Network Topologies For Contact Rail Systems; Term Definitions - Siemens 6ES7 972-4AA02-0XA0 User Manual

User´s Guide Power Rail Booster Version 12/2005

4 Network Topologies for Contact Rail Systems

4.1 Term Definitions

Contact Rail System
The communication between stationary plant control system and mobile vehicles
takes place over PROFIBUS DP. Signals from the master are amplified by the PRB
and fed into the contact rails. The vehicle picks off the amplified signals with the
collector. The moving PRB then transforms the signals back to the Standard
PROFIBUS signal level.
DP Master Segment
A contact rail system can be connected to the PROFIBUS via one or more than one
PROFIBUS master. The segment of a contact rail system in which data interchange
takes place via a PROFIBUS master is referred to as a "DP master segment".
Normally, a contact rail system consists of only one DP master segment. If there are
multiple DP master segments, care must be taken to see that no electrical
connection (short circuit) can be established between DP master segments via the
double collector. This can be done using rail sections (see Chapter 4.4 „Rail
sections").
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 (see Chapter
4.4 „Rail sections").
Fig. 3: Block diagram of a DP master segment with two PRB segments
Copyright © Siemens AG 2005 All rights reserved.
6ES7 972-4AA02-0XA0 Page 14 of 49
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com