System overview
8
RS4/AS-i
Leuze electronic
DEUTSCH
E
NGLISH
FRANÇAIS
IT
A
LIANO
ESPAÑOL
N
EDERLANDS
2.2
Short description of the AS-Interface
The actuator-sensor interface (AS-interface, in short: AS-i) has established itself as a
system for net-working primarily binary sensors and actuators at the lowest level of the
automation hierarchy. The high number of installed systems, the ease of use and the
reliable operating behaviour also make the AS-interface interesting in the area of machine
safety.
The safe AS-Interface system is intended for safety applications up to category 4 in
accordance with EN 954-1. A mixed manner of operation, using both AS-i standard
components and AS-i safety-related components, is possible.
Note:
A comprehensive description of safe AS-i transmission will be found in the Connecting and
Operating Instructions for the AS-i safety monitor, chapter 11.
2.2.1
The AS-i safety monitor
Within an AS-i system, corresponding to the configuration that the user has specified by
means of the configuration software, the AS-i safety monitor keeps a check on the safety-
related AS-i slaves that are allocated to it. Depending on the device model, up to two
dependent or independent OSSDs with contactor monitoring are available. In case of a
Stop request or of a fault occurring, the AS-i safety monitor in protective mode will safely
switch the system off, with a maximum response time of 40 ms when the system is fully
extended. It is possible in this connection to link as many as 31 safety-related AS-i slaves
into a system.
a PLC controls with AS-i Master
b Standard module
c AS-i safety monitor
d EMERGENCY STOP button, with integrated
AS-i interface
e Safe AS-i input module
f
Position switch, with integrated AS-i
interface
g Standard module
h Safety light grid, with integrated AS-i inter-
face
i AS-i power supply unit
j
Position switch, with integrated AS-i
interface
Fig. 2.2-1:
Safe and standard components in an AS-i network
a
b
c
d
e
f
g
h
i
j
