Beckhoff EL3681 Operator's manual

Documentation | EN
EL3681
Digital Multimeter Terminal
2023-12-14 | Version: 3.0

Table of contents
EL3681 3Version: 3.0
Table of contents
1 Foreword....................................................................................................................................................7
1.1 Notes on the documentation .............................................................................................................7
1.2 Guide through documentation...........................................................................................................8
1.3 Safety instructions.............................................................................................................................9
1.4 Documentation issue status ............................................................................................................10
1.5 Version identification of EtherCAT devices .....................................................................................11
1.5.1 General notes on marking................................................................................................11
1.5.2 Version identification of EL terminals ............................................................................... 12
1.5.3 Beckhoff Identification Code (BIC) ................................................................................... 13
1.5.4 Electronic access to the BIC (eBIC).................................................................................15
2 Product description ................................................................................................................................17
2.1 Introduction .....................................................................................................................................17
2.2 Technical data.................................................................................................................................19
2.3 Technology......................................................................................................................................20
2.4 Note on Beckhoff calibration certificates .........................................................................................23
2.5 Start.................................................................................................................................................25
3 Basics communication ...........................................................................................................................26
3.1 EtherCAT basics .............................................................................................................................26
3.2 EtherCAT cabling – wire-bound ......................................................................................................26
3.3 General notes for setting the watchdog ..........................................................................................27
3.4 EtherCAT State Machine ................................................................................................................29
3.5 CoE Interface ..................................................................................................................................31
3.6 Distributed Clock .............................................................................................................................36
4 Mounting and wiring ...............................................................................................................................37
4.1 Instructions for ESD protection .......................................................................................................37
4.2 Installation on mounting rails...........................................................................................................38
4.3 Connection ......................................................................................................................................41
4.3.1 Connection system........................................................................................................... 41
4.3.2 Wiring ...............................................................................................................................43
4.3.3 Shielding ..........................................................................................................................44
4.4 Positioning of passive Terminals.....................................................................................................45
4.5 Installation positions........................................................................................................................46
4.6 LEDs and connection ......................................................................................................................48
4.7 Disposal ..........................................................................................................................................49
5 Commissioning .......................................................................................................................................50
5.1 TwinCAT Quick Start.......................................................................................................................50
5.1.1 TwinCAT 2 .......................................................................................................................53
5.1.2 TwinCAT 3 .......................................................................................................................63
5.2 TwinCAT Development Environment ..............................................................................................77
5.2.1 Installation of the TwinCAT real-time driver ..................................................................... 77
5.2.2 Notes regarding ESI device description ........................................................................... 83
5.2.3 TwinCAT ESI Updater......................................................................................................87
5.2.4 Distinction between Online and Offline ............................................................................ 87

Table of contents
EL36814 Version: 3.0
5.2.5 OFFLINE configuration creation....................................................................................... 88
5.2.6 ONLINE configuration creation ........................................................................................ 93
5.2.7 EtherCAT subscriber configuration ................................................................................ 101
5.2.8 Import/Export of EtherCAT devices with SCI and XTI.................................................... 110
5.3 General Commissioning Instructions for an EtherCAT Slave .......................................................117
5.4 Notices on analog specifications...................................................................................................125
5.4.1 Full scale value (FSV), output end value ....................................................................... 125
5.4.2 Measurement error/measurement deviation/measurement uncertainty, output uncertainty
.......................................................................................................................................126
5.4.3 Temperature coefficient tK [ppm/K]................................................................................ 127
5.4.4 Long-term use ................................................................................................................ 128
5.4.5 Ground reference: single-ended/differential typification.................................................129
5.4.6 Common-mode voltage and reference ground (based on differential inputs) ................ 134
5.4.7 Dielectric strength .......................................................................................................... 135
5.4.8 Temporal aspects of analog/digital or digital/analog conversion.................................... 136
5.4.9 Explanation of the term GND/Ground ............................................................................ 139
5.4.10 Sampling type: Simultaneous vs. multiplexed................................................................141
5.5 Basic function principles/functional description.............................................................................144
5.5.1 Measuring ranges and output ........................................................................................ 144
5.5.2 Selecting a measuring range ........................................................................................ 144
5.5.3 Autorange....................................................................................................................... 145
5.5.4 Filter ...............................................................................................................................145
5.5.5 Frequency ......................................................................................................................145
5.5.6 Presentation ...................................................................................................................146
5.5.7 Zero Compensation Interval...........................................................................................146
5.5.8 Calibration ......................................................................................................................146
5.6 Process data .................................................................................................................................147
5.6.1 Process image ............................................................................................................... 147
5.6.2 Control, Status, Settings-Word....................................................................................... 149
5.6.3 PDO Assignment............................................................................................................ 150
5.6.4 Calculation of process data............................................................................................151
5.6.5 Determining (user) gain values ...................................................................................... 153
5.7 Object description and parameterization.......................................................................................154
5.7.1 Restore object ................................................................................................................ 155
5.7.2 Configuration data..........................................................................................................155
5.7.3 Configuration data (vendor-specific) .............................................................................. 157
5.7.4 Input data ....................................................................................................................... 158
5.7.5 Output data .................................................................................................................... 159
5.7.6 Information and diagnostic data ..................................................................................... 159
5.7.7 Standard objects (0x1000-0x1FFF) ............................................................................... 159
5.8 Sample Program ...........................................................................................................................164
6 Error handling and diagnostics ...........................................................................................................168
7 Appendix................................................................................................................................................169
7.1 Accessories...................................................................................................................................169
7.2 EtherCAT AL Status Codes ..........................................................................................................170
7.3 Firmware compatibility ..................................................................................................................171

Table of contents
EL3681 5Version: 3.0
7.4 Firmware Update EL/ES/EM/ELM/EP/EPP/ERPxxxx ...................................................................172
7.4.1 Device description ESI file/XML ..................................................................................... 173
7.4.2 Firmware explanation.....................................................................................................176
7.4.3 Updating controller firmware *.efw ................................................................................. 177
7.4.4 FPGA firmware *.rbf ....................................................................................................... 179
7.4.5 Simultaneous updating of several EtherCAT devices .................................................... 183
7.5 Restoring the delivery state...........................................................................................................184
7.6 Support and Service......................................................................................................................186

Table of contents
EL36816 Version: 3.0

Foreword
EL3681 7Version: 3.0
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.
The qualified personnel is obliged to always use the currently valid documentation.
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®, TwinCAT/BSD®, TC/BSD®, 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.

Foreword
EL36818 Version: 3.0
1.2 Guide through documentation
NOTICE
Further components of documentation
This documentation describes device-specific content. It is part of the modular
documentation concept for Beckhoff I/O components. For the use and safe operation of the
device / devices described in this documentation, additional cross-product descriptions are
required, which can be found in the following table.
Title Description
EtherCAT System Documentation (PDF)• System overview
• EtherCAT basics
• Cable redundancy
• Hot Connect
• EtherCAT devices configuration
Infrastructure for EtherCAT/Ethernet (PDF)Technical recommendations and notes for design,
implementation and testing
Software Declarations I/O (PDF)Open source software declarations for
Beckhoff I/O components
The documentations can be viewed at and downloaded from the Beckhoff website (www.beckhoff.com) via:
• the “Documentation and Download” area of the respective product page,
• the Download finder,
• the Beckhoff Information System.

Foreword
EL3681 9Version: 3.0
1.3 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.
Signal words
The signal words used in the documentation are classified below. In order to prevent injury and damage to
persons and property, read and follow the safety and warning notices.
Personal injury warnings
DANGER
Hazard with high risk of death or serious injury.
WARNING
Hazard with medium risk of death or serious injury.
CAUTION
There is a low-risk hazard that could result in medium or minor injury.
Warning of damage to property or environment
NOTICE
The environment, equipment, or data may be damaged.
Information on handling the product
This information includes, for example:
recommendations for action, assistance or further information on the product.

Foreword
EL368110 Version: 3.0
1.4 Documentation issue status
Version Comment
2.9 • Update chapter "Technical data"
• Update structure
2.8 • Update chapter "Technical data"
• Chapter “Disposal” added
• Update structure
2.7 • Update chapter "Technical data"
• Update structure
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