AS-Interface is an industrial networking solution for automation systems. It is designed for connecting simple field I/O devices such as binary ON/OFF, analog and safety I/O devices according to EN 50295, IEC 62023-2. Using only a two conductor flat or round cable (AS-i cable, 2 x 1.5 mm2, 16 AWG) to connect all slaves to the master using a free topology. This is the main advantage of this system compared to conventional, parallel wiring, where every single signal has to be wired directly to the control system.
Data and power are available in the same AS-i cable. Every slave or module has its own address for accessing its data. The slaves can be addressed from 1 to 31 (single slaves), or, with extended addressing, there are 62 slaves available (1A to 31A and 1B to 31B). Single slaves and modules with extended addressing (AB modules) can share the same network.