AS-Interface utilizes a single, trapezoidal, unshielded two-wire cable, which eliminated the extensive parallel control wiring required with most installations. The existing controller sees AS-Interface as remote I/O; therefore, AS-Interface connect to the existing network with minimal programming changes.

The AS-Interface system utilizes only one master per network to control the exchange of data. This allows the master to interrogate up to 31 slaves and update all I/O information within 5 ms (10 msec for 62 slaves). For slave connection, an insulated two-wire cable is recommended to prevent reversing polarity. The electrical connection is made using contacts which pierce the cable's insulation, contacting the two wires, thus eliminating the need to strip the cable and wire to screw terminals. For data exchange to occur, each slave must be programmed with an address which is stored internally in non-volatile memory and remains even after power is removed.

The maximum cable length for each master is 100 m without repeaters. Using repeaters, distances to 300 m are possible