Siemens 6ES7 972-4AA02-0XA0 User Manual page 48

User´s Guide Power Rail Booster
OLM
Optical Link Module
PELF
Protective Extra Low Voltage
Power Rail Booster
Amplifier for PROFIBUS. For transmitting bus signals via contact rail
PR
Power Rail
PRB Segment
As a rule, more than one stationary Power Rail Booster is required to supply a
contact rail system with PROFIBUS signals. The subsegment of a contact rail system
in which data interchange takes place via a PRB is referred to as "PRB segment". A
PRB segment is thus a subsegment of a DP master segment. It must be ensured that
no electrical connection (short circuit) can be established between two PRB
segments via the double collector. This can be done using rail sections.
PROFIBUS
PROcess FIeld BUS,
Volume 2, PROFIBUS which defines functional, electrical and mechanical properties
and characteristics for a bit-serial fieldbus system. PROFIBUS is available with DP (=
Distributed I/Os), FMS (= Fieldbus Message Specification), PA (= Process
Automation) or TF (= Technological Functions) protocol.
PROFIBUS Address
Every bus node must have a PROFIBUS address for unambiguous identification of
that node on the PROFIBUS. PCs/PGs have the PROFIBUS address "0".
PTP Connection
Point-to-point connection.
Reference Potential
Potential at which the voltages flowing through electrical circuits are viewed and/or
measured.
Segment
The section of bus cable between two terminating resistors forms a segment. A
PROFIBUS DP segment contains between 0 and 32 bus nodes. Segments can be
joined to one another using RS485 repeaters. All galvanically connected contact rails
forma a contact rail segment. As many as 124 bus nodes can be operated on one
contact rail segment. Segments can be coupled over RS485.
SELF
Safety Extra Low Voltage
Self-cleaning
The cleaning of contact rail and sliding contact caused by operation of the contact rail
system. The movement of a sliding contact over a contact rail pushes aside dust
Copyright © Siemens AG 2005 All rights reserved.
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a German process- und fieldbus standard to EN 50170,
6ES7 972-4AA02-0XA0
Version 12/2005
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