IO-Link sensors

IO-Link was launched at the beginning of 2000 by a consortium of large sensor manufacturers. The aim was to find a solution so that communication between sensors and actuators would be bi-directional, digital and continuous. This should make it possible to configure and diagnose these devices during operation.

For more than 10 years, IO-Link has been a fixed standard according to IEC 61131-9. This has the advantage that products from different manufacturers can communicate with each other without any problems. Machine builders and plant operators can thus realise IO concepts without investment risks, compatibility issues or dependencies on manufacturers.

IO-Link components are connected via the IO-Link master to bus systems such as fieldbus, Profinet, Modbus or via Ethernet to the corresponding system control. In addition to IO-Link sensors and actuators, conventional binary sensors and binary actuators can also be connected to the IO-Link system.

TRI-MATIC offers IO-Link solutions for pressure transmitters, digital pressure switches, flow meters and EB80 valve terminals for pneumatics. Position indicators for automation with IO-Link are also available.

IO-Link is a standardised point-to-point communication protocol in accordance with IEC 61131-9 that enables bidirectional digital communication between sensors/actuators and the control level. It uses unshielded standard cables and allows the transmission of process data, diagnostic information and parameters.

Modbus, on the other hand, is an older, widely used protocol that is based on a master-slave architecture and supports both serial RS-485 connections and Ethernet connections. It is known for its simplicity and wide acceptance, but offers less flexibility in the transmission of diagnostic data and parameter information compared to IO-Link.

Main differences:
 

• Topology: IO-Link uses a point-to-point connection, while Modbus uses a bus topology.
• Data transmission: IO-Link enables the transmission of process, diagnostic and parameter data; Modbus focuses mainly on process data.
• Integration: IO-Link can be seamlessly integrated into existing automation systems and supports automatic device identification and device parameterisation.

IO-Link Safety extends the standard protocol with safety functions in accordance with IEC 61139-2. It enables safe communication between the controller and field devices, which is particularly advantageous in safety-critical applications.

IO-Link Wireless offers the option of connecting IO-Link devices wirelessly. This reduces cabling effort and increases flexibility when installing sensors and actuators, especially in moving or difficult-to-access areas.