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ifm
Device Manual SmartSPS AC14 with EtherNet/IP interface (AC1421, AC1422), Firmware 3.1.2
2015-11-30
Glossary of Terms
9
Glossary of Terms
A
A/B slave
AS-i slave with an A or B being appended to its
address number and which may therefore be
present twice on the
→master.
>
Acyclic data transmission
In general data from the
→ master are
transmitted once per
→ cycle to one each of
the
→ slaves (= → cyclic data transmission).
Data transmission only at certain events (e.g.
when the device is switched on or when values
have been changed) is called acyclic data
transmission.
>
Address
This is the "name" of the bus participant. All
participants need a unique address so that the
signals can be exchanged without problem.
>
Application software
Software specific to the application,
implemented by the machine manufacturer,
generally containing logic sequences, limits
and expressions that control the appropriate
inputs, outputs, calculations and decisions.
>
Architecture
Specific configuration of hardware and/or
software elements in a system.
>
AS-i
The AS-Interface (AS-i = Actuator Sensor
Interface) is a standard for fieldbus
communication to EN 50295 and IEC 62026-2.
It was developed for the connection of
actuators and sensors with a simple wiring to
replace the conventional parallel wiring.
An unscreened two-wire yellow flat cable (max.
500 m) serves for data transmission as well as
for voltage supply (24...30 V DC) for the
communication electronics and for participants
with a low current requirement. Loads with a
greater energy requirement additionally
receive a separate (black) flat cable for energy
supply with 24 V DC.
AS-Interface is a single master system. Up to
62 slaves can be connected per
master. Each of these slaves needs an
unambiguous address. The master cyclically
polls (
→Polling)) all projected slaves and
exchanges the up to 248 input data and
186 output data with them.
Association (user association)
>
AS-i cycle
An AS-i cycle contains the data exchange of
up to 31 slaves plus a telegram inclusion
phase plus, if required, a telegram
management phase (
→
AS-i phases (status
machine)
(
)). In the case of the
extended addressing mode, two AS-i cycles
are required for data transfer to all A/B slaves.
>
AS-i phases (status machine)
Offline phase: No AS-i data traffic takes
place during initialisation.
Detection phase: In the detection phase,
the AS-i master first of all searches for
existing slaves - irrespective of whether
they are projected or not.
Activation phase: In this phase, the found
slaves are activated depending on the
operating mode.
Data exchange phase: The AS-i master
carries out cyclical data exchange with the
activated slaves.
Management phase: At the end of a cycle
the AS-i master goes into the management
phase, during which the master can send a
command to a specific slave (if requested).
