IOL-TS is a pathfinder application experiment done by TEConcept GmbH (Freiburg, Germany) and Budapest University of Technology and Economics (BME, Budapest, Hungary) on developing a proof of concept prototype time synchronization extension for IO-Link. TEConcept GmbH is a leading provider of IO-Link master and device implementations, including reference hardware designs, and master and device software stacks. The demonstrator is built by the modification of TEConcept IO-Link hardware and software products by BME, which has expertise in time synchronization related research and development, and various intellectual properties (software components for time synchronization).

IOLink must be extended with time synchronization to support the integration of IO-Link to TSN industrial solutions. Currently, IO-Link has no support for time or time synchronization, and this is a clear disadvantage, as the industry moves towards TSN solutions, which are strictly time-driven by utilizing precise time synchronization. With the extension, IO-Link devices will be able to sample, actuate, and collect timestamps based on the global clock of the system utilizing a time-driven paradigm, and therefore, can be integrated into TSN networks.

Objectives

Develop a prototype time synchronization extension for IO-Link utilizing TEConcept hardware and software products and BME intellectual property for technology demonstration and standardization. Explore hardware and software complexity and achievable precision of IO-Link time synchronization.

Challenges

IO-Link is a low-speed (maximum 230.4 kbit/s) low-cost solution utilizing low-performance parts, especially for IO-Link devices. On the other hand, current time synchronization solutions in TSN, such as IEEE 1588 and its profiles, are complex protocols with substantial hardware, software and communication bandwidth requirements relative to the capabilities of IO-Link products. Therefore, the architectural, protocol, software and hardware design of the IOL-TS solution is a delicate process in which performance and cost optimum must be met.

Technology

Utilizing the intellectual property of TEConcept GmbH and BME IOL-TS the project has developed the following prototype components for the demonstrator:Time-driven TSN to IO-Link gateway and IO-Link master hardware and software architecture design and functional prototype on TEConcept GmbH.Time-driven IO-Link device architectural design and functional prototype on TEConcept GmbH hardware.Time transfer architecture design and prototype in the master (from TSN) and on the devices. Both master and device prototypes include BME’s time synchronization and peripheral synchronization intellectual property integrated with the TEConcept GmbH solutions.The IOL-TS solution requires minimal hardware changes, that can be done using PCB rework on the prototypes, and the protocol overhead and additional software resource needs are kept at a minimal, acceptable level according to our initial evaluations.The prototype is capable of achieving sub-microsecond time synchronization precision even if the device is implemented on a low-cost microcontroller.

Market

IO-Link Industrial Communication Protocol is a dynamically growing and developing, multivendor, standardized (IEC 61131) solution for sensor and actuator connection in the industrial automation field (see https://www.alliedmarketresearch.com/io-link-market-A13766). All market studies project in the range of 30% year-to-year growth until at least 2030 for the IO-Link market. By extending IO-Link with TSN capabilities developed in IOL-TS, this growth can be sustained, hopefully at least into the late 2030s.

Consortium