whitepaper –––––––– 2021

Industrialcommunication

Industrial communication ................................................................................................... 2
1.

Field devices with direct Ethernet connections ......................................................... 3
Integration.......................................................................................................................... 3Web server ........................................................................................................................ 3
Transmission media ........................................................................................................... 3
Redundancy functions ....................................................................................................... 4

2.

Gateway systems ......................................................................................................... 6
Efficient Device Integration Platform (EDIP) ....................................................................... 6
Gateway configuration ....................................................................................................... 7
Central configuration management .................................................................................... 7

3.

Field devices with IO-Link ........................................................................................... 8
Push-in connectors and port classes ................................................................................. 8Cabling .............................................................................................................................10Diagnostics ....................................................................................................................... 11
Device replacement .......................................................................................................... 11Integration......................................................................................................................... 114.

Summary ......................................................................................................................125.

Further information and contact: ...............................................................................13

Industrial communication

A large number of field devices are installed in factory and process automation
systems. In the process of digitalisation as part of Industry 4.0, the numberof intelligent network participants is ever-increasing and Ethernet-based
technologies such as PROFINET or EtherNet/IP are being added to the traditional
fieldbuses like PROFIBUS.
Existing plants with evolved structures need to be adapted according ly to meet thechanged market or legal requirements as well as the current demands for efficiency
and availability. Traditional analogue sensors and actuators often no longer meet theincreased requirements because they can only deliver a limited range of process data.
Simple remote access, at best even automatic integration into modern networks,
or complete self-diagnosis "on demand" are thus not possible. Sensor, actuatorand network technology must therefore be adapted accordingly.
When it comes to network technology there are different options depending on thetechnology being used. This way, devices with their own Ethernet connection can be
integrated directly into the process technology network. A second variant is to use

2gateways that establish the connection between the PLC and the field devices using asubnet. A third option is the use of IO-Link field devices.

1. Field devices with direct Ethernet connections
Field devices with a direct Ethernet connection offer numerous advantages for different
user groups. The integrator has direct access to the unit and can specify all necessary
parameters directly. These field devices also frequently offer simplified integration intohigher-level systems, making easy access to the device’s web server an option for t heplant operator. This allows diagnostics information to be read directly from the fielddevice without the need for special programmes or other devices. This reduces
maintenance and contributes to efficient troubleshooting.
Integration
One of the most important features of an Ethernet field device is the simple and efficient
project planning in the higher-level system. For example, some field devices can bequickly integrated into the Rockwell Engineering environment using an Add -On Profile(AOP). Alternatively, integration into a Siemens environment using a Hardware Support
Package (HSP) is also conceivable. Such integration methods save the integrator a lotof time because he can select all important parameters directly in a graphical interface.
Any device parameters configured in this way can then be copied directly into theengineering environment for further use.
Web server
Most Ethernet-capable devices have an integrated web server. This can often be used toconfigure devices, read out diagnostics data or display process data. As the devices arealready connected and addressed via Ethernet, no additional effort is required to enable
access to the web server. Password-protected access prevents unauthorised changes todevice settings. The assignment of user rights also enables a high level of security whenapproving the various functions.
Transmission media
Ethernet-capable field devices can be wired easily and quickly, even over longer
distances. The maximum distance between two devices is up to 100 metr es with copper
cables. If this distance is not sufficient, a fibre optic cable can be used that bridges
distances of up to 14 km. However, additional infrastructure components are necessaryfor this. In the near future, topics such as Single Pair Ethernet (SPE) and Advanced
Physical Layer (APL) will allow new possibilities in terms of wiring, line lengths andcommunication speeds. Wiring concepts in industrial plants will change as a result.

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Redundancy functions
These days the redundancy of systems is becoming increasingly important. In the eventof errors or peripheral failures, the system should continue to operate and machine
downtime should be reduced to a minimum. To do this, there are different protocols
with different redundancy functions that enable different safety standards.
Setting up the network as a ring topology allows the system to establish alternative
communication channels when a communication line is interrupted. This ensures thatthe field device does not lose communication with the higher-level system. In aPROFINET network, for example, this function is called “Media Redundancy Protocol”(MRP); in EtherNet/IP, it is called a “Device Level Ring” (DLR).

Figure: EtherNet/IP network with Device Level Ring (DLR) function.

A variety of redundancy systems exist for PROFINET. They are called S1, S2, R1 andR2. Depending on the variant, the requirements for controllers and field devices arecorrespondingly high. If field devices and controllers use multiple PROFINET interfaces,
so-called Network Access Points (NAPs), they can maintain the connection even in theevent of hardware errors. S1 and S2 are so-called singular systems. This means that thePROFINET device can only connect to a single NAP. For R1 and R2, the R stands forRedundant. The PROFINET field device can connect to several NAPs. The number after
the S or R stands for the number of possible communication relations (ApplicationRelation – AR).

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S2 redundancy is becoming increasingly important for PROFINET networks in fielddevices and is already widespread on the market. The integration and wiring are very
simple. For S2 redundancy, the IO-unit interface is connected to two redundant
controllers. The controllers communicate with each other via a backbone bus. In doing
so, the PROFINET device establishes a communication relationship with each controller.
However, only one connection is active and the reserve connection only intervenes
when the primary connection is interrupted.

Figure: Setup of a network with S2 redundancy.

Such redundancy systems are not limited to PROFINET. Such redundancy systems also
exist for other protocols such as EtherNet/IP.

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2. Gateway systems
Another interesting option for device integration in an industrial environment is the use ofgateways. Gateways then become the only device with a direct Ethernet connection andis itself the connection to the higher-level controller. The other field devices on thesensor-actuator level communicate with each other through a lower-level subsystem. A
variety of solutions are possible for communicating in the subsystem, such as AS Interface or CANopen. This approach enables the creation of a cost-efficient solutionthat is perfectly tailored to the customer’s application, e.g. via Bürkert’s own EDIP
platform (Efficient Device Integration Platform).
Efficient Device Integration Platform (EDIP)

Figure: Mass Flow Controller (MFC) on the field level connected to a gateway with three
I/O modules.

EDIP allows fast, prepared and simple networking as well as the installation of Bürkert
devices that have CANopen-based büS interfaces (büS stands for Bürkert system bus).
The heart of an EDIP network is the gateway. It manages the data exchange between
the field devices and the higher-level controller. Bürkert gateways are available with6

different Industrial Ethernet protocols such as PROFINET, EtherNet/IP, Modbus TCP,
EtherCAT and CC-Link IE Field Basic. Conventional fieldbuses such as PROFIBUS andCC-Link are also supported.
The PC software Bürkert Communicator is also part of the platform. The program is used
to configure or parameterise all new Bürkert products with electrical components. In
addition, the software also includes data loggers, an oscilloscope, a graphicalprogramming interface and licence management, among other things. Settings createdusing the software can be saved, modified, printed and copied to other devices. Accessto the network is possible during operation and even several devices can be connected
simultaneously. The field device firmware updates can be carried out via the software.
Optionally, individual devices can be updated as well as several devices consecutively.
Gateway configuration
The focus of a gateway solution is to create the appropriate configuration. There aremany different ways to do this, depending on the manufacturer. This often involves
simply keeping input or output memory space free. The variables are then assigned via
an external representation. The focus is not on the customer-specific solution, but on
the general use of a uniform description file on the control side. It is different with EDIP.
Here, a customer-specific configuration is created via the Bürkert Communicator.
The process data of the individual field devices are thus quickly and easily created in
the wizard. There is no unnecessary consumption of storage capacity. After it has beencreated, the respective configuration can be output for all supported protocols. T his isof great interest to OEMs in particular, as they often build the same or similar plantcomponents. It is also easy to adjust the configuration. After a successful change,
the configuration files are output in a new version. This makes all changes tr ackableat any time.
Central configuration management
The central configuration management feature makes it possible to quickly replace
Bürkert devices with no extra configuration effort. After parameterisation and activation,no additional software is required. Instead, there is a configuration provider in thenetwork that reads out the configurations of all devices and stores them centrally on
the gateway. Replacement of a managed device is recognised by the configuration
provider, as is the replacement device, which is automatically parameterised withthe stored configuration of the predecessor device since it has the same identification
number. The process takes about one minute. After a restart, all necessary parameters
are stored in the device.

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3. Field devices with IO-Link
IO-Link is a standardised I/O (Input/Output) technology (IEC 61131-9) that enables
communication between sensors and actuators. With IO-Link, field devices can beconnected to and controlled at Control Level via a cost-effective point-to-pointconnection. IO-Link is therefore not a fieldbus but a communication protocol that builds
on the traditional connection sensor and actuator technology and offers integrated
communication right down to field device level. The data exchange between the higherlevel controller and the IO-Link devices is bidirectional, i.e. takes place in bothdirections. Both cyclic (e.g. process values) and acyclic (e.g. diagnostic messages) data
can thus be transmitted separately.

Figure: Field devices connected to a controller via IO-Link master.

Push-in connectors and port classes
There is a variety of IO-Link plug-in connections for use in the control cabinet or in thefield. Various push-in connectors with screw-type terminals or spring contacts can beused in the control cabinet. In the field, however, protection against foreign bodies and8

moisture is essential. The most common push-in connector used for IO-Link is an Acoded M12 plug (according to DIN EN 61076-2-101), whereby a four-pole push-in
connector is usually used for sensors and a five-pole push-in connector for actuators.
M12-A coded connections are available for port class A and B. Additionally, M5 and M8
push-in connectors are specified for port class A.

Figure: IO-Link push-in connectors for field devices.

For port class A devices, a current consumption of up to 200 mA is permissible. The
device’s supply voltage is on pins 1 and 3 here. This is sufficient for sensors and smaller
actuators. If a device requires current consumption of more than 200 mA, port class B
must be selected. A second supply voltage is available there on pins 2 and 5. Currentsof up to approx. 4 A are possible; this is the limit for M12 A-coded connectors. The
additional supply voltage should be operated separately from the first supply voltage andshould have a separate fuse. One advantage is that the second supply voltage can beswitched using a safety relay. In the event of a fault, for example from an emergency
stop, all actuators can be deactivated.

9Figure: Pin assignment of push-in connector ports class A and B.

Cabling
Simple rules apply to the cabling for IO-Link. The most important one states that thetotal length from a port of the master to an IO-Link device must not exceed 20 metres.
Since IO-Link is a point-to-point connection, no further dependencies on other devices
need to be taken into account, such as baud rate, number of participants or amount ofprocess data. Attention should also be paid to the type of cable. It is permitted to use
unshielded cables here. For a port class A device, at least a three-wire cable is required,optionally also a four-wire cable if the device supports a digital input or output on
pin 2. A 5-pin cable is always used for a port class B device.

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Diagnostics
IO-Link offers the user good diagnostics options as well as troubleshooting support.
An IO-Link device can generate events and exchange them directly with the master.
These events are then forwarded to the PLC or to an HMI (Human Machine Interface).
This makes it possible to transmit errors and warnings, but also maintenance requests.
This sets IO-Link apart from proven, older technologies. A unit can transmit both a lot ofparameterisation data and diagnostics data at the same time. Compared to a 4-20 mA
interface, the advantages of an IO-Link connection are therefore obvious.
Device replacement
IO-Link greatly simplifies and accelerates device replacement. This reduces themaintenance costs and the downtime of a plant. This mechanism is called “Backup &Restore”. For this purpose, specified parameterisation data in IO-Link devices is saved
directly on the master. In the event of a replacement, the new device is automaticallyparameterised with the settings of the replaced device. This function can be optionallydeactivated or also restricted. Entering the authorised vendor and device IDs at eachindividual port prevents exchanges with non-matching devices.
Integration
IO-Link devices are configured via the engineering tools of the controller. Often just asufficiently large memory space is selected. This can contain input and output values,depending on the unit functions; in the case of sensors, only input values can bepresent. The exact arrangement of the bytes can be seen in the IODD (IO Device
Description). Some manufacturers offer direct integration of the configuration tool into
the engineering tool. Others integrate the IO-Link device description files as part of themaster’s description file. With PROFINET, this information would be contained in theGSDML device description of the master. However, it is also possible to load the IODD
using another (external) tool and use it to parameterise the units. Another variant is theintegration of a web server in the master, which completely takes over administration.
The advantage here is that no further tool is needed and the connection to the device
via Ethernet is available anyway. This avoids additional work and costs. In themeantime, many of these solutions offer a direct connection to the IODD Finder, which
provides a manufacturer-independent database. From there, the IODDs can be loaded
directly into the configuration tool. This eliminates the tedious work on the customer sidesearching for the IODDs of different manufacturers on their websites.
Another possible solution for the integration of IO-Link devices using modules that allow
parameterisation. Bürkert follows this approach for some field devices and offers, for11example, add-on instructions for Rockwell and faceplates for Siemens PCS7. This
supports the customer efficiently in both integration and diagnostics.

4. Summary
Ethernet devices offer an enormous number of wiring advantages in terms of line lengths
and added values such as web servers, redundancy functions or the highcommunication speed. In addition, there is a diverse selection of protocols. The higher
price of the Ethernet devices is offset by the reduced effort in wiring and planning theplant section. This usually compensates for part of the additional costs.
A gateway offers a customised solution for the customer. The gateway as the core of thesubnet also has web servers and redundancy functions, like other Ethernet devices.
Yet, the devices in the subsystem are not directly accessible via Ethernet and thus notconnected via the redundancy function. Still, solutions like this offer an enormous costadvantage. All device data in the subnet are digitally available and a diagnostics statusis available for all participants. At the lowest field level, IO-Link is a very effective andefficient way to automate plant components. There are now many manufacturers whooffer both sensors and actuators with IO-Link. This means that classic technologies suchas existing 4...20 mA devices can simply be replaced by IO-Link. Further advantages
such as simple parameterisation and diagnostics data evaluation are virtually freeof charge.
Key finding: There is no one-size-fits-all solution. The choice of technology always
depends on the customer’s requirements and the area of application. The number anddistribution of devices in the system as well as the costs and communication speed
requirements also come into play. Each of the individual technologies has strengths,
but also weaknesses. No matter which of the approaches is chosen, they all offer
solutions for transmitting more useful device data to higher control levels than would
be possible with analogue technologies.

125. Further information and contact:
You can also find out more about this topic on our website:
https://www.burkert.com/en/more-about/EDIP-Efficient-Device-Integration-Platform
https://www.burkert.com/en/Media/plm/MAN/MA/MAME43-Software-EUEN.pdf?id=MAN0000000000000001000353712ENB
https://www.burkert.com/en/Service-Support/Support/Glossary/IO-Link-The-opencommunication-standard-for-sensors-and-actuators
https://www.burkert.com/en/Landingpage/Automating-and-controlling-hygienicproduction-processes
We are also be happy to help you personally:
Contact:
Michael RauschSegment & Project Manager.hygienic
Phone: +49 7940 10 91 821
E-mail: michael.rausch@burkert.com

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