The Technology

AS-i is the simplest of the industrial networking protocols used in PLC, DCS and PC-based automation systems. It is designed for connecting actuators and sensors in manufacturing and process applications using a single cable. It is an 'open' technology supported by hundreds of automation vendors. Many millions of AS-i field devices are installed and proven globally.


AS-i is a highly efficient networking alternative to the hard wiring of field devices. It is an excellent partner for fieldbus networks such as PROFIBUS, DeviceNet, Interbus and Industrial Ethernet, for whom it offers a low-cost remote I/O solution. It is proven in hundreds of thousands of applications, including conveyors, process control valves, bottling plants, electrical distribution systems, airport carousels, elevators, bottling lines and food production lines. AS-i is even available in a cut-down version known as AS-i SW for ultra-simple devices such as panel switches and indicators.


Functional Safety too! AS-i provides the ideal basis for Functional Safety in machinery safety/emergency stop applications. A special profile called Safety at Work (sometimes called ASi-Safe) is used. Safety devices are connected on the same cable as the control system and can provide Safety support up to SIL (Safety Integrity Level) 3 according to IEC 61508. (Important note: implementation of a functional safety system using any technology must, of course, be done by competent personnel who are fully qualified in providing risk assessments, validation and installation.)