall if EoE
support

602

5.8.2

EoE Endpoint toOperation Systems

Interface to the Operation System on top of the EoE
layershouldshould if
EoE support

603

5.8.3

FoE Protocol

Support FoE Protocol

shall

shall if FoE
support

701

5.9.1

Firmware Up/Download

Password, FileName should be given by theapplication

shallshould702

5.9.1

Boot State

Support Boot-State for Firmware Up/Download

shall

shall
if FW UP/
Download

703

5.9.2

Support SoE Services

shallshouldif SoE
support801

5.10.1

Support AoE Protocol

shouldshould901

5.11.1

External Connectivity supported

may

may

1001

5.12.1shall

shall if DC
support1101

5.13.1shall if ENI
Importsupported

EoE

FoE

SoE
SoE Services

AoE
AoE Protocol
VoE
VoE Protocol

Synchronization with Distributed Clock (DC)DC support

Support of Distributed Clock

ETG.1500, EtherCAT Master Classes

8Master Classes Requirement Specification
Feature name

Short description

MasterClass A

MasterClass B

FeatureID

seeContinuous
Propagation Delay
compensation

Continuous Calculation of the propagation delay

shouldshould1102

5.13.2

Sync window
monitoring

Continuous monitoring of the Synchronizationdifference in the slaves

shouldshould1103

5.13.3

shall

shall

1201

5.14

shouldmay

1301

5.15.1

Slave-to-Slave Communication
via Master

Information is given in ENI file or can be part of any
other network configuration
Copying of the data can be handled by master stackor master’s application

Master information
Master Object
Dictionary

5.3
5.3.1

Support of Master Object Dictionary(ETG.5001 MDP sub profile 1100)

Basic Functions
Service Commands

Description
The EtherCAT datagrams (DLPDU) uses several service commands to address data in the network.
Reference
ETG.1000.3 and ETG.1000.4
Note
Some slaves do not support LRW commands. The configurator has to take care if the flag UseLrdLwr
is set in the ESI file / SII.
Implementation Aspect
The network configuration is done by the configuration tool (even a separated configuration tool or
integrated in the master functionality). This configuration tool may use several commands to start-up
the network and to cyclic update the process image.
If the Master supports internal configuration capability, it may reduce the variety of commands
5.3.2

IRQ Field in datagram

Description
The EtherCAT datagrams (DLPDU) contains an IRQ field. The Master may use the IRQ field to get
information from the slaves.
Reference
ETG.1000.3 and ETG.1000.4
Note
It has to be considered, that the IRQ bits are ORed by all slaves and that the bits are set in all
datagrams of a frame.
Use Case
Detect a change of the DL Status event, e.g. when a device is connected to or disconnected from the
network; especially for hot connect applications

ETG.1500, EtherCAT Master Classes

9Master Classes Requirement Specification
5.3.3

Slaves with Device Emulation

Description
There are slaves which confirm the AL Management services with (device emulation = true) or without(device emulation = false) any reaction within the local application.
Reference
ETG.8000 topic Device Emulation
ETG.1000.5 clause Simple Slave Device; clause Complex Slave Device
Implementation Aspect
The master should not set the Error Indication Acknowledge bit for slaves with device emulation = trueat all, because setting this bit would result in setting the Error Indication bit – although no error
occurred.
5.3.4

EtherCAT State Machine (ESM)

Description
The EtherCAT State Machine defines the network behaviour of the master and of the slaves.
Reference
ETG.1000.5 and ETG.1000.6
ETG.1020, SII Specification
Implementation Aspect
The Timeout values for the ESM transitions from the ESI / SII shall be used. If no timeout values areavailable the default timeouts defined in ETG.1020 shall be used.
If the OpOnly Flag is set in the ESI file / SII the Master shall disable the SyncManager of all outputs if
not in state Operational (this can be part of the network configuration Init Commands).
5.3.5

Error Handling

Description
The Error Handling defines a unique behaviour of EtherCAT devices (Masters and Slaves) in cases ofcommunication problems.
Reference
ETG.1020  Error Handling
Implementation Aspect
Evaluation of the PDO Parameter, like PDO Toggle or PDO state, can be done in the application.
Master shall support an interface to the application which provides access to error and diagnosis
information (e.g. error register, Diagnosis object).
5.3.6

VLAN

Description
The VLAN Tag can be used for classification of a frame.
Reference
ETG.1000.4  DLPDU structure

ETG.1500, EtherCAT Master Classes

10Master Classes Requirement Specification
5.3.7

Ethernet Frame Types

Description
The EtherCAT datagrams are transferred inside an Ethernet frames with EtherType = 0x88A4 andwith EtherCAT Header  Type = 1.
The EtherCAT Frame may also be transferred inside a UDP datagram (EtherType = 0x0800, UDPPort = 0x88A4).
Reference
ETG.1000.3 and ETG.1000.4
Note
When using UDP datagrams system performance obviously depends on the real-time characteristicsof the control and its Ethernet protocol implementation.
5.4
5.4.1

Process Data Exchange
Cyclic PDO

Description
Cyclic frames to update the process image are defined in the network configuration.
Reference
ETG.1000.3 and ETG.1000.4
Implementation Aspect
The trigger for sending the cyclic frames can be done by the Master or by the user (application) of the
Master.
5.4.2

Multiple Tasks

Description
A master may support different Cycle Tasks (Task ID) and sends different Frames or Frame sets withdifferent cycle times.
The ENI schema (ETG.2100) defines different Task IDs to distinguish these different Frames or Frame
sets.
Reference
ETG.2100
Implementation Aspect
Some Slaves (drives, oversampling) need fix cycle time. The Master shall give a message, if a slave
type is not supported
5.4.3

Frame repetition

Description
For the improvement of robustness the cyclic frames may be sent multiple times within one cycle.
Only Slaves supporting the frame repetition shall be charged with multiple frames per cycle. This
information is given in the ESI / SII (Flag FrameRepeatSupport), ETG.2000
Reference
ETG.2000

ETG.1500, EtherCAT Master Classes

11

Master Classes Requirement Specification
Implementation Aspect
At least three identical frames per cycle should be supported. This is part of the network configuration,
ETG.2100.
5.5

Network Configuration

5.5.1

Getting Network Configuration

Description
The Network Configuration shall be build by one of the following ways:-

Online configuration by scanning the Network and read SII content
The content of the Slave Information Interface (SII) is described in ETG.1000.6 and enhancedin the ETG.1020-

Import ENI File
With the import of the ENI file, defined in ETG.2100 the master can boot-up and run a
network. The ENI configuration comes from a configuration tool. The contained Validate
information in the ENI file for the Init-Commands shall be processed

Reference
ETG.1000.6 and ETG.1020
ETG.2100
5.5.2

Compare network configuration during boot-up

Description
During boot-up the master shall compare the configured network configuration with the existing
network configuration according to the configured behaviour.
The network configuration can contain the comparison of-

VendorID, ProductCode, RevisionNo, SerialNo in the SII of the devices-

Identification information (IdentificationAdo)-

Topology information

Reference
ETG.2100
Implementation Aspect
The indispensable compare values shall be part of the Network Configuration coming from the ENI,
ETG.2100, or the online configuration
5.5.3

Explicit Station Identification

Description
The use of EtherCAT Device identification is to identify a device explicitly. This can be used for Hot
Connect applications and prevention against cable swapping.
Reference
ETG.1020

5.5.4

Station Alias Addressing

Description
A slave can be addressed by a fixed address stored in SII; this address is called Configured Station
Alias. The Configured Station Alias address is loaded from SII to Register 0x0012 (Configured Station
ETG.1500, EtherCAT Master Classes

12

Master Classes Requirement Specification
Alias register) during Power-on of the device. The Configured Station Alias has to be enabled by themaster.
Reference
ETG.1000.4
Implementation Aspect
The use of this alias is activated by Register DL Control Bit 24 (0x0100.24/0x0103.0). If the bit is set in
DL Control Configured Station Alias address can be used for all configured address command types(FPRD, FPWR, FPRW, FPMW).
5.5.5

Access to EEPROM

Description
The Master shall support read access to the EEPROM, which contains the SII. This is done via therelevant Registers of the slave’s ESC.
The write access to the EEPROM can be used for configuration issues.
Reference
ETG.1000.4
NoteThis includes a state machine for EEPROM access
5.6
5.6.1

Mailbox Support
Support Mailbox

Description
Mailbox transfer is a non real-time service used to access application configuration data (CoE, SoE),
transfer files (FoE) or transfer standard IT data (EoE).
Reference
ETG.1000.3, ETG.1000.4 and ETG.1000.6
5.6.2

Mailbox Resilient Layer

Description
The Resilient Mailbox State machine (RMSM) is responsible for recover lost frames with mailbox
information. It is independent of the upper Mailbox protocol.
Reference
ETG.1000.4
5.6.3

Simultaneous Mailbox protocol transfer to one device

Description
A Master may support the simultaneous transfer of two or more mailbox communication to the samedeviceReference-Implementation Aspect
The slave must support multiple mailbox protocols in parallel (which is not usual).

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Master Classes Requirement Specification
5.6.4

Mailbox polling

Description
The master shall evaluate the Input- Mailbox for new data.
Reference
ETG.2100
Details
Polling of Input Mailbox:
If the element MailboxRecvInfoType:PollTime is given in the ENI (ETG.2100) the Input Mailbox shallbe read within the configured poll time by auto increment or fixed addressing commands.
Polling of Input-Mailbox-Status-Bit
If the element MailboxRecvInfoType:StatusBitAddr is given in the ENI (ETG.2100) an FMMU shall be
configured to map the status flag of the SyncManager (0x0805.0 *y; y = number of SyncManager
starting with 0) to the cyclic data.
If the status bit indicates a written Input mailbox the master shall read the mailbox service data.
Note
To support polling of input-Mailbox-Status-Bit the slave needs an additional FMMU. This is indicated in
the ESI DeviceType:FMMU = MBoxState (see ETG.2000).
5.7

CAN application layer over EtherCAT (CoE)The CAN application layer over EtherCAT (CoE) protocol shall be supported by every master.
5.7.1

SDO Up-/Download

Description
The SDO Up-/Download protocol and services are used for access to the object dictionary. The
expedited and normal SDO Up-/Download services shall be supported by every master
Reference
ETG.1000.5 and ETG.1000.6
5.7.2

Segmented Transfer

Description
The SDO segmented transfer is used, if the service data exceeds the mailbox data length.
Reference
ETG.1000.5 and ETG.1000.6
5.7.3

Complete Access

Description
The SDO complete access service allows one to transfer the entire object at once. The data of all subindices is transferred subsequently.
Reference
ETG.1000.5 and ETG.1000.6
5.7.4

SDO Information Service

Description
With the SDO information services the object dictionary of a server can be read by a client.

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Master Classes Requirement Specification
Reference
ETG.1000.5 and ETG.1000.6
5.7.5

Emergency Message

Description
Emergency messages are triggered by the occurrence of a device internal error situation.
Reference
ETG.1000.5 and ETG.1000.6
Implementation Aspect
The evaluation of the Emergency messages does not have to be done by the master. Usually it isdone by the masters’ application.
5.7.6

PDO transmission with CoE

Description
With the PDO services process data objects can be transmitted via the mailbox Interface acyclicallyfrom the client to the server (RxPDO) or from the server to the client (TxPDO).
Reference
ETG.1000.5 and ETG.1000.6
Use Case
No relevant use case known.
5.8
5.8.1

Ethernet over EtherCAT (EoE)
EoE Protocol

Description
Ethernet over EtherCAT (EoE) protocol is used to tunnel standard Ethernet frames through the
EtherCAT network.
Reference
ETG.1000.5 and ETG.1000.6
ETG.1020
5.8.2

Virtual Switch

Description
The software-integrated Ethernet switch functionality is responsible for the routing of the individual
Ethernet frames from and to the devices and the IP stack of the host operating system. The switch
functionality is identical with that of a standard layer 2 Ethernet switch and responds to the Ethernet
addresses used irrespective of the protocol.
Reference
ETG.1000.5
5.8.3

EoE Endpoint to Operating Systems

Description
An Interface to the Operation System on top of the EoE layer.The EtherCAT master stack, in thisregard functioning as a standard Ethernet network interface (compare with NIC).

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Master Classes Requirement Specification
5.9
5.9.1

File Access over EtherCAT (FoE)FoE Protocol

Description
The File access over EtherCAT (FoE) mailbox command specifies a standard way to download afirmware or any other files from a client to a server or to upload a firmware or any other files from aserver to a client.
Reference
ETG.1000.5 and ETG.1000.6
Implementation Aspect
The password and file name needed for the Up/Download should be given by the master’s application
therefore an interface between Master and application is required.
5.9.2

Boot State

Description
For the download of firmware the BOOT state in the EtherCAT state machine is defined.
Reference
ETG.1000.5 and ETG.1000.6
Note
A special Mailbox size can be supported by the slave for the Boot state (ETG.2000). This is part of theInit-Commands in the network configuration.
5.10 Servo drive profile over EtherCAT (SoE)
5.10.1 SoE Services
Description
Servo drive profile over EtherCAT (SoE) communication services are used to access the IDNs of a
SoE slave.
The SoE drive profile is part of an extra master application, not of the master itself.
Reference
IEC 61800-7-304
5.11 ADS over EtherCAT (AoE)
5.11.1 AoE Protocol
Description
The AoE protocol is used to access the Object dictionary of slave devices of underlying fieldbuses,
e.g. for a CANopen Slave connected to a EtherCAT-CANopen gateway device. It is also used inrelation with the EtherCAT Automation Protocol (EAP).
Reference
ETG.1020  AoE

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Master Classes Requirement Specification
5.12 Vendor-specific over EtherCAT (VoE)
5.12.1 VoE Protocol
Description
By supporting the Mailbox protocol, Vendor-specific protocol over EtherCAT (VoE) date can betransferred. No additional services are required for the master.
5.13 Synchronization with Distributed Clocks (DC)5.13.1 DC support
Description“DC-slave” is defined as slave which shall be synchronized by means of distributed clocks.
During network start-up several steps have to be performed to set-up a consistent time base in all DCslaves:-

Initial propagation delay measurement (ETG.8000)-

Offset compensation (ETG.8000)-

Set start time (ETG.8000)-

After network start-up: continuous drift compensation (ETG.8000)-

The Master must synchronize itself on the reference clock (ETG.1020)

Initial propagation delay measurement and Offset compensation commands are not part of the
Network configuration. Cyclic ARMW commands for drift compensation are part of the network
configuration.
Reference
ETG.1000.3 and ETG.1000.4
ETG.1020  Synchronization
ETG.8000  Distributed Clocks
Implementation Aspect
To achieve best synchronization results the first DC-slave after the master should be the reference
clock.
Note

The ETG.8000 gives an example for the clock synchronization initialization, containing propagation
delay measurement, Offset compensation to the Reference clock and drift compensation
5.13.2 Continuous Propagation delay measurement
Description
Continuous measurement of Propagation Delay enhances the long time accuracy of synchronization.
Reference-Implementation Aspect
Some configuration tools add a NOP command to register 0x0900 DC Receive Time Port 0 to thecyclic commands. This NOP command is meant to be replaced from time to time (several seconds) by
a BWR command to start the continuous propagation measurement.

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Master Classes Requirement Specification
5.13.3 Sync window monitoring
Description
To monitor the time deviation of the DC-slaves from the Reference clock the master reads out theRegister 0x092C System Time Difference.
Reference-Implementation Aspect
This can be done by a BRD datagram in each cycle. The ORed result can be compared to a limit
value.
5.14 Slave-to-Slave Communication
Description
Slave-to-Slave communication via the Master is the generic approach independent of the topology.
The data of the server are copied to the client by the master stack so that the maximum transfer timeis two communication cycles.
Reference-Implementation Aspect
The copy information is part of the ENI file (ETG.2100) or can be part of any other network
configuration.
Note
In addition to the mapping of slave-to-slave data in the master stack a master may provide an API to
configure the mapping of slave-to-slave data which is then done by the master application.
Slave-to-Slave communication via LRW commands and corresponding configuration of the devices isrestricted to a fixed topology. Another drawback of this solution is that the Working Counter cannot bechecked by the receiving slave. Therefore, it cannot verify if the received data is valid
Use Case
Slave-to-Slave communication is necessary to support Safety-over-EtherCAT Master and Slave
devices within the EtherCAT segment

5.15 Master information
5.15.1 Master Object Dictionary
Description
The Master Object dictionary contains information about the network configuration and EtherCAT
slave diagnosis data.
Reference
ETG.5001 MDP sub profile 1100
Note
As an interface to access the Master Object Dictionary the master should support AoE (ETG.1020).

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Feature Packs

6

Feature Packs

6.1

FP Cable Redundancy

6.1.1

Version history FP Cable Redundancy

Version history
VersionComment

1.0.0First release

6.1.2

FP Cable Redundancy description

FP Cable Redundancy maintains the communication in case of a cable break or node failure in the
EtherCAT system. A ring topology, which normally is operated in both directions, is therefore used.
Both branches can nevertheless still be reached if the ring is interrupted at some point.

Figure 2: The cable redundancy principle

A second network port is used for ring closure at the EtherCAT master control system. Both cyclic andacyclic frames are sent simultaneously through both ports, and are transported through the system.
In the absence of any fault, all the EtherCAT slaves are reached in the forward direction (so called
processing direction) from the primary port. This means that they are processed, since the EtherCAT
Slave Controller (ESC) is only passed through in the forward sense.
When there is no fault, all the EtherCAT slaves are reached from the secondary port in the reverse
direction - the data in the "redundancy" frame is therefore not changed.
In each case, the EtherCAT frames arrive, possibly modified, at the other port, and are checked by the
EtherCAT master. In case of a cable break, both frames are processed - each one on the respectiveside of the failure. Therefore both frames contain a part of the input data. The master has to combine
the data of both frames, and gets one frame with all the input data. The working counters from both
frames are added to check for its validity. It is unimportant whether an EtherCAT slave is reached fromthe primary or redundancy port. The EtherCAT master has to consider that a frame on one side is lost
and the other frame returns. To find the matching frame it is useful to mark the frames with an
identification or use appropriate mechanism.
The cable redundancy is single-error tolerant, i.e. communication with the slaves can continue if thecable is interrupted in one place. When the communication is restored the original communication
direction is restored. If the communication is interrupted in more than one place, all connections haveto be restored before another fault may occur.

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19Feature Packs
Table 2 lists features for the FP Cable Redundancy.
Table 2: FP Cable Redundancy specification
Function name

Short description

Category

Feature ID

Chapter

Basic Functions

Basic functions to handle cable redundancy

M

FPCR_101

6.1.3

Diagnosis Functions

Localization of cable break.

M

FPCR_102

6.1.4

Redundancy with Hot
Connect

Combination of feature packs Hot Connect and Cable
Redundancy

O

FPCR_103

6.1.5

Redundancy with DC

Combination of FP Cable Redundancy with Distributed
Clocks slaves

O

FPCR_104

6.1.6

Implementation Aspect
Auto Increment Address changes in case of a cable break. Typically the same address exists twice.
Therefore it is necessary to adjust the address in the frame sent on the primary port combined withdisabling the command on the secondary port and vice versa.
Note
In ETG.8000Redundancy, [12], an example of the Cable redundancy is shown.
6.1.3

Basic Functions

Description
In case of cable break all types of EtherCAT communications (process data and mailbox protocols)
shall be supported without any restrictions.
Handling of the following use cases:Normal operation



Stay operational in case of cable break between two slaves

Stay operational in case of cable break between primary port and first slave

Stay operational in case of cable break between secondary port and last slave

Stay operational in case of cable fixedStart/Stop (State change) in case of cable break

Adjustment of Auto Increment address in case of cable breakFrame loss in case of cable break (partner frame was not received)

Reference
In ETG.8000Redundancy, [12], an example of the Cable redundancy is shown.
6.1.4

Diagnosis Functions

Description
Localization of cable break shall be possible (Number of slaves on each port)
Support function to check link status of primary port and of secondary port.
6.1.5

Redundancy with Hot Connect

Description
Combination of feature packs Hot Connect and Cable Redundancy

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6.1.6

Redundancy with DC

Description
Combination of feature pack Cable Redundancy and DC synchronization
Implementation Aspects
Special measures need to be taken for a combination of cable redundancy with Distributed Clocks
slaves

6.2

FP Motion Control

6.2.1

Version history FP Motion Control

Version history
VersionComment

1.0.0First release

6.2.2

FP Motion Control description

For EtherCAT drives two drive profiles, CiA 402 and SERCOS™, are defined. Within these profiles the
support of a drive state machines and modes of operation are specified for example. Synchronization
capabilities of the master are indispensible to support the drive profiles.
The drive profiles can be part of the master application.
Table 3 lists features for the FP Motion Control.
Table 3: FP Motion control specification
Function name

Short description

Category

Feature ID

ChapterDrive Profile CiA402

Support Profile CiA402

M

FPMC_101

6.2.3

Drive Profile SERCOS

Support Profile SERCOS drive profileO

FPMC_102

6.2.4

Synchronization with DC

Support Synchronization with DC

M

FPMC_103

6.2.5

6.2.3

Drive Profile CiA402

Description
The CiA402 Drive Profile defined in IEC 61800-78-201 shall be supported.
For EtherCAT-based servo drives with CiA402 drive profile the Implementation Guideline ETG.6010
defines a common behaviour for the implementation of the drive profile. At least the requirements inthis guideline (Control/Status word, Modes of Operation, supported objects etc.) shall be fulfilled.
References
IEC 61800-7-201
Mapping to EtherCAT in IEC 61800-7-301
ETG.6010
6.2.4

Drive Profile SERCOS

Description
The SERCOS™ Drive Profile defined in IEC 61800-7-204 should be supported.
References
SEROC Drive Profile in IEC 61800-7-204
Mapping to EtherCAT in IEC 61800-7-304
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Feature Packs

6.2.5

Synchronization with DC

Description
The master shall support synchronization with DC, as defined in chapter 5.13
Reference
see 5.13

6.3

FP Hot Connect

6.3.1

Version history FP Hot Connect

Version history
VersionComment

0.0.0

to be defined

6.3.2

FP Hot Connect description

The FP Hot Connect still needs to be defined.

6.4

FP External Synchronization

6.4.1

Version history FP External Synchronization

Version history
VersionComment

0.0.0

to be defined

6.4.2

FP External Synchronization description

The FP External Synchronization still needs to be defined.

6.5

FP EtherCAT Automation Protocol

6.5.1

Version history FP EtherCAT Automation Protocol

Version history
VersionComment

0.0.0

to be defined

6.5.2

FP EtherCAT Automation Protocol description

The FP EtherCAT Automation Protocol still needs to be defined.

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Feature Packs
6.6

FP Device Replacement

6.6.1

Version history FP Device Replacement

Version history
VersionComment

0.0.0

to be defined

6.6.2

FP Device Replacement description

The FP Device Replacement still needs to be defined.

6.7

FP Mailbox Gateway

6.7.1

Version history FP Mailbox Gateway

Version history
VersionComment

0.0.0

to be defined

6.7.2

FP Mailbox Gateway description

The FP Mailbox Gateway still needs to be defined.

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