In the industrial automation sector, I/O-LINK serves as the final link to various actuators and sensors. With the advancement of interconnected communication technologies, I/O-LINK is driving the continuous implementation of innovative applications in industrial control and communication, industrial digitalization, and the Industrial Internet under the era of Industry 4.0 smart manufacturing. Today's industrial automation field requires measurement sensors with sufficient flexibility-enabling quick parameter adjustments and seamless interoperability with mixed sensor types. This demands flexible communication interface technology, explaining I/O-LINK's immense application potential in the industrial automation market.
The Thriving I/O-LINK Market
According to a market research report by QYR, the global I/O-LINK technology market reached $2.403 billion in sales in 2021 and is projected to grow to $4.742 billion by 2028, representing a compound annual growth rate (CAGR) of 10.24%. Regionally, the Asia-Pacific and European markets currently dominate globally, with China experiencing particularly rapid growth. China's I/O-LINK market size in 2021 was approximately $286 million, accounting for about 11.88% of the global total. It is projected to reach $745 million by 2028, representing 15.70% of the global market share at that time. Additionally, based on the I/O-Link Association's calculations of terminal licensing fees, the number of I/O-Link nodes has experienced explosive growth in recent years. Global shipments remained around 11.4 million nodes from 2018 to 2019, but surged to 21 million by 2021-nearly doubling in just one year. Beyond terminal node growth, the I/O-Link Association's membership has expanded from 100 companies in 2016 to over 400 today, with numbers continuing to rise. Market demand is clear: as a point-to-point serial digital communication protocol, I/O-Link significantly advances industrial automation. Its increasingly widespread adoption will bridge the "last mile" of communication for underlying field devices.
I/O-LINK Bridges the Industrial Communication Gap
In the industrial sector, industrial Ethernet communication protocols like PROFINET, CC-Link, EtherNet/IP, and EtherCAT are undoubtedly familiar to many. As another communication technology, I/O-Link has swept from the European market into the Asia-Pacific region, effectively addressing various challenges in sensor design such as heat dissipation, size constraints, and current drive capabilities. One might assume I/O-Link competes with established industrial communications like PROFINET, CC-Link, and EtherNet/IP. This is not the case. Within industrial sensor network architectures, I/O-Link occupies the lowest layer, functioning as a communication technology specifically engineered for sensor networks. While it can connect to the control layer to open the door to industrial interconnectivity, its fundamental capability lies in independently addressing communication challenges at the field device level, free from reliance on or interference from fieldbuses. The bottlenecks of traditional industrial automation control systems are evident: all sensors report data or receive commands from PLCs via physical cables. Adjusting sensor parameters requires numerous steps, resulting in weak configuration capabilities. Moreover, these systems predominantly rely on proprietary protocols for one-way, analog information exchange, lacking diagnostic capabilities. Analog data is also susceptible to noise interference, making it difficult to maintain integrity in the diverse electromagnetic environments of industrial settings. I/O-Link revolutionizes the underlying industrial communication architecture, transforming traditional automation control systems. Simply put, it delivers flexible sensor configuration, reliable digital signal communication, and highly scalable bidirectional capabilities to industrial environments. I/O-Link's packet transmission method allocates multiple substations between the PLC and lower-level sensors. These substations aggregate sensor data before upward transmission, resulting in progressively simpler communication cabling as data ascends the hierarchy. As a manufacturer-independent and fieldbus-independent technology, I/O-Link delivers process data and diagnostic identification across entire plant structures even with the simplest sensors and actuators, eliminating complex connections.
Semiconductor Manufacturers' Support for I/O-LINK
Numerous semiconductor manufacturers have developed matching transceiver ICs for both master and slave devices, recognizing I/O-LINK's potential in industrial communication. STMicroelectronics, for instance, offers transceiver ICs for both I/O-LINK master and slave devices, with differentiated enhancements tailored for various sensors. For instance, the L6360 incorporates internal high-side, low-side, and push-pull circuitry for efficient I/O-Link signal line driving. The L6364 features dual communication channels, including a DC/DC converter and dual-mode UART, while also enabling configurable output doubling for enhanced drive strength. This facilitates flexible diagnostic configuration for end devices. TI places particular emphasis on I/O-Link transceiver reliability. All released transceiver ICs incorporate surge protection, adjustable drivers for overcurrent limiting, and reduced overshoot effects through lower driver slew rates. ADI's acquisitions of Lintek and Maxim have completed its industrial communication portfolio. Transceiver ICs like Maxim's MAX14819 feature enhanced core metrics such as current limiting, on-resistance, and maximum operating temperature. They also include additional components like buck regulators and LDOs, simplifying power delivery to electronic components within sensors and actuators.
Summary
As the world's first standardized I/O technology, IO-LINK effectively integrates device-level and control-level protocols. It addresses the shortcomings of fieldbus technologies, ensuring reliable integrated communication from the lower-level field level to the control level. IO-LINK technology is poised to become the "USB of the automation industry."