What is IO-Link and what is it suitable for?

What is IO-Link?

IO-Link is an open and standardized communication protocol that enables direct connection between sensors, actuators, and control systems. Unlike traditional solutions, there is no need to set sensor addresses. All IO-Link components from manufacturers involved in the IO-Link consortium are mutually compatible.

Is IO-Link a fieldbus?

No. IO-Link is not a fieldbus but a point-to-point communication technology. In the automation structure, it is located below the fieldbus level. The connection between sensors and the bus is provided by the IO-Link master, which acts as a gateway to the control system.

How to integrate IO-Link sensors into an existing control unit?

Process data from an IO-Link sensor is read directly by the control unit without the need for conversion.

What does the abbreviation IODD mean?

IODD (IO-Link Device Description) is a file that contains:

• Device identification data,
• Process and diagnostic data,
• Parameters required for integration into the IO-Link infrastructure.
  Each IO-Link sensor has its own IODD file.

Where to find them?

• Balluff provides IODD files for each product with IO-Link technology on its website in the “Downloads” section.
• In the BET (Balluff Engineering Tool) software, which is also used for parameter settings, port configuration, etc.
• In the open IO-Link IODD Finder library: https://ioddfinder.io-link.com/

How do IO-Link sensors transmit measured values?

Values are transmitted digitally, without conversion, directly from the sensor to the control unit.

Diagnostics: What functions does IO-Link offer?

• Wire break detection: The IO-Link master checks devices in every communication cycle. If a sensor does not respond, the error is immediately reported.
• Fault signaling: Sensors use so-called events to inform the master about incorrect operating conditions.

What is an IO-Link master?

An IO-Link master is the interface between IO-Link devices and the fieldbus. It enables communication with the control system.
For each master port, the user must configure the following settings according to the specific application requirements:

• Port configuration (DI, DO, IO-Link),
• Definition of process data width and length,
• Device parameterization (upload/download of data).

Can I use IO-Link sensors without IO-Link infrastructure?

Yes. IO-Link sensors also work without infrastructure but behave like standard sensors and do not provide extended data. When upgrading to IO-Link later, you will gain all the benefits of this technology.