Operating Instructions for

EL2904

TwinSAFE Terminal with 4 digital fail-safe outputs

Version: 2.1.1
Date: 2017-02-07
 Table of contents

Table of contents
1 Foreword .................................................................................................................................................... 5
1.1 Notes on the documentation...........................................................................................................  5
1.2 Safety instructions ..........................................................................................................................  6
1.2.1 Delivery state ..................................................................................................................... 6
1.2.2 Operator's obligation to exercise diligence ........................................................................ 6
1.2.3 Description of safety symbols ............................................................................................ 7
1.3 Documentation issue status............................................................................................................  8

2 System description ................................................................................................................................... 9

2.1 The Beckhoff Bus Terminal system ................................................................................................  9
2.1.1 Bus Coupler ..................................................................................................................... 10
2.1.2 Bus Terminals .................................................................................................................. 11
2.1.3 E-bus................................................................................................................................ 11
2.1.4 Power contacts................................................................................................................. 11
2.2 TwinSAFE.....................................................................................................................................  12
2.2.1 The I/O construction kit is extended safely ...................................................................... 12
2.2.2 Safety concept ................................................................................................................. 12
2.2.3 EL1904, EL2904 - Bus Terminals with 4 fail-safe inputs or outputs ................................ 13
2.2.4 EL6900 - TwinSAFE logic terminal .................................................................................. 13
2.2.5 The fail-safe principle (Fail Stop) ..................................................................................... 13

3 Product description................................................................................................................................. 14
3.1 EL2904 – TwinSAFE terminal with 4 digital fail-safe outputs .......................................................  14
3.2 Intended use .................................................................................................................................  14
3.3 Technical data ..............................................................................................................................  16
3.4 Safety parameters ........................................................................................................................  17
3.5 Dimensions ...................................................................................................................................  18
3.6 Block diagram of the EL2904........................................................................................................  19

4 Operation.................................................................................................................................................. 20
4.1 Environmental conditions..............................................................................................................  20
4.2 Installation.....................................................................................................................................  20
4.2.1 Safety instructions............................................................................................................ 20
4.2.2 Transport / storage........................................................................................................... 20
4.2.3 Mechanical installation ..................................................................................................... 20
4.2.4 Electrical installation......................................................................................................... 24
4.2.5 TwinSAFE reaction times................................................................................................. 30
4.2.6 Tested EL2904 devices ................................................................................................... 31
4.3 Operation in potentially explosive atmospheres (ATEX) ..............................................................  32
4.3.1 Special conditions ............................................................................................................ 32
4.3.2 Identification ..................................................................................................................... 33
4.3.3 Date code and serial number ........................................................................................... 33
4.3.4 Further ATEX documentation .......................................................................................... 33
4.4 Configuration of the terminal in TwinCAT .....................................................................................  33
4.4.1 Inserting a Bus Coupler ................................................................................................... 33
4.4.2 Inserting a Bus Terminal .................................................................................................. 34
4.4.3 Inserting an EL2904 ......................................................................................................... 34
4.4.4 Address settings on TwinSAFE terminals with 1023 possible addresses........................ 35
4.4.5 Entering a TwinSAFE address and parameters in the System Manager......................... 35
4.5 Diagnostics ...................................................................................................................................  37
4.5.1 Diagnostic LEDs............................................................................................................... 37
4.5.2 Diagnostic objects ............................................................................................................ 39

EL2904 Version: 2.1.1 3

Table of contents

4.5.3 Possible causes of diagnostic messages ........................................................................ 41

4.6 Maintenance .................................................................................................................................  41
4.7 Service life ....................................................................................................................................  42
4.8 Decommissioning .........................................................................................................................  43

5 Appendix .................................................................................................................................................. 44
5.1 Support and Service .....................................................................................................................  44
5.2 Certificates....................................................................................................................................  45

4 Version: 2.1.1 EL2904

 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 following notes and explanations are followed when installing and commissioning
these components.

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.

Origin of the document

This documentation was originally written in German. All other languages are derived from the German
original.

Currentness

Please check whether you are using the current and valid version of this document. The current version can
be downloaded from the Beckhoff homepage at http://www.beckhoff.com/english/download/twinsafe.htm.
In case of doubt, please contact Technical Support [} 44].

Product features

Only the product features specified in the current user documentation are valid. Further information given on
the product pages of the Beckhoff homepage, in emails or in other publications is not authoritative.

Disclaimer

The documentation has been prepared with care. The products described are subject to cyclical revision. For
that reason the documentation is not in every case checked for consistency with performance data,
standards or other characteristics. 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.

EL2904 Version: 2.1.1 5

Foreword

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.

Delivery conditions

In addition, the general delivery conditions of the company Beckhoff Automation GmbH & Co. KG apply.

1.2 Safety instructions

1.2.1 Delivery state

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.

1.2.2 Operator's obligation to exercise diligence

The operator must ensure that
• the TwinSAFE products are only used as intended (see chapter Product description);
• the TwinSAFE products are only operated in sound condition and in working order.
• the TwinSAFE products are operated only by suitably qualified and authorized personnel.
• the personnel is instructed regularly about relevant occupational safety and environmental protection
aspects, and is familiar with the operating instructions and in particular the safety instructions contained
herein.
• the operating instructions are in good condition and complete, and always available for reference at the
location where the TwinSAFE products are used.
• none of the safety and warning notes attached to the TwinSAFE products are removed, and all notes
remain legible.

6 Version: 2.1.1 EL2904

 Foreword

1.2.3 Description of safety symbols

In these operating instructions the following symbols are used with an accompanying safety instruction or
note. The safety instructions must be read carefully and followed without fail!

Serious risk of injury!

Failure to follow the safety instructions associated with this symbol directly endangers the
life and health of persons.
DANGER

Risk of injury!
Failure to follow the safety instructions associated with this symbol endangers the life and
health of persons.
WARNING

Personal injuries!
Failure to follow the safety instructions associated with this symbol can lead to injuries to
persons.
CAUTION

Damage to the environment or devices

Failure to follow the instructions associated with this symbol can lead to damage to the en-
vironment or equipment.
Attention

Tip or pointer
This symbol indicates information that contributes to better understanding.

Note

EL2904 Version: 2.1.1 7

Foreword

1.3 Documentation issue status

Version Comment
2.1.1 • Technical data permissible air pressure expanded
2.1.0 • Chapter Address settings on TwinSAFE terminals with 1023 possible addresses updated
• Links in technical data corrected
2.0.1 • Links at chapter Diagnostic LEDs corrected
2.0.0 • Migration and structural adaptation
• Reliability document updated
• Safety parameters updated
• Foreword revised
1.6.2 • Block diagram updated
• Numbering/table of contents changed
• Description of the reaction times added
• Reliability document updated
1.6.1 • Certificate updated
1.6.0 • Company address amended
• Safety parameters extended
1.5.0 • Extended temperature range amended
• Notes regarding temperature measurement and EMC added
• Description of date code extended
1.4.1 • Document origin added
1.4.0 • Note regarding cable length and signal routing extended
• Table listing causes for diagnostic messages amended
1.3.0 • Block diagram for EL2904 added
1.2.1 • Reference to EN 60068-2-29 removed
1.2.0 • ATEX notes amended
• Installation position / minimum distances extended
• Notes regarding overvoltage protection amended
• Notes regarding cable length and clocked signals extended
• EN954 wiring example removed
• Diagnostics for CoE object 0x800E described
1.1.0 • Minor amendments for EtherCAT
• Copyright / disclaimer modified
• Support / service addresses updated
1.0.0 • First released version

8 Version: 2.1.1 EL2904

 System description

2 System description

2.1 The Beckhoff Bus Terminal system

The Beckhoff Bus Terminal system is used for decentralized connection of sensors and actuators to a
control system. The Beckhoff Bus Terminal system components are mainly used in industrial automation and
building management applications. In its minimum configuration, a bus station consists of a Bus Coupler or a
Bus Terminal Controller and Bus Terminals connected to it. The Bus Coupler forms the communication
interface to the higher-level controller, and the terminals are the interface to sensors and actuators. The
whole bus station is clipped onto a 35 mm DIN mounting rail (EN 60715). The mechanical cross connection
of the bus station is established via a slot and key system at the Bus Coupler and the Bus Terminals.

The sensors and actuators are connected with the terminals via the screwless (spring-loaded) connection
system.

Fig. 1: Slot and key system and screwless (spring-loaded) connection system.

In order to accommodate the wide range of different communication standards encountered in industrial
automation, Beckhoff offers Bus Couplers for a number of common bus systems (e.g. EK1100 for
EtherCAT).

EL2904 Version: 2.1.1 9

System description

2.1.1 Bus Coupler

Mechanical data Bus Coupler
Material polycarbonate, polyamide (PA6.6).
Dimensions (W x H x D) 44 mm x 100 mm x 68 mm
Mounting on 35 mm mounting rail (EN 60715) with locking
Attachable by double slot and key connection

Fig. 2: Bus Coupler (EtherCAT)

Connection technology Bus Coupler

Wiring spring-loaded system
Connection cross-section 0.08 mm² ... 2.5 mm², stranded wire, solid wire
Fieldbus connection depending on fieldbus
Power contacts 3 spring contacts
Current load 10 A
Rated voltage 24 VDC

10 Version: 2.1.1 EL2904

 System description

2.1.2 Bus Terminals

Mechanical data Bus Terminal
Material polycarbonate, polyamide (PA6.6).
Dimensions (W x H x D) 12 mm x 100 mm x 68 mm or 24 mm x 100 mm x 68 mm
Mounting on 35 mm mounting rail (EN 60715) with locking
Attachable by double slot and key connection

Fig. 3: TwinSAFE Terminals (EtherCAT)

Connection technology Bus Terminal

Wiring spring-loaded system
Connection cross-section 0.08 mm² ... 2.5 mm², stranded wire, solid wire
Fieldbus connection E-bus
Power contacts up to 3 blade/spring contacts
Current load 10 A
Rated voltage depends on Bus Terminal type

2.1.3 E-bus
The E-bus is the data path within a terminal strip. The E-bus is led through from the Bus Coupler through all
the terminals via six contacts on the terminals' side walls.

2.1.4 Power contacts

The operating voltage is passed on to following terminals via three power contacts. Terminal strip can be
split into galvanically isolated groups by means of potential feed terminals as required. The power feed
terminals play no part in the control of the terminals, and can be inserted at any locations within the terminal
strip.

EL2904 Version: 2.1.1 11

System description

2.2 TwinSAFE

2.2.1 The I/O construction kit is extended safely

With the TwinSAFE Terminals, Beckhoff offers the option of simply expanding the proven Bus Terminal
system, and to transfer the complete cabling for the safety circuit into the already existing fieldbus cable.
Safe signals can be mixed with standard signals without restriction. This saves design effort, installation and
material. Maintenance is simplified significantly through faster diagnosis and simple replacement of only a
few components.

The new ELx9xx series Bus Terminals only include three basic functionalities: digital inputs EL19xx, digital
outputs EL29xx and a logic unit EL6900. For a large number of applications, all sensors and actuators can
be wired on these Bus Terminals. The required logical link of the inputs and the outputs is handled by the
EL6900. For small to medium-sized configurations, the tasks of a fail-safe PLC can thus be handled within
the Bus Terminal system.

2.2.2 Safety concept

TwinSAFE: Safety and I/O technology in one system

• Extension of the familiar Beckhoff I/O system with TwinSAFE terminals
• Freely selectable mix of safe and standard signals
• Logical link of the I/Os in the EL6900 TwinSAFE logic terminal
• Safety-relevant networking of machines via bus systems

TwinSAFE protocol (FSoE)

• Transfer of safety-relevant data via any media (“genuine black channel”)
• TwinSAFE communication via fieldbus systems such as EtherCAT, Lightbus, PROFIBUS or Ethernet
• IEC 61508:2010 SIL 3 compliant

Configuring instead of wiring: the TwinSAFE configurator

• Configuration of the TwinSAFE system via the TwinCAT System Manager
• System Manager for editing and displaying all bus parameters
• Certified function blocks such as emergency stop, operation mode, etc.
• Simple handling
• Typical function blocks for machine safety
• any bus connection with the EL6900 TwinSAFE logic terminal

TwinSAFE logic Bus Terminal EL6900

• Link unit between TwinSAFE input and output terminals
• Configuration of a simple, flexible, cost-effective, decentralized safety controller
• No safety requirements for higher-level control system
• TwinSAFE enables networks with up to 65535 TwinSAFE devices
• TwinSAFE logic terminal can establish up to 128 connections (TwinSAFE connections).
• Several TwinSAFE logic terminals are cascadable in a network
• Safety functions such as emergency stop, protective door, etc. are already included
• Suitable for applications up to SIL 3 according to IEC 61508:2010 and
DIN EN ISO 13849-1:2006 (Cat 4, PL e).

TwinSAFE digital input (EL1904) and output terminal (EL2904)

• All current safety sensors can be connected

12 Version: 2.1.1 EL2904

 System description

• Operation with a TwinSAFE logic terminal

• EL1904 with 4 fail-safe inputs for sensors (24 VDC) with floating contacts
• EL2904 with four safe channels for actuators (24 VDC, 0.5 A per channel)
• Conforming to IEC 61508:2010 SIL 3 and DIN EN ISO 13849-1:2006 (Cat 4, PL e) requirements.

2.2.3 EL1904, EL2904 - Bus Terminals with 4 fail-safe inputs or

outputs
The EL1904 and EL2904 Bus Terminals enable connection of common safety sensors and actuators. They
are operated with the EL6900 TwinSAFE logic terminal. The TwinSAFE logic terminal is the link unit between
the TwinSAFE input and output terminals. It enables the configuration of a simple, flexible and cost-effective
decentralized safety control system.

Therefore, there are no safety requirements for the higher-level controller! The typical safety functions
required for the automation of machines, such as emergency stop, protective door, two-hand etc., are
already permanently programmed in the EL6900. The user configures the EL6900 terminal according to the
safety requirements of his application.

2.2.4 EL6900 - TwinSAFE logic terminal

The TwinSAFE logic terminal is the link unit between the TwinSAFE input and output terminals. The EL6900
meets the requirements of IEC 61508:2010 SIL 3, EN 954 Cat. 4 and DIN EN ISO 13849-1:2006 (Cat 4, PL
e).

2.2.5 The fail-safe principle (Fail Stop)

The basic rule for a safety system such as TwinSAFE is that failure of a part, a system component or the
overall system must never lead to a dangerous condition. The safe state is always the switched off and
wattless state.

EL2904 Version: 2.1.1 13

Product description

3 Product description

3.1 EL2904 – TwinSAFE terminal with 4 digital fail-safe

outputs
The EL2904 is a safe output terminal with digital outputs for connecting actuators (contactors, relays, etc.)
with a maximum current 0.5 A (24 VDC). The Bus Terminal has 4 fail-safe outputs.

The EL2904 meets the requirements of IEC 61508:2010 SIL 3, DIN EN ISO 13849-1:2006 (Cat 4, PL e),
NRTL, UL508, UL1998 and UL991.

The TwinSAFE terminal has the typical design of an EtherCAT terminal.

Fig. 4: EL2904 – TwinSAFE terminal with 4 digital fail-safe outputs

3.2 Intended use

Caution - Risk of injury!
TwinSAFE components may only be used for the purposes described below!

WARNING

The TwinSAFE terminals expand the application range of Beckhoff Bus Terminal system with functions that
enable them to be used for machine safety applications. The TwinSAFE terminals are designed for machine
safety functions and directly associated industrial automation tasks. They are therefore only approved for
applications with a defined fail-safe state. This safe state is the wattless state. Fail-safety according to the
relevant standards is required.

The TwinSAFE Terminals enable connection of:

• 24 VDC sensors (EL1904) such as
emergency off pushbutton switches, pull cord switches, position switches, two-hand switches, safety
mats, light curtains, light barriers, laser scanner, etc.

14 Version: 2.1.1 EL2904

 Product description

• 24 VDC actuators (EL2904) such as

contactors, protection door switches with tumbler, signal lamps, servo drives, etc.

Test pulses
When selecting actuators please ensure that the EL2904 test pulses do not lead to actuator
switching or diagnostic message from the EL2904.
Note

The following TwinSAFE components have been developed for these tasks:
• The EL1904 is an EtherCAT Terminal with 4 digital fail-safe inputs.
• The EL2904 is an EtherCAT Terminal with 4 digital fail-safe outputs.
• The EL6900 is an EtherCAT Terminal with integrated TwinSAFE logic.

These TwinSAFE components are suitable for operation on the

• Beckhoff EKxxxx series Bus Couplers
• Beckhoff CXxxxx series Embedded PCs with E-bus connection

Power supply from SELV/PELV power supply unit!

The TwinSAFE components must be supplied with 24 VDC by an SELV/PELV power supply
unit with an output voltage limit Umax of 36 VDC. Failure to observe this can result in a loss of
WARNING safety.

Follow the machinery directive!

The TwinSAFE components may only be used in machines as defined in the machinery di-
rective.
CAUTION

Ensure traceability!
The buyer has to ensure the traceability of the device via the serial number.

CAUTION

EL2904 Version: 2.1.1 15

Product description

3.3 Technical data

Product designation EL2904
Number of outputs 4
Status display 4 (one green LED per output)
Error reaction time ≤ watchdog times
Output current per channel max. 500 mA, min. 20 mA with parameter current measurement
active set
Actuators When selecting actuators please ensure that the EL2904 test
pulses do not lead to actuator switching.
Cable length between actuator and terminal unshielded max. 100 m
shielded max. 100 m
Wire cross section min. 0.75 mm2
Input process image 6 bytes
Output process image 6 bytes
EL2904 supply voltage (PELV) 24 VDC (–15%/+20%)
Current consumption via E-bus approx. 221 mA
Power dissipation of the terminal typically 2 W
Electrical isolation (between the channels) no
Electrical isolation (between the channels and the E-bus) yes
Insulation voltage (between the channels and the E-bus, under com- insulation tested with 500 VDC
mon operating conditions)
Dimensions (W x H x D) 24mm x 100mm x 68mm
Weight approx. 100 g
Permissible ambient temperature (operation) 0°C to +55°C (see notes in chapter Example configuration for
up to SW 03 temperature measurement [} 22])
Permissible ambient temperature (operation) -25°C to +55 °C (see notes in chapter Example configuration for
from SW 04 (week 02/2014) temperature measurement [} 22])
Permissible ambient temperature (transport/storage) -40°C to +70°C
Permissible air humidity 5% to 95%, non-condensing
Permissible air pressure (operation/storage/transport) 750 hPa to 1100 hPa
(this corresponds to a height of approx. -690 m to 2450 m over
sea level assuming an international standard atmosphere)
Climate category according to EN 60721-3-3 3K3
(the deviation from 3K3 is possible only with optimal environmen-
tal conditions and also applies only to the technical data which
are specified differently in this documentation)
Permissible level of contamination level of contamination 2
according to EN 60664-1 (comply with the chapter Maintenance [} 41])
Impermissible operating conditions TwinSAFE terminals must not be used under the following oper-
ating conditions:
• under the influence of ionizing radiation (that exceeds the
level of the natural environmental radiation)
• in corrosive environments
• in an environment that leads to unacceptable soiling of
the Bus Terminal
EMC immunity/emission conforms to EN 61000-6-2 / EN 61000-6-4
Vibration/shock resistance conforms to EN 60068-2-6 / EN 60068-2-27
Shocks 15 g with pulse duration 11 ms in all three axes
Protection class IP20
Permitted operating environment In the control cabinet or terminal box, with minimum protection
class IP54 according to IEC 60529
Permissible installation position see chapter Installation position and minimum distances [} 21]
Approvals CE, cULus, ATEX, TÜV SÜD

16 Version: 2.1.1 EL2904

 Product description

3.4 Safety parameters

Key figures EL2904
Lifetime [a] 20
Prooftest Interval [a] not required 1
PFHD 1.25E-09
%SIL3 1,25 %
PFD 8.45E-05
%SIL3 8,45 %
MTTFd high
DC high
Performance level PL e
Category 4
HFT 1
Element classification 2 Type B

1. Special proof tests are not required during the entire service life of the EL2904 EtherCAT terminal.
2. Classification according to IEC 61508-2:2010 (chapter 7.4.4.1.2 and 7.4.4.1.3)

The EL2904 EtherCAT Terminal can be used for safety-related applications within the meaning of
IEC 61508:2010 up to SIL3 and EN ISO 13849-1 up to PL e (Cat4).

For the calculation or estimation of the MTTFd value from the PFHD value, further information can be found in
the TwinSAFE application manual or in ISO 13849-1:2015 Table K.1.

EL2904 Version: 2.1.1 17

Product description

3.5 Dimensions

Fig. 5: Dimensions of the EL2904

Width: 24 mm (side-by-side installation)

Height: 100 mm
Depth: 68 mm

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 Product description

3.6 Block diagram of the EL2904

Fig. 6: Block diagram of the EL2904

The block diagram shows the basic configuration of a channel in the EL2904. The part with a red border is
present four times in the terminal. The high-side and low-side switches only exist once for all channels. This
means that each channel has a total of four stop paths.

EL2904 Version: 2.1.1 19

Operation

4 Operation

4.1 Environmental conditions

Please ensure that the TwinSAFE components are only transported, stored and operated under the specified
conditions (see technical data)!

Risk of injury!
The TwinSAFE components must not be used under the following operating conditions.
• under the influence of ionizing radiation (that exceeds the level of the natural environ-
WARNING
mental radiation)
• in corrosive environments
• in an environment that leads to unacceptable soiling of the TwinSAFE component

Electromagnetic compatibility
The TwinSAFE components comply with the current standards on electromagnetic compat-
ibility with regard to spurious radiation and immunity to interference in particular.
Attention However, in cases where devices such as mobile phones, radio equipment, transmitters or
high-frequency systems that exceed the interference emissions limits specified in the stan-
dards are operated near TwinSAFE components, the function of the TwinSAFE compo-
nents may be impaired.

4.2 Installation

4.2.1 Safety instructions

Before installing and commissioning the TwinSAFE components please read the safety instructions in the
foreword of this documentation.

4.2.2 Transport / storage

Use the original packaging in which the components were delivered for transporting and storing the
TwinSAFE components.

Note the specified environmental conditions

Please ensure that the digital TwinSAFE components are only transported and stored un-
der the specified environmental conditions (see technical data).
CAUTION

4.2.3 Mechanical installation

Risk of injury!
Bring the bus system into a safe, de-energized state before starting installation, disassem-
bly or wiring of the devices!
DANGER

4.2.3.1 Control cabinet / terminal box

The TwinSAFE terminals must be installed in a control cabinet or terminal box with IP54 protection class
according to IEC 60529 as a minimum.

20 Version: 2.1.1 EL2904

 Operation

4.2.3.2 Installation position and minimum distances

For the prescribed installation position the mounting rail is installed horizontally and the mating surfaces of
the EL/KL terminals point toward the front (see illustration below). The terminals are ventilated from below,
which enables optimum cooling of the electronics through convection. The direction indication “down”
corresponds to the direction of positive acceleration due to gravity.

Fig. 7: Installation position and minimum distances

In order to ensure optimum convection cooling, the distances to neighboring devices and to control cabinet
walls must not be smaller than those shown in the diagram.

EL2904 Version: 2.1.1 21

Operation

4.2.3.3 Example configuration for temperature measurement

Fig. 8: Example configuration for temperature measurement

The example configuration for the temperature measurement consists of an EK1100 EtherCAT coupler with
connected terminals that match the typical distribution of digital and analog signal types at a machine. On the
EL6900 a safety project is active, which reads safe inputs and enables all 4 safe outputs during the
measurement.

External heat sources / radiant heat / impaired convection

The maximum permissible ambient temperature of 55°C was checked with the above ex-
ample configuration. Impaired convection, an unfavorable location near heat sources or an
Note unfavorable configuration of the EtherCAT Terminals may result in overheating of the termi-
nals.
The key parameter is always the maximum permitted internally measured temperature of
95°C, above which the TwinSAFE terminals switch to safe state and report an error. The in-
ternal temperature can be read from the TwinSAFE components via CoE (see chapter Di-
agnose).

22 Version: 2.1.1 EL2904

 Operation

4.2.3.4 Installation on mounting rails

Mounting

The Bus Couplers and Bus Terminals are attached to commercially available 35 mm mounting rails
(according to EN 60715) by applying slight pressure:

Fig. 9: Installation on the mounting rail

1. First attach the Fieldbus Coupler to the mounting rail.

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

Fastening of mounting rails

The locking mechanism of the terminals and couplers protrudes into the profile of the
mounting rail. When installing the components, make sure that the locking mechanism
Note doesn't come into conflict with the fixing bolts of the mounting rail. For fastening mounting
rails with a height of 7.5 mm under the terminals and couplers, use flat fastening compo-
nents such as countersunk head screws or blind rivets.

EL2904 Version: 2.1.1 23

Operation

Removal

Fig. 10: Removal of mounting rails

1. Carefully pull the orange-colored lugs approximately 1 cm out of the disassembled terminal, until they
protrude loosely. The lock with the mounting rail is now released for this terminal, and the terminal can
be pulled from the mounting rail without excessive force.
2. Grasp the released terminal with thumb and index finger simultaneous at the upper and lower grooved
housing surfaces and pull the terminal away from the mounting rail.

4.2.4 Electrical installation

4.2.4.1 Connections within a Bus Terminal block

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

Spring contacts (E-bus)

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

Observe the E-bus current

Observe the maximum current that your Bus Coupler can supply to the E-bus! Use the
EL9410 Power Supply Terminal if the current consumption of your terminals exceeds the
Note maximum current that your Bus Coupler can feed to the E-bus supply.

Power contacts

The power contacts deal with the supply for the field electronics and thus represent a supply rail within the
Bus Terminal block. The power contacts are supplied via terminals on the Bus Coupler.

Note the connection of the power contacts

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

24 Version: 2.1.1 EL2904

 Operation

PE power contact

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

Fig. 11: PE power contact

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

Serious risk of injury!

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

DANGER

4.2.4.2 Overvoltage protection

If protection against overvoltage is necessary in your plant, provide a surge filter for the voltage supply to the
Bus Terminal blocks and the TwinSAFE terminals.

EL2904 Version: 2.1.1 25

Operation

4.2.4.3 Wiring

Fig. 12: Connection of a cable to a terminal point

Up to eight connections enable the connection of solid or finely stranded cables to the Bus Terminals. The
connections are implemented in spring-loaded technology. Connect the cables as follows:

1. Open a spring-loaded terminal by slightly pushing with a screwdriver or a rod into the square opening
above the terminal.
2. The wire can now be inserted into the round terminal opening without any force.
3. The terminal closes automatically when the pressure is released, holding the wire safely and perma-
nently.
Wire cross section 0,08 ... 2.5 mm2
Strip length 8 ... 9 mm

26 Version: 2.1.1 EL2904

 Operation

4.2.4.4 EL2904 pin assignment

Fig. 13: EL2904 pin assignment

Terminal point Output Signal

1 - not used, no function
2 positive power contact
3 - negative power contact
4 not used, no function
5 - not used, no function
6 positive power contact
7 - negative power contact
8 not used, no function
1’ 1 Output 1+
2’ Output 1-
3’ 3 Output 3+
4’ Output 3-
5’ 2 Output 2+
6’ Output 2-
7’ 4 Output 4+
8’ Output 4-

Test pulses
When selecting actuators please ensure that the EL2904 test pulses do not lead to actuator
switching or diagnostic message from the EL2904.
Note

EL2904 Version: 2.1.1 27

Operation

4.2.4.5 Signal cables

Permitted cable length

Fig. 14: Permitted cable length

When connecting a single actuator via its own continuous cabling (or via a sheathed cable), the maximum
permitted cable length is 100 m.

The use of contact points, connectors or additional actuators in the cabling reduces the maximum
propagation.

Cable routing

Fig. 15: Cable routing

28 Version: 2.1.1 EL2904

 Operation

Route the signal cable separately

The signal cable must be routed separately from potential sources of interference, such as
motor supply cables, 230 VAC power cables etc.!
Attention Interference caused by cables routed in parallel can influence the signal form of the test
pulses and thus cause diagnostic messages (e.g. sensor errors or OpenLoad errors).
D: Distance between the cable ducts should be as large as possible
blue arrows: signal line
red arrows: potential source of interference

The common routing of signals together with other clocked signals in a common cable also reduces the
maximum propagation, since crosstalk of the signals can occur over long cable lengths and cause diagnostic
messages.

If connection via a bus cable is unavoidable, the test pulses can be switched off (parameters Testing of
outputs active and Current measurement active). However, this then leads to a reduction in the degree of
diagnostic cover when calculating the performance level.

Test pulses

The typical length of test pulse (switching from 24 V to 0 V and back to 24 V) is 300 µs to 800 µs. Testing
usually takes place 5 to 7 times per second.

Test pulses for the outputs

The following diagram shows a typical test pulse curve for the four outputs of an EL2904.
The parameters Current measurement active and Testing of outputs active are enabled.
Note

Fig. 16: Typical course of test pulses of the outputs

EL2904 Version: 2.1.1 29

Operation

4.2.5 TwinSAFE reaction times

The TwinSAFE terminals form a modular safety system that exchanges safety-oriented data via the Safety-
over-EtherCAT protocol. This chapter is intended to help you determine the system's reaction time from the
change of signal at the sensor to the reaction at the actuator.

Typical reaction time

The typical reaction time is the time that is required to transmit information from the sensor to the actuator, if
the overall system is working without error in normal operation.

Fig. 17: Typical reaction time

Definition Description
RTSensor Reaction time of the sensor until the signal is provided at the interface. Typically supplied by
the sensor manufacturer.
RTInput Reaction time of the safe input, such as EL1904 or EP1908. This time can be found in the
technical data. In the case of the EL1904 it is 4 ms.
RTComm Reaction time of the communication This is typically 3x the EtherCAT cycle time, because
new data can only be sent in a new Safety-over-EtherCAT telegram. These times depend
directly on the higher-level standard controller (cycle time of the PLC/NC).
RTLogic Reaction time of the logic terminal. This is the cycle time of the logic terminal and typically
ranges from 500 µs to 10 ms for the EL6900, depending on the size of the safety project.
The actual cycle time can be read from the terminal.
RTOutput Reaction time of the output terminal. This typically lies within the range of 2 to 3 ms.
RTActor Reaction time of the actuator. This information is typically supplied by the actuator
manufacturer
WDComm Watchdog time of the communication

This results in the following equation for the typical reaction time:

with, for example

Worst-case reaction time

The worst case reaction time is the maximum time required to switch off the actuator in the case of an error.

30 Version: 2.1.1 EL2904

 Operation

Fig. 18: Worst-case reaction time

This assumes that a signal change occurs at the sensor and is transmitted to the input. A communication
error occurs at precisely the moment when the signal is to be transferred to the communication interface.
This is detected by the logic following the watchdog time of the communication link. This information should
then be transferred to the output, but a further communication error occurs here. This error is detected at the
output following the expiry of the watchdog time and leads to the switch-off.

This results in the following equation for the worst-case reaction:

with, for example

4.2.6 Tested EL2904 devices

The following list contains devices that were tested together with the EL2904 TwinSAFE terminal. The
results only apply for the current device hardware version at the time of testing. The tests were carried out in
a laboratory environment. Modifications of these products cannot be considered here. If you are unsure
please test the hardware together with the TwinSAFE terminal.

Manufacturer Type Comment

Beckhoff AX5801 TwinSAFE Drive option card: safe restart lock
Beckhoff AX2000 AS option safe restart lock
Siemens SIRIUS series S00 Contactor
3RT1016-1BB42
Telemecanique LP1K09 Contactor

The tests were carried out as function tests only. The information provided in the respective manufacturer
documentation remains valid.

Recommended protective circuits

We recommend R/C or diode-based protective circuits for these devices.
Varistor-based protective circuits should not be used.
Note

EL2904 Version: 2.1.1 31

Operation

4.3 Operation in potentially explosive atmospheres (ATEX)

4.3.1 Special conditions

Observe the special conditions for the intended use of Beckhoff fieldbus
components in potentially explosive areas (directive 94/9/EU)!
The certified components are to be installed in a suitable housing that guarantees a protec-
WARNING tion class of at least IP54 in accordance with EN 60529! The environmental conditions dur-
ing use are thereby to be taken into account!
If the temperatures during rated operation are higher than 70 °C at the feed-in points of ca-
bles, lines or pipes, or higher than 80°C at the wire branching points, then cables must be
selected whose temperature data correspond to the actual measured temperature values!
Observe the permissible ambient temperature range of 0 to 55 °C when using Beckhoff
fieldbus components in potentially explosive atmospheres!
Measures must be taken to protect against the rated operating voltage being exceeded by
more than 40% due to short-term interference voltages!
The individual terminals may only be unplugged or removed from the Bus Terminal system
if the supply voltage has been switched off or if a non-explosive atmosphere is ensured!
The connections of the certified components may only be connected or disconnected if the
supply voltage has been switched off or if a non-explosive atmosphere is ensured!
The fuses of the EL92xx power feed terminals may only be exchanged if the supply voltage
has been switched off or if a non-explosive atmosphere is ensured!
Address selectors and ID switches may only be adjusted if the supply voltage has been
switched off or if a non-explosive atmosphere is ensured!

The fundamental health and safety requirements are fulfilled by compliance with the following standards:
• EN 60079-0: 2006
• EN 60079-15: 2005

32 Version: 2.1.1 EL2904

 Operation

4.3.2 Identification
Beckhoff fieldbus components that are certified for use in potentially explosive atmospheres bear one of the
following markings:

II 3 G Ex nA II T4 KEMA 10ATEX0075 X Ta: 0 - 55°C

or

II 3 G Ex nA nC IIC T4 KEMA 10ATEX0075 X Ta: 0 - 55°C

4.3.3 Date code and serial number

The TwinSAFE terminals bear a date code, which is composed as follows:

Date code: CW  YY  SW  HW
Legend: Sample: Date code 29 10 02 01
CW: Calendar week of manufacture Calendar week: 29
YY: Year of manufacture Year: 2010
SW: Software version Software version: 02
HW: Hardware version Hardware version: 01

In addition the TwinSAFE terminals bear a unique serial number.

4.3.4 Further ATEX documentation

Please also refer to the further documentation
Notes regarding application of the Bus Terminal system in areas potentially explosive at-
mosphere are available in the Download section of the Beckhoff website at http://
Note
www.beckhoff.de.

4.4 Configuration of the terminal in TwinCAT

Do not change CoE objects!
Do not change any of the CoE objects in the TwinSAFE terminals. Any modifications (e.g.
via TwinCAT) of the CoE objects will permanently set the terminals to the Fail-Stop state or
CAUTION lead to unexpected behavior of the terminals!

4.4.1 Inserting a Bus Coupler

See TwinCAT automation software documentation.

EL2904 Version: 2.1.1 33

Operation

4.4.2 Inserting a Bus Terminal

See TwinCAT automation software documentation.

4.4.3 Inserting an EL2904

An EL2904 is inserted in the same way as any other Beckhoff Bus Terminal. In the list open Safety
Terminals (ELx9xx) and select the EL2904.

Fig. 19: Inserting an EL2904

34 Version: 2.1.1 EL2904

 Operation

4.4.4 Address settings on TwinSAFE terminals with 1023 possible

addresses

Fig. 20: Address settings on TwinSAFE terminals with 1023 possible addresses

The TwinSAFE address of the terminal is set via the 10-way DIP switch on the left-hand side of the
TwinSAFE terminal. TwinSAFE addresses between 1 and 1023 are available.

DIP switch Address

1 2 3 4 5 6 7 8 9 10
ON OFF OFF OFF OFF OFF OFF OFF OFF OFF 1
OFF ON OFF OFF OFF OFF OFF OFF OFF OFF 2
ON ON OFF OFF OFF OFF OFF OFF OFF OFF 3
OFF OFF ON OFF OFF OFF OFF OFF OFF OFF 4
ON OFF ON OFF OFF OFF OFF OFF OFF OFF 5
OFF ON ON OFF OFF OFF OFF OFF OFF OFF 6
ON ON ON OFF OFF OFF OFF OFF OFF OFF 7
... ... ... ... ... ... ... ... ... ... ...
ON ON ON ON ON ON ON ON ON ON 1023

TwinSAFE address
Each TwinSAFE address may only be used once within a network / a configuration!
The address 0 is not a valid TwinSAFE address!
WARNING

4.4.5 Entering a TwinSAFE address and parameters in the System

Manager
The FSoE address set at the DIP switch must also be entered under the FSoE tab (FSoE_Address entry).

EL2904 Version: 2.1.1 35

Operation

Fig. 21: Entering the FSoE address

The EL2904 parameters are set under the respective TwinSAFE connection in the Connection and
Parameter tabs.

Fig. 22: Setting the connection of the TwinSAFE connection

36 Version: 2.1.1 EL2904

 Operation

Fig. 23: Setting the parameters of the TwinSAFE connection

Parameter overview

PrmName Meaning Values

Standard outputs In addition the output can be switched off from the standard PLC. The safe true /
active output is linked with the standard logic signal AND. false
Current Current measurement for the outputs is activated true /
measurement false
active
Testing of outputs Test pulses for the outputs are activated true /
active false
Error acknowledge True: true /
active Terminal errors lead to a reset of the TwinSAFE connection (error code 14 false
(0x0E)). This error code is shown in the diagnostic data for the connection
until the user acknowledges it via ErrAck in the TwinSAFE group.
False (Default):
Terminal errors can only be reset by switching the power supply off and back
on again.
Store Code This parameter is required for the TwinSAFE Restore Mode 0x0000
Project CRC This parameter is required for the TwinSAFE Restore Mode 0x0000

Test pulses
If the parameters Current Measurement active or Testing of outputs active are set to TRUE,
the terminal generates test pulses at the outputs.
Note
To avoid generating test pulses at the channel outputs, Testing of outputs active and Cur-
rent measurement active must be set to FALSE.
Please note that deactivating of Current measurement active and/or Testing of outputs ac-
tive may reduce the achievable performance level.
A calculation example for the performance level can be found in the TwinSAFE application
manual.
There are no known application for which it would make sense to set Testing of outputs ac-
tive to FALSE, while Current measurement active is set to TRUE.

4.5 Diagnostics

4.5.1 Diagnostic LEDs

The LEDs Diag 1 to Diag 4 display diagnostic information for the EL2904.

EL2904 Version: 2.1.1 37

Operation

Fig. 24: Diagnostic LEDs

Diag 1 (green)

The Diag 1 LED indicates the state of the TwinSAFE interface (in preparation).

Flashing Code Meaning

LED illuminated continuously Diagnostic flashing code in preparation

Diag 2 (red)

The Diag 2 LED indicates the state of the digital outputs.

Flashing Code Meaning (see chapterPossible causes of diagnos-

tic messages [} 41])
rapid flickering, alternating with 1 flash pulse Error at output 1
rapid flickering, alternating with 2 flash pulses Error at output 2
rapid flickering, alternating with 3 flash pulses Error at output 3
rapid flickering, alternating with 4 flash pulses Error at output 4
rapid flickering, alternating with 5 flash pulses Field voltage too low
rapid flickering, alternating with 6 flash pulses Field voltage too high
rapid flickering, alternating with 7 flash pulses Internal terminal temperature too low
rapid flickering, alternating with 8 flash pulses Internal terminal temperature too high
rapid flickering, alternating with 9 flash pulses Temperature difference error
rapid flickering, alternating with 10 flash pulses Error in output circuit

These errors can only be reset by switching the power supply for the TwinSAFE terminal off and back on
again.

Diag 3 (red) and Diag 4 (red)

If the Diag 3 LED is lit, the Diag 4 LED indicates internal terminal errors.

These errors lead to shutdown of the terminal. The terminal must be checked by Beckhoff Automation GmbH
& Co. KG.

Flashing Code

In the case of such an error, the Diag 4 LED on the EL2904 displays flashing codes that describe the error in
more detail.

A flashing code consists of four sequences, which are interrupted in each case by a short break. After the
four sequences there is a long break, following which the flashing code is displayed again.

Count the individual sequences of the flashing code.

38 Version: 2.1.1 EL2904

 Operation

Note the flashing codes and return the terminal

Note the flashing code displayed and include this information with the terminal when you
return it.
Note

4.5.2 Diagnostic objects

Do not change CoE objects!
Do not make any modifications to the CoE objects in the TwinSAFE components! Any mod-
ifications (e.g. using TwinCAT) of the CoE objects will permanently set the TwinSAFE com-
CAUTION ponents to the Fail-Stop state.

Index FA80hex: Internal temperature values

The CoE objects FA80hex indicate the current internal temperature values of the EL2904.

Index Name Meaning Flags Default

FA80:01 Temperature 1 Temperature measurement 1 (left board) RO 0bin
FA80:02 Temperature 2 Temperature measurement 2 (left board) RO 0bin
FA80:03 Temperature Outputs Temperature measurement (right board) RO 0bin

Index 800Ehex: Diagnostic objects

The CoE objects 800Ehex display further diagnostic information.

EL2904 Version: 2.1.1 39

Operation

Index Name Meaning Flags Default

800E:0 Diag The following sub-indices contain detailed diagnostic RO
information.
800E:0C Error at Bit External supply or cross-circuit* RO
the output 0 1bin: Output 1 0bin
1 1bin: Output 2 0bin
2 1bin: Output 3 0bin
3 1bin: Output 4 0bin
Bit Open load 0bin
or current below minimum value of 20 mA
or current above maximum value of 500 mA**
4 1bin: Output 1
5 1bin: Output 2 0bin
6 1bin: Output 3 0bin
7 1bin: Output 4 0bin
800E:0D Supply error Bit Field voltage (power contacts) outside the specification RO
0 1bin: Field voltage too high 0bin
1 1bin: Field voltage too low 0bin
800E:0E Temperature Bit Terminal temperature outside the specification. RO
error 0 1bin: Overtemperature µC1 0bin
1 1bin: Overtemperature µC2 0bin
2 1bin: Overtemperature of the output board 0bin
3 1bin: Temperature too low µC1 0bin
4 1bin: Temperature too low µC2 0bin
5 1bin: Temperature of the output board too low 0bin
6 1bin: Temperature difference on the processor board too 0bin
large
7 1bin: Temperature difference between the boards is too 0bin
large

*) These diagnostic messages are displayed only if Current Measurement active = false.

**) These diagnostic messages are displayed only if Current Measurement active = true. If no channel-
specific diagnostic is possible, all bits (4...7) are set. This is independent of the parameter settings.

Differing diagnostic messages possible

Due to the variable order or execution of the test series, diagnostic messages differing from
those given in the table above are possible.
Note

40 Version: 2.1.1 EL2904

 Operation

4.5.3 Possible causes of diagnostic messages

Diagnostics Possible cause Remedial actions
Diag 2 LED If parameters "Testing of outputs active" and/or "Cur-
Flash code 1 to 4 or rent measurement active" are enabled:
10 Faulty test pulses. Eliminate cross-circuit or external supply.
Cause: external supply or cross-circuit.
Faulty test pulses. Isolate lines and lay in separate non-metallic sheathed ca-
ble.
Cause: parallel routed cables with high capacitive
coupling and dynamized signals, possibly also in Create a distance between the non-metallic sheathed ca-
common cables bles.
Cause: Current is below the limit of 20 mA or above Select actuator accordingly.
the limit of 500 mA.
Current > 20mA and
< 500mA
Regardless of whether the parameters "Testing of
outputs active" and/or "Current measurement active"
are enabled:
The output voltage lies below the permissible voltage Eliminate short-circuit.
range (24V -15%/+20%).
Design power supply accordingly.
A possible cause is a short-circuit at the output or
e.g. a voltage drop at the instant of switching. Check supply lines for voltage drop.
EMC faults Take suitable EMC measures
Internal defect Replace terminal
Diag 2 LED Voltage at the power contacts not switched on. Switch on voltage at the power contacts and reset the error
Flash code 5 display through PowerOn Reset of the terminal
Voltage at the power contacts was switched on after Switch on voltage at the power contacts before or at the
the terminal supply same time as the terminal supply and reset the error dis-
play through PowerOn Reset of the terminal
Voltage on the power contacts too low. Increase the voltage at the power contacts and reset the
error display through PowerOn Reset of the terminal
EMC faults Take suitable EMC measures
Internal defect Replace terminal
Diag 2 LED Field voltage too high. Reduce the voltage at the power contacts and reset the er-
Flash code 6 ror display through PowerOn Reset of the terminal
Voltage on the power contacts too high.
Voltage briefly too high due to external influences, Use an R/C or diode-based protective circuit on the actua-
such as switching contactors off. tors
EMC faults Take suitable EMC measures
Internal defect Replace terminal
Diag 2 LED Terminal temperature too low Comply with the specified temperature range
Flash code 7 EMC faults Take suitable EMC measures
Internal defect Replace terminal
Diag 2 LED Terminal temperature too high Comply with the specified temperature range
Flash code 8 EMC faults Take suitable EMC measures
Internal defect Replace terminal
Diag 2 LED Terminal temperature difference too large: Replace terminal
Flash code 9
one of the 3 internal measuring points is faulty
Terminal temperature difference too large: Check the installation position of the terminal and modify it
according to the specifications in section Mechanical instal-
An internal measuring point shows an elevated tem-
lation, if required
perature due to inadequate convection.
EMC faults Take suitable EMC measures
Internal defect Replace terminal

4.6 Maintenance
Maintenance

The TwinSAFE components are maintenance-free!

EL2904 Version: 2.1.1 41

Operation

Environmental conditions

Observe the specified environmental conditions!

Please ensure that the TwinSAFE components are only stored and operated under the
specified conditions (see technical data).
WARNING

If the TwinSAFE component is operated outside the permitted temperature range it will switch to Global
Shutdown state.

Cleaning

Protect the TwinSAFE component from unacceptable soling during operation and storage!

If the TwinSAFE component was subjected to unacceptable soiling it may no longer be operated!

Have soiled terminals checked!

Cleaning of the TwinSAFE component by the user is not permitted!
Please send soiled terminals to the manufacturer for inspection and cleaning!
WARNING

4.7 Service life

The TwinSAFE terminals are designed for a service life of 20 years.

Due to the high diagnostic coverage within the lifecycle no special proof tests are required.

The TwinSAFE terminals bear a date code, which is composed as follows:

Date code: CW  YY  SW  HW
Legend: Sample: Date Code 17 11 05 00
CW: Calendar week of manufacture Calendar week: 17
YY: Year of manufacture Year: 2011
SW: Software version Software version: 05
HW: Hardware version Hardware version: 00

In addition the TwinSAFE terminals bear a unique serial number.

Fig. 25: Unique serial number of a TwinSAFE terminal

42 Version: 2.1.1 EL2904

 Operation

4.8 Decommissioning
Serious risk of injury!
Bring the bus system into a safe, de-energized state before starting disassembly of the de-
vices!
DANGER

Disposal

In order to dispose of the device, it must be removed and fully dismantled.

• Housing components (polycarbonate, polyamide (PA6.6)) are suitable for plastic recycling.
• Metal parts can be sent for metal recycling.
• Electronic parts such as disk drives and circuit boards must be disposed of in accordance with national
electronics scrap regulations.

EL2904 Version: 2.1.1 43

Appendix

5 Appendix

5.1 Support and Service

Beckhoff and their partners around the world offer comprehensive support and service, making available fast
and competent assistance with all questions related to Beckhoff products and system solutions.

Beckhoff's branch offices and representatives

Please contact your Beckhoff branch office or representative for local support and service on Beckhoff
products!

The addresses of Beckhoff's branch offices and representatives round the world can be found on her internet
pages:
http://www.beckhoff.com

You will also find further documentation for Beckhoff components there.

Beckhoff Headquarters

Beckhoff Automation GmbH & Co. KG

Huelshorstweg 20
33415 Verl
Germany

Phone: +49(0)5246/963-0
Fax: +49(0)5246/963-198
e-mail: info@beckhoff.com

Beckhoff Support

Support offers you comprehensive technical assistance, helping you not only with the application of
individual Beckhoff products, but also with other, wide-ranging services:
• support
• design, programming and commissioning of complex automation systems
• and extensive training program for Beckhoff system components

Hotline: +49(0)5246/963-157
Fax: +49(0)5246/963-9157
e-mail: support@beckhoff.com

Beckhoff Service

The Beckhoff Service Center supports you in all matters of after-sales service:
• on-site service
• repair service
• spare parts service
• hotline service

Hotline: +49(0)5246/963-460
Fax: +49(0)5246/963-479
e-mail: service@beckhoff.com

44 Version: 2.1.1 EL2904

 Appendix

5.2 Certificates

EL2904 Version: 2.1.1 45

Appendix

46 Version: 2.1.1 EL2904

 List of illustrations

List of illustrations
Fig. 1 Slot and key system and screwless (spring-loaded) connection system..................................... 9
Fig. 2 Bus Coupler (EtherCAT).............................................................................................................. 10
Fig. 3 TwinSAFE Terminals (EtherCAT)................................................................................................ 11
Fig. 4 EL2904 – TwinSAFE terminal with 4 digital fail-safe outputs ...................................................... 14
Fig. 5 Dimensions of the EL2904........................................................................................................... 18
Fig. 6 Block diagram of the EL2904....................................................................................................... 19
Fig. 7 Installation position and minimum distances ............................................................................... 21
Fig. 8 Example configuration for temperature measurement................................................................. 22
Fig. 9 Installation on the mounting rail ................................................................................................... 23
Fig. 10 Removal of mounting rails ........................................................................................................... 24
Fig. 11 PE power contact......................................................................................................................... 25
Fig. 12 Connection of a cable to a terminal point .................................................................................... 26
Fig. 13 EL2904 pin assignment ............................................................................................................... 27
Fig. 14 Permitted cable length ................................................................................................................. 28
Fig. 15 Cable routing ............................................................................................................................... 28
Fig. 16 Typical course of test pulses of the outputs................................................................................. 29
Fig. 17 Typical reaction time.................................................................................................................... 30
Fig. 18 Worst-case reaction time ............................................................................................................. 31
Fig. 19 Inserting an EL2904..................................................................................................................... 34
Fig. 20 Address settings on TwinSAFE terminals with 1023 possible addresses ................................... 35
Fig. 21 Entering the FSoE address.......................................................................................................... 36
Fig. 22 Setting the connection of the TwinSAFE connection................................................................... 36
Fig. 23 Setting the parameters of the TwinSAFE connection .................................................................. 37
Fig. 24 Diagnostic LEDs .......................................................................................................................... 38
Fig. 25 Unique serial number of a TwinSAFE terminal............................................................................ 42

EL2904 Version: 2.1.1 47