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PROFIBUS Power Hub Segment Coupler 3 (SK3)
Glossary
9
Glossary
This appendix gives explanations concerning the explosion protection declarations used in this
manual. It also contains a glossary of terms often used in connection with fieldbus applications.
Term
Explanation
acyclic data exchange
Event-driven communication used to read or write parameters
into or out of a field device.
advanced diagnostic module Module of the FieldConnex
®
system which is plugged onto the
Power Hub motherboard and which delivers diagnostic
functions such as advanced physical layer diagnostics.
basic diagnostic module
Module of the FieldConnex
®
system which is plugged onto the
Power Hub motherboard and delivers basic diagostic
information such as redundant supply of segments, supply
voltage failure of a module, etc.
CREST
Crosstalk and resonance suppression technology. Prevents
signal overlay and resonance, increases the signal-to-noise-
ratio and thus maintains a high signal quality level.
crosstalk
Signal overlay. Signals of one segemtn partly appear on
another. Can be caused by capacitive coupling. Remedy:
Drilled cable connections, CREST.
cyclic data exchange
Cyclic exchange of process data and setpoint values between
master and sensors/actuators which are connected over the
fieldbus.
daisy chaining
Series connection of devices.
DIP switch
Switch used to assign an address for configuration of a device.
DTM
Common abbreviation for device type manager. Software
which allows parameterization and diagnostics of field devices
via a GUI. Parameterization can be done online, i.e., with
instant effect of changes, or offline.
earth leakage
Short circuit via earth. Causes signal deviations (asymmetry)
in case of redundant supply.
galvanic isolation
Physical separation of circuits. Charge carriers cannot flow
from one circuit into another.
GSD converter
Fuchs software which converts GSD files from
PROFIBUS DP to PROFIBUS PA.
GSD file
Text file which describes communication behavior and
supported functions of a PROFIBUS device.
intrinsic safety
Safety concept. Uses energy limitation to ensure that no
temperatures or sparks are present which could lead to
ignition of an explosive atmosphere. In an intrinsically safe
circuit current, voltage, and power are so low that in case of
short circuit, circuit breakage, or earth leakage ignition cannot
take place. Intrinsically safe devices can be removed from or
added to circuits during operation.
jitter
Deviation from ideal timing of an event. Here: Deviation from
the ideal zero passage of the signal as compared to the last
zero passage.
mobile advanced diagnostic
module
Module which offers the functionality of the advanced
diagnostic module but which is designed for mobile use in the
field since it is USB–powered.
noise
Often caused by overlay of a number of disturbances. Leads
to signal deterioration.
physical layer
Layer 1 of the OSI–7–layer model. This is where physical data
exchange takes place.
