IO-Link Safety

IO-Link Safety is a functional safety communication protocol that uses IO-Link as a black channel for safety-related data. It is standardized as IEC 61139-2 and supports applications up to SIL 3 over point-to-point IO-Link connections. IO-Link Safety Masters integrate the safety communication into higher-level systems, and mix mode allows safety-related and standard data to be transmitted at the same time.

Source checked3/3 values · 2026-10-25

Specification

1 source

Transports	other
Architecture	master slave
Encoding	binary
Standard body	IEC
Standard ref	IEC 61139-2

Study notes

IO-Link Safety uses IO-Link as a black channel for safety-related data.
Designed for IO-Link point-to-point communication; described as simpler than corresponding fieldbus safety protocols.
IO-Link Safety Masters take over implementation in higher-level systems.
Master ports can always be configured for IO-Link, enabling mixed standard and safety applications.
Safety Masters can offer ports configurable for OSSD sensors for migration from conventional technology.
Safety Devices may be operable with OSSD as well as IO-Link Safety.
Suitable for sensors, actuators and mechatronic components.
Mix mode transmits safety-related and standard data simultaneously.
IODD is used for parameterization and integration.
A Dedicated Device Tool is used for parameterizing safety functions; DTI is a standardized software interface.

Safety

Supports safety-related applications up to SIL 3.
Transmits safety-related data over IO-Link as a black channel.
Allows simultaneous transmission of safety-related and standard data in mix mode.
IO-Link Safety Masters can provide ports configurable for OSSD sensors.
Safety function parameterization requires a permanently assigned, approved Dedicated Device Tool for the device.
Standardized as IEC 61139-2.