As-I Safety - Siemens SIMATIC ET200SP Function Manual

3.1.6

AS-i Safety

AS-i Safety enables safety-related components – such as EMERGENCY-STOP devices,
protective door switches or safety light arrays – to be integrated in an AS-Interface network.
The safety-related slaves are fully compatible with the familiar AS-Interface components
(masters, slaves, power supplies, repeaters, etc.) in accordance with IEC 62026-2 and are
operated in conjunction with them on the yellow AS-Interface cable.
The transmission method for safety-related signals is approved for applications up to PL e
according to EN ISO 13849-1 and up to SIL 3 according to EN 62061.
As usual, nodes on the AS-Interface bus are controlled in operation by the standard program
of the higher-level SIMATIC (F) CPU or by a SINUMERIK controller.
In order to implement safe functions, the information from the safe and standard nodes must
be combined logically, and additional parameters set. The configuration of the safety
functions depends on which safety solution is being used:
In conjunction with the modular safe AS-i master, which is formed by combining the
CM AS-i Master ST and F-CM AS-i Safety ST modules in an ET 200SP station, all safety
functions and combinations are configured via STEP 7 and processed in the controller
(F-CPU) by the fail-safe program.
The AS-i communication modules in the ET 200SP facilitate the use of an AS-Interface under
fail-safe SIMATIC or SINUMERIK controllers.
Tasks are allocated as follows:
• Acquisition of safety-related signals is via safe input slaves on the AS-Interface bus.
Further signals can be detected through F-DI modules of the SIMATIC.
• Evaluation and processing of signals is via the fail-safe SIMATIC or SINUMERIK controller
• Reaction via safe output modules on the AS-Interface bus or via F-DQ modules of the
SIMATIC
Simple combination of the CM AS-i Master ST and F-CM AS-i Safety ST modules in one
ET 200SP station results in a powerful, safety-related router between PROFINET (or PROFIBUS)
and PROFIsafe and AS-Interface, which can be expanded further in a modular fashion with
further I/O modules of the ET 200SP.
In this way, it is possible to create expansion versions for almost all cases. Besides the single
AS-i master, double, triple or generally multiple masters can also be realized with or without
fail-safe functionality.
Note
The SIRIUS 3RK3 modular safety system, MSS for short, with connection to AS-Interface can
be used for a safety application without a fail-safe controller (F-CPU). This system is not
covered in this documentation. Further information can be found on the Internet
(http://www.siemens.de/sirius-mss).
AS-i Safety is also referred to as ASIsafe.
Safety engineering with AS‑Interface in the SIMATIC ET 200SP, including typical circuit diagram
Function Manual, 08/2020, A5E44991382002A/RS-AB/002
Introduction
3.1 AS-Interface
15