Specifications
AS-Interface
ASIsafe
Introduction
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Siemens LV 1 · 2007
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Overview
Master information (through regular I/O transfer)
Safety is included
The ASIsafe concept supports the direct integration of safety-
related components, such as emergency stop switches, protec-
tive door switches or safety light arrays, in the AS-Interface net-
work. These are fully compatible with the familiar AS-Interface
components (masters, slaves, power supplies, repeaters, etc.)
according to IEC 62062/EN 50295 and are operated in conjunc-
tion with them on the yellow AS-Interface cable.
The signals of the safety sensors are evaluated by a safety mon-
itor which not only monitors the switching signals of the safety
sensors but also continuously checks that the data transmission
works correctly. The safety monitor has one or two enabling cir-
cuits which are configured with two channels and are used to
switch the machine or plant to the safe state. Sensors and mon-
itors can be connected to any points of the AS-Interface network.
Also, several monitors can be used on one network.
A failsafe controller or a special master is not required. The mas-
ter regards safety slaves like all other slaves and receives the
safety data solely for information purposes. Hence it is also pos-
sible to expand all existing AS-Interface networks.
ASIsafe ensures a maximum response time of 40 ms. This is the
time between the signal being applied to the input of the safe
slave and the output on the safety monitor being switched off.
Tested safety
The system was tested and approved by TÜV (Germany), NRTL
(USA) and INRS (France). The transmission method for safety-
oriented signals is designed so that applications up to
Category 4 according to EN 954-1 and SIL 3 according to
IEC 61508 can be realized.
Software
The safety-oriented applications can be compiled and trans-
ferred into the monitor using the configuration software. The soft-
ware also enables online diagnostics.
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Benefits
• No failsafe PLC or special master is required
• Simple system structure thanks to standardized AS-Interface
technique
• Safety-related and standard data on the same bus
• Existing systems can be expanded quickly and easily
• Optimum integration in TIA (Safety Diagnostics) and Safety
Integrated
• Safe signals can be combined in groups
• Inclusion of the safety signals in the plant diagnostics, also on
existing HMI panels
• Approved up to Category 4 according to EN 954-1 or SIL 3
according to IEC 61508
• ASIsafe is certified by TÜV (Germany), NRTL (USA) and INRS
(France)
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Application
Integrated safety technology in the AS-Interface system is used
wherever EMERGENCY-STOP pushbuttons, protective door in-
terlocks, stop Category 0 and 1, two-hand operator controls and
light arrays are now installed.
NSA0_00005c
Standard PLC
Standard-Master
Standard-
Slave
Safety monitor
Safe slave with
EMERGENCY
STOP
Power
supply unit
Signal evaluation of slave/safety monitor
AS-i POWER
© Siemens AG 2007