Building Automation with ASi

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AS-Interface – Building Automation

The advantages of AS-Interface – such as simple, cost-saving installation and high degree of flexibility – have now become familiar in Building Automation as well. Numerous companies are relying on the ASi installation system for applications such as controlling fire and smoke damper systems, shutter drives or heating and cooling ceilings using analog output modules. Damper actuators with flow regulators can also be connected to the controller through the MP-Bus Gateway. It is also possible to process EnOcean signals from wireless buttons and sensors through ASi. Customer proximity is our hallmark, which means we stand by you in word and deed and are open to custom-tailored solutions. Just contact us.

Basic Concept of AS-Interface 

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 (ASi cable, 2 x 1.5 mm2, 16 AWG) to connect all nodes 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 ASi cable . Every node or module has its own address for accessing its data. The nodes can be addressed from 1 to 31 (single address, or, with extended addressing, there are 62 addresses available (1A to 31A and 1B to 31B). Single addresses and modules with extended addressing (AB modules) can share the same network.

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The Structure

The ASi Master/Gateway controls the ASi network and acts as a direct link to the host (PLC, Building Management Systems, etc.). Combined with an integrated mini-PLC functionality the master can also be used for pre-processing or as a stand-alone device without the need for a host controller (programming language IL or C).

A Gateway is an ASi Master, and simultaneously a node to higher level network ( PROFIBUS , EtherNet/IP , Modbus , etc.). AS-Interface is the lowest level of the automation pyramid intended for Actuator/Sensor networking.

Free Topology

ASi supports free topology such as Star, Ring, Linear, Tree and Mesh network (see examples below).

The simple and highly flexible ASi network bus is one of the great strengths of the system. The polling  principle allows the use of any topology and features a variety of different field and control cabinet modules. Whatever the requirements in your building we make it possible to record both digital and analog values and control either type of actuator. Whether a ventilation flap with four digital and four analog outputs, an analog output module for controlling heating/cooling ceilings, or special equipment such as an MP-Bus or EnOcean gateways.

You can also process both ASi standard and ASi Safety (up to SIL3) data over the same ASi network. The data can be processed in the master or passed on to the higher level building management system through the fieldbus interface on the master.

Benefits at a glance

• Save hardware by reducing I/O cards, cabinets and wiring
• Robust, globally standardized industrial bus with already more than 27 million installed nodes
• Simple electronics with robust performance in industrial quality
• Free choice of network topology
• Quick installation, reduce maintenance and shorten testing time,fast commisioning and ability to expand the system
• Easy commissioning, and opportunity to expand the system
• Transmission in real-time
• Avoid wiring errors (no risk of faulty electrical connection)
• High resistance against EMC noise
• Fast error localization, spontaneous diagnostics and enhanced diagnostic options

Compatibility

ASi is fully backwards compatible. This means that a master according to the last specification 3.0 can communicate with all existing nodes according to the different specifications 2.0, 2.11 and 3.0. This guarantees a future proof investment.