Engineering System - Siemens Automation and Drives Group

9
Communication
PROFIBUS PA
Basic components
■ Overview
The DP/PA Link is a very simple gateway that interconnects the
two bus systems PROFIBUS DP and PROFIBUS PA, but decouples
their data transfer rates. It is thus possible to combine
PROFIBUS DP and PROFIBUS PA without impairing the time-related
performance of PROFIBUS DP.
■ Design
The DP/PA Link can be operated on PROFIBUS DP standard
masters and enables the construction of large systems with
large addressing ranges and high demands of cycle time.
It is formed from the IM 157 interface module and up to
five DP/PA couplers. DP/PA couplers are available in Ex and
non-Ex versions. All components of the DP/PA Link are interconnected
through the S7 backplane bus.
The use of active bus modules as the backplane bus enables
hot swapping of individual modules and redundant configuration
of the IM 157 interface module for PROFIBUS DP. Applications
with a high level of availability are thus possible in conjunction
with the AS 414H / AS 417H automation systems.
The semi-modular DP/PA Link can be extended to a maximum of
five PROFIBUS PA lines per DP connection, according to the
number of DP/PA couplers. The PROFIBUS PA lines are physically
separated as regards current input, but form one bus system
in communication terms.
Following basic components are available to configure the
DP/PA Link:
Load power supply PS 307 for 120/230 V AC; 24 V DC, version
in 2, 5 or 10 A, or
load power supply PS 305 for 24/48/60/110 V DC; 24 V DC,
2A
IM 157 interface module
DP/PA coupler (Ex and non-Ex version)
Hot swapping
Following components are required in addition or as alternatives
to the DP/PA Link basic components for the hot swapping function
and for a redundant PROFIBUS DP interface module:
Bus modules for hot swapping
- BM IM 157 for two IM 157 modules, for redundant and nonredundant
design, for extended temperature range
- BM DP/PA for one DP/PA coupler, for extended temperature
range (up to five DP/PA couplers per DP/PA Link possible)
Profile rail for hot swapping (as an alternative to the standard
profile rail)
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Siemens ST PCS 7 · October 2004
■ Technical specifications
DP/PA coupler
Connection for PROFIBUS PA
Intrinsically safe version 2-pin screw-type terminal, permanently
integrated terminating
resistor
Output current max. 110 mA
Output voltage 13...14 V DC
Non-intrinsically safe version 4-pin screw-type terminal, switchable
terminating resistor
Output current max. 400 mA
Output voltage 19... V DC
Connection for PROFIBUS DP 9-pin Sub-D plug,
contact assignment as described
in IEC 61158/EN 50170
Backplane bus Connection through S7 backplane
bus connector (only necessary
for PA Link ); non-isolated
The active BM DP/PA bus modules
are required for the hot
swapping function
Displays Bus activity DP (yellow)
Bus activity PA (yellow)
Supply voltage 24 V DC (green)
Current consumption
Ex version Max. 400 mA
Non-Ex version Max. 750 mA
Power loss
Ex version Approx. 7 W
Non-Ex version Approx. 7 W
Operating temperature
Ex version -25 ... +60 °C
Non-Ex version -25 ... +60 °C
Dimensions (W x H x D) in mm 80 x 125 x 130