Io-Link - Basics; Fig. 2 Peer-To-Peer Communication Io-Link - Beckhoff KL6224 Documentation

Product overview
2.3

IO-Link - Basics

IO-Link represents a communication system for the connection of intelligent sensors and actuators to an
automation system in the IEC 61131-9 standard under the designation "Single-drop digital communication
interface for small sensors and actuators" (SDCI).
Both the electrical connection data and the communication protocol are standardized and summarized in the
IO-Link Spec.
IO-Link specification
The development of the EL6224 was subject to the IO-Link specification 1.1. At the time of
the preparation of this documentation, the IO-Link specification is entering the IEC stan-
Note
dardization and will be adopted in extended form as IEC 61131-9. The new designation
SDCI will be introduced at the same time.
As a member of the respective committee, Beckhoff supports the development of IO-Link
and reflects changes to the specification in its products.
An IO-Link system consists of an IO-Link master and one or more IO-Link devices, i.e. sensors or actuators.
The IO-Link master provides the interface to the higher-level controller and controls communication with the
connected IO-Link devices. The Beckhoff EL6224 IO-Link Master Terminal has four IO-Link ports. One IO-
Link device can be connected to each of them. Therefore, IO-Link is not a fieldbus, but a peer-to-peer
connection (see Fig. Peer-to-peer communication IO-Link).
Fig. 2: Peer-to-peer communication IO-Link
The connected IO-Link devices have individual parameter information in the form of an IO device description
(IODD), which is set with the KS2000 configuration software (see chapter KS2000 - Settings [} 26]).
10 Version: 2.0.0 KL6224