Weidmuller SAI Active Universal Pro Series, Руководство пользователя

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Appendix
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5663600000/1.4/09.09
PROFIBUS slave
PROFIBUS slaves exchange data cyclically with a
PROFIBUS master. In addition, parameterization,
configuration and, in the case of a malfunction, di-
agnostic data is transmitted. Typical PROFIBUS
slaves include connection terminals, repeaters,
gateways, communication terminals, valve blocks
and others.
PROFIBUS User Organisation
More than 260 vendors and users of the standard-
ised communication system PROFIBUS have come
together in the registered association PROFIBUS
User Organisation (PUO; German = PNO) to jointly
support further technical improvements and estab-
lish the use of the technology internationally. The
PROFIBUS User Organisation is a registered asso-
ciation. Membership is open to any company or re-
search facility anywhere in the world.
PROFIBUS-DP
This is a special application for automating factory
production. DP = Decentralised Periphery.
PROFIBUS-DP address
With the PROFIBUS address you determine at
which address your SAI distributor will be identified
on PROFIBUS-DP.
PROFIBUS-FMS
This is utilised for the universal, object-oriented, cy-
clical and acyclic exchange of data at a medium
speed. FMS is particularly suitable for exchanging
data between intelligent slaves such as PCs and
PLCs. PROFIBUS-DP and PROFIBUS-PA are spe-
cial variants. FMS = Fieldbus Message Specifica-
tion.
PROFIBUS-Master
PROFIBUS-DP differentiates between Class 1 and
Class 2 masters. The Class 2 master is utilised for
parameterization of PROFIBUS slaves by means of
software; it is mainly used to set the PROFIBUS
address. As well as exchanging data with the slave,
the Class 1 master supplies the PROFIBUS slave
with configuration and parameter data.
PROFIBUS-PA
This is used to control field devices by means of a
process control system in the processing industry.
This variant of PROFIBUS is used in hazardous ar-
eas (Ex-Zone 0 & 1). Low currents only are used so
that no sparks flashover in the case of a malfunc-
tion; it uses a slower data transmission rate. PA =
Process Automation. Vendor-independent compati-
bility is guaranteed by technical guidelines to en-
sure implementation of PROFIBUS technology. The
technical guidelines are published and distributed
centrally by the PROFIBUS User Organisation
(PUO) to underline the fact that these are effectively
a standard. Diverse PROFIBUS guidelines are
available, for example: the "Optical transfer tech-
nology for PROFIBUS".
Protective earth
Protective earth conductors are often used in elec-
trical equipment and cable lines. This is also known
as the protective lead, earth, earth connection or PE
(protective earth).
The task of the protective earth conductor in electri-
cal systems is to protect human beings from dan-
gerous touch voltages as well as to protect the sys-
tem from damage. The PE conductor is fitted in
such a manner that there is an electrical connection
between the outer metal housing of the electrical
equipment (for example lamps, fridges, motors).
Should a fault occur and the electrical supply volt-
age comes into contact with the exterior of a piece
of electrical equipment, the short-circuit to ground
via the PE conductor should ensure that the voltage
between the housing of the respective electrical
equipment and the ground, with which humans and
animals are generally in contact, is reduced to a
harmless level.
At the same time, the high short-circuit currents trip
the fuse. That ensures that the electrical equipment
with the fault is disconnected extremely quickly from
the supply voltage.
German regulations stipulate that the PE conductor
must be identifiable by the colour combination
green/yellow.
Repeaters
Repeaters are necessary in order to create a
PROFIBUS-DP network with more than 32 stations
or establish a larger network extension. The re-
peater represents the beginning of a new segment
in which the maximum number of stations can be
used or the maximum extension is defined.