Specifications

AS-Interface
AS-Interface specification
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Siemens IK PI · 2009
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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
expanded 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 "inte-
grated" means that no special function blocks are required for
accessing the analog values. It is just as easy to access 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 connection of a
maximum of 1000 digital inputs/outputs (profile S-7.A.A:
8DI/8DO as A/B slave).
New profiles have also enabled the option of expanded
addressing for analog slaves.
Acceleration of analog value transfer through "Fast Analog
Profile".
Variable use of analog modules: Optional parameterization
of resolution (12/14 bit) and 1 and 2-channel capability.
Asynchronous serial protocol 100 baud or 50 baud bidirec-
tional.
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
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