Beckhoff EL3692 User Manual
Documentation | EN
EL3692
2 channel resistance measurement terminal, high-precision
2021-03-12 | Version: 2.9
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)................................................................................... 13
2 Product overview.....................................................................................................................................15
2.1 Introduction......................................................................................................................................15
2.2 Technology ......................................................................................................................................16
2.3 Technical data .................................................................................................................................18
2.4 Note on Beckhoff calibration certificates .........................................................................................19
2.5 Start .................................................................................................................................................20
3 Basics communication ...........................................................................................................................21
3.1 EtherCAT basics..............................................................................................................................21
3.2 EtherCAT cabling – wire-bound.......................................................................................................21
3.3 General notes for setting the watchdog...........................................................................................22
3.4 EtherCAT State Machine.................................................................................................................24
3.5 CoE Interface...................................................................................................................................25
3.6 Distributed Clock .............................................................................................................................30
4 Installation................................................................................................................................................31
4.1 Instructions for ESD protection........................................................................................................31
4.2 Installation on mounting rails ...........................................................................................................31
4.3 Installation instructions for enhanced mechanical load capacity .....................................................34
4.4 Connection ......................................................................................................................................35
4.4.1 Connection system .......................................................................................................... 35
4.4.2 Wiring............................................................................................................................... 37
4.4.3 Shielding .......................................................................................................................... 38
4.5 Installation positions ........................................................................................................................38
4.6 ATEX - Special conditions (standard temperature range) ...............................................................40
4.7 Continuative documentation for ATEX and IECEx ..........................................................................41
4.8 LEDs and connection ......................................................................................................................41
4.9 Electrical connection........................................................................................................................42
4.10 UL notice .........................................................................................................................................44
4.11 Positioning of passive Terminals .....................................................................................................45
5 Commissioning........................................................................................................................................46
5.1 TwinCAT Quick Start .......................................................................................................................46
5.1.1 TwinCAT 2 ....................................................................................................................... 49
5.1.2 TwinCAT 3 ....................................................................................................................... 59
5.2 TwinCAT Development Environment ..............................................................................................72
5.2.1 Installation of the TwinCAT real-time driver..................................................................... 73
5.2.2 Notes regarding ESI device description........................................................................... 78
5.2.3 TwinCAT ESI Updater ..................................................................................................... 82
5.2.4 Distinction between Online and Offline............................................................................ 82
EL3692 3Version: 2.9
Table of contents
5.2.5 OFFLINE configuration creation ...................................................................................... 83
5.2.6 ONLINE configuration creation ........................................................................................ 88
5.2.7 EtherCAT subscriber configuration.................................................................................. 96
5.3 General Notes - EtherCAT Slave Application................................................................................105
5.4 Notices on analog specifications ...................................................................................................113
5.4.1 Full scale value (FSV).................................................................................................... 113
5.4.2 Measuring error/ measurement deviation ...................................................................... 113
5.4.3 Temperature coefficient tK [ppm/K] ............................................................................... 114
5.4.4 Long-term use................................................................................................................ 115
5.4.5 Single-ended/differential typification .............................................................................. 115
5.4.6 Common-mode voltage and reference ground (based on differential inputs)................ 120
5.4.7 Dielectric strength .......................................................................................................... 120
5.4.8 Temporal aspects of analog/digital conversion.............................................................. 121
5.5 Quick start......................................................................................................................................124
5.6 Operating behavior, diagnostics ....................................................................................................126
5.6.1 Control ........................................................................................................................... 126
5.6.2 Basic operation .............................................................................................................. 127
5.6.3 Default state................................................................................................................... 127
5.6.4 Process data.................................................................................................................. 127
5.6.5 4/2-wire mode ................................................................................................................ 127
5.6.6 Measuring mode ............................................................................................................ 128
5.6.7 Autorange function......................................................................................................... 129
5.6.8 Filter............................................................................................................................... 129
5.6.9 Conversion time............................................................................................................. 130
5.6.10 Error Codes ................................................................................................................... 131
5.7 Process data..................................................................................................................................131
5.8 Specific data ..................................................................................................................................135
5.8.1 Measuring currents and voltages................................................................................... 136
5.8.2 Capacitive and inductive influences............................................................................... 136
5.8.3 Heating of the test specimen ......................................................................................... 136
5.8.4 Calculating the resistance value .................................................................................... 136
5.8.5 Error analysis................................................................................................................. 138
5.8.6 Resolution...................................................................................................................... 139
5.9 Data processing.............................................................................................................................139
5.10 DC operation mode .......................................................................................................................141
5.11 Example program ..........................................................................................................................141
5.12 CoE................................................................................................................................................145
5.12.1 Most important CoE entries ........................................................................................... 145
5.12.2 Object description and parameterization ....................................................................... 147
5.12.3 Restore object................................................................................................................ 148
5.12.4 Configuration data ......................................................................................................... 149
5.12.5 Input data....................................................................................................................... 150
5.12.6 Output data .................................................................................................................... 151
5.12.7 Configuration data (vendor-specific).............................................................................. 151
5.12.8 Information and diagnostic data..................................................................................... 151
5.12.9 Standard objects (0x1000-0x1FFF) ............................................................................... 152
EL36924 Version: 2.9
Table of contents
6 Appendix ................................................................................................................................................157
6.1 EtherCAT AL Status Codes...........................................................................................................157
6.2 Firmware compatibility...................................................................................................................157
6.3 Firmware Update EL/ES/EM/ELM/EPxxxx ....................................................................................158
6.3.1 Device description ESI file/XML..................................................................................... 159
6.3.2 Firmware explanation .................................................................................................... 162
6.3.3 Updating controller firmware *.efw................................................................................. 163
6.3.4 FPGA firmware *.rbf....................................................................................................... 164
6.3.5 Simultaneous updating of several EtherCAT devices.................................................... 168
6.4 Restoring the delivery state ...........................................................................................................169
6.5 Support and Service ......................................................................................................................170
EL3692 5Version: 2.9
Table of contents
EL36926 Version: 2.9
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®, EtherCATG®, EtherCATG10®, EtherCATP®, SafetyoverEtherCAT®,
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.
EL3692 7Version: 2.9
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.
EL36928 Version: 2.9
1.3 Documentation issue status
Version Comment
2.9 - Addenda EL3692-0020 and EL3692-0030
- Update chapter "Technical data"
- Update revision status
- Update structure
2.8 - Update chapter „Specific data“
- Update revision status
- Update structure
2.7 - Update chapter "Introduction“
- Update chapter "Technical data"
- Update chapter "Technology"
- Update chapter „Specific data“
- Update chapter "CoE"
- Update structure
2.6 - Update chapter "CoE”
- Update structure
2.5 - Update chapter "CoE”
- Update structure
2.4 - Update chapter "Specific data"
- Update revision status
- Update structure
2.3 - Update chapter "Example program"
- Update structure
2.2 - Update of Technical data
- Addenda chapter "Instructions for ESD protection"
- Update chapter "Notices on Analog specification"
2.1 - Update chapter "Notes on the documentation"
- Update of Technical data
- Addenda chapter "Installation instructions for enhanced mechanical load capacity"
- Update chapter "TwinCAT 2.1x" -> "TwinCAT Development Environment" and "TwinCAT
Quick Start"
2.0 - Migration
- Update structure
1.4 - Addenda chapter "Notices on analog specifications"
- Update chapter "Operating behavior, diagnostics"
- Update chapter "Technical data"
- Update revision status
- Update structure
1.3 - Update chapter "Technical data"
1.2 - Addenda AutoRange operation mode
1.1 - Addenda
1.0 - Addenda
- First publication
0.1 - Preliminary documentation for EL3692
Foreword
EL3692 9Version: 2.9
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: KKYYFFHH
KK - week of production (CW, calendar week)
YY - year of production
FF - firmware version
HH - hardware version
EL369210 Version: 2.9
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
Examples of markings
Fig.1: EL5021 EL terminal, standard IP20 IO device with serial/ batch number and revision ID (since
2014/01)
Fig.2: EK1100 EtherCAT coupler, standard IP20 IO device with serial/ batch number
EL3692 11Version: 2.9
Foreword
Fig.3: EL3202-0020 with serial/ batch number 26131006 and unique ID-number 204418
EL369212 Version: 2.9
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.4: 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
(ANSIMH10.8.2-2016). 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:
EL3692 13Version: 2.9
Foreword
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
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.
EL369214 Version: 2.9
2 Product overview
2.1 Introduction
Product overview
Fig.5: EL3692
2 channel resistance measurement terminal
The EL3692 analog input terminal allows direct resistance measurement in 9 measuring ranges from 0..100
MΩ to 0..10 mΩ on 2 channels.
The circuitry of the EtherCAT Terminal enables measurement in 2- and 4-wire versions. The EL3692 offers
measuring range selection, either automatic or through the controller. It is possible to determine the
connected resistance with an update rate up to 100 Hz.
Due to the galvanic isolation of 1500 V between the field side and the E-bus, in single-channel mode
measurements can be carried out at live points (within the permissible range). The EtherCAT Terminal
indicates its state through LEDs. Malfunctions such as broken wires are indicated by error LEDs.
As further variants the EL3692-0020 with individual factory calibration certificate and the EL3692-0030 with
external calibration certificate are available.
Please read the notes on the calibration certificate [}19] and identification features [}19] of these
terminals.
Quick links
• EtherCAT basics
• Technology EL3692 [}16]
• Most important CoE entries [}145]
• Quick start [}124]
• Process data [}131]
EL3692 15Version: 2.9
Product overview
2.2 Technology
The EL3692 resistance measuring terminal can measure resistances between milliohm (mΩ) and megohm
(MΩ). 2- and 4-wire measurements are supported. The terminal is fully configurable via the Bus Coupler or
the control system. Different output formats may be selected or own scaling activated.
Measuring principle of the terminal
The terminal actively applies a current to the test specimen. This current simultaneously flows through
internal reference resistances. The actual resistance is determined from the proportion of the measured
voltages. The terminal measures ratiometrically, i.e. fluctuations in the supply voltage and/or the measuring
current have no influence on the accuracy.
Fig.6: Principle of operation
The figure illustrates the following relationship between the known resistance R
and the unknown
ref
resistance Rx:
Rx / R
Rx = R
= Ux / U
ref
* Ux / U
ref
ref
ref
The two channels of the EL3692 are measured alternately. To compensate capacitive processes the
conversion time depends on the measuring range: the larger measuring range the longer the conversion. To
measure a resistance at short intervals, the EL3692 should be used in single-channel mode. For measuring
inductive/capacitive loads it should be noted that transition processes influence the result. A delay time can
be specified in the channel settings in the CoE. The measurement and updating of the process data will only
take place once this delay time (in [ms]) has elapsed (CoE 0x80n0:05 and :31 [}145]). This delay time is
particularly significant in Autorange mode: If it is too small, the measuring range may not change in
Autorange mode because the respective measuring range limits are not reached. The automatic control in
the EL3692 will try to optimize the waiting times, although manual adaptation may still be required.
The measuring frequency is determined from the filter setting for each channel. The lower the filter setting,
the more measurements are carried out and averaged, and the more reliable is therefore the measurement.
The 9 measuring ranges each cover one decade. They each measure from 0 Ohm to 110% of full scale with
their typical measuring current, see table. The measuring ranges of the two channels can be used
independently of each other.
Although all measuring ranges theoretically measure down to 0 Ohm, the relatively large measuring error
and the 2/4-wire connection technology must be taken into account with such small resistances. Apart from
that, it will hardly be possible to achieve a "correct" zero measured value, because not even a connected
(short) wire bridge has a resistance of 0 Ω.
EL369216 Version: 2.9
Product overview
In AutoRange mode, the measuring range used is determined by the terminal itself. For AutoRange
operation, each measuring range can measure up to 110% above the respective measuring range end
value. In this range, the measuring range is then switched to the next higher measuring range. Accordingly,
below 10% of the measuring range, the changeover to the next smaller measuring range takes place. This
method results in the following naming of the measuring ranges e.g. as "10..100 Ω", with 100Ω as measuring
range end value and 10 Ω as lower threshold for the measuring range switchover.
In the manual mode, the measuring range is specified by the user via process data or CoE, in this case
0..110% of the respective measuring range can be measured.
The respective resistance is measured with 24 bit resolution (incl. sign). The measured value transmission
takes place as 32 bit process date, in float (fixed point) or integer representation. Since no negative
resistances can occur, the sign bit is used for the representation up to 110%
For more detailed information on settings and operating modes please refer to the sections on Process data
[}131], Operational characteristics, Diagnostics [}126] and Specific data [}135].
EL3692 17Version: 2.9
Product overview
2.3 Technical data
Technical data EL3692 EL3692-0020 EL3692-0030
Number of inputs 2
Connection technology 2 or 4 wire
Measuring range 9 measuring ranges 100 mΩ ... 10 MΩ:
0.1 Ω, 1 Ω, 10 Ω, 100 Ω, 1 kΩ, 10 kΩ, 100 kΩ, 1 MΩ, 10 MΩ MΩ, 10 MΩ
Resolution 24bits incl. sign
Conversion time 10ms ..400ms; depends on measuring range; operation mode (alternating, one
channel), waiting time, filter settings
Broken wire detection yes
Internal resistance >100MΩ
Filter characteristics Hardware 5kHz, Firmware adjustable 2.5 - 100Hz
Measuring error <0.5% (relative to the respective full scale value with 4-wire connection)
Supply voltage for
electronics
Current consumption via
E-bus
Distributed Clocks No
Special features automatic range selection; "auto range", pulse and continuous measurement
Width in the process image max. 24bytes input, max. 4bytes output
Electrical isolation 1500V (E-bus/field voltage)
Configuration via TwinCAT System Manager
Weight approx. 60g
permissible ambient
temperature range during
operation
permissible ambient
temperature range during
storage
permissible relative
humidity
Dimensions (W x H x D) approx. 15mm x 100mm x 70mm (width aligned: 12mm)
Mounting [}31]
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 CE , EAC
via the E-bus
typ. 220mA
0°C ... + 55°C
-25 °C ... + 85 °C
95%, no condensation
on 35 mm mounting rail conforms to EN 60715
see also installation instructions for terminals with increased mechanical load
capacity [}34]
cULus [}44]
ATEX [}40]
Ex markings
Standard Marking
ATEX II 3 G Ex nA IIC T4 Gc
EL369218 Version: 2.9
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.
EL3692 19Version: 2.9
Product overview
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.
Fig.7: 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”.
2.5 Start
For commissioning:
• Install the EL3692 as described in chapter Mounting and wiring [}31].
• configure the EL3692 in TwinCAT or another EtherCAT Master as described in the chapter
Commissioning [}46].
EL369220 Version: 2.9
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 5V; a coupler is
thereby loadable up to 2A 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.
EL3692 21Version: 2.9
Basics communication
Fig.8: 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.
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Fig.9: 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) = 100µs (for default setting of 2498 for the multiplier)
The standard setting of 1000 for the SM watchdog corresponds to a release time of 100ms.
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 100ms. 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.
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Calculation
Multiplier = 2498 → watchdog base time = 1 / 25MHz * (2498 + 2) = 0.0001seconds = 100µs
SM watchdog = 10000 → 10000 * 100µs = 1second 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.10: States of the EtherCAT State Machine
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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 [}22] 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.
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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.11: “CoE Online” tab
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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.
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Fig.12: 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.13: Offline list
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• 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.14: 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...10V 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.
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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.
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