IO-Link is a serial, digital communication protocol for use in automation technology. It is used to connect sensors or actuators to an automation system. With IO-Link, the “last meter” of communication with sensors and actuators is digitized. IO-Link is standardized in IEC 61131-9. Where previously only binary switching states (on/off) or analog signals were transferred, now status information can also be read by the sensor or actuator and configuration data transferred to the sensor and actuator.
IO-Link is not another bus system, but rather a point-to-point connection between the IO-Link device and a connection unit, the IO-Link master.