Specifications

AS-Interface
AS-Interface specification
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Siemens IK PI · 2009
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■ Overview (continued)
AS-Interface master
To be able to operate A/B slaves on an AS-Interface network you
must also use master modules that meet the minimum require-
ments of Specification 2.1.
A/B technology is supported by the masters of the SIMATIC S7
and the DP/AS-Interface links from Siemens. Only standard
slaves and A slaves (= A/B slave with an A address) can be
operated on masters which do not support Specification 2.1.
The subaddress of A/B slaves is set to "A" in the as-delivered
state.
The new masters that comply with Specification 3.0 support all
new slave profiles, but are also fully backwards compatible.
The AS-Interface specification relevant for the respective slave
can be found in the section Selection and ordering data.
The exact slave profile is shown in the section
Technical Specifications in Technical information LV 1 T
Communication cycle
Standard slaves are queried in each cycle (max. cycle time:
5 ms). If only one A or B slave is installed at an address, this
slave will be queried in each cycle (max. cycle time: 5 ms). If an
A/B slave pair is installed at an address, the A slave will be que-
ried in one cycle and the B slave in the next cycle (max. cycle
time: 10 ms). If only standard and/or A slaves are installed in a
network, the cycle time is identical to the standard masters (max.
cycle time: 5 ms).
Whether an AS-Interface slave is a standard slave or an A/B
slave is noted in the section Selection and Ordering data in the
column Slave Type and can be deduced from the section
Technical Specifications of the slave in question in the Technical
information LV 1 T.
All slave types can be combined within a single AS-Interface
network.
■ Benefits
• Lower costs for masters and power supply units thanks to
increased number of slaves or I/Os per AS-Interface string
• Enhanced decentralization in installations with numerous,
widely distributed signals
• Existing AS-Interface systems can be expanded further
■ More information
More information pertaining to AS-Interface is available in the
AS-Interface system manual.
The German AS-Interface system manual is available free of
charge as a download in the Internet under
http://support.automation.siemens.com/WW/view/de/26250840
The English AS-Interface system manual is available free of
charge as a download in the Internet under
http://support.automation.siemens.com/WW/view/en/26250840
The AS-Interface system manual is also available in print in both
languages, see under "System Components and Accessories"
--> "Miscellaneous Accessories".
AS-Interface specification Available masters
Version 2.1
S7-200 (CP 243-2), DP/ASi Link 20E
Version 3.0
DP/AS-i Link Advanced, DP/AS-i F-Link,
IE/AS-i Link PN IO, S7-300 (CP 343-2, 343-2P)
AS-Interface specification Maximum cycle time Slave profile
Version 2.0
5 ms S-X.0, S-X.1, S-X.F
Version 2.1
5 ms with 31 slaves
10 ms with 62 slaves
S-X.A, S-7.3, S-7.4, S-7.F
Version 3.0
as for Version 2.1, and profile-specific 10 ms for
inputs/outputs (e.g. 20 ms for 4DI/4DO and 40 ms for
8DI/8DO)
S-7.5.5;
S-7.A.5, S-B.A.5;
S-7.A.7, S-7.A.8;
S-7.A.9, S-7.A.A, S-6.0