Safety Architecture Proposal for Low-Latency Sensor/Actuator Networks using IO-Link Wireless

In the field of production automation, IO-Link Wireless (IOLW) offers energy-efficient and cost-effective solutions for networking wireless sensors and actuators close to the machines on the industrial shop-floor. In this paper, a concept is presented to enhance IOLW with security-for-safety and safety features in order to make safety critical systems in industrial environments with performance characteristics dedicated to demanding applications feasible. As data security is of paramount importance, security mechanisms already implemented in other wireless protocols are investigated and security-for-safety mechanisms for IOLW are introduced. Potential cryptographic algorithms are evaluated for IOLW with respect to energy consumption and timing. Taking performance parameters into account, which are crucial for industrial manufacturing processes, a safety protocol data unit (SPDU) is described and evaluated for different payload length and cycle times. Finally, an outlook towards the implementation of a demonstrator setup completes this work.