What is IO-Link?

IO-Link Overview

IOLink LogoIO-Link is a worldwide open-standard peer-to-peer serial communication protocol (IEC 61131-9) that allows sensors and actuators to easily integrate into The Connected Enterprise. Through IO-Link you can access all sensor configuration parameters, process
data and diagnostics. You can go beyond detecting products on your machine – now you can MONITOR your machine‘s health as it runs. Plus, IO-Link simplifies setup and commissioning while offering enhanced flexibility for your current – and future – processes.

Easy and compatible (universal)

The connection between IO-Link master and device is established via a max. 20 m long, unscreened 3-wire cable. The wiring is standardised on the basis of M5, M8 and M12. The vast majority of IO-Link devices is equipped with M12 connectors which can be used without any restrictions for IO-Link’s switching mode and communication mode. Each port of an IO-Link master is capable of processing binary switching signals and analogue values (e.g. 8 bits, 12 bits, 16 bits). Serial IO-Link communication takes place via the same port. Easy wiring, automated parameter setting and extended diagnosis are but a few advantages of IO-Link.

High functionality (smart)

As a standard, 2 bytes of process data are available per cycle. The transmission between IO-Link master and device takes 400 μs at a speed of 230 kBaud. The user can also choose larger frame types. Therefore, greater process data with up to 32 bytes length can also be transmitted at a correspondingly lower cycle time. To ensure that the parameter data of a device are not lost when replacing a device, they can be automatically stored directly in the IO-Link master. If a new, identical substitution device is connected, the parameters of the previous device are automatically transferred onto the new device.

How Does IO-Link work?

Smart sensors featuring embedded IO-Link act the same as the standard I/O sensors you’re already using until connected to a master. But by interfacing these sensors with an IO-Link master, you can access all the advanced data and configuration capabilities
IO-Link has to offer. This means you have the flexibility to install smart sensors as standard I/O today and activate IO-Link functionality later – whenever and wherever you want it – without having to install costly new wiring or sensors.

Allen-Bradley IO-Link Enabled Products


IO-Link Masters

  • Enable connection of up to eight devices (IO-Link enabled or standard I/O)
  • POINT I/O™ master for in-cabinet (IP20)
  • ArmorBlock™ version for on-machine (IP67) applications
  • Timestamp functionality in ArmorBlock model provides visibility to sensor data for better quality metrics

Photoelectric Sensors

  • Notifies system when lens is dirty
  • Parameter changes supported through controller during line/tool changes for flexible manufacturing (e.g. set points)
  • Indication of sensor signal strength for monitoring machine wear and tear
  • Locking options are available to lock local settings when operating in IO-Link mode, and therefore any user changes will not change the settings of the sensor.

Proximity Sensors

  • Margin status helps optimize sensor installation for best performance
  • Monitor the distance to detected targets (detect machine wear and tear)
  • Immediate indication of damaged sensing element
  • Application-specific names help the user quickly locate the sensor on the machine.

Pressure and Temperature Sensors

  • Actual Pressure and Temperature values available at the controller
  • Change set points via controller when process changes are needed
  • Use controller to adjust parameters and use local display for current values
  • Configure sensor data units (i.e. PSI or bar for pressure sensors)

Additional IO-Link Resources

Useful Videos