PI has published the physical layer and protocol specification of IO-Link, the open, fieldbus-independent communication interface for sensors and actuators. PROFINEWS 57 reports about the first IO Link products.


IO-Link makes it possible to integrate sensors and actuators into an automation system easily and quickly. First products were presented at the Hanover Fair in April 2007. These ranged from simple sensors providing mainly binary information to multifunctional devices capable of indicating various process values (so called ?function islands?), which showed the actuators and their associated check-back signals as a unit.


Work is now focused on open systems integration and the creation of IO-Link profiles to ensure products can be easily and quickly replaced by alternatives without restricting manufacturer-specific functionality.


IO-Link can already be integrated into PROFIBUS and PROFINET to enable convenient configuration and commissioning at all levels of the manufacturer-specific functions. Calibration is supported in the same way as detailed diagnostics.


At the Hanover Fair, PI gave an impressive demonstration of how devices from different manufacturers are able to interact. The integration definitions that are currently being specified are intended to allow integration by means of a simple ?device description?, which is the key to ensuring standardized mapping to higher-level communication systems (both fieldbuses and Ethernet-based systems).


Within PI, 26 members are now working on IO-Link. In addition to the major sensor manufacturers, this includes manufacturers of I/O modules and automation systems. Semiconductor manufacturers recently joined the team in order to contribute to specifying integrated interfaces for implementing IO-Link into products in the most cost-effective way possible.

By: Mayer