IO-Link is an independent sensor/actuator interface solution for use with several industrial fieldbus and industrial network solutions, including PROFIBUS and PROFINET. The presentation will provide an introduction to this technology, the types of devices available, how they are parameterised and how they are integrated within a programmable control system. IO-Link – What is it? • IO-Link is the first standardised IO technology worldwide (IEC 61131-9) for the communication with sensors and also actuators. • It is typically used in an automation environment below the I/O level for individual linking of field devices • It uses point-to-point communication based on the long established 3-wire sensor and actuator connection without additional requirements regarding cabling. • IO-Link is not a fieldbus, nor is it a replacement for AS-i. It is however evidence of the further development of the existing, tried-and-tested connection technology for sensors and actuators. • Since 2010, IO-Link has been incorporated within the PROFIBUS & PROFINET User Organisation (PNO)

1. An Introduction to
October 2015
Peter Thomas
(Control Specialists Ltd)
Chairman of the
PROFINET & PROFIBUS
International Training Centres
(PITC‘s)

2. IO-Link – What is it?
2
• IO-Link is the first standardised IO technology worldwide (IEC 61131-9) for
the communication with sensors and also actuators.
• It is typically used in an automation environment below the I/O level for
individual linking of field devices
• It uses point-to-point communication based on the long established 3-wire
sensor and actuator connection without additional requirements regarding
cabling.
• IO-Link is not a fieldbus, nor is it a replacement for AS-i. It is however
evidence of the further development of the existing, tried-and-
tested connection technology for sensors and actuators.
• Since 2010, IO-Link has been incorporated within the PROFIBUS &
PROFINET User Organisation (PNO)

3. IO-Link – Benefits
3
• IEC 61131-9 compliance means that IO-Link devices can be integrated using
the same methods used to integrate PROFIBUS and PROFINET devices.
• Simple, standardised wiring and significantly reduced variety of interfaces
for sensors and actuators.
• Standardised interface for the configuration of all IO-Link devices
irrespective of their complexity.
• Faster commissioning.
• Access to diagnostic data and device information as well as process data.
• Sensors with and without an IO-Link interface can operate together via the
same IO-Link Master.
• Dynamic changing of device parameters by PLC (or HMI) during normal plant
operation.

4. IO-Link and AS-i
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• IO-Link should be considered as a supplement system for intelligent wiring
systems like AS-Interface and not a replacement.
• Unlike AS-i, IO-Link is based on conventional point-to-point wiring
• IO-Link is directly integrated in the sensor, requires no special cables,
requires no sensor addressing and has no station limitation.
• IO-Link is the natural choice for organisations wishing to follow an
Industrie 4.0 philosophy.
• IO-Link cannot be used in safety-critical applications at the moment.

5. IO-Link – Main Components - Masters
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IO-Link Masters
Provide the gateway between IO-Link device and the
higher-level communication system such as PROFINET
or a device-specific backplane bus.

6. IO-Link – Main Components – IO-Link Devices
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IO-Link Devices
These are the communication-capable field devices
such as sensors, relays, valve actuators, RFID devices,
signal lamps etc.
Proximity Detector Fibre-Optic Sensor
Light-Grids
Valve Manifold
Contactor

7. IO-Link – Main Components – IODD Files
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• IODD (IO-Link Device Description)
files are XML files that define all the
properties of a given device.
• They perform a similar function to
GSDML files in PROFINET and GSD
files in PROFIBUS.
• IODD files are created by the IO-Link
device manufacturer and are specific
to a given device.
• IODD files are usually read by the IO-
Link device configuration software and
are not usually viewed in an XML
viewer like this example.
• You should always go to the web site of
the IO-Link device manufacturer for
the correct IODD file for your device.

8. IO-Link – Main Components – Cabling & Connectors
8
Cabling
To connect an IO-Link to device to a single port on an IO-Link Master, IO-Link
only requires standard, un-shielded 3-core cable together with one of two types
(4-pin or 5-pin) of A-coded M8 or M12 connectors. Generally. Sensors use 4-pin,
Actuators and Masters use 5-pin.
Type A Connector
(Pins 2 & 5 are optional)
Type B Connector
(Pins 2 & 5 for additional power)

9. IO-Link – PROFINET to IO-Link Interconnection (Eg.1)
9
Standard 3-wire sensor
Max cable length of 20m
Only ONE device per port
IODD File
IODD File
GSDML File
PROFINET IO Controller (PLC)

10. IO-Link – PROFINET to IO-Link Interconnection (E.g 2)
10
Up to four
3-wire Sensors
IO-Link HUB
IO-Link Master IODD File
GSDML File
IODD File
IODD File
PROFINET IO Controller (PLC)
Max cable length of 20m

11. IO-Link – Transmission Speed
11
Transmission Speed
IO-Link supports three transmission
speeds known as COM-1, COM2 and COM-3
• COM-1: 4.8 Kbit/s
• COM-2: 38.4 Kbits/s
• COM-3: 230.4 Kbits/s *
An IO-Device only has to support one of
the three transmission rates, IO-Masters
must support all 3.
* Note – COM-3 only became part of the
IO-Link specification in Version 1.1

12. IO-Link – Cycle Time
12
Cycle Time
The rate at which an IO-Link master polls a
given IO-Link device is known as the cycle
time. The cycle time of every IO-Link device
can be set independently from each other.
Every IO-Link device has a MINIMUM CYCLE
TIME defined in the IODD file of the device
in mS * 1000 as “minCycleTime”.
The Master must NOT poll a device faster
than the minCycleTime value of that device.
The cycle time is also affected by the cycle
time between the CPU of the PLC and the IO-
Link master.
A typical cycle time of 2.3mS can be achieved
at 38.4 Kbit/s.

13. IO-Link – Modes of Operation
13
Modes of Operation
IO-Link devices can operate in one of two
modes, Standard IO (SIO) mode and
SDCI (or IO-Link) mode.
In SIO mode, pin 4 of the IO-Link device
acts as a conventional digital input or
digital output.
In IO-Link mode, pin 4 of the IO-Link
device is used for transmission of IO-Link,
device-related data.

14. IO-Link – Configuration
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IO-Link Master Configuration
The IO-Link master appears as an IO Device on a PROFINET network. By definition,
IO-Link masters must have a GSDML file. GSDML files contain a description of the
communication properties and other properties of the IO-Link master, such as the
number of ports.
IO-Link Device Configuration
An IO-Link Master GSDML file will not contain any device-related information about
the IO-Link devices connected to the ports of the Master. This aspect of the
configuration will be performed by an IO-Link configuration tool which will require
IO-Link device description (IODD) files for each device that will be connected to the
ports of the master.
If you are a Siemens user, the configuration tool is called PCT (Port Configuration
Tool) which can be launched from within the TIA portal programming environment

15. IO-Link – Configuration – Siemens TIA Portal
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IO-Link Masters

16. IO-Link – Configuration – Siemens TIA Portal
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Click to Start IO-Link Port Configuration Tool (PCT)

17. IO-Link – Configuration – Siemens PCT Tool
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18. IO-Link – Configuration – Siemens PCT Tool
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19. IO-Link – Configuration – FDT Tools
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It is also possible to configure IO-Link devices outside of the programming environment using an
FDT (Field Device Tool) application like PACTware. Instead of an IODD file, you will need a
CommDTM file for the IO-Link Master and a DTM file for the IO-Link Device,
3-wire IO-Link connection
USB
Master
Device
DTM
Comm DTM

20. IO-Link – Configuration – PACTWare
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CommDTM
DTM

21. 21
Demonstration

22. IO-Link Analyzers
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IO-Link Analysers allow you to monitor the IO-Link telegrams passing between an IO-Link Master
and an IO-Link device.

23. IO-Link Analyzers
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24. PROFINET – Questions?