Specifications

AS-Interface
Introduction
System overview
Transmission technology
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Siemens IK PI · 2012
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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 communication processors (CPs) and
network transitions (links) which control the process or field com-
munication as masters, and actuators and sensors which are ac-
tivated as AS-Interface slaves.
■ Benefits
A key feature of AS-Interface technology is the use of a shared
two-conductor cable for data transmission and the distribution of
auxiliary power to the sensors/actuators. A power supply unit
which meets the requirements of the AS-Interface transmission
method and has an external data decoupling module if required
is used for the distribution of auxiliary power. The AS-Interface
cable used for the wiring is mechanically coded and hence pro-
tected 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 transmission
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
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 information
read out from user programs.
Control and
monitoring system
Telecontrol and
substation control
Remote access,
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Field device for
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Coupler
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G_IK10_XX_20002
Kap_06_en.book Seite 2 Mittwoch, 7. September 2011 10:09 10
© Siemens AG 2011