AS-i and IO-Link IO-Link is the intelligent connection between the device (sensor or actuator) on one side and PLC or field module on the other side. With the IO-Link AS-i module you combine the advantages of the AS-i wiring system with the standardised IO-Link communication. Using the simple AS-i connection technology you establish the data connection and energy supply for IO-Link devices - sensors and actuators. The sensor settings are saved in the AS-i module and can be transferred to a new sensor, if necessary.