Beckhoff EL3681 User Manual

Documentation | EN

EL3681

Digital Multimeter Terminal

2021-03-17 | Version: 2.6

Table of contents

Table of contents

1 Foreword ....................................................................................................................................................7

1.1 Notes on the documentation..............................................................................................................7

1.2 Safety instructions .............................................................................................................................8

1.3 Documentation issue status ..............................................................................................................9

1.4 Version identification of EtherCAT devices .....................................................................................10

1.4.1 Beckhoff Identification Code (BIC)................................................................................... 14

2 Product overview.....................................................................................................................................16

2.1 Introduction......................................................................................................................................16

2.2 Technical data .................................................................................................................................18

2.3 Technology ......................................................................................................................................19

2.4 Note on Beckhoff calibration certificates .........................................................................................22

2.5 Start .................................................................................................................................................24

3 Basics communication ...........................................................................................................................25

3.1 EtherCAT basics..............................................................................................................................25

3.2 EtherCAT cabling – wire-bound.......................................................................................................25

3.3 General notes for setting the watchdog...........................................................................................26

3.4 EtherCAT State Machine.................................................................................................................28

3.5 CoE Interface...................................................................................................................................29

3.6 Distributed Clock .............................................................................................................................34

4 Mounting and wiring................................................................................................................................35

4.1 Instructions for ESD protection........................................................................................................35

4.2 Installation on mounting rails ...........................................................................................................35

4.3 Connection ......................................................................................................................................38

4.3.1 Connection system .......................................................................................................... 38

4.3.2 Wiring............................................................................................................................... 41

4.3.3 Shielding .......................................................................................................................... 42

4.4 Positioning of passive Terminals .....................................................................................................43

4.5 Installation positions ........................................................................................................................43

4.6 LEDs and connection ......................................................................................................................46

5 Commissioning........................................................................................................................................47

5.1 TwinCAT Quick Start .......................................................................................................................47

5.1.1 TwinCAT 2 ....................................................................................................................... 50

5.1.2 TwinCAT 3 ....................................................................................................................... 60

5.2 TwinCAT Development Environment ..............................................................................................73

5.2.1 Installation of the TwinCAT real-time driver..................................................................... 74

5.2.2 Notes regarding ESI device description........................................................................... 79

5.2.3 TwinCAT ESI Updater ..................................................................................................... 83

5.2.4 Distinction between Online and Offline............................................................................ 83

5.2.5 OFFLINE configuration creation ...................................................................................... 84

5.2.6 ONLINE configuration creation ........................................................................................ 89

5.2.7 EtherCAT subscriber configuration.................................................................................. 97

5.2.8 Import/Export of EtherCAT devices with SCI and XTI ................................................... 106

5.3 General Notes - EtherCAT Slave Application................................................................................112

EL3681 3Version: 2.6

Table of contents

5.4 Notices on analog specifications ...................................................................................................120

5.4.1 Full scale value (FSV).................................................................................................... 120

5.4.2 Measuring error/ measurement deviation ...................................................................... 120

5.4.3 Temperature coefficient tK [ppm/K] ............................................................................... 121

5.4.4 Long-term use................................................................................................................ 122

5.4.5 Single-ended/differential typification .............................................................................. 122

5.4.6 Common-mode voltage and reference ground (based on differential inputs)................ 127

5.4.7 Dielectric strength .......................................................................................................... 127

5.4.8 Temporal aspects of analog/digital conversion.............................................................. 128

5.5 Basic function principles/functional description .............................................................................131

5.5.1 Measuring ranges and output ........................................................................................ 131

5.5.2 Selecting a measuring range ........................................................................................ 131

5.5.3 Autorange ...................................................................................................................... 132

5.5.4 Filter............................................................................................................................... 132

5.5.5 Frequency...................................................................................................................... 132

5.5.6 Presentation................................................................................................................... 133

5.5.7 Zero Compensation Interval .......................................................................................... 133

5.5.8 Calibration...................................................................................................................... 133

5.6 Process data..................................................................................................................................134

5.6.1 Process image ............................................................................................................... 134

5.6.2 Control, Status, Settings-Word ...................................................................................... 135

5.6.3 PDO Assignment ........................................................................................................... 136

5.6.4 Calculation of process data ........................................................................................... 137

5.6.5 Determining (user) gain values...................................................................................... 138

5.7 Object description and parameterization .......................................................................................139

5.7.1 Restore object................................................................................................................ 140

5.7.2 Configuration data ......................................................................................................... 141

5.7.3 Configuration data (vendor-specific).............................................................................. 143

5.7.4 Input data....................................................................................................................... 144

5.7.5 Output data .................................................................................................................... 145

5.7.6 Information and diagnostic data..................................................................................... 145

5.7.7 Standard objects (0x1000-0x1FFF) ............................................................................... 145

5.8 Sample Program............................................................................................................................149

6 Error handling and diagnostics............................................................................................................154

7 Appendix ................................................................................................................................................155

7.1 Accessories ...................................................................................................................................155

7.2 EtherCAT AL Status Codes...........................................................................................................156

7.3 Firmware compatibility...................................................................................................................157

7.4 Firmware Update EL/ES/EM/ELM/EPxxxx ....................................................................................158

7.4.1 Device description ESI file/XML..................................................................................... 159

7.4.2 Firmware explanation .................................................................................................... 162

7.4.3 Updating controller firmware *.efw................................................................................. 163

7.4.4 FPGA firmware *.rbf....................................................................................................... 164

7.4.5 Simultaneous updating of several EtherCAT devices.................................................... 168

7.5 Restoring the delivery state ...........................................................................................................169

EL36814 Version: 2.6

Table of contents

7.6 Support and Service ......................................................................................................................170

EL3681 5Version: 2.6

Table of contents

EL36816 Version: 2.6

Foreword

1 Foreword

1.1 Notes on the documentation

Intended audience

This description is only intended for the use of trained specialists in control and automation engineering who
are familiar with the applicable national standards.
It is essential that the documentation and the following notes and explanations are followed when installing
and commissioning these components.
It is the duty of the technical personnel to use the documentation published at the respective time of each
installation and commissioning.

The responsible staff must ensure that the application or use of the products described satisfy all the
requirements for safety, including all the relevant laws, regulations, guidelines and standards.

Disclaimer

The documentation has been prepared with care. The products described are, however, constantly under
development.

We reserve the right to revise and change the documentation at any time and without prior announcement.

No claims for the modification of products that have already been supplied may be made on the basis of the
data, diagrams and descriptions in this documentation.

Trademarks

Beckhoff®, TwinCAT®, EtherCAT®, EtherCATG®, EtherCATG10®, EtherCATP®, SafetyoverEtherCAT®,
TwinSAFE®, XFC®, XTS® and XPlanar® are registered trademarks of and licensed by Beckhoff Automation
GmbH. 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.

Patent Pending

The EtherCAT Technology is covered, including but not limited to the following patent applications and
patents: EP1590927, EP1789857, EP1456722, EP2137893, DE102015105702 with corresponding
applications or registrations in various other countries.

EtherCAT® is registered trademark and patented technology, licensed by Beckhoff Automation GmbH,
Germany.

Copyright

© Beckhoff Automation GmbH & Co. KG, Germany.
The reproduction, distribution and utilization of this document as well as the communication of its contents to
others without express authorization are prohibited.
Offenders will be held liable for the payment of damages. All rights reserved in the event of the grant of a
patent, utility model or design.

EL3681 7Version: 2.6

Foreword

1.2 Safety instructions

Safety regulations

Please note the following safety instructions and explanations!
Product-specific safety instructions can be found on following pages or in the areas mounting, wiring,
commissioning etc.

Exclusion of liability

All the components are supplied in particular hardware and software configurations appropriate for the
application. Modifications to hardware or software configurations other than those described in the
documentation are not permitted, and nullify the liability of Beckhoff Automation GmbH & Co. KG.

Personnel qualification

This description is only intended for trained specialists in control, automation and drive engineering who are
familiar with the applicable national standards.

Description of instructions

In this documentation the following instructions are used.
These instructions must be read carefully and followed without fail!

DANGER

Serious risk of injury!

Failure to follow this safety instruction directly endangers the life and health of persons.

WARNING

Risk of injury!

Failure to follow this safety instruction endangers the life and health of persons.

CAUTION

Personal injuries!

Failure to follow this safety instruction can lead to injuries to persons.

NOTE

Damage to environment/equipment or data loss

Failure to follow this instruction can lead to environmental damage, equipment damage or data loss.

Tip or pointer

This symbol indicates information that contributes to better understanding.

EL36818 Version: 2.6

1.3 Documentation issue status

Version Comment

2.6 • Addenda EL3681-0020 and EL3681-0030

• Update chapter "Technical data"

• Update structure

• Update revision status

2.5 • Update chapter "UL notes"

• Update structure

2.4 • Update chapter "Technical data"

• Update structure

• Update revision status

2.3 • Update chapter "Sample Program"

• Update structure

• Update revision status

2.2 • Addenda chapter "Instructions for ESD protection"

• Addenda chapter "Notices on Analog specification"

2.1 • Update chapter "Notes on the documentation"

• Correction of Technical data

• Update chapter "TwinCAT 2.1x" -> "TwinCAT Development Environment" and
"TwinCAT Quick Start"

• Update revision status

2.0 • Migration

• Update structure

1.6 • Update structure

• Update chapter "Technical data"

1.5 • Update chapter "Basic function principles"

1.4 • Update firmware status

• Update chapter "Technology"

1.3 • Update firmware status

• Update application note

1.2 • Update TrueRMS, Crest factor

1.1 • Update LED description

1.0 • First public issue

0.2 • Corrections and addenda

0.1 • Preliminary documentation for EL3681

Foreword

EL3681 9Version: 2.6

Foreword

1.4 Version identification of EtherCAT devices

Designation

A Beckhoff EtherCAT device has a 14-digit designation, made up of

• family key

• type

• version

• revision

Example Family Type Version Revision

EL3314-0000-0016 EL terminal

(12 mm, non­pluggable connection
level)

ES3602-0010-0017 ES terminal

(12 mm, pluggable
connection level)

CU2008-0000-0000 CU device 2008 (8-port fast ethernet switch) 0000 (basic type) 0000

3314 (4-channel thermocouple
terminal)

3602 (2-channel voltage
measurement)

0000 (basic type) 0016

0010 (high­precision version)

0017

Notes

• The elements mentioned above result in the technical designation. EL3314-0000-0016 is used in the
example below.

• EL3314-0000 is the order identifier, in the case of “-0000” usually abbreviated to EL3314. “-0016” is the
EtherCAT revision.

• The order identifier is made up of

- family key (EL, EP, CU, ES, KL, CX, etc.)

- type (3314)

- version (-0000)

• The revision -0016 shows the technical progress, such as the extension of features with regard to the
EtherCAT communication, and is managed by Beckhoff.
In principle, a device with a higher revision can replace a device with a lower revision, unless specified
otherwise, e.g. in the documentation.
Associated and synonymous with each revision there is usually a description (ESI, EtherCAT Slave
Information) in the form of an XML file, which is available for download from the Beckhoff web site.
From 2014/01 the revision is shown on the outside of the IP20 terminals, see Fig. “EL5021 EL terminal,
standard IP20 IO device with batch number and revision ID (since 2014/01)”.

• The type, version and revision are read as decimal numbers, even if they are technically saved in
hexadecimal.

Identification number

Beckhoff EtherCAT devices from the different lines have different kinds of identification numbers:

Production lot/batch number/serial number/date code/D number

The serial number for Beckhoff IO devices is usually the 8-digit number printed on the device or on a sticker.
The serial number indicates the configuration in delivery state and therefore refers to a whole production
batch, without distinguishing the individual modules of a batch.

Structure of the serial number: KKYYFFHH

KK - week of production (CW, calendar week)
YY - year of production
FF - firmware version
HH - hardware version

EL368110 Version: 2.6

Foreword

Example with
Ser. no.: 12063A02: 12 - production week 12 06 - production year 2006 3A - firmware version 3A 02 ­hardware version 02

Exceptions can occur in the IP67 area, where the following syntax can be used (see respective device
documentation):

Syntax: D ww yy x y z u

D - prefix designation
ww - calendar week
yy - year
x - firmware version of the bus PCB
y - hardware version of the bus PCB
z - firmware version of the I/O PCB
u - hardware version of the I/O PCB

Example: D.22081501 calendar week 22 of the year 2008 firmware version of bus PCB: 1 hardware version
of bus PCB: 5 firmware version of I/O PCB: 0 (no firmware necessary for this PCB) hardware version of I/O
PCB: 1

Unique serial number/ID, ID number

In addition, in some series each individual module has its own unique serial number.

See also the further documentation in the area

• IP67: EtherCAT Box

• Safety: TwinSafe

• Terminals with factory calibration certificate and other measuring terminals

Examples of markings

Fig.1: EL5021 EL terminal, standard IP20 IO device with serial/ batch number and revision ID (since
2014/01)

EL3681 11Version: 2.6

Foreword

Fig.2: EK1100 EtherCAT coupler, standard IP20 IO device with serial/ batch number

Fig.3: CU2016 switch with serial/ batch number

Fig.4: EL3202-0020 with serial/ batch number 26131006 and unique ID-number 204418

EL368112 Version: 2.6

Foreword

Fig.5: EP1258-00001 IP67 EtherCAT Box with batch number/ date code 22090101 and unique serial
number 158102

Fig.6: EP1908-0002 IP67 EtherCAT Safety Box with batch number/ date code 071201FF and unique serial
number 00346070

Fig.7: EL2904 IP20 safety terminal with batch number/ date code 50110302 and unique serial number
00331701

Fig.8: ELM3604-0002 terminal with unique ID number (QR code) 100001051 and serial/ batch number
44160201

EL3681 13Version: 2.6

Foreword

1.4.1 Beckhoff Identification Code (BIC)

The Beckhoff Identification Code (BIC) is increasingly being applied to Beckhoff products to uniquely identify
the product. The BIC is represented as a Data Matrix Code (DMC, code scheme ECC200), the content is
based on the ANSI standard MH10.8.2-2016.

Fig.9: BIC as data matrix code (DMC, code scheme ECC200)

The BIC will be introduced step by step across all product groups.

Depending on the product, it can be found in the following places:

• on the packaging unit

• directly on the product (if space suffices)

• on the packaging unit and the product

The BIC is machine-readable and contains information that can also be used by the customer for handling
and product management.

Each piece of information can be uniquely identified using the so-called data identifier
(ANSIMH10.8.2-2016). The data identifier is followed by a character string. Both together have a maximum
length according to the table below. If the information is shorter, spaces are added to it. The data under
positions 1 to 4 are always available.

The following information is contained:

EL368114 Version: 2.6

Item

Type of

no.

information

1 Beckhoff order

number

2 Beckhoff Traceability

Number (BTN)

3 Article description Beckhoff article

4 Quantity Quantity in packaging

5 Batch number Optional: Year and week

6 ID/serial number Optional: Present-day

7 Variant number Optional: Product variant

...

Explanation Data

Beckhoff order number 1P 8 1P072222

Unique serial number,
see note below

description, e.g.
EL1008

unit, e.g. 1, 10, etc.

of production

serial number system,
e.g. with safety products
or calibrated terminals

number on the basis of
standard products

Foreword

Number of digits

identifier

S 12 SBTNk4p562d7

1K 32 1KEL1809

Q 6 Q1

2P 14 2P401503180016

51S 12 51S678294104

30P 32 30PF971, 2*K183

incl. data identifier

Example

Further types of information and data identifiers are used by Beckhoff and serve internal processes.

Structure of the BIC

Example of composite information from item 1 to 4 and 6. The data identifiers are marked in red for better
display:

BTN

An important component of the BIC is the Beckhoff Traceability Number (BTN, item no.2). The BTN is a
unique serial number consisting of eight characters that will replace all other serial number systems at
Beckhoff in the long term (e.g. batch designations on IO components, previous serial number range for
safety products, etc.). The BTN will also be introduced step by step, so it may happen that the BTN is not yet
coded in the BIC.

NOTE

This information has been carefully prepared. However, the procedure described is constantly being further
developed. We reserve the right to revise and change procedures and documentation at any time and with­out prior notice. No claims for changes can be made from the information, illustrations and descriptions in
this information.

EL3681 15Version: 2.6

Product overview

2 Product overview

2.1 Introduction

Fig.10: EL3681

Digital multimeter terminal

The EL3681 EtherCAT Terminal enables measurement of currents and voltages in wide input range. The
measuring ranges are switched automatically, as usual in advanced digital multimeters. There are two
current paths available for current measurement. One of them is a high current path for up to 10 A.

The current and the voltage measurement facility can be used for DC and AC. The alternating parameters
are output as true RMS values. The input signal can cover a range up to 1 kHz, without affecting the
measuring accuracy. A non-sinus signal form is allowed, if the Crest factor is < 3.

The measurement readings can be read and processed with EtherCAT. At the same time, the EL3681
enables the measuring type and range to be set via the bus.

Excellent interference immunity is achieved through the fully electrically isolated design of the electronic
measuring system and the dual slope conversion system. High precision and simple, high impedance
measurement from 300 mV to 300 V allow the EtherCAT terminals to be used like a modern digital
multimeter. The sample rate lies between approx. 500 ms if the filter is activated and approx. 62 ms if the
filter is deactivated.

The selected measuring type and overload are indicated by LEDs.
In measuring applications in particular, the voltage to be expected is often not yet known during the planning
phase. Automatic adjustment of the measurement range simplifies use and reduces stock levels.

As high-precision variants, the EL3681-0020 with individual factory calibration certificate and the EL3681-0030
with external calibration certificate are available.

Please read the notes on the calibration certificate [}22] and identification features [}22] of these
terminals.

EL368116 Version: 2.6

Quick links

• EtherCAT basics

• Basic function principles EL3681 [}131]

• Process data [}134]

• CoE object description and parameterization [}139]

• Sample programs [}149]

• Error handling [}154]

• Accessories [}155]

Product overview

EL3681 17Version: 2.6

Product overview

2.2 Technical data

Technical data EL3681 EL3681-0020 EL3681-0030

Measured values current, voltage (AC/DC)

Measuring voltage 300mV, 3V, 30V, 300V

Measuring current 100 mA, 1 A and 10 A via high-current path

Resolution 18 bit + sign in each measurement range

Internal resistance Measuring range DC 300 mV - 300 V: 12.5MΩ

Measuring range DC 100 mA - 1 A: 0.2 Ω

Measuring range DC 10A: 3mΩ

Measuring range AC 300mV - 300V: 1MΩ, approx. 33pF

Measuring rangeAC 100 mA - 1 A: 0.2 Ω

Measuring range AC 10A: 3mΩ

Measuring error

Measuring procedure DC with arithmetic averaging

Update time 0.5 s, 1 s for measuring range selection

Electrical isolation 1,500V (connection terminal/E-bus)

Supply voltage for electronic via the E-bus

Current consumption via E-bus typ. 150 mA

Configuration via TwinCAT System Manager

Weight approx. 70 g

Permissible ambient temperature range during opera­tion

Permissible ambient temperature range during storage -40 °C ... +85 °C

Permissible relative humidity 95%, no condensation

Dimensions (W x H x D) approx. 15 mm x 100 mm x 70 mm (width aligned: 12 mm)

Mounting [}35]

Vibration/shock resistance conforms to EN 60068-2-6 / EN 60068-2-27

EMC immunity/emission conforms to EN 61000-6-2 / EN 61000-6-4

Protection class IP20

Installation position variable

Approval / marking CE CE

see table [}20] in chapter “Accuracy”

AC with TrueRMS, 0..1 kHz input signal, Crest factor < 3 allowed

-25 °C ... +60 °C (extended temperature range)

on 35 mm mounting rail conforms to EN 60715

CE

with factory calibration

certificate [}22]

with external calibration
certificate [}22]

EL368118 Version: 2.6

Product overview

2.3 Technology

Table of contents

General description [}19]

Specifications [}20]
- Accuracy [}20]
- Internal resistances [}21] - Fuse [}21]

Default setting [}21]

General description

The functionality of the EL3681 is similar to that of a commercial digital multimeter. The terminal offers the
following features:

• Single-channel measurement

• AC/DC voltage measurement, range selection automatic through Autorange function or through the
controller; measuring ranges 300mV, 3V, 30V, 300V

• AC/DC current measurement in the 1A path (internal fuse: 1.25A) or 10A path (no internal fuse),
measuring ranges: 100mA, 1A, 10A

• Formation of measured values:
AC current/voltage is calculated as a true RMS value without DC component, an integration of the
signal waveform in the ADC takes place
DC current/voltage is calculated as an arithmetic mean value, an integration of the signal waveform in
the ADC takes place

• Electrical isolation from the fieldbus

• Very good interference immunity through dual-slope conversion technique

• Display of measurement type (current/voltage) and overload through LED

• Typical update rate approx. 2/s, after measuring range change up to approx. 1/s, with deactivated filter
approx. 16/s.

The data collection is shown in fig. Data flow EL3681.

Fig.11: Data flow EL3681

Application note

For the measurement of a 60Hz signal, the CoE(0x8000:0A [}141])object should be set accordingly. For all
other signal frequencies the 50Hz preset is valid, because of the longer integration time. The accuracy
information shown below refer to a input signal of a frequency range of >0 .. 1kHz. With higher frequencies
the measurement accuracy decreases (-3dB>500kHz).

It is possible to measure a non-sinus AC input signal, if the Crest factor is < 3. The accuracy information
below refers to a Crest factor of max. 2.

EL3681 19Version: 2.6

Product overview

The simultaneous electrical connection of both current paths (10, 1A) and the voltage path for a following
alternating measurement of values is possible, but not recommended. In case of AC components in the
signal, a parasitic crosstalk from path to path can occur. After switching over, the process data update time
can be up to 1 second.

Specifications

Accuracy

The unused measurement input should be connected to the COM port of the terminal in order to make the
analysis as accurate as possible and minimize interference.

• Possible measuring inputs at the terminal:

◦ Voltage measurement 300mV – 300V (connection points 1 + 5)

◦ Current measurement 100mA – 1A (connection point 7)

◦ Current measurement 10A (connection point 3)

The measuring accuracy depends on the type of signal to be measures and on the terminal settings.
The accuracy values specified in the following table apply to the default settings for the terminal parameters:

- Enable vendor calibration true

- Enable filter true

- Frequency 50 Hz

- Zero compensation interval Off (0)

- Presentation Scaled (1Bit/1µV) (2)

Signal to be measured Typical max. tolerance in % of full scale

Measure-

Measuring range 40°C

value

1)

3)

0 .. 55°C ppm/°C

Typical temperature drift

2)6)

ment type

DC 3V - 300V

300mV

100mA

8)

8)

7)

0.01 0.2 35

0.05 0.2 35

0.1 0.5 50

1A 0.1 0.5 50

10A 0.2 1.2 170

4) 5)

AC

3V - 300V 0.25 0.75 130

300mV 0.25 0.5 50

100mA 0.5 1 50

1A 0.5 0.7 50

10A 0.5 1.2 150

Table 1: Measuring tolerances depending on temperatures. MBE = full scale value.

1) In 60Hz mode of ADC 0.02 should be added to the specified tolerance

2) The values apply to a minimum terminal warm-up time of 30 minutes

3) The compensation temperature is 40 °C

4) All AC voltage and current ranges are specified for a range of 5% to 100%

5) Crest factor < 2

6) In 60 Hz mode an additional temperature drift of 20 ppm / °C is to be expected.

7) The maximum deviation under EMC test conditions according to IEC 61131 is 1 %

8) The maximum deviation under EMC test conditions according to IEC 61131 is 0.2 %

Measuring procedure

The measuring technique in the terminal is based on the dual-slope technique.
The Zero Offset Compensation function reads the internal ADC offset and corrects the analog value
accordingly. The additional temperature drift can thus be partly compensated, either cyclically or through
external control.

EL368120 Version: 2.6

Product overview

Operating conditions

• To avoid interference shielded cables must be used for the analog signals. The maximum cable length
is 30m.

• For DC voltage measurements may the AC component may not exceed 150Vpp.

• For AC voltage measurements may the DC component may not exceed 150V (sine voltage).

• The peak voltage (relative to the COM terminal) may not exceed 600V.

Internal resistance

Measurement type Measuring range Internal resistance

DC 300mV - 300V 12.5MΩ

100mA - 1A 0.2Ω

10A 3mΩ

4) 5)

AC

300mV - 300V 1MΩ, approx. 33pF

100mA - 1A 0.2Ω

10A 3mΩ

Table 2: Internal resistances

Fuse

Notes on replacing the fuse can be found in section Accessories [}155].

Default Setting

The factory setting for the multimeter terminal enables voltages up to 300VDC to be measured directly
without additional settings. The Autorange function is active and selects the measuring range automatically.
The measured value is displayed with 1 bit/µV, i.e. no adjustment is required. Fig. Display of measured value
in TwinCAT shows an example for measured values in the TwinCAT tree. In the example the value
10448400 corresponds to a voltage of 10.448400 V

Fig.12: Display of measured value in TwinCAT

The terminal is supplied with a sample program [}149] that enables the process data of the EL3681 to be
modified and the terminal to be re-parameterized.

EL3681 21Version: 2.6

Product overview

2.4 Note on Beckhoff calibration certificates

Basically every Beckhoff analogue device (input or output) will be justified i.e. will be calibrated during
production. This procedure won’t be documented unique. This documentation as a calibration certificate is
only provided for devices that are expressly delivered with a certificate.

The calibration certificate (or German: “Kalibrierschein”) entitles the residual error after compensation/
adjustment to the used standard (reference device). The calibration certificate (as a PDF document) is to be
assigned to the device via a unique number. It is therefore not a statement about a device class such as e.g.

an approval, but always only applies to a single, named device. It is available for download.

The calibration certificate documents the measurement accuracy at the time the certificate was issued and
contains, among other things, information on the ambient conditions and the reference instrument used. It
does not contain statement about the behavior or the change of the measuring accuracy in the future. A
calibration certificate acts as a backtracking view to the previous time of usage. By reiterated certification
procedures over years (without justification) it allows making conclusions about its ageing behavior, so called
calibrate history.

Performance levels of the calibration certificates

Different "qualities" of a calibration certificate are common:

• Beckhoff calibration certificates
Such IP20 terminals can be usually identified by the product suffix -0020. The certificate is issued in
Beckhoff production as PDF.
The terminals can be obtained from Beckhoff and recalibrated by the Beckhoff service department.

• ISO17025 calibration certificates
Such IP20 terminals can be usually identified by the product suffix -0030. The certificate is issued by a
service provider on behalf of Beckhoff as part of Beckhoff production and delivered by Beckhoff as a
PDF.
The terminals can be obtained from Beckhoff and recalibrated by the Beckhoff service department.

• DAkkS calibration certificates (German: "Deutsche Akkreditierungsstelle GmbH")
Such IP20 terminals can be usually identified by the product suffix -0030. The certificate is issued by a
accredited service provider on behalf of Beckhoff as a part of Beckhoff production and delivered by
Beckhoff as a PDF.
The terminals can be obtained from Beckhoff and recalibrated by the Beckhoff service department.

EL368122 Version: 2.6

Unique device number

Depending on the device, the following numbers are used for identification:

• EL/ELM terminals up to year of manufacture 2020: the ID number which is lasered on the side.

Product overview

Fig.13: ID number

• From year of manufacture 2021 onwards, the BTN number (Beckhoff Traceability Number) will
gradually replace the ID number, this is also lasered on the side.

Beckhoff produces a wide range of analog input/output devices as IP20 terminal or IP67 box. A selection of
these is also available with factory/ISO/DAkkS calibration certificates. For specific details and availability, see
the technical data of the devices or contact Beckhoff Sales.

Linguistic note

In American English, "calibration" or "alignment" is understood to mean compensation/adjustment,
thus a modifying effect on the device. "Verification", on the other hand, refers to observational deter­mination and documentation of the residual error, referred in German language use as “Kalib-
rierung”.

EL3681 23Version: 2.6

Product overview

2.5 Start

For commissioning:

• mount the EL3681 as described in the chapter Mounting and wiring [}35]

• configure the EL3681 in TwinCAT as described in the chapter Commissioning [}131].

EL368124 Version: 2.6

Basics communication

3 Basics communication

3.1 EtherCAT basics

Please refer to the EtherCAT System Documentation for the EtherCAT fieldbus basics.

3.2 EtherCAT cabling – wire-bound

The cable length between two EtherCAT devices must not exceed 100 m. This results from the FastEthernet
technology, which, above all for reasons of signal attenuation over the length of the cable, allows a maximum

link length of 5 + 90 + 5 m if cables with appropriate properties are used. See also the Design
recommendations for the infrastructure for EtherCAT/Ethernet.

Cables and connectors

For connecting EtherCAT devices only Ethernet connections (cables + plugs) that meet the requirements of
at least category 5 (CAt5) according to EN 50173 or ISO/IEC 11801 should be used. EtherCAT uses 4 wires
for signal transfer.

EtherCAT uses RJ45 plug connectors, for example. The pin assignment is compatible with the Ethernet
standard (ISO/IEC 8802-3).

Pin Color of conductor Signal Description

1 yellow TD + Transmission Data +

2 orange TD - Transmission Data -

3 white RD + Receiver Data +

6 blue RD - Receiver Data -

Due to automatic cable detection (auto-crossing) symmetric (1:1) or cross-over cables can be used between
EtherCAT devices from Beckhoff.

Recommended cables

It is recommended to use the appropriate Beckhoff components e.g.

- cable sets ZK1090-9191-xxxx respectively

- RJ45 connector, field assembly ZS1090-0005

- EtherCAT cable, field assembly ZB9010, ZB9020

Suitable cables for the connection of EtherCAT devices can be found on the Beckhoff website!

E-Bus supply

A bus coupler can supply the EL terminals added to it with the E-bus system voltage of 5V; a coupler is
thereby loadable up to 2A as a rule (see details in respective device documentation).
Information on how much current each EL terminal requires from the E-bus supply is available online and in
the catalogue. If the added terminals require more current than the coupler can supply, then power feed

terminals (e.g. EL9410) must be inserted at appropriate places in the terminal strand.

The pre-calculated theoretical maximum E-Bus current is displayed in the TwinCAT System Manager. A
shortfall is marked by a negative total amount and an exclamation mark; a power feed terminal is to be
placed before such a position.

EL3681 25Version: 2.6

Basics communication

Fig.14: System manager current calculation

NOTE

Malfunction possible!

The same ground potential must be used for the E-Bus supply of all EtherCAT terminals in a terminal block!

3.3 General notes for setting the watchdog

ELxxxx terminals are equipped with a safety feature (watchdog) that switches off the outputs after a
specifiable time e.g. in the event of an interruption of the process data traffic, depending on the device and
settings, e.g. in OFF state.

The EtherCAT slave controller (ESC) in the EL2xxx terminals features two watchdogs:

• SM watchdog (default: 100 ms)

• PDI watchdog (default: 100 ms)

SM watchdog (SyncManager Watchdog)

The SyncManager watchdog is reset after each successful EtherCAT process data communication with the
terminal. If no EtherCAT process data communication takes place with the terminal for longer than the set
and activated SM watchdog time, e.g. in the event of a line interruption, the watchdog is triggered and the
outputs are set to FALSE. The OP state of the terminal is unaffected. The watchdog is only reset after a
successful EtherCAT process data access. Set the monitoring time as described below.

The SyncManager watchdog monitors correct and timely process data communication with the ESC from the
EtherCAT side.

PDI watchdog (Process Data Watchdog)

If no PDI communication with the EtherCAT slave controller (ESC) takes place for longer than the set and
activated PDI watchdog time, this watchdog is triggered.
PDI (Process Data Interface) is the internal interface between the ESC and local processors in the EtherCAT
slave, for example. The PDI watchdog can be used to monitor this communication for failure.

The PDI watchdog monitors correct and timely process data communication with the ESC from the
application side.

The settings of the SM- and PDI-watchdog must be done for each slave separately in the TwinCAT System
Manager.

EL368126 Version: 2.6

Basics communication

Fig.15: EtherCAT tab -> Advanced Settings -> Behavior -> Watchdog

Notes:

• the multiplier is valid for both watchdogs.

• each watchdog has its own timer setting, the outcome of this in summary with the multiplier is a
resulting time.

• Important: the multiplier/timer setting is only loaded into the slave at the start up, if the checkbox is
activated.
If the checkbox is not activated, nothing is downloaded and the ESC settings remain unchanged.

Multiplier

Both watchdogs receive their pulses from the local terminal cycle, divided by the watchdog multiplier:

1/25 MHz * (watchdog multiplier + 2) = 100µs (for default setting of 2498 for the multiplier)

The standard setting of 1000 for the SM watchdog corresponds to a release time of 100ms.

The value in multiplier + 2 corresponds to the number of basic 40 ns ticks representing a watchdog tick.
The multiplier can be modified in order to adjust the watchdog time over a larger range.

Example “Set SM watchdog”

This checkbox enables manual setting of the watchdog times. If the outputs are set and the EtherCAT
communication is interrupted, the SM watchdog is triggered after the set time and the outputs are erased.
This setting can be used for adapting a terminal to a slower EtherCAT master or long cycle times. The
default SM watchdog setting is 100ms. The setting range is 0...65535. Together with a multiplier with a
range of 1...65535 this covers a watchdog period between 0...~170 seconds.

EL3681 27Version: 2.6

Basics communication

Calculation

Multiplier = 2498 → watchdog base time = 1 / 25MHz * (2498 + 2) = 0.0001seconds = 100µs
SM watchdog = 10000 → 10000 * 100µs = 1second watchdog monitoring time

CAUTION

Undefined state possible!

The function for switching off of the SM watchdog via SM watchdog = 0 is only implemented in terminals
from version -0016. In previous versions this operating mode should not be used.

CAUTION

Damage of devices and undefined state possible!

If the SM watchdog is activated and a value of 0 is entered the watchdog switches off completely. This is
the deactivation of the watchdog! Set outputs are NOT set in a safe state, if the communication is inter­rupted.

3.4 EtherCAT State Machine

The state of the EtherCAT slave is controlled via the EtherCAT State Machine (ESM). Depending upon the
state, different functions are accessible or executable in the EtherCAT slave. Specific commands must be
sent by the EtherCAT master to the device in each state, particularly during the bootup of the slave.

A distinction is made between the following states:

• Init

• Pre-Operational

• Safe-Operational and

• Operational

• Boot

The regular state of each EtherCAT slave after bootup is the OP state.

Fig.16: States of the EtherCAT State Machine

EL368128 Version: 2.6

Basics communication

Init

After switch-on the EtherCAT slave in the Init state. No mailbox or process data communication is possible.
The EtherCAT master initializes sync manager channels 0 and 1 for mailbox communication.

Pre-Operational (Pre-Op)

During the transition between Init and Pre-Op the EtherCAT slave checks whether the mailbox was initialized
correctly.

In Pre-Op state mailbox communication is possible, but not process data communication. The EtherCAT
master initializes the sync manager channels for process data (from sync manager channel 2), the FMMU
channels and, if the slave supports configurable mapping, PDO mapping or the sync manager PDO
assignment. In this state the settings for the process data transfer and perhaps terminal-specific parameters
that may differ from the default settings are also transferred.

Safe-Operational (Safe-Op)

During transition between Pre-Op and Safe-Op the EtherCAT slave checks whether the sync manager
channels for process data communication and, if required, the distributed clocks settings are correct. Before
it acknowledges the change of state, the EtherCAT slave copies current input data into the associated DP­RAM areas of the EtherCAT slave controller (ECSC).

In Safe-Op state mailbox and process data communication is possible, although the slave keeps its outputs
in a safe state, while the input data are updated cyclically.

Outputs in SAFEOP state

The default set watchdog [}26] monitoring sets the outputs of the module in a safe state - depend­ing on the settings in SAFEOP and OP - e.g. in OFF state. If this is prevented by deactivation of the
watchdog monitoring in the module, the outputs can be switched or set also in the SAFEOP state.

Operational (Op)

Before the EtherCAT master switches the EtherCAT slave from Safe-Op to Op it must transfer valid output
data.

In the Op state the slave copies the output data of the masters to its outputs. Process data and mailbox
communication is possible.

Boot

In the Boot state the slave firmware can be updated. The Boot state can only be reached via the Init state.

In the Boot state mailbox communication via the file access over EtherCAT (FoE) protocol is possible, but no
other mailbox communication and no process data communication.

3.5 CoE Interface

General description

The CoE interface (CAN application protocol over EtherCAT)) is used for parameter management of
EtherCAT devices. EtherCAT slaves or the EtherCAT master manage fixed (read only) or variable
parameters which they require for operation, diagnostics or commissioning.

CoE parameters are arranged in a table hierarchy. In principle, the user has read access via the fieldbus.
The EtherCAT master (TwinCAT System Manager) can access the local CoE lists of the slaves via
EtherCAT in read or write mode, depending on the attributes.

EL3681 29Version: 2.6

Basics communication

Different CoE parameter types are possible, including string (text), integer numbers, Boolean values or larger
byte fields. They can be used to describe a wide range of features. Examples of such parameters include
manufacturer ID, serial number, process data settings, device name, calibration values for analog
measurement or passwords.

The order is specified in two levels via hexadecimal numbering: (main)index, followed by subindex. The
value ranges are

• Index: 0x0000 …0xFFFF (0...65535

• SubIndex: 0x00…0xFF (0...255

dez

)

dez

)

A parameter localized in this way is normally written as 0x8010:07, with preceding “0x” to identify the
hexadecimal numerical range and a colon between index and subindex.

The relevant ranges for EtherCAT fieldbus users are:

• 0x1000: This is where fixed identity information for the device is stored, including name, manufacturer,
serial number etc., plus information about the current and available process data configurations.

• 0x8000: This is where the operational and functional parameters for all channels are stored, such as
filter settings or output frequency.

Other important ranges are:

• 0x4000: here are the channel parameters for some EtherCAT devices. Historically, this was the first
parameter area before the 0x8000 area was introduced. EtherCAT devices that were previously
equipped with parameters in 0x4000 and changed to 0x8000 support both ranges for compatibility
reasons and mirror internally.

• 0x6000: Input PDOs (“input” from the perspective of the EtherCAT master)

• 0x7000: Output PDOs (“output” from the perspective of the EtherCAT master)

Availability

Not every EtherCAT device must have a CoE list. Simple I/O modules without dedicated processor
usually have no variable parameters and therefore no CoE list.

If a device has a CoE list, it is shown in the TwinCAT System Manager as a separate tab with a listing of the
elements:

Fig.17: “CoE Online” tab

EL368130 Version: 2.6

Basics communication

The figure above shows the CoE objects available in device “EL2502”, ranging from 0x1000 to 0x1600. The
subindices for 0x1018 are expanded.

Data management and function “NoCoeStorage”

Some parameters, particularly the setting parameters of the slave, are configurable and writeable. This can
be done in write or read mode

• via the System Manager (Fig. “CoE Online” tab) by clicking
This is useful for commissioning of the system/slaves. Click on the row of the index to be
parameterized and enter a value in the “SetValue” dialog.

• from the control system/PLC via ADS, e.g. through blocks from the TcEtherCAT.lib library
This is recommended for modifications while the system is running or if no System Manager or
operating staff are available.

Data management

If slave CoE parameters are modified online, Beckhoff devices store any changes in a fail-safe
manner in the EEPROM, i.e. the modified CoE parameters are still available after a restart.
The situation may be different with other manufacturers.

An EEPROM is subject to a limited lifetime with respect to write operations. From typically 100,000
write operations onwards it can no longer be guaranteed that new (changed) data are reliably saved
or are still readable. This is irrelevant for normal commissioning. However, if CoE parameters are
continuously changed via ADS at machine runtime, it is quite possible for the lifetime limit to be
reached. Support for the NoCoeStorage function, which suppresses the saving of changed CoE val­ues, depends on the firmware version.
Please refer to the technical data in this documentation as to whether this applies to the respective
device.

• If the function is supported: the function is activated by entering the code word 0x12345678 once
in CoE 0xF008 and remains active as long as the code word is not changed. After switching the
device on it is then inactive. Changed CoE values are not saved in the EEPROM and can thus
be changed any number of times.

• Function is not supported: continuous changing of CoE values is not permissible in view of the
lifetime limit.

Startup list

Changes in the local CoE list of the terminal are lost if the terminal is replaced. If a terminal is re­placed with a new Beckhoff terminal, it will have the default settings. It is therefore advisable to link
all changes in the CoE list of an EtherCAT slave with the Startup list of the slave, which is pro­cessed whenever the EtherCAT fieldbus is started. In this way a replacement EtherCAT slave can
automatically be parameterized with the specifications of the user.

If EtherCAT slaves are used which are unable to store local CoE values permanently, the Startup
list must be used.

Recommended approach for manual modification of CoE parameters

• Make the required change in the System Manager
The values are stored locally in the EtherCAT slave

• If the value is to be stored permanently, enter it in the Startup list.
The order of the Startup entries is usually irrelevant.

EL3681 31Version: 2.6

Basics communication

Fig.18: Startup list in the TwinCAT System Manager

The Startup list may already contain values that were configured by the System Manager based on the ESI
specifications. Additional application-specific entries can be created.

Online/offline list

While working with the TwinCAT System Manager, a distinction has to be made whether the EtherCAT
device is “available”, i.e. switched on and linked via EtherCAT and therefore online, or whether a
configuration is created offline without connected slaves.

In both cases a CoE list as shown in Fig. “CoE online tab” is displayed. The connectivity is shown as offline/
online.

• If the slave is offline

◦ The offline list from the ESI file is displayed. In this case modifications are not meaningful or

possible.

◦ The configured status is shown under Identity.

◦ No firmware or hardware version is displayed, since these are features of the physical device.

◦ Offline is shown in red.

Fig.19: Offline list

EL368132 Version: 2.6

Basics communication

• If the slave is online

◦ The actual current slave list is read. This may take several seconds, depending on the size and

cycle time.

◦ The actual identity is displayed

◦ The firmware and hardware version of the equipment according to the electronic information is

displayed

◦ Online is shown in green.

Fig.20: Online list

Channel-based order

The CoE list is available in EtherCAT devices that usually feature several functionally equivalent channels.
For example, a 4-channel analog 0...10V input terminal also has four logical channels and therefore four
identical sets of parameter data for the channels. In order to avoid having to list each channel in the
documentation, the placeholder “n” tends to be used for the individual channel numbers.

In the CoE system 16 indices, each with 255 subindices, are generally sufficient for representing all channel
parameters. The channel-based order is therefore arranged in 16

dec

/10

steps. The parameter range

hex

0x8000 exemplifies this:

• Channel 0: parameter range 0x8000:00 ... 0x800F:255

• Channel 1: parameter range 0x8010:00 ... 0x801F:255

• Channel 2: parameter range 0x8020:00 ... 0x802F:255

• ...

This is generally written as 0x80n0.

Detailed information on the CoE interface can be found in the EtherCAT system documentation on the
Beckhoff website.

EL3681 33Version: 2.6

Basics communication

3.6 Distributed Clock

The distributed clock represents a local clock in the EtherCAT slave controller (ESC) with the following
characteristics:

• Unit 1 ns

• Zero point 1.1.2000 00:00

• Size 64 bit (sufficient for the next 584 years; however, some EtherCAT slaves only offer 32-bit support,
i.e. the variable overflows after approx. 4.2 seconds)

• The EtherCAT master automatically synchronizes the local clock with the master clock in the EtherCAT
bus with a precision of < 100 ns.

For detailed information please refer to the EtherCAT system description.

EL368134 Version: 2.6

Mounting and wiring

4 Mounting and wiring

4.1 Instructions for ESD protection

NOTE

Destruction of the devices by electrostatic discharge possible!

The devices contain components at risk from electrostatic discharge caused by improper handling.

• Please ensure you are electrostatically discharged and avoid touching the contacts of the device directly.

• Avoid contact with highly insulating materials (synthetic fibers, plastic film etc.).

• Surroundings (working place, packaging and personnel) should by grounded probably, when handling
with the devices.

• Each assembly must be terminated at the right hand end with an EL9011 or EL9012 bus end cap, to en­sure the protection class and ESD protection.

Fig.21: Spring contacts of the Beckhoff I/O components

4.2 Installation on mounting rails

WARNING

Risk of electric shock and damage of device!

Bring the bus terminal system into a safe, powered down state before starting installation, disassembly or
wiring of the bus terminals!

EL3681 35Version: 2.6

Mounting and wiring

Assembly

Fig.22: Attaching on mounting rail

The bus coupler and bus terminals are attached to commercially available 35mm mounting rails (DIN rails
according to EN60715) by applying slight pressure:

1. First attach the fieldbus coupler to the mounting rail.

2. The bus terminals are now attached on the right-hand side of the fieldbus coupler. Join the compo­nents with tongue and groove and push the terminals against the mounting rail, until the lock clicks
onto the mounting rail.
If the terminals are clipped onto the mounting rail first and then pushed together without tongue and
groove, the connection will not be operational! When correctly assembled, no significant gap should
be visible between the housings.

Fixing of mounting rails

The locking mechanism of the terminals and couplers extends to the profile of the mounting rail. At
the installation, the locking mechanism of the components must not come into conflict with the fixing
bolts of the mounting rail. To mount the mounting rails with a height of 7.5mm under the terminals
and couplers, you should use flat mounting connections (e.g. countersunk screws or blind rivets).

EL368136 Version: 2.6

Mounting and wiring

Disassembly

Fig.23: Disassembling of terminal

Each terminal is secured by a lock on the mounting rail, which must be released for disassembly:

1. Pull the terminal by its orange-colored lugs approximately 1cm away from the mounting rail. In doing
so for this terminal the mounting rail lock is released automatically and you can pull the terminal out of
the bus terminal block easily without excessive force.

2. Grasp the released terminal with thumb and index finger simultaneous at the upper and lower grooved
housing surfaces and pull the terminal out of the bus terminal block.

Connections within a bus terminal block

The electric connections between the Bus Coupler and the Bus Terminals are automatically realized by
joining the components:

• The six spring contacts of the K-Bus/E-Bus deal with the transfer of the data and the supply of the Bus
Terminal electronics.

• The power contacts deal with the supply for the field electronics and thus represent a supply rail within
the bus terminal block. The power contacts are supplied via terminals on the Bus Coupler (up to 24V)
or for higher voltages via power feed terminals.

Power Contacts

During the design of a bus terminal block, the pin assignment of the individual Bus Terminals must
be taken account of, since some types (e.g. analog Bus Terminals or digital 4-channel Bus Termi­nals) do not or not fully loop through the power contacts. Power Feed Terminals (KL91xx, KL92xx
or EL91xx, EL92xx) interrupt the power contacts and thus represent the start of a new supply rail.

PE power contact

The power contact labeled PE can be used as a protective earth. For safety reasons this contact mates first
when plugging together, and can ground short-circuit currents of up to 125A.

EL3681 37Version: 2.6

Mounting and wiring

Fig.24: Power contact on left side

NOTE

Possible damage of the device

Note that, for reasons of electromagnetic compatibility, the PE contacts are capacitatively coupled to the
mounting rail. This may lead to incorrect results during insulation testing or to damage on the terminal (e.g.
disruptive discharge to the PE line during insulation testing of a consumer with a nominal voltage of 230V).
For insulation testing, disconnect the PE supply line at the Bus Coupler or the Power Feed Terminal! In or­der to decouple further feed points for testing, these Power Feed Terminals can be released and pulled at
least 10mm from the group of terminals.

WARNING

Risk of electric shock!

The PE power contact must not be used for other potentials!

4.3 Connection

4.3.1 Connection system

WARNING

Risk of electric shock and damage of device!

Bring the bus terminal system into a safe, powered down state before starting installation, disassembly or
wiring of the bus terminals!

Overview

The bus terminal system offers different connection options for optimum adaptation to the respective
application:

• The terminals of ELxxxx and KLxxxx series with standard wiring include electronics and connection
level in a single enclosure.

• The terminals of ESxxxx and KSxxxx series feature a pluggable connection level and enable steady
wiring while replacing.

• The High Density Terminals (HD Terminals) include electronics and connection level in a single
enclosure and have advanced packaging density.

EL368138 Version: 2.6

Standard wiring (ELxxxx / KLxxxx)

Fig.25: Standard wiring

The terminals of ELxxxx and KLxxxx series have been tried and tested for years.
They feature integrated screwless spring force technology for fast and simple assembly.

Pluggable wiring (ESxxxx / KSxxxx)

Mounting and wiring

Fig.26: Pluggable wiring

The terminals of ESxxxx and KSxxxx series feature a pluggable connection level.
The assembly and wiring procedure is the same as for the ELxxxx and KLxxxx series.
The pluggable connection level enables the complete wiring to be removed as a plug connector from the top
of the housing for servicing.
The lower section can be removed from the terminal block by pulling the unlocking tab.
Insert the new component and plug in the connector with the wiring. This reduces the installation time and
eliminates the risk of wires being mixed up.

The familiar dimensions of the terminal only had to be changed slightly. The new connector adds about 3
mm. The maximum height of the terminal remains unchanged.

A tab for strain relief of the cable simplifies assembly in many applications and prevents tangling of individual
connection wires when the connector is removed.

Conductor cross sections between 0.08mm2 and 2.5mm2 can continue to be used with the proven spring
force technology.

The overview and nomenclature of the product names for ESxxxx and KSxxxx series has been retained as
known from ELxxxx and KLxxxx series.

High Density Terminals (HD Terminals)

Fig.27: High Density Terminals

The terminals from these series with 16 terminal points are distinguished by a particularly compact design,
as the packaging density is twice as large as that of the standard 12mm bus terminals. Massive conductors
and conductors with a wire end sleeve can be inserted directly into the spring loaded terminal point without
tools.

EL3681 39Version: 2.6

Mounting and wiring

Wiring HD Terminals

The High Density Terminals of the ELx8xx and KLx8xx series doesn't support pluggable wiring.

Ultrasonically “bonded” (ultrasonically welded) conductors

Ultrasonically “bonded” conductors

It is also possible to connect the Standard and High Density Terminals with ultrasonically
“bonded” (ultrasonically welded) conductors. In this case, please note the tables concerning the
wire-size width!

EL368140 Version: 2.6

Mounting and wiring

4.3.2 Wiring

WARNING

Risk of electric shock and damage of device!

Bring the bus terminal system into a safe, powered down state before starting installation, disassembly or
wiring of the bus terminals!

Terminals for standard wiring ELxxxx/KLxxxx and for pluggable wiring ESxxxx/KSxxxx

Fig.28: Connecting a cable on a terminal point

Up to eight terminal points enable the connection of solid or finely stranded cables to the bus terminal. The
terminal points are implemented in spring force technology. Connect the cables as follows:

1. Open a terminal point by pushing a screwdriver straight against the stop into the square opening
above the terminal point. Do not turn the screwdriver or move it alternately (don't toggle).

2. The wire can now be inserted into the round terminal opening without any force.

3. The terminal point closes automatically when the pressure is released, holding the wire securely and
permanently.

See the following table for the suitable wire size width.

Terminal housing ELxxxx, KLxxxx ESxxxx, KSxxxx

Wire size width (single core wires) 0.08 ... 2.5mm

Wire size width (fine-wire conductors) 0.08 ... 2.5mm

Wire size width (conductors with a wire end sleeve) 0.14 ... 1.5mm

2

2

2

0.08 ... 2.5mm

0,08 ... 2.5mm

0.14 ... 1.5mm

2

2

2

Wire stripping length 8 ... 9mm 9 ... 10mm

High Density Terminals (HD Terminals [}39]) with 16 terminal points

The conductors of the HD Terminals are connected without tools for single-wire conductors using the direct
plug-in technique, i.e. after stripping the wire is simply plugged into the terminal point. The cables are
released, as usual, using the contact release with the aid of a screwdriver. See the following table for the
suitable wire size width.

EL3681 41Version: 2.6

Mounting and wiring

Terminal housing High Density Housing

Wire size width (single core wires) 0.08 ... 1.5mm

Wire size width (fine-wire conductors) 0.25 ... 1.5mm

Wire size width (conductors with a wire end sleeve) 0.14 ... 0.75mm

Wire size width (ultrasonically “bonded" conductors) only 1.5mm

2

2

2

2

Wire stripping length 8 ... 9mm

4.3.3 Shielding

Shielding

Encoder, analog sensors and actors should always be connected with shielded, twisted paired
wires.

EL368142 Version: 2.6

4.4 Positioning of passive Terminals

Hint for positioning of passive terminals in the bus terminal block

EtherCAT Terminals (ELxxxx / ESxxxx), which do not take an active part in data transfer within the
bus terminal block are so called passive terminals. The passive terminals have no current consump­tion out of the E-Bus.
To ensure an optimal data transfer, you must not directly string together more than two passive ter­minals!

Examples for positioning of passive terminals (highlighted)

Mounting and wiring

Fig.29: Correct positioning

Fig.30: Incorrect positioning

4.5 Installation positions

NOTE

Constraints regarding installation position and operating temperature range

Please refer to the technical data for a terminal to ascertain whether any restrictions regarding the installa­tion position and/or the operating temperature range have been specified. When installing high power dissi­pation terminals ensure that an adequate spacing is maintained between other components above and be­low the terminal in order to guarantee adequate ventilation!

EL3681 43Version: 2.6

Mounting and wiring

Optimum installation position (standard)

The optimum installation position requires the mounting rail to be installed horizontally and the connection
surfaces of the EL/KL terminals to face forward (see Fig. Recommended distances for standard installation
position). The terminals are ventilated from below, which enables optimum cooling of the electronics through
convection. “From below” is relative to the acceleration of gravity.

Fig.31: Recommended distances for standard installation position

Compliance with the distances shown in Fig. Recommended distances for standard installation position is
recommended.

Other installation positions

All other installation positions are characterized by different spatial arrangement of the mounting rail - see
Fig Other installation positions.

The minimum distances to ambient specified above also apply to these installation positions.

EL368144 Version: 2.6

Mounting and wiring

Fig.32: Other installation positions

EL3681 45Version: 2.6

Mounting and wiring

4.6 LEDs and connection

Fig.33: EL3681 Connection

Connection EL3681

Terminal point No. Comment

V 1 Terminal point for voltage measurement (internally connected with terminal point 5)

COM 2 Ground (internally connected with terminal point 6)

10A 3 Terminal point for current measurement, 10 A range

Shield 4 Shield (internally connected to terminal point 8)

V 5 Terminal point for voltage measurement (internally connected with terminal point 1)

COM 6 Ground (internally connected with terminal point 2)

1A 7 Terminal point for current measurement, 1 A range

Shield 8 Shield (internally connected to terminal point 4)

LEDs

LED Color Meaning

RUN green This LED indicates the terminal's operating state:

off

flashing State of the EtherCAT State Machine: PREOP = function for mailbox communication and different

single flash

on State of the EtherCAT State Machine: OP = normal operating state; mailbox and process data com-

Term. Error red

Voltage green Indicates voltage measurement

Current green Indicates current measurement

An error has occurred (see chapter "Error handling and diagnosis [}154]")

State of the EtherCAT State Machine [}28]: INIT = initialization of the terminal or BOOTSTRAP =
function for firmware updates [}158] of the terminal

standard-settings set

State of the EtherCAT State Machine: SAFEOP = verification of the Sync Manager [}98] channels
and the distributed clocks.
Outputs remain in safe state

munication is possible

EL368146 Version: 2.6

Commissioning

5 Commissioning

5.1 TwinCAT Quick Start

TwinCAT is a development environment for real-time control including multi-PLC system, NC axis control,
programming and operation. The whole system is mapped through this environment and enables access to a
programming environment (including compilation) for the controller. Individual digital or analog inputs or
outputs can also be read or written directly, in order to verify their functionality, for example.

For further information please refer to http://infosys.beckhoff.com:

• EtherCAT Systemmanual:
Fieldbus Components → EtherCAT Terminals → EtherCAT System Documentation → Setup in the
TwinCAT System Manager

• TwinCAT2 → TwinCAT System Manager → I/O - Configuration

• In particular, TwinCAT driver installation:
Fieldbus components → Fieldbus Cards and Switches → FC900x – PCI Cards for Ethernet →
Installation

Devices contain the terminals for the actual configuration. All configuration data can be entered directly via
editor functions (offline) or via the “Scan” function (online):

• “offline”: The configuration can be customized by adding and positioning individual components.
These can be selected from a directory and configured.

◦ The procedure for offline mode can be found under http://infosys.beckhoff.com:

TwinCAT2 → TwinCAT System Manager → IO - Configuration → Adding an I/O Device

• “online”: The existing hardware configuration is read

◦ See also http://infosys.beckhoff.com:

Fieldbus components → Fieldbus cards and switches → FC900x – PCI Cards for Ethernet →
Installation → Searching for devices

The following relationship is envisaged from user PC to the individual control elements:

EL3681 47Version: 2.6

Commissioning

Fig.34: Relationship between user side (commissioning) and installation

The user inserting of certain components (I/O device, terminal, box...) is the same in TwinCAT2 and
TwinCAT3. The descriptions below relate to the online procedure.

Sample configuration (actual configuration)

Based on the following sample configuration, the subsequent subsections describe the procedure for
TwinCAT2 and TwinCAT3:

• Control system (PLC) CX2040 including CX2100-0004 power supply unit

• Connected to the CX2040 on the right (E-bus):
EL1004 (4-channel digital input terminal 24VDC)

• Linked via the X001 port (RJ-45): EK1100 EtherCAT Coupler

• Connected to the EK1100 EtherCAT coupler on the right (E-bus):
EL2008 (8-channel digital output terminal 24VDC;0.5A)

• (Optional via X000: a link to an external PC for the user interface)

EL368148 Version: 2.6

Commissioning

Fig.35: Control configuration with Embedded PC, input (EL1004) and output (EL2008)

Note that all combinations of a configuration are possible; for example, the EL1004 terminal could also be
connected after the coupler, or the EL2008 terminal could additionally be connected to the CX2040 on the
right, in which case the EK1100 coupler wouldn’t be necessary.

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Commissioning

5.1.1 TwinCAT 2

Startup

TwinCAT basically uses two user interfaces: the TwinCAT System Manager for communication with the
electromechanical components and TwinCAT PLC Control for the development and compilation of a
controller. The starting point is the TwinCAT System Manager.

After successful installation of the TwinCAT system on the PC to be used for development, the TwinCAT2
System Manager displays the following user interface after startup:

Fig.36: Initial TwinCAT2 user interface

Generally, TwinCAT can be used in local or remote mode. Once the TwinCAT system including the user
interface (standard) is installed on the respective PLC, TwinCAT can be used in local mode and thereby the

next step is “Insert Device [}52]”.

If the intention is to address the TwinCAT runtime environment installed on a PLC as development
environment remotely from another system, the target system must be made known first. In the menu under

“Actions” → “Choose Target System...”, via the symbol “ ” or the “F8” key, open the following window:

EL368150 Version: 2.6

Fig.37: Selection of the target system

Use “Search (Ethernet)...” to enter the target system. Thus a next dialog opens to either:

Commissioning

• enter the known computer name after “Enter Host Name / IP:” (as shown in red)

• perform a “Broadcast Search” (if the exact computer name is not known)

• enter the known computer IP or AmsNetID.

Fig.38: Specify the PLC for access by the TwinCAT System Manager: selection of the target system

Once the target system has been entered, it is available for selection as follows (a password may have to be
entered):

After confirmation with “OK” the target system can be accessed via the System Manager.

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Commissioning

Adding devices

In the configuration tree of the TwinCAT2 System Manager user interface on the left, select “I/ODevices”
and then right-click to open a context menu and select “ScanDevices…”, or start the action in the menu bar

via . The TwinCAT System Manager may first have to be set to “Configmode” via or via menu
“Actions” → “Set/Reset TwinCAT to Config Mode…” (Shift + F4).

Fig.39: Select “Scan Devices...”

Confirm the warning message, which follows, and select “EtherCAT” in the dialog:

Fig.40: Automatic detection of I/O devices: selection the devices to be integrated

Confirm the message “Find new boxes”, in order to determine the terminals connected to the devices. “Free
Run” enables manipulation of input and output values in “Config mode” and should also be acknowledged.

Based on the sample configuration [}48] described at the beginning of this section, the result is as follows:

EL368152 Version: 2.6

Commissioning

Fig.41: Mapping of the configuration in the TwinCAT2 System Manager

The whole process consists of two stages, which may be performed separately (first determine the devices,
then determine the connected elements such as boxes, terminals, etc.). A scan can also be initiated by
selecting “Device ...” from the context menu, which then reads the elements present in the configuration
below:

Fig.42: Reading of individual terminals connected to a device

This functionality is useful if the actual configuration is modified at short notice.

Programming and integrating the PLC

TwinCAT PLC Control is the development environment for the creation of the controller in different program
environments: TwinCAT PLC Control supports all languages described in IEC 61131-3. There are two text­based languages and three graphical languages.

• Text-based languages

◦ Instruction List (IL)

EL3681 53Version: 2.6

Commissioning

◦ Structured Text (ST)

• Graphical languages

◦ Function Block Diagram (FBD)

◦ Ladder Diagram (LD)

◦ The Continuous Function Chart Editor (CFC)

◦ Sequential Function Chart (SFC)

The following section refers to Structured Text (ST).

After starting TwinCAT PLC Control, the following user interface is shown for an initial project:

Fig.43: TwinCAT PLC Control after startup

Sample variables and a sample program have been created and stored under the name “PLC_example.pro”:

EL368154 Version: 2.6

Commissioning

Fig.44: Sample program with variables after a compile process (without variable integration)

Warning 1990 (missing “VAR_CONFIG”) after a compile process indicates that the variables defined as
external (with the ID “AT%I*” or “AT%Q*”) have not been assigned. After successful compilation, TwinCAT
PLC Control creates a “*.tpy” file in the directory in which the project was stored. This file (“*.tpy”) contains
variable assignments and is not known to the System Manager, hence the warning. Once the System
Manager has been notified, the warning no longer appears.

First, integrate the TwinCAT PLC Control project in the System Manager via the context menu of the PLC
configuration; right-click and select “Append PLC Project…”:

Fig.45: Appending the TwinCAT PLC Control project

EL3681 55Version: 2.6

Commissioning

Select the PLC configuration “PLC_example.tpy” in the browser window that opens. The project including the
two variables identified with “AT” are then integrated in the configuration tree of the System Manager:

Fig.46: PLC project integrated in the PLC configuration of the System Manager

The two variables “bEL1004_Ch4” and “nEL2008_value” can now be assigned to certain process objects of
the I/O configuration.

Assigning variables

Open a window for selecting a suitable process object (PDO) via the context menu of a variable of the
integrated project “PLC_example” and via “Modify Link...” “Standard”:

Fig.47: Creating the links between PLC variables and process objects

In the window that opens, the process object for the variable “bEL1004_Ch4” of type BOOL can be selected
from the PLC configuration tree:

EL368156 Version: 2.6

Commissioning

Fig.48: Selecting PDO of type BOOL

According to the default setting, certain PDO objects are now available for selection. In this sample the input
of channel 4 of the EL1004 terminal is selected for linking. In contrast, the checkbox “All types” must be
ticked for creating the link for the output variables, in order to allocate a set of eight separate output bits to a
byte variable. The following diagram shows the whole process:

Fig.49: Selecting several PDOs simultaneously: activate “Continuous” and “All types”

Note that the “Continuous” checkbox was also activated. This is designed to allocate the bits contained in the
byte of the variable “nEL2008_value” sequentially to all eight selected output bits of the EL2008 terminal. In
this way it is possible to subsequently address all eight outputs of the terminal in the program with a byte

corresponding to bit 0 for channel 1 to bit 7 for channel 8 of the PLC. A special symbol ( ) at the yellow or
red object of the variable indicates that a link exists. The links can also be checked by selecting a “Goto Link
Variable” from the context menu of a variable. The object opposite, in this case the PDO, is automatically
selected:

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Commissioning

Fig.50: Application of a “Goto Link” variable, using “MAIN.bEL1004_Ch4” as a sample

The process of assigning variables to the PDO is completed via the menu selection “Actions” → “Generate

Mappings”, key Ctrl+M or by clicking on the symbol in the menu.

This can be visualized in the configuration:

The process of creating links can also take place in the opposite direction, i.e. starting with individual PDOs
to variable. However, in this example it would then not be possible to select all output bits for the EL2008,
since the terminal only makes individual digital outputs available. If a terminal has a byte, word, integer or
similar PDO, it is possible to allocate this a set of bit-standardized variables (type “BOOL”). Here, too, a
“Goto Link Variable” from the context menu of a PDO can be executed in the other direction, so that the
respective PLC instance can then be selected.

Activation of the configuration

The allocation of PDO to PLC variables has now established the connection from the controller to the inputs
and outputs of the terminals. The configuration can now be activated. First, the configuration can be verified

via (or via “Actions” → “Check Configuration”). If no error is present, the configuration can be

activated via (or via “Actions” → “Activate Configuration…”) to transfer the System Manager settings
to the runtime system. Confirm the messages “Old configurations are overwritten!” and “Restart TwinCAT
system in Run mode” with “OK”.

A few seconds later the real-time status is displayed at the bottom right in the System Manager.
The PLC system can then be started as described below.

Starting the controller

Starting from a remote system, the PLC control has to be linked with the Embedded PC over Ethernet via
“Online” → “Choose Run-Time System…”:

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Fig.51: Choose target system (remote)

In this sample “Runtime system 1 (port 801)” is selected and confirmed. Link the PLC with the real-time

system via menu option “Online” → “Login”, the F11 key or by clicking on the symbol .The control
program can then be loaded for execution. This results in the message “No program on the controller!
Should the new program be loaded?”, which should be acknowledged with “Yes”. The runtime environment
is ready for the program start:

EL3681 59Version: 2.6

Commissioning

Fig.52: PLC Control logged in, ready for program startup

The PLC can now be started via “Online” → “Run”, F5 key or .

5.1.2 TwinCAT 3

Startup

TwinCAT makes the development environment areas available together with Microsoft Visual Studio: after
startup, the project folder explorer appears on the left in the general window area (cf. “TwinCAT System
Manager” of TwinCAT2) for communication with the electromechanical components.

After successful installation of the TwinCAT system on the PC to be used for development, TwinCAT3
(shell) displays the following user interface after startup:

EL368160 Version: 2.6

Commissioning

Fig.53: Initial TwinCAT3 user interface

First create a new project via (or under “File”→“New”→ “Project…”). In the
following dialog make the corresponding entries as required (as shown in the diagram):

Fig.54: Create new TwinCAT project

The new project is then available in the project folder explorer:

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Commissioning

Fig.55: New TwinCAT3 project in the project folder explorer

Generally, TwinCAT can be used in local or remote mode. Once the TwinCAT system including the user
interface (standard) is installed on the respective PLC, TwinCAT can be used in local mode and thereby the

next step is “Insert Device [}63]”.

If the intention is to address the TwinCAT runtime environment installed on a PLC as development
environment remotely from another system, the target system must be made known first. Via the symbol in
the menu bar:

expand the pull-down menu:

and open the following window:

Fig.56: Selection dialog: Choose the target system

EL368162 Version: 2.6

Use “Search (Ethernet)...” to enter the target system. Thus a next dialog opens to either:

• enter the known computer name after “Enter Host Name / IP:” (as shown in red)

• perform a “Broadcast Search” (if the exact computer name is not known)

• enter the known computer IP or AmsNetID.

Commissioning

Fig.57: Specify the PLC for access by the TwinCAT System Manager: selection of the target system

Once the target system has been entered, it is available for selection as follows (a password may have to be
entered):

After confirmation with “OK” the target system can be accessed via the Visual Studio shell.

Adding devices

In the project folder explorer of the Visual Studio shell user interface on the left, select “Devices” within

element “I/O”, then right-click to open a context menu and select “Scan” or start the action via in the

menu bar. The TwinCAT System Manager may first have to be set to “Config mode” via or via the
menu “TwinCAT” → “Restart TwinCAT (Config mode)”.

Fig.58: Select “Scan”

Confirm the warning message, which follows, and select “EtherCAT” in the dialog:

EL3681 63Version: 2.6

Commissioning

Fig.59: Automatic detection of I/O devices: selection the devices to be integrated

Confirm the message “Find new boxes”, in order to determine the terminals connected to the devices. “Free
Run” enables manipulation of input and output values in “Config mode” and should also be acknowledged.

Based on the sample configuration [}48] described at the beginning of this section, the result is as follows:

Fig.60: Mapping of the configuration in VS shell of the TwinCAT3 environment

The whole process consists of two stages, which may be performed separately (first determine the devices,
then determine the connected elements such as boxes, terminals, etc.). A scan can also be initiated by
selecting “Device ...” from the context menu, which then reads the elements present in the configuration
below:

EL368164 Version: 2.6

Commissioning

Fig.61: Reading of individual terminals connected to a device

This functionality is useful if the actual configuration is modified at short notice.

Programming the PLC

TwinCAT PLC Control is the development environment for the creation of the controller in different program
environments: TwinCAT PLC Control supports all languages described in IEC 61131-3. There are two text­based languages and three graphical languages.

• Text-based languages

◦ Instruction List (IL)

◦ Structured Text (ST)

• Graphical languages

◦ Function Block Diagram (FBD)

◦ Ladder Diagram (LD)

◦ The Continuous Function Chart Editor (CFC)

◦ Sequential Function Chart (SFC)

The following section refers to Structured Text (ST).

In order to create a programming environment, a PLC subproject is added to the project sample via the
context menu of “PLC” in the project folder explorer by selecting “Add New Item….”:

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Fig.62: Adding the programming environment in “PLC”

In the dialog that opens select “Standard PLC project” and enter “PLC_example” as project name, for
example, and select a corresponding directory:

Fig.63: Specifying the name and directory for the PLC programming environment

The “Main” program, which already exists by selecting “Standard PLC project”, can be opened by double­clicking on “PLC_example_project” in “POUs”. The following user interface is shown for an initial project:

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Fig.64: Initial “Main” program of the standard PLC project

To continue, sample variables and a sample program have now been created:

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Fig.65: Sample program with variables after a compile process (without variable integration)

The control program is now created as a project folder, followed by the compile process:

Fig.66: Start program compilation

The following variables, identified in the ST/ PLC program with “AT%”, are then available in under
“Assignments” in the project folder explorer:

Assigning variables

Via the menu of an instance - variables in the “PLC” context, use the “Modify Link…” option to open a
window for selecting a suitable process object (PDO) for linking:

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Fig.67: Creating the links between PLC variables and process objects

In the window that opens, the process object for the variable “bEL1004_Ch4” of type BOOL can be selected
from the PLC configuration tree:

Fig.68: Selecting PDO of type BOOL

According to the default setting, certain PDO objects are now available for selection. In this sample the input
of channel 4 of the EL1004 terminal is selected for linking. In contrast, the checkbox “All types” must be
ticked for creating the link for the output variables, in order to allocate a set of eight separate output bits to a
byte variable. The following diagram shows the whole process:

EL3681 69Version: 2.6

Commissioning

Fig.69: Selecting several PDOs simultaneously: activate “Continuous” and “All types”

Note that the “Continuous” checkbox was also activated. This is designed to allocate the bits contained in the
byte of the variable “nEL2008_value” sequentially to all eight selected output bits of the EL2008 terminal. In
this way it is possible to subsequently address all eight outputs of the terminal in the program with a byte

corresponding to bit 0 for channel 1 to bit 7 for channel 8 of the PLC. A special symbol ( ) at the yellow or
red object of the variable indicates that a link exists. The links can also be checked by selecting a “Goto Link
Variable” from the context menu of a variable. The object opposite, in this case the PDO, is automatically
selected:

Fig.70: Application of a “Goto Link” variable, using “MAIN.bEL1004_Ch4” as a sample

The process of creating links can also take place in the opposite direction, i.e. starting with individual PDOs
to variable. However, in this example it would then not be possible to select all output bits for the EL2008,
since the terminal only makes individual digital outputs available. If a terminal has a byte, word, integer or

EL368170 Version: 2.6

Commissioning

similar PDO, it is possible to allocate this a set of bit-standardized variables (type “BOOL”). Here, too, a
“Goto Link Variable” from the context menu of a PDO can be executed in the other direction, so that the
respective PLC instance can then be selected.

Note on the type of variable assignment

The following type of variable assignment can only be used from TwinCAT version V3.1.4024.4 on­wards and is only available for terminals with a microcontroller.

In TwinCAT it is possible to create a structure from the mapped process data of a terminal. An instance of
this structure can then be created in the PLC, so it is possible to access the process data directly from the
PLC without having to declare own variables.

The procedure for the EL3001 1-channel analog input terminal -10...+10V is shown as an example.

1. First the required process data must be selected in the “Process data” tab in TwinCAT.

2. After that, the PLC data type must be generated in the tab “PLC” via the check box.

3. The data type in the “Data Type” field can then be copied using the “Copy” button.

Fig.71: Creating a PLC data type

4. An instance of the data structure of the copied data type must then be created in the PLC.

Fig.72: Instance_of_struct

5. Then the project folder must be created. This can be done either via the key combination “CTRL +
Shift + B” or via the “Build” tab in TwinCAT.

6. The structure in the “PLC” tab of the terminal must then be linked to the created instance.

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Commissioning

Fig.73: Linking the structure

7. In the PLC the process data can then be read or written via the structure in the program code.

Fig.74: Reading a variable from the structure of the process data

Activation of the configuration

The allocation of PDO to PLC variables has now established the connection from the controller to the inputs

and outputs of the terminals. The configuration can now be activated with or via the menu under
“TwinCAT” in order to transfer settings of the development environment to the runtime system. Confirm the
messages “Old configurations are overwritten!” and “Restart TwinCAT system in Run mode” with “OK”. The
corresponding assignments can be seen in the project folder explorer:

A few seconds later the corresponding status of the Run mode is displayed in the form of a rotating symbol

at the bottom right of the VS shell development environment. The PLC system can then be started as

described below.

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Commissioning

Starting the controller

Select the menu option “PLC” → “Login” or click on to link the PLC with the real-time system and load
the control program for execution. This results in the message No program on the controller! Should the new
program be loaded?, which should be acknowledged with “Yes”. The runtime environment is ready for

program start by click on symbol , the “F5” key or via “PLC” in the menu selecting “Start”. The started
programming environment shows the runtime values of individual variables:

Fig.75: TwinCAT development environment (VS shell): logged-in, after program startup

The two operator control elements for stopping and logout result in the required action
(accordingly also for stop “Shift + F5”, or both actions can be selected via the PLC menu).

5.2 TwinCAT Development Environment

The Software for automation TwinCAT (The Windows Control and Automation Technology) will be
distinguished into:

• TwinCAT2: System Manager (Configuration) & PLC Control (Programming)

• TwinCAT3: Enhancement of TwinCAT2 (Programming and Configuration takes place via a common
Development Environment)

Details:

• TwinCAT2:

◦ Connects I/O devices to tasks in a variable-oriented manner

◦ Connects tasks to tasks in a variable-oriented manner

◦ Supports units at the bit level

◦ Supports synchronous or asynchronous relationships

◦ Exchange of consistent data areas and process images

◦ Datalink on NT - Programs by open Microsoft Standards (OLE, OCX, ActiveX, DCOM+, etc.)

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◦ Integration of IEC 61131-3-Software-SPS, Software- NC and Software-CNC within Windows

NT/2000/XP/Vista, Windows 7, NT/XP Embedded, CE

◦ Interconnection to all common fieldbusses

◦ More…

Additional features:

• TwinCAT3 (eXtended Automation):

◦ Visual-Studio®-Integration

◦ Choice of the programming language

◦ Supports object orientated extension of IEC 61131-3

◦ Usage of C/C++ as programming language for real time applications

◦ Connection to MATLAB®/Simulink®

◦ Open interface for expandability

◦ Flexible run-time environment

◦ Active support of Multi-Core- und 64-Bit-Operatingsystem

◦ Automatic code generation and project creation with the TwinCAT Automation Interface

◦ More…

Within the following sections commissioning of the TwinCAT Development Environment on a PC System for
the control and also the basically functions of unique control elements will be explained.

Please see further information to TwinCAT2 and TwinCAT3 at http://infosys.beckhoff.com.

5.2.1 Installation of the TwinCAT real-time driver

In order to assign real-time capability to a standard Ethernet port of an IPC controller, the Beckhoff real-time
driver has to be installed on this port under Windows.

This can be done in several ways. One option is described here.

In the System Manager call up the TwinCAT overview of the local network interfaces via Options → Show
Real Time Ethernet Compatible Devices.

Fig.76: System Manager “Options” (TwinCAT2)

This have to be called up by the Menü “TwinCAT” within the TwinCAT3 environment:

Fig.77: Call up under VS Shell (TwinCAT3)

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Commissioning

The following dialog appears:

Fig.78: Overview of network interfaces

Interfaces listed under “Compatible devices” can be assigned a driver via the “Install” button. A driver should
only be installed on compatible devices.

A Windows warning regarding the unsigned driver can be ignored.

Alternatively an EtherCAT-device can be inserted first of all as described in chapter Offline configuration
creation, section “Creating the EtherCAT device” [}84] in order to view the compatible ethernet ports via its

EtherCAT properties (tab “Adapter”, button “Compatible Devices…”):

Fig.79: EtherCAT device properties(TwinCAT2): click on “Compatible Devices…” of tab “Adapte””

TwinCAT 3: the properties of the EtherCAT device can be opened by double click on “Device .. (EtherCAT)”
within the Solution Explorer under “I/O”:

After the installation the driver appears activated in the Windows overview for the network interface
(Windows Start → System Properties → Network)

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Fig.80: Windows properties of the network interface

A correct setting of the driver could be:

Fig.81: Exemplary correct driver setting for the Ethernet port

Other possible settings have to be avoided:

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Fig.82: Incorrect driver settings for the Ethernet port

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IP address of the port used

IP address/DHCP

In most cases an Ethernet port that is configured as an EtherCAT device will not transport general
IP packets. For this reason and in cases where an EL6601 or similar devices are used it is useful to
specify a fixed IP address for this port via the “Internet Protocol TCP/IP” driver setting and to disable
DHCP. In this way the delay associated with the DHCP client for the Ethernet port assigning itself a
default IP address in the absence of a DHCP server is avoided. A suitable address space is

192.168.x.x, for example.

Fig.83: TCP/IP setting for the Ethernet port

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5.2.2 Notes regarding ESI device description

Installation of the latest ESI device description

The TwinCAT EtherCAT master/System Manager needs the device description files for the devices to be
used in order to generate the configuration in online or offline mode. The device descriptions are contained
in the so-called ESI files (EtherCAT Slave Information) in XML format. These files can be requested from the
respective manufacturer and are made available for download. An *.xml file may contain several device
descriptions.

The ESI files for Beckhoff EtherCAT devices are available on the Beckhoff website.

The ESI files should be stored in the TwinCAT installation directory.

Default settings:

• TwinCAT2: C:\TwinCAT\IO\EtherCAT

• TwinCAT3: C:\TwinCAT\3.1\Config\Io\EtherCAT

The files are read (once) when a new System Manager window is opened, if they have changed since the
last time the System Manager window was opened.

A TwinCAT installation includes the set of Beckhoff ESI files that was current at the time when the TwinCAT
build was created.

For TwinCAT2.11/TwinCAT3 and higher, the ESI directory can be updated from the System Manager, if the
programming PC is connected to the Internet; by

• TwinCAT2: Option → “Update EtherCAT Device Descriptions”

• TwinCAT3: TwinCAT → EtherCAT Devices → “Update Device Descriptions (via ETG Website)…”

The TwinCAT ESI Updater [}83] is available for this purpose.

ESI

The *.xml files are associated with *.xsd files, which describe the structure of the ESI XML files. To
update the ESI device descriptions, both file types should therefore be updated.

Device differentiation

EtherCAT devices/slaves are distinguished by four properties, which determine the full device identifier. For
example, the device identifier EL2521-0025-1018 consists of:

• family key “EL”

• name “2521”

• type “0025”

• and revision “1018”

Fig.84: Identifier structure

The order identifier consisting of name + type (here: EL2521-0010) describes the device function. The
revision indicates the technical progress and is managed by Beckhoff. In principle, a device with a higher
revision can replace a device with a lower revision, unless specified otherwise, e.g. in the documentation.

Each revision has its own ESI description. See further notes [}10].

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Online description

If the EtherCAT configuration is created online through scanning of real devices (see section Online setup)
and no ESI descriptions are available for a slave (specified by name and revision) that was found, the
System Manager asks whether the description stored in the device should be used. In any case, the System
Manager needs this information for setting up the cyclic and acyclic communication with the slave correctly.

Fig.85: OnlineDescription information window (TwinCAT2)

In TwinCAT3 a similar window appears, which also offers the Web update:

Fig.86: Information window OnlineDescription (TwinCAT3)

If possible, the Yes is to be rejected and the required ESI is to be requested from the device manufacturer.
After installation of the XML/XSD file the configuration process should be repeated.

NOTE

Changing the “usual” configuration through a scan

ü If a scan discovers a device that is not yet known to TwinCAT, distinction has to be made between two

cases. Taking the example here of the EL2521-0000 in the revision 1019

a) no ESI is present for the EL2521-0000 device at all, either for the revision 1019 or for an older revision.

The ESI must then be requested from the manufacturer (in this case Beckhoff).

b) an ESI is present for the EL2521-0000 device, but only in an older revision, e.g. 1018 or 1017.

In this case an in-house check should first be performed to determine whether the spare parts stock al­lows the integration of the increased revision into the configuration at all. A new/higher revision usually
also brings along new features. If these are not to be used, work can continue without reservations with
the previous revision 1018 in the configuration. This is also stated by the Beckhoff compatibility rule.

Refer in particular to the chapter “General notes on the use of Beckhoff EtherCAT IO components” and for
manual configuration to the chapter “Offline configuration creation [}84]”.

If the OnlineDescription is used regardless, the System Manager reads a copy of the device description from
the EEPROM in the EtherCAT slave. In complex slaves the size of the EEPROM may not be sufficient for the
complete ESI, in which case the ESI would be incomplete in the configurator. Therefore it’s recommended
using an offline ESI file with priority in such a case.

The System Manager creates for online recorded device descriptions a new file
“OnlineDescription0000...xml” in its ESI directory, which contains all ESI descriptions that were read online.

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Fig.87: File OnlineDescription.xml created by the System Manager

Is a slave desired to be added manually to the configuration at a later stage, online created slaves are
indicated by a prepended symbol “>” in the selection list (see Figure Indication of an online recorded ESI of
EL2521 as an example).

Fig.88: Indication of an online recorded ESI of EL2521 as an example

If such ESI files are used and the manufacturer's files become available later, the file OnlineDescription.xml
should be deleted as follows:

• close all System Manager windows

• restart TwinCAT in Config mode

• delete “OnlineDescription0000...xml”

• restart TwinCAT System Manager

This file should not be visible after this procedure, if necessary press <F5> to update

OnlineDescription for TwinCAT3.x

In addition to the file described above “OnlineDescription0000...xml”, a so called EtherCAT cache
with new discovered devices is created by TwinCAT3.x, e.g. under Windows 7:

(Please note the language settings of the OS!)
You have to delete this file, too.

Faulty ESI file

If an ESI file is faulty and the System Manager is unable to read it, the System Manager brings up an
information window.

Fig.89: Information window for faulty ESI file (left: TwinCAT2; right: TwinCAT3)

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Reasons may include:

• Structure of the *.xml does not correspond to the associated *.xsd file → check your schematics

• Contents cannot be translated into a device description → contact the file manufacturer

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5.2.3 TwinCAT ESI Updater

For TwinCAT2.11 and higher, the System Manager can search for current Beckhoff ESI files automatically, if
an online connection is available:

Fig.90: Using the ESI Updater (>= TwinCAT2.11)

The call up takes place under:
“Options” → “Update EtherCAT Device Descriptions”

Selection under TwinCAT3:

Fig.91: Using the ESI Updater (TwinCAT3)

The ESI Updater (TwinCAT3) is a convenient option for automatic downloading of ESI data provided by
EtherCAT manufacturers via the Internet into the TwinCAT directory (ESI = EtherCAT slave information).
TwinCAT accesses the central ESI ULR directory list stored at ETG; the entries can then be viewed in the
Updater dialog, although they cannot be changed there.

The call up takes place under:
“TwinCAT” → “EtherCAT Devices” → “Update Device Description (via ETG Website)…”.

5.2.4 Distinction between Online and Offline

The distinction between online and offline refers to the presence of the actual I/O environment (drives,
terminals, EJ-modules). If the configuration is to be prepared in advance of the system configuration as a
programming system, e.g. on a laptop, this is only possible in “Offline configuration” mode. In this case all
components have to be entered manually in the configuration, e.g. based on the electrical design.

If the designed control system is already connected to the EtherCAT system and all components are
energised and the infrastructure is ready for operation, the TwinCAT configuration can simply be generated
through “scanning” from the runtime system. This is referred to as online configuration.

In any case, during each startup the EtherCAT master checks whether the slaves it finds match the
configuration. This test can be parameterised in the extended slave settings. Refer to note “Installation of
the latest ESI-XML device description” [}79].

For preparation of a configuration:

• the real EtherCAT hardware (devices, couplers, drives) must be present and installed

• the devices/modules must be connected via EtherCAT cables or in the terminal/ module strand in the
same way as they are intended to be used later

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• the devices/modules be connected to the power supply and ready for communication

• TwinCAT must be in CONFIG mode on the target system.

The online scan process consists of:

• detecting the EtherCAT device [}89] (Ethernet port at the IPC)

• detecting the connected EtherCAT devices [}90]. This step can be carried out independent of the
preceding step

• troubleshooting [}93]

The scan with existing configuration [}94] can also be carried out for comparison.

5.2.5 OFFLINE configuration creation

Creating the EtherCAT device

Create an EtherCAT device in an empty System Manager window.

Fig.92: Append EtherCAT device (left: TwinCAT2; right: TwinCAT3)

Select type “EtherCAT” for an EtherCAT I/O application with EtherCAT slaves. For the present publisher/
subscriber service in combination with an EL6601/EL6614 terminal select “EtherCAT Automation Protocol
via EL6601”.

Fig.93: Selecting the EtherCAT connection (TwinCAT2.11, TwinCAT3)

Then assign a real Ethernet port to this virtual device in the runtime system.

Fig.94: Selecting the Ethernet port

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This query may appear automatically when the EtherCAT device is created, or the assignment can be set/
modified later in the properties dialog; see Fig. “EtherCAT device properties (TwinCAT2)”.

Fig.95: EtherCAT device properties (TwinCAT2)

TwinCAT 3: the properties of the EtherCAT device can be opened by double click on “Device .. (EtherCAT)”
within the Solution Explorer under “I/O”:

Selecting the Ethernet port

Ethernet ports can only be selected for EtherCAT devices for which the TwinCAT real-time driver is
installed. This has to be done separately for each port. Please refer to the respective installation
page [}74].

Defining EtherCAT slaves

Further devices can be appended by right-clicking on a device in the configuration tree.

Fig.96: Appending EtherCAT devices (left: TwinCAT2; right: TwinCAT3)

The dialog for selecting a new device opens. Only devices for which ESI files are available are displayed.

Only devices are offered for selection that can be appended to the previously selected device. Therefore the
physical layer available for this port is also displayed (Fig. “Selection dialog for new EtherCAT device”, A). In
the case of cable-based Fast-Ethernet physical layer with PHY transfer, then also only cable-based devices
are available, as shown in Fig. “Selection dialog for new EtherCAT device”. If the preceding device has
several free ports (e.g. EK1122 or EK1100), the required port can be selected on the right-hand side (A).

Overview of physical layer

• “Ethernet”: cable-based 100BASE-TX: EK couplers, EP boxes, devices with RJ45/M8/M12 connector

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• “E-Bus”: LVDS “terminal bus”, “EJ-module”: EL/ES terminals, various modular modules

The search field facilitates finding specific devices (since TwinCAT2.11 or TwinCAT3).

Fig.97: Selection dialog for new EtherCAT device

By default only the name/device type is used as selection criterion. For selecting a specific revision of the
device the revision can be displayed as “Extended Information”.

Fig.98: Display of device revision

In many cases several device revisions were created for historic or functional reasons, e.g. through
technological advancement. For simplification purposes (see Fig. “Selection dialog for new EtherCAT
device”) only the last (i.e. highest) revision and therefore the latest state of production is displayed in the
selection dialog for Beckhoff devices. To show all device revisions available in the system as ESI
descriptions tick the “Show Hidden Devices” check box, see Fig. “Display of previous revisions”.

EL368186 Version: 2.6

Fig.99: Display of previous revisions

Device selection based on revision, compatibility

The ESI description also defines the process image, the communication type between master and
slave/device and the device functions, if applicable. The physical device (firmware, if available) has
to support the communication queries/settings of the master. This is backward compatible, i.e.
newer devices (higher revision) should be supported if the EtherCAT master addresses them as an
older revision. The following compatibility rule of thumb is to be assumed for Beckhoff EtherCAT
Terminals/ Boxes/ EJ-modules:

device revision in the system >= device revision in the configuration

This also enables subsequent replacement of devices without changing the configuration (different
specifications are possible for drives).

Commissioning

Example

If an EL2521-0025-1018 is specified in the configuration, an EL2521-0025-1018 or higher (-1019, -1020) can
be used in practice.

Fig.100: Name/revision of the terminal

If current ESI descriptions are available in the TwinCAT system, the last revision offered in the selection
dialog matches the Beckhoff state of production. It is recommended to use the last device revision when
creating a new configuration, if current Beckhoff devices are used in the real application. Older revisions
should only be used if older devices from stock are to be used in the application.

In this case the process image of the device is shown in the configuration tree and can be parameterized as
follows: linking with the task, CoE/DC settings, plug-in definition, startup settings, ...

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Fig.101: EtherCAT terminal in the TwinCAT tree (left: TwinCAT2; right: TwinCAT3)

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5.2.6 ONLINE configuration creation

Detecting/scanning of the EtherCAT device

The online device search can be used if the TwinCAT system is in CONFIG mode. This can be indicated by
a symbol right below in the information bar:

• on TwinCAT2 by a blue display “Config Mode” within the System Manager window: .

• on TwinCAT3 within the user interface of the development environment by a symbol .

TwinCAT can be set into this mode:

• TwinCAT2: by selection of in the Menubar or by “Actions” → “Set/Reset TwinCATtoConfig
Mode…”

• TwinCAT3: by selection of in the Menubar or by “TwinCAT” → “RestartTwinCAT(ConfigMode)”

Online scanning in Config mode

The online search is not available in RUN mode (production operation). Note the differentiation be­tween TwinCAT programming system and TwinCAT target system.

The TwinCAT2 icon ( ) or TwinCAT3 icon ( ) within the Windows-Taskbar always shows the
TwinCAT mode of the local IPC. Compared to that, the System Manager window of TwinCAT2 or the user
interface of TwinCAT3 indicates the state of the target system.

Fig.102: Differentiation local/target system (left: TwinCAT2; right: TwinCAT3)

Right-clicking on “I/O Devices” in the configuration tree opens the search dialog.

Fig.103: Scan Devices (left: TwinCAT2; right: TwinCAT3)

This scan mode attempts to find not only EtherCAT devices (or Ethernet ports that are usable as such), but
also NOVRAM, fieldbus cards, SMB etc. However, not all devices can be found automatically.

Fig.104: Note for automatic device scan (left: TwinCAT2; right: TwinCAT3)

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Ethernet ports with installed TwinCAT real-time driver are shown as “RT Ethernet” devices. An EtherCAT
frame is sent to these ports for testing purposes. If the scan agent detects from the response that an
EtherCAT slave is connected, the port is immediately shown as an “EtherCAT Device” .

Fig.105: Detected Ethernet devices

Via respective checkboxes devices can be selected (as illustrated in Fig. “Detected Ethernet devices” e.g.
Device 3 and Device 4 were chosen). After confirmation with “OK” a device scan is suggested for all selected
devices, see Fig.: “Scan query after automatic creation of an EtherCAT device”.

Selecting the Ethernet port

Ethernet ports can only be selected for EtherCAT devices for which the TwinCAT real-time driver is
installed. This has to be done separately for each port. Please refer to the respective installation
page [}74].

Detecting/Scanning the EtherCAT devices

Online scan functionality

During a scan the master queries the identity information of the EtherCAT slaves from the slave
EEPROM. The name and revision are used for determining the type. The respective devices are lo­cated in the stored ESI data and integrated in the configuration tree in the default state defined
there.

Fig.106: Example default state

NOTE

Slave scanning in practice in series machine production

The scanning function should be used with care. It is a practical and fast tool for creating an initial configu­ration as a basis for commissioning. In series machine production or reproduction of the plant, however, the

function should no longer be used for the creation of the configuration, but if necessary for comparison
[}94] with the defined initial configuration.Background: since Beckhoff occasionally increases the revision

version of the delivered products for product maintenance reasons, a configuration can be created by such
a scan which (with an identical machine construction) is identical according to the device list; however, the
respective device revision may differ from the initial configuration.

Example:

Company A builds the prototype of a machine B, which is to be produced in series later on. To do this the
prototype is built, a scan of the IO devices is performed in TwinCAT and the initial configuration “B.tsm” is
created. The EL2521-0025 EtherCAT terminal with the revision 1018 is located somewhere. It is thus built
into the TwinCAT configuration in this way:

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Fig.107: Installing EthetCAT terminal with revision -1018

Likewise, during the prototype test phase, the functions and properties of this terminal are tested by the
programmers/commissioning engineers and used if necessary, i.e. addressed from the PLC “B.pro” or the
NC. (the same applies correspondingly to the TwinCAT3 solution files).

The prototype development is now completed and series production of machine B starts, for which Beckhoff
continues to supply the EL2521-0025-0018. If the commissioning engineers of the series machine production
department always carry out a scan, a B configuration with the identical contents results again for each
machine. Likewise, A might create spare parts stores worldwide for the coming series-produced machines
with EL2521-0025-1018 terminals.

After some time Beckhoff extends the EL2521-0025 by a new feature C. Therefore the FW is changed,
outwardly recognizable by a higher FW version and a new revision -1019. Nevertheless the new device
naturally supports functions and interfaces of the predecessor version(s); an adaptation of “B.tsm” or even
“B.pro” is therefore unnecessary. The series-produced machines can continue to be built with “B.tsm” and

“B.pro”; it makes sense to perform a comparative scan [}94] against the initial configuration “B.tsm” in order
to check the built machine.

However, if the series machine production department now doesn’t use “B.tsm”, but instead carries out a
scan to create the productive configuration, the revision -1019 is automatically detected and built into the
configuration:

Fig.108: Detection of EtherCAT terminal with revision -1019

This is usually not noticed by the commissioning engineers. TwinCAT cannot signal anything either, since
virtually a new configuration is created. According to the compatibility rule, however, this means that no
EL2521-0025-1018 should be built into this machine as a spare part (even if this nevertheless works in the
vast majority of cases).

In addition, it could be the case that, due to the development accompanying production in company A, the
new feature C of the EL2521-0025-1019 (for example, an improved analog filter or an additional process
data for the diagnosis) is discovered and used without in-house consultation. The previous stock of spare
part devices are then no longer to be used for the new configuration “B2.tsm” created in this way. Þ if series
machine production is established, the scan should only be performed for informative purposes for
comparison with a defined initial configuration. Changes are to be made with care!

If an EtherCAT device was created in the configuration (manually or through a scan), the I/O field can be
scanned for devices/slaves.

Fig.109: Scan query after automatic creation of an EtherCAT device (left: TwinCAT2; right: TwinCAT3)

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Fig.110: Manual triggering of a device scan on a specified EtherCAT device (left: TwinCAT2; right:
TwinCAT3)

In the System Manager (TwinCAT2) or the User Interface (TwinCAT3) the scan process can be monitored
via the progress bar at the bottom in the status bar.

Fig.111: Scan progressexemplary by TwinCAT2

The configuration is established and can then be switched to online state (OPERATIONAL).

Fig.112: Config/FreeRun query (left: TwinCAT2; right: TwinCAT3)

In Config/FreeRun mode the System Manager display alternates between blue and red, and the EtherCAT
device continues to operate with the idling cycle time of 4ms (default setting), even without active task (NC,
PLC).

Fig.113: Displaying of “Free Run” and “Config Mode” toggling right below in the status bar

Fig.114: TwinCAT can also be switched to this state by using a button (left: TwinCAT2; right: TwinCAT3)

The EtherCAT system should then be in a functional cyclic state, as shown in Fig. Online display example.

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Fig.115: Online display example

Please note:

• all slaves should be in OP state

• the EtherCAT master should be in “Actual State” OP

• “frames/sec” should match the cycle time taking into account the sent number of frames

• no excessive “LostFrames” or CRC errors should occur

The configuration is now complete. It can be modified as described under manual procedure [}84].

Troubleshooting

Various effects may occur during scanning.

• An unknown device is detected, i.e. an EtherCAT slave for which no ESI XML description is available.
In this case the System Manager offers to read any ESI that may be stored in the device. This case is
described in the chapter “Notes regarding ESI device description”.

• Device are not detected properly
Possible reasons include:

◦ faulty data links, resulting in data loss during the scan

◦ slave has invalid device description

The connections and devices should be checked in a targeted manner, e.g. via the emergency
scan.
Then re-run the scan.

Fig.116: Faulty identification

In the System Manager such devices may be set up as EK0000 or unknown devices. Operation is not
possible or meaningful.

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Scan over existing Configuration

NOTE

Change of the configuration after comparison

With this scan (TwinCAT2.11 or 3.1) only the device properties vendor (manufacturer), device name and
revision are compared at present! A “ChangeTo” or “Copy” should only be carried out with care, taking into
consideration the Beckhoff IO compatibility rule (see above). The device configuration is then replaced by
the revision found; this can affect the supported process data and functions.

If a scan is initiated for an existing configuration, the actual I/O environment may match the configuration
exactly or it may differ. This enables the configuration to be compared.

Fig.117: Identical configuration (left: TwinCAT2; right: TwinCAT3)

If differences are detected, they are shown in the correction dialog, so that the user can modify the
configuration as required.

Fig.118: Correction dialog

It is advisable to tick the “Extended Information” check box to reveal differences in the revision.

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Color Explanation

green This EtherCAT slave matches the entry on the other side. Both type and revision match.

blue This EtherCAT slave is present on the other side, but in a different revision. This other revision can

have other default values for the process data as well as other/additional functions.
If the found revision is higher than the configured revision, the slave may be used provided
compatibility issues are taken into account.

If the found revision is lower than the configured revision, it is likely that the slave cannot be used.
The found device may not support all functions that the master expects based on the higher
revision number.

light
blue

red • This EtherCAT slave is not present on the other side.

This EtherCAT slave is ignored (“Ignore” button)

• It is present, but in a different revision, which also differs in its properties from the one specified.
The compatibility principle then also applies here: if the found revision is higher than the
configured revision, use is possible provided compatibility issues are taken into account, since
the successor devices should support the functions of the predecessor devices.
If the found revision is lower than the configured revision, it is likely that the slave cannot be
used. The found device may not support all functions that the master expects based on the
higher revision number.

Device selection based on revision, compatibility

The ESI description also defines the process image, the communication type between master and
slave/device and the device functions, if applicable. The physical device (firmware, if available) has
to support the communication queries/settings of the master. This is backward compatible, i.e.
newer devices (higher revision) should be supported if the EtherCAT master addresses them as an
older revision. The following compatibility rule of thumb is to be assumed for Beckhoff EtherCAT
Terminals/ Boxes/ EJ-modules:

device revision in the system >= device revision in the configuration

This also enables subsequent replacement of devices without changing the configuration (different
specifications are possible for drives).

Example

If an EL2521-0025-1018 is specified in the configuration, an EL2521-0025-1018 or higher (-1019, -1020) can
be used in practice.

Fig.119: Name/revision of the terminal

If current ESI descriptions are available in the TwinCAT system, the last revision offered in the selection
dialog matches the Beckhoff state of production. It is recommended to use the last device revision when
creating a new configuration, if current Beckhoff devices are used in the real application. Older revisions
should only be used if older devices from stock are to be used in the application.

In this case the process image of the device is shown in the configuration tree and can be parameterized as
follows: linking with the task, CoE/DC settings, plug-in definition, startup settings, ...

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Fig.120: Correction dialog with modifications

Once all modifications have been saved or accepted, click “OK” to transfer them to the real *.tsm
configuration.

Change to Compatible Type

TwinCAT offers a function Change to Compatible Type… for the exchange of a device whilst retaining the
links in the task.

Fig.121: Dialog “Change to Compatible Type…” (left: TwinCAT2; right: TwinCAT3)

This function is preferably to be used on AX5000 devices.

Change to Alternative Type

The TwinCAT System Manager offers a function for the exchange of a device: Change to Alternative Type

Fig.122: TwinCAT2 Dialog Change to Alternative Type

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If called, the System Manager searches in the procured device ESI (in this example: EL1202-0000) for
details of compatible devices contained there. The configuration is changed and the ESI-EEPROM is
overwritten at the same time – therefore this process is possible only in the online state (ConfigMode).

5.2.7 EtherCAT subscriber configuration

In the left-hand window of the TwinCAT2 System Manager or the Solution Explorer of the TwinCAT3
Development Environment respectively, click on the element of the terminal within the tree you wish to
configure (in the example: EL3751 Terminal 3).

Fig.123: Branch element as terminal EL3751

In the right-hand window of the TwinCAT System Manager (TwinCAT2) or the Development Environment
(TwinCAT3), various tabs are now available for configuring the terminal. And yet the dimension of
complexity of a subscriber determines which tabs are provided. Thus as illustrated in the example above the
terminal EL3751 provides many setup options and also a respective number of tabs are available. On the
contrary by the terminal EL1004 for example the tabs “General”, “EtherCAT”, “Process Data” and “Online“
are available only. Several terminals, as for instance the EL6695 provide special functions by a tab with its
own terminal name, so “EL6695” in this case. A specific tab “Settings” by terminals with a wide range of
setup options will be provided also (e.g. EL3751).

“General” tab

Fig.124: “General” tab

Name Name of the EtherCAT device
Id Number of the EtherCAT device
Type EtherCAT device type
Comment Here you can add a comment (e.g. regarding the system).
Disabled Here you can deactivate the EtherCAT device.
Create symbols Access to this EtherCAT slave via ADS is only available if this control box is

activated.

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“EtherCAT” tab

Fig.125: “EtherCAT” tab

Type EtherCAT device type
Product/Revision Product and revision number of the EtherCAT device
Auto Inc Addr. Auto increment address of the EtherCAT device. The auto increment address can

be used for addressing each EtherCAT device in the communication ring through
its physical position. Auto increment addressing is used during the start-up phase
when the EtherCAT master allocates addresses to the EtherCAT devices. With
auto increment addressing the first EtherCAT slave in the ring has the address
0000

. For each further slave the address is decremented by 1 (FFFF

hex

, FFFE

hex

etc.).

EtherCAT Addr. Fixed address of an EtherCAT slave. This address is allocated by the EtherCAT

master during the start-up phase. Tick the control box to the left of the input field in
order to modify the default value.

Previous Port Name and port of the EtherCAT device to which this device is connected. If it is

possible to connect this device with another one without changing the order of the
EtherCAT devices in the communication ring, then this combination field is
activated and the EtherCAT device to which this device is to be connected can be
selected.

Advanced Settings This button opens the dialogs for advanced settings.

hex

The link at the bottom of the tab points to the product page for this EtherCAT device on the web.

“Process Data” tab

Indicates the configuration of the process data. The input and output data of the EtherCAT slave are
represented as CANopen process data objects (Process Data Objects, PDOs). The user can select a PDO
via PDO assignment and modify the content of the individual PDO via this dialog, if the EtherCAT slave
supports this function.

EL368198 Version: 2.6

Fig.126: “Process Data” tab

Commissioning

The process data (PDOs) transferred by an EtherCAT slave during each cycle are user data which the
application expects to be updated cyclically or which are sent to the slave. To this end the EtherCAT master
(Beckhoff TwinCAT) parameterizes each EtherCAT slave during the start-up phase to define which process
data (size in bits/bytes, source location, transmission type) it wants to transfer to or from this slave. Incorrect
configuration can prevent successful start-up of the slave.

For Beckhoff EtherCAT EL, ES, EM, EJ and EP slaves the following applies in general:

• The input/output process data supported by the device are defined by the manufacturer in the ESI/XML
description. The TwinCAT EtherCAT Master uses the ESI description to configure the slave correctly.

• The process data can be modified in the System Manager. See the device documentation.
Examples of modifications include: mask out a channel, displaying additional cyclic information, 16-bit
display instead of 8-bit data size, etc.

• In so-called “intelligent” EtherCAT devices the process data information is also stored in the CoE
directory. Any changes in the CoE directory that lead to different PDO settings prevent successful
startup of the slave. It is not advisable to deviate from the designated process data, because the
device firmware (if available) is adapted to these PDO combinations.

If the device documentation allows modification of process data, proceed as follows (see Figure Configuring
the process data).

• A: select the device to configure

• B: in the “Process Data” tab select Input or Output under SyncManager (C)

• D: the PDOs can be selected or deselected

• H: the new process data are visible as linkable variables in the System Manager
The new process data are active once the configuration has been activated and TwinCAT has been
restarted (or the EtherCAT master has been restarted)

• E: if a slave supports this, Input and Output PDO can be modified simultaneously by selecting a so­called PDO record (“predefined PDO settings”).

EL3681 99Version: 2.6

Commissioning

Fig.127: Configuring the process data

Manual modification of the process data

According to the ESI description, a PDO can be identified as “fixed” with the flag “F” in the PDO
overview (Fig. Configuring the process data, J). The configuration of such PDOs cannot be
changed, even if TwinCAT offers the associated dialog (“Edit”). In particular, CoE content cannot be
displayed as cyclic process data. This generally also applies in cases where a device supports
download of the PDO configuration, “G”. In case of incorrect configuration the EtherCAT slave usu­ally refuses to start and change to OP state. The System Manager displays an “invalid SM cfg” log­ger message: This error message (“invalid SM IN cfg” or “invalid SM OUT cfg”) also indicates the
reason for the failed start.

A detailed description [}105] can be found at the end of this section.

“Startup” tab

The Startup tab is displayed if the EtherCAT slave has a mailbox and supports the CANopen over EtherCAT
(CoE) or Servo drive over EtherCAT protocol. This tab indicates which download requests are sent to the
mailbox during startup. It is also possible to add new mailbox requests to the list display. The download
requests are sent to the slave in the same order as they are shown in the list.

EL3681100 Version: 2.6