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Consider the General Notes on the Information in the Pepperl+Fuchs Product Catalogs
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16.08.12
AS-Interface
Configuration of the master/gateway and moni-
tor
You must then specify which nodes are connected to the AS‑Interface
segment in the master/gateway.
Fieldbus master simulation is available for PROFIBUS, DeviceNet and
MODBUS. You can use AS-i Control Tools to simulate Ethernet and
MODBUS gateways and test them in conjunction with the higher-level
fieldbus connection.
Most K20/K30 masters have a separate serial diagnostic interface
for connecting to a PC. You can use AS-i Control Tools to perform
diagnostics on the AS‑Interface segment.
To execute safety-related functions, the logic must be stored in the
monitor using the ASIMON+ software. Function blocks are used to
define and store the logic. This configuration is loaded to the monitor
from the PC. The safe code sequences are then taught in.
10.10
Masters and Gateways
The AS-lnterface master/gateways control communication and are also
available with an integrated safety monitor with various different gateway
interfaces.You can enter the parameters easily via the graphical display
on the master or call up diagnostic information in plain text. All the
diagnostic data can be transferred to the control unit. The standard
menu structure and universal operating concept make this system easy
to use despite the wide variety of different devices.
Many masters/gateways are also available with a control function and,
similarly to a small PLC, can directly control the inputs and outputs
on the AS‑Interface segment. This reduces the upward data volume,
reduces response times, and renders a small control unit superfluous.
7.7
Power Supplies
With AS-lnterface, the data and power supply are transferred on the
same two strands. Data communication is modulated to 30.5 V
DC
voltage. A special AS‑Interface power supply with data decoupling
is therefore required to supply the AS‑Interface segment. All power
supplies comply with the PELV (protective extra low voltage)
requirements of EN 50178 and EN 60204. Therefore no earth ground
(
PE) is required for the AS‑Interface current circuit. Since AS‑Interface
is constructed symmetrically, the shield terminal on the power supply
must have ground potential.
A ground connection monitoring function is integrated into some power
supplies to increase plant safety. This reliably indicates a non-compliant
contact on the AS‑Interface cable to the ground potential, which can
result in communication errors.
Depending on the size of the plant you can use power units from 2 A to
8
A at any point within the AS‑Interface segment. If there are particularly
heavy consumers, you should position the power units close to them.
The total input current for all the AS‑Interface nodes must be lower than
the maximum output current of the power supply. Current consumption
is made up of the following for the modules:
•
Operating current
•
Current consumption of the sensors supplied from AS‑Interface
•
Required current for operating the outputs, provided these
are not supplied externally.
11.11
Repeaters, Bus Termination, and
Analyzers
If the segment length is longer than 100 m, you need bus termination
in order to extend the segment to 200 m. The bus termination reduces
the reflections at the cable ends. It must be positioned as far away as
possible from the master. As each AS‑Interface network functions
differently, the bus termination has two impedances that cover the entire
required range depending on the application.
For segment lengths over 200 m, you can use repeaters that reprocess
the signal and transmit it to the next galvanically isolated decoupled
segment. A separate AS‑Interface power supply is therefore also
required for this segment. In principle, you can use as many repeaters
as you wish in parallel for star topology, although there must be a
maximum of just two repeaters between the master and the last node.
The analyzer is used to test AS‑Interface networks. In applications
with many powerful noise sources or with very long cable lengths, it
is advisable to check the signal quality on the AS‑Interface segment.
You can transfer the measured data to the PC and use the diagnostic
software to perform a more accurate analysis. The device can detect
sources of interference and makes it easier to implement a suitable fix.
You can also set up test protocols for plant transfer.
12.12
AS‑Interface Safety at Work
AS‑Interface Safety at Work describes the safe communication on the
AS‑Interface network in accordance with the latest machine guidelines.
This globally implemented safety system enables you to achieve the
highest safety class. You can connect all known safety devices to the
AS‑Interface segment via modules or directly as an integrated solution.
Parallel wiring is avoided entirely. Especially when several machines are
linked together using safety-related components, the easily configured
AS‑Interface Safety at Work solution quickly proves its worth even with a
small number of slaves.
The safety principle
Neither special cabling nor special control units are required to make the
most of these benefits. You can retrofit each existing AS‑Interface line
with safety-related devices by integrating one or more safety monitors
into the AS‑Interface segment. The monitor observes the responses
from the "safe" nodes to the master. The higher-level standard master
continues to operate all components in a network. The AS‑Interface
transfer protocol is so noise-immune and failsafe that safety-related
telegrams may be transmitted. Additional monitoring of the "safe" nodes
is carried out by the safety monitor that continuously monitors the
communication between the standard master and the "safe" slaves.This
functional principle is extremely reliable and can therefore be used up
to Performance Level e (PLe) in accordance with ISO 13849-1 "Safety
of machinery - Safety-related parts of control systems" and up to SIL3
in accordance with IEC 61508. TÜV has certified the devices and the
BGIA (German Institute for Occupational Safety) has also classified the
communication as "safe." The system offers the following functions:
•
Safe coupling of up to 32 AS‑Interface segments
•
Safe local outputs with the option of creating groups
•
Replacement of a failsafe PLC
AS-Interface
AS-Interface,
Master/Gateways
7 7
.1
AS-Interface,
Power Supplies, Power Extender and Repeater
7
.2
AS-Interface,
Safety at Work
7
.3
AS-Interface,
Modules
7
.4
AS-Interface,
Indicating/Operating
7
.5
AS-Interface,
Accessories
7
.6
