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AS-i bus system

The AS-i bus system consists of four components: the AS-i master, an AS-i power supply, the yellow AS-i cable, and the AS-i slaves.


The sensors and actuators are connected directly to the AS-i cable using the piercing technology. This is a two-conductor, unshielded cable which carries power as well as the functional and safety signals. No cumbersome parallel wiring is necessary.


The AS-Interface standard was expanded in 2012, so that in addition to the cable with a conductor cross-section of 1.5mm2 there is also one with increased rated current capacity (2.5mm2 cross-section).


The AS-i master organizes data communication in the network and as a gateway establishes the connection between the AS-i network and the higher level controller. It is treated by the higher level fieldbus as a fieldbus slave. Incorporating an AS-i network into an existing fieldbus or ethernet system is thus no more complicated than integrating any other I/O module.

ASi bus addressing

AS-i bus addressing is done either directly by the master or using an AS-i bus addressing device. Up to 62 slaves can be addressed on one master.

ASi handheld addressing device

The AS-i handheld addressing device (BW1191, BW1646) is a compact unit for addressing AS-i slaves and can also be used for reading and writing slave data. The electromechanical connection is made via the universal connecting cable. The AS-i addressing device can be used to address AS-i slaves per AS-i specification 2.0, 2.1 or 3.0.

ASi addressing cable

The AS-i addressing cable (BW1935) is a required accessory for signal transmission between the AS-i handheld addressing device and an AS-i module with infrared interface for addressing. The TTL signals from the addressing device are converted into optical signals for the AS-i module and vice-versa. The AS-i addressing cable is connected to the AS-i addressing device using the M12 connector and to the AS-i module using the infrared head.

Connection cable

The connection cable (BW1802) is used for addressing AS-i slaves.

ASi bus components

An AS-i bus system consists of four components: the AS-i master, the AS-i slave, the AS-i power supply and the AS-i cable. Each slave has a unique address assigned to it which is used for exchanging in- and output data with the master. The modules can be quickly installed or moved thanks to the piercing technology of the AS-i cable.

AS-Interface cable (ASi cable)

The AS-i bus cable transmits power and data on two conductors.

AS-Interface power supply (ASi power supply)

The AS-i bus power supply provides 30 V to the AS-i network.

AS-Interface slave (ASi slave)

The AS-i bus slave reports to the master its input data and receives the output data, has its own address and up to four in- and outputs.

AS-Interface master (ASi master)

The AS-i master connects sensors and actuators to the host controller through the AS-i slaves.

Communication interfaces between a fieldbus system and ASi gateway

Bihl+Wiedemann offers products with interfaces for nearly every standardized fieldbus system in industrial automation technology.