Beckhoff EL5101, EL5101-0010, EL5101-0011 Documentation
Documentation
EL5101, EL5101-0010, EL5101-0011
Incremental Encoder Interface
4.2
2017-07-31
Version:
Date:
Table of contents
EL5101, EL5101-0010, EL5101-0011 3Version: 4.2
Table of contents
1 Overview Incremental Encoder Interface ................................................................................................5
2 Foreword ....................................................................................................................................................6
2.1 Notes on the documentation........................................................................................................... 6
2.2 Safety instructions .......................................................................................................................... 7
2.3 Documentation issue status............................................................................................................ 8
2.4 Version identification of EtherCAT devices..................................................................................... 8
3 Product overview.....................................................................................................................................13
3.1 Introduction ................................................................................................................................... 13
3.2 Technology ................................................................................................................................... 15
3.3 Technical data .............................................................................................................................. 18
3.4 Start .............................................................................................................................................. 18
4 Basics communication ...........................................................................................................................20
4.1 EtherCAT basics........................................................................................................................... 20
4.2 EtherCAT cabling – wire-bound.................................................................................................... 20
4.3 General notes for setting the watchdog ........................................................................................ 21
4.4 EtherCAT State Machine .............................................................................................................. 23
4.5 CoE Interface................................................................................................................................ 25
4.6 DC settings ................................................................................................................................... 29
5 Mounting and wiring ...............................................................................................................................34
5.1 Installation on mounting rails ........................................................................................................ 34
5.2 Installation instructions for enhanced mechanical load capacity .................................................. 36
5.3 Connection.................................................................................................................................... 37
5.3.1 Connection system...........................................................................................................37
5.3.2 Wiring...............................................................................................................................39
5.3.3 Shielding ..........................................................................................................................40
5.4 Installation positions ..................................................................................................................... 40
5.5 Mounting of Passive Terminals..................................................................................................... 42
5.6 UL notice....................................................................................................................................... 43
5.7 ATEX - Special conditions (extended temperature range) ........................................................... 45
5.8 ATEX Documentation ................................................................................................................... 46
5.9 LEDs and connection.................................................................................................................... 46
5.9.1 EL5101-00x0....................................................................................................................46
5.9.2 EL5101-0011 ...................................................................................................................48
6 Commissioning........................................................................................................................................50
6.1 TwinCAT Quick Start .................................................................................................................... 50
6.1.1 TwinCAT2 .......................................................................................................................52
6.1.2 TwinCAT 3 .......................................................................................................................62
6.2 TwinCAT Development Environment............................................................................................ 74
6.2.1 Installation of the TwinCAT real-time driver .....................................................................74
6.2.2 Notes regarding ESI device description...........................................................................80
6.2.3 TwinCAT ESI Updater......................................................................................................84
6.2.4 Distinction between Online and Offline ............................................................................84
6.2.5 OFFLINE configuration creation ......................................................................................85
6.2.6 ONLINE configuration creation ........................................................................................90
6.2.7 EtherCAT subscriber configuration ..................................................................................98
6.2.8 NC configuration ............................................................................................................108
Table of contents
EL5101, EL5101-0010, EL5101-00114 Version: 4.2
6.3 General Notes - EtherCAT Slave Application ............................................................................. 111
6.4 EL5101-00x0 .............................................................................................................................. 119
6.4.1 Normal operation mode .................................................................................................119
6.4.2 Enhanced operation mode.............................................................................................129
6.5 EL5101-0011 .............................................................................................................................. 157
6.5.1 Principles of the oversampling function .........................................................................157
6.5.2 Process data and configuration .....................................................................................159
6.5.3 Object description and parameterization - enhanced operation mode ..........................162
7 Appendix ................................................................................................................................................176
7.1 EtherCAT AL Status Codes ........................................................................................................ 176
7.2 Firmware compatibility ................................................................................................................ 176
7.3 Firmware Update EL/ES/EM/EPxxxx.......................................................................................... 177
7.4 Restoring the delivery state ........................................................................................................ 187
7.5 Support and Service ................................................................................................................... 188
Overview Incremental Encoder Interface
EL5101, EL5101-0010, EL5101-0011 5Version: 4.2
1 Overview Incremental Encoder Interface
EL5101-0000 [}13] (Incremental Encoder Interface)
EL5101-0010 [}13] (Incremental Encoder Interface, 20 Mio. increments/s)
EL5101-0011 [}14] (Incremental Encoder Interface, with oversampling)
Foreword
EL5101, EL5101-0010, EL5101-00116 Version: 4.2
2 Foreword
2.1 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®, Safety over EtherCAT®, TwinSAFE®, XFC® and XTS® 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, DE102004044764, DE102007017835 with corresponding applications or
registrations in various other countries.
The TwinCAT Technology is covered, including but not limited to the following patent applications and
patents: EP0851348, US6167425 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
EL5101, EL5101-0010, EL5101-0011 7Version: 4.2
2.2 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 symbols
In this documentation the following symbols are used with an accompanying safety instruction or note. The
safety instructions must be read carefully and followed without fail!
DANGER
Serious risk of injury!
Failure to follow the safety instructions associated with this symbol directly endangers the
life and health of persons.
WARNING
Risk of injury!
Failure to follow the safety instructions associated with this symbol endangers the life and
health of persons.
CAUTION
Personal injuries!
Failure to follow the safety instructions associated with this symbol can lead to injuries to
persons.
Attention
Damage to the environment or devices
Failure to follow the instructions associated with this symbol can lead to damage to the environment or equipment.
Note
Tip or pointer
This symbol indicates information that contributes to better understanding.
Foreword
EL5101, EL5101-0010, EL5101-00118 Version: 4.2
2.3 Documentation issue status
Version Comment
4.2 - Update chapter “Technology”
- Update structure
- Update revision status
4.1 - Addenda EL5101-00111
- Update structure
- Update revision status
4.0 - Migration in ST4
- Update structure
- Update revision status
3.7 - Update chapter "Technical data"
- Addenda chapter "Installation instructions for enhanced mechanical load capacity"
- Update structure
- Update revision status
3.6 - Update chapter "Technical data"
- Update structure
- Update revision status
3.5 - Addenda in the chapter "Process data"
3.4 - Addenda in the chapter "Process data"
3.3 - Addenda for EL5101-0010
3.2 - Note on single-ended connection added
3.1 - Note on period/frequency measurement added
3.0 - Object description and further notes added
2.9 - EL5101-0010 added
2.8 - New safety instructions added
2.7 - Technical data added
2.6 - Object description and Technical notes added
2.5 - Note for compatibility added
2.4 - Object description added
2.3 - Division of operating modes
2.2 - Technical data added, object description added
2.1 - Technical data added
2.0 - Technical data added, object description added
1.1.1 - Technical data corrected
1.1 - Correction of the note "Non-Volatile Settings"
1.0 - Extended description for status LEDs added
0.1 - First provisional documentation for EL5101
2.4 Version identification of EtherCAT devices
Designation
A Beckhoff EtherCAT device has a 14-digit designation, made up of
• family key
• type
• version
• revision
Foreword
EL5101, EL5101-0010, EL5101-0011 9Version: 4.2
Example Family Type Version Revision
EL3314-0000-0016 EL terminal
(12 mm, nonpluggable connection
level)
3314 (4-channel thermocouple
terminal)
0000 (basic type) 0016
ES3602-0010-0017 ES terminal
(12 mm, pluggable
connection level)
3602 (2-channel voltage
measurement)
0010 (highprecision version)
0017
CU2008-0000-0000 CU device 2008 (8-port fast ethernet switch) 0000 (basic type) 0000
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
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
Foreword
EL5101, EL5101-0010, EL5101-001110 Version: 4.2
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 batch number and revision ID (since 2014/01)
Fig.2: EK1100 EtherCAT coupler, standard IP20 IO device with batch number
Foreword
EL5101, EL5101-0010, EL5101-0011 11Version: 4.2
Fig.3: CU2016 switch with batch number
Fig.4: EL3202-0020 with batch numbers 26131006 and unique ID-number 204418
Fig.5: EP1258-00001 IP67 EtherCAT Box with batch number 22090101 and unique serial number 158102
Fig.6: EP1908-0002 IP67 EtherCAT Safety Box with batch number 071201FF and unique serial number
00346070
Foreword
EL5101, EL5101-0010, EL5101-001112 Version: 4.2
Fig.7: EL2904 IP20 safety terminal with batch number/date code 50110302 and unique serial number
00331701
Fig.8: ELM3604-0002 terminal with ID number (QR code) 100001051 and unique serial number 44160201
Product overview
EL5101, EL5101-0010, EL5101-0011 13Version: 4.2
3 Product overview
3.1 Introduction
Interface terminal for incremental encoder
EL5101-00x0
Fig.9: EL5101
The EL5101-00x0 EtherCAT Terminal is an interface for direct connection of incremental encoders with
differential inputs (RS422). A 16-bit counter (in normal operating mode) or a switchable 16/32-bit counter (in
enhanced operating mode) with a quadrature decoder and a 16-bit latch (in normal operating mode) or 32-bit
latch (in enhanced operating mode) for the zero pulse can be read, set or enabled. Incremental encoders
with alarm output can be connected at the negative switching status input of the interface. The measurement
of period and frequency is possible. The gate input allows the locking of the counter, alternatively with a high
or low level. The latch input is similarly configurable and evaluates high or low levels. The EL5101-0000 can
also be used as bidirectional counter on channel A; channel B specifies the count direction.
Through the further development of the EL5101-0000 an enhanced operating mode is available (from
firmware 14 / hardware 09 [}176]), which can be parameterized in the TwinCAT System Manager,
depending on the hardware used.
Older EL5101-0000 devices do not support this enhanced operating mode (see Table 1)!
Version from FW/HW ESI Functional description
normal operating mode
EL5101-0000
03/05 from EL5101-0000-0000 All basic functions as described above
enhanced operating mode
EL5101-0000
14/09 from EL5101-0000-1018 Changes to the normal operating mode
- Distributed clock support
- Micro-increments
- Open circuit detection
- Connection of SingleEnded signals possible
Table 1: Operating modes EL5101-0000
Product overview
EL5101, EL5101-0010, EL5101-001114 Version: 4.2
The EL5101-0010 with a resolution of 20 mio. increments/s at 5 MHz and 4-fold evaluation is only applicable
for the enhanced operating mode. The inputs can process differential signals according to RS485. The
microincrement mode is not available for the EL5101-0010.
The EL5101-00x0 supports distributed clocks in the enhanced operating mode, i.e. the input data can be
recorded synchronously with other data that are also linked to Distributed Clock slaves. The accuracy across
the system is < 100 ns.
The documentation is divided in the chapter "Commissioning [}50]" into the handling of the two operating
modes, for which reason the decision must be made during commissioning as to which operating mode is to
be used.
EL5101-0011
Fig.10: EL5101-0011
The EL5101-0011 EtherCAT Terminal is also an interface for the direct connection of incremental encoders
with differential inputs (RS422). A 32-bit counter with quadrature decoder can be read and set. The
EL5101-0011 supports the oversampling principle. Using this method the resolution of the position value can
be increased to n times the bus cycle time. The current counter value is thereby read at several configurable
and equidistant times between two fieldbus communication cycles with an adjustable whole number multiple
(oversampling factor: n) of the bus cycle time. The transfer of a packet of n position values of 32 bits each to
the higher-level controller takes place in the next fieldbus communication cycle. The minimum sampling time
here is 10 µs (100 kSps). Areas of application of the EL5101-0011 lie in particular in the area of highresolution position detection.
The EL5101-0011 supports distributed clocks, i.e. the input data can be synchronously acquired with other
data that, similarly distributed, are connected to distributed slave clocks. The system accuracy is around <
100ns.
Quick links
• Basics communication [}20]
• Creation of the TwinCAT configuration [}90]
• EL5101-00x0 – process data, modes, object description [}119]
• EL5101-0011 – process data, modes, object description [}157]
• LEDs and connection [}46]
Product overview
EL5101, EL5101-0010, EL5101-0011 15Version: 4.2
3.2 Technology
The EL5101-00x0 incremental encoder interface terminal enables connection of incremental encoders with
A/B/C track to the Bus Coupler and the PLC. A 16-bit counter (in normal operating mode) or a switchable
16/32-bit counter (in enhanced operating mode) with a quadrature decoder and a 16-bit latch (in normal
operating mode) or 32-bit latch (in enhanced operating mode) can be read, set or enabled. Differential
signals based on RS485 are provided as encoder connection. From hardware09 [}176] single-ended 5 V
signals are possible for the EL5101-0000 based on pull-up resistors.
In addition to the encoder inputs A, B and C, an additional latch input G1 (24 V) and a gate input G2 (24 V)
for locking the counter during operation are available.
The terminal is supplied as a 4-fold quadrature decoder with complementary analysis of the sensor signals
A, B, C. If the incremental encoder has an alarm output it can be connected to the INPUT 1 status input of
the EL5101-00x0. The EL5101-0000 can optionally be operated as a bidirectional counter terminal on
channel A.
Through the further development of the EL5101-0000 an enhanced operating mode is available (from
firmware 14 / hardware 09 [}176]), which can be parameterized in the TwinCAT System Manager,
depending on the hardware used.
Older EL5101-0000 devices do not support this extended operating mode (see Table 1)!
Version from FW/HWESI Functional description
normal operating mode
EL5101-0000
03/05 from
EL5101-0000-0000
All basic functions as described above
enhanced operating
mode
EL5101-0000
14/09 from
EL5101-0000-1018
Changes to the normal operating mode
- Distributed clock support
- Micro-increments
- Broken wire detection
- Connection of SingleEnded signals
possible
Table 1: Operating modes EL5101-0000
The EL5101-0010 with a resolution of 20 mio. increments/s at 5 MHz and 4-fold evaluation is only applicable
for the enhanced operating mode. The inputs can process differential signals according to RS485. The
microincrement mode is not available for the EL5101-0010.
Note
Compatibility in the case of service
An EL5101-0000 designed for and used in enhanced operating mode cannot be replaced
with an EL5101-0000 with older hardware version (< 09)! An EL5101-0010 only supports
the enhanced operating mode and is not exchange-compatible with an EL5101-0000 (hardware version < 09)!
Irrespective of the hardware/firmware version, after integration into a system an EL5101-0000 reports in
normal operating mode.
During commissioning the user has to decide with what functionality, i.e. in what operating mode, the
EL5101-0000 is to be used. This depends on the required functions and, of course, the hardware version.
Hardware older then firmware 14/hardware 09 [}176], for example, will not support enhanced operating
mode functions.
Combination of functions from different operating modes is not possible.
Specific settings are described in the following two sections.
Product overview
EL5101, EL5101-0010, EL5101-001116 Version: 4.2
Note
Process data monitoring
• WcState: if ≠ 0, this EtherCAT device does not take part in the process data traffic
• State: if ≠ 8, the EtherCAT device is not in OP (operational) status
• TxPDO state, SyncError: if ≠ 0, then no valid process data are available, e.g. caused
by broken wire
• TxPDO Toggle: if this bit is toggling, a new set of process data is available
EtherCAT cycle time
For the EL5101 a minimum EtherCAT cycle time of >100 µs is recommended. If a faster cycle time is used,
the toggling process record TxPDO Toggle should be used to monitor when new process data are supplied
by the EL5101.
EL5101 input impedance
The signal source must be able to operate the input impedance of the EL5101 (typically 220Ω, subject to
modification) with adequate voltage levels according to RS485.
Gate/latch input
For gate and latch inputs (24 V) a max. input frequency of 1 MHz is permitted. Subject to modification.
Level on interface
In differential mode the EL5101-00xx expects the signal levels after RS422. The data are transferred without
ground reference as voltage difference between two cables (signal A and inverted signal /A). The terminal
analyses signal levels in the range -200 mV < Vid < +200 mV as valid signals. The differential signal must be
in the common mode range (<+13.2 V and >-10 V, with respect to GND) (cf. diagram). Signal levels outside
this range can lead to destruction.
Product overview
EL5101, EL5101-0010, EL5101-0011 17Version: 4.2
Fig.11: Level interface
In differential mode only the voltage difference is evaluated, so that common-mode interference on the
transmission link does not lead to corruption of the wanted signal, since any interference affects both cables
simultaneously.
If the EL5101 is only operated in single-ended mode, a nominal level voltage between 3.5V and 5.5V is
expected.
The EL5101-0010 and EL5101-0011 do not support single-ended mode.
In the EL5101-0010 and EL5101-0011 versions, open circuit detection (Index 0x80n0:0B, 0x80n0:0C,
0x880n0:0C) is typically activated in the range -0.475V > Vid >+0.475V. For the EL5101, it is typically
activated for the range -1.5V > Vid > +1.5V (subject to change).
Product overview
EL5101, EL5101-0010, EL5101-001118 Version: 4.2
3.3 Technical data
Technical data EL5101-0000 EL5101-0010 EL5101-0011
Sensor connection A, ¬A, B, ¬B, C, ¬C (RS422 dif-
ferential inputs)
from hardware 09 [}176]: also
single-ended connection (5V
±20%) possible
A, ¬A, B, ¬B, C, ¬C (RS422 differential inputs)
Additional inputs gate, latch (24VDC, both max. 1 MHz permitted),
status input (max. 5VDC, potential-free, switching to negative potential)
-
Sensor supply 5 V
DC
Sensor output current 0.5A
Counter 16bit, 16/32bit switchable
(from firmware 14 / hardware 09
[}176])
16bit, 16/32bit switchable 32 bit
Zero pulse latch 16bit, 16/32bit switchable
(from firmware 14 / hardware 09
[}176])
16bit, 16/32bit switchable -
Limit frequency 1 MHz
(equals 4million increments with
4-fold evaluation)
5 MHz
(equals 20million increments with 4-fold evaluation)
Quadrature decoder 4-fold evaluation
Distributed Clocks in enhanced operating mode
(from firmware 14 / hardware 09
[}176])
yes
Broken wire detection to sensor
in enhanced operating mode
(from firmware 14 / hardware 09
[}176])
yes
Commands read, set, enable read, set
Oversampling factor - n = 1..100, adjustable
Cycle time min. 100 µs min. 500 µs
Conversion time - 10 µs / 100 kSps
Current consumption via Ebus
typ. 130 mA
Current consumption from the
power contacts
0.1A (excluding sensor load current)
Electrical isolation 500 V (E-bus/field voltage)
Bit width in process image up to 6bytes outputs, 22bytes inputs, depends on parameterization
Configuration
via TwinCAT System Manager [}98]
Weight approx. 100 g
Permissible ambient temperature range during operation
-25 °C ... +60 °C (extended temperature range)
Permissible ambient temperature range during storage
-40 °C ... +85 °C
Permissible relative humidity 95%, no condensation
Dimensions (W x H x D) approx. 27 mm x 100 mm x 70 mm (width aligned: 24 mm)
Mounting [}34]
on 35 mm mounting rail conforms to EN 60715
Vibration/shock resistance conforms to EN 60068-2-6 / EN 60068-2-27,
see also installation instructions [}36] for enhanced mechanical load capacity
EMC immunity/emission conforms to EN 61000-6-2 / EN 61000-6-4
Protection class IP20
Installation position variable
Approval CE
ATEX [}45]
cULus [}43]
3.4 Start
For commissioning:
• mount the EL5101 as described in the chapter Mounting and wiring [}34]
Product overview
EL5101, EL5101-0010, EL5101-0011 19Version: 4.2
• configure the EL5101 in TwinCAT as described in the chapter Commissioning [}50].
Basics communication
EL5101, EL5101-0010, EL5101-001120 Version: 4.2
4 Basics communication
4.1 EtherCAT basics
Please refer to the chapter EtherCAT System Documentation for the EtherCAT fieldbus basics.
4.2 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.
Note
Recommended cables
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.
Basics communication
EL5101, EL5101-0010, EL5101-0011 21Version: 4.2
Fig.12: System manager current calculation
Attention
Malfunction possible!
The same ground potential must be used for the E-Bus supply of all EtherCAT terminals in
a terminal block!
4.3 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 2 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.
Basics communication
EL5101, EL5101-0010, EL5101-001122 Version: 4.2
Fig.13: 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
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.
Basics communication
EL5101, EL5101-0010, EL5101-0011 23Version: 4.2
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.
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.
4.4 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.
Basics communication
EL5101, EL5101-0010, EL5101-001124 Version: 4.2
Fig.14: States of the EtherCAT State Machine
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.
Note
Outputs in SAFEOP state
The default set watchdog [}21] 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.
Basics communication
EL5101, EL5101-0010, EL5101-0011 25Version: 4.2
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.
4.5 CoE Interface
General description
The CoE interface (CANopen 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.
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 2 levels via hexadecimal numbering: (main)index, followed by subindex. The value
ranges are
• Index: 0x0000 …0xFFFF (0...65535
dez
)
• SubIndex: 0x00…0xFF (0...255
dez
)
A parameter localized in this way is normally written as 0x8010:07, with preceding "x" 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: In some EtherCAT devices the channel parameters are stored here (as an alternative to the
0x8000 range).
• 0x6000: Input PDOs ("input" from the perspective of the EtherCAT master)
• 0x7000: Output PDOs ("output" from the perspective of the EtherCAT master)
Note
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:
Basics communication
EL5101, EL5101-0010, EL5101-001126 Version: 4.2
Fig.15: "CoE Online " tab
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
parameterised 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.
Basics communication
EL5101, EL5101-0010, EL5101-0011 27Version: 4.2
Note
Data management
If slave CoE parameters are modified online, Beckhoff devices store any changes in a failsafe 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.
Note
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.
Fig.16: 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.
Basics communication
EL5101, EL5101-0010, EL5101-001128 Version: 4.2
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.17: Offline list
• 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.
Basics communication
EL5101, EL5101-0010, EL5101-0011 29Version: 4.2
Fig.18: 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 4 logical channels and therefore 4 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
hex
steps. The parameter range
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.
4.6 DC settings
Distributed Clocks (DC)
Note
EtherCAT and Distributed Clocks
A basic introduction into EtherCAT and distributed clocks is available for download from the
Beckhoff website: the “Distributed clocks system description”.
The incremental encoder terminals support the distributed clocks function (EL5101: from Hardware 09 /
Firmware 14; EL5151 from Hardware 01 / Firmware 05). In order for the EL51xx to be able to make the
current counter value available in the designated process data in time before the arrival of the querying
EtherCAT datagram, a suitable signal must be generated cyclically within the terminal. This signal can be
triggered in the EL51xx through two events: the SyncManager (SM) and the distributed clock (DC). Under
operation mode selection the following options are available (see Fig. 1)
Basics communication
EL5101, EL5101-0010, EL5101-001130 Version: 4.2
Fig.19: “DC” tab (Distributed Clocks)
• FreeRun/SM-Synchron
The SynManager event occurs when an EtherCAT frame successfully exchanges process data with
the EL51xx. Frame-triggered, the current counter value is thus cyclically determined, but with the low
temporal jitter of the Ethernet frame. In this mode an Ethernet frame triggers the process data provision
for the next retrieving frame. This generally only occurs after 1x cycle time.
• DC Synchronous
In DC mode, a counter reading is triggered by the integrated DC unit with a constant cycle, usually in
synchrony with the bus cycle, although with a constant shift (phase, shift time, offset). Sampling is
significantly more uniform (synchronization accuracy: 100 ns), which means a higher-level control
algorithm can be supplied with higher-quality position data, for example. In the EL51xx the trigger is the
SYNC0 signal, which is set like an output component in “DC-synchron” mode. See Distributed Clocks
system description.
The DC modes enable the start time of the process data provision to be offset by an offset value (shift
value). This offset value can only by set on EtherCAT startup and can then no longer be changed
during the uptime. Based on the general distributed clocks SYNC function model, the terminal-specific
SYNC signal can either occur before or after the expect frame pass-through time: For input terminals
the SYNC signal is generated before the frame, in order to make current input data available for
forwarding. For output terminals the SYNC signal is set to a time after the frame has passed through,
so that the just supplied data are output immediately. Since only one of the two modes is possible, the
user can set the optimum mode for his application.
"DC Synchronous" corresponds to the output module configuration. The local SYNC event is triggered
shortly after the EtherCAT frame has passed.
• DC-Synchron (input based)
In the “DC-Synchronous (input based)” mode this EL51xx is assigned to the group of input modules
and the shift time (see Fig. Advanced Distributed Clock (DC) settings, EL51xx terminal) is calculated
accordingly.
When “DC-Synchronous” operating mode is activated, TwinCAT selects settings that ensure reliable
operation of the EL51xx and the acquisition of current position data. This means that determination of the
current counter value is started by the SYNC0 signal at highly constant intervals and in the operating mode
“DC-Synchronous (input based)” in good time – i.e. with an adequate safety buffer – before the retrieving
EtherCAT datagram.
Note
Duration of the process data provision in the EL51x1
The EL5101 (from Hardware 09 / Firmware 14) or the EL5151 (from Hardware 01/
Firmware 05) requires approx. 80µs after the SYNC event to determine the position data
and provide them for retrieval. This value depends on the configuration and parameterization. The actual current duration can be read using the internal DC functions, see CoE setting in 1C32:08 and the result in 1C32:05.
If necessary, the SYNC0 signal can be shifted along the time axis to the right/later or left/earlier in associated
dialogs by specifying a “User defined Shift Time”, see Fig. Advanced Distributed Clock (DC) settings, EL51xx
terminal.
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