Specifications

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AS-Interface

Introduction

AS-Interface specification

2/11

Siemens LV 1 · 2007

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Overview

Technology development of the AS-Interface

System limitations of AS-Interface specification

Expansions of AS-Interface Specification 2.1

• AS-Interface Specification 2.1 enables the number of network

stations to be doubled from 31 to 62. Using the so-called ex-

panded addressing system, the 31 addresses available in an

AS-Interface network can be split into two.

• If this option is used for each of the 31 slaves, the maximum

number of stations in an AS-Interface network is then 62. The

so-called A/B slaves can have a maximum of four inputs and

three outputs. Expanded addressing is only possible for digi-

tal slaves, not for analog slaves and safety-oriented slaves

(ASIsafe).

• Another function of the AS-Interface Specification V2.1 is the

integrated analog value transfer function. In this case

"integrated" means that no special function blocks are re-

quired for accessing the analog values. It is just as easy to ac-

cess the analog values as the digital values. The integrated

analog value transfer function can be used with analog slaves

which support the profiles 7.3 and 7.4.

Expansions of AS-Interface specification 3.0

• The AS-Interface Specification 3.0 enables the connection of

up to 1000 digital inputs and outputs (profile S-7.A.A: 8DI/8DO

as A/B slave).

• New profiles have also enabled the option of expanded ad-

dressing for analog slaves.

• Acceleration of analog value transfer through "Fast Analog

Profile".

• Variable use of analog modules: optional parameterization of

the resolution (12/14 bit) and one or two channels.

• Asynchronous serial protocol 100 baud or 50 baud, bidirec-

tional.

ASi Spec. V2.0

ASi Spec. V2.1

1994

1998

2001 2005/2006

ASIsafe

ASi Spec. V3.0

5 ms bus cycle time

NSA0_00453a

31 Slaves

•

62 Slaves (10 ms)

•

Speed/Flexibility

Analog profiles

Diagnostics peripherals

4DI/4DO in A/B technology

8DI/8DO in A/B technology

Additional analog profiles

Transmission of serial data

Safety monitor

Safe input slaves

AS-Interface Specification Maximum number of slaves Number of digital inputs Number of digital outputs

Digital Analog ASIsafe

Version 2.0 31 31 31 31 × 4 = 124 31 × 4 = 124

Version 2.1 62 31 31 62 × 4 = 248 62 × 3 = 186

Version 3.0 62 62 31 62 × 8 = 496 62 × 8 = 496