Specifications

AS-Interface
Introduction
Transmission technology
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Siemens LV 1 · 2007
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■ Overview
AS-Interface is an open, international standard according to
EN 50295 and IEC 62026-2 for process and field communica-
tion. Leading manufacturers of actuators and sensors all over
the world support the AS-Interface. Interested companies are
provided with the electrical and mechanical specifications by
the AS-Interface Association.
AS-Interface is a single master system. For automation systems
from Siemens there are communications processors (CPs) and
routers (links) which control the process or field communication
as masters, and actuators and sensors which are activated as
AS-Interface slaves.
■ Benefits
A key feature of AS-Interface technology is the use of a shared
two-wire cable for data transmission and the distribution of aux-
iliary power to the sensors/actuators. An AS-Interface power
supply unit that meets the requirements of the AS-Interface
transmission method is used for the distribution of auxiliary
power. The AS-Interface cable used for the wiring is mechani-
cally coded and hence protected against polarity reversal and
can be easily contacted by the insulation piercing method.
Elaborately wired control cables in the control cabinet and mar-
shalling racks can be replaced by AS-Interface.
The AS-Interface cable can be connected to any points thanks
to a specially developed cable and connection by the insulation
piercing method.
With this concept you become extremely flexible and achieve
high savings.
■ Application
Operating modes
Generally, master interfaces have the following operating
modes:
I/O data exchange
In this operating mode the inputs and outputs of the binary
AS-Interface slaves are read and written.
Analog value transfer
AS-Interface masters according to the AS-Interface Specifica-
tion V2.1 or V3.0 support integrated analog value processing.
This means that data exchange with analog AS-Interface slaves
(according to Analog Profile 7.3 or 7.4) is just as easy as with
digital slaves.
Command interface
In addition to I/O data exchange with binary and analog
AS-Interface slaves the AS-Interface masters provide a number
of other functions through the command interface.
Hence it is possible, for example, for slave addresses to be
issued, parameter values transferred or diagnostics informa-
tion read out from user programs.
Industrial Ethernet
PROFIBUSPROFIBUS PA
KNX
AS-Interface
AS-Interface
PROFINET
Industrial Ethernet
Industrial Ethernet
PROFIBUSPROFIBUS PA
KNX
AS-InterfaceAS-Interface
PROFINET
Industrial Ethernet
G_IK_XX_20002
© Siemens AG 2007