Siemens ST PCS 7 Manual De Usuario
Communication
PROFIBUS DP
Electrical networks
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Siemens ST PCS 7 · November 2007
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Overview
Shielded twisted-pair cables are used as the transmission me-
dium for electric PROFIBUS DP networks. The PROFIBUS DP
stations are connected to these bus lines through a bus connec-
tor (max. 32 stations per segment).
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Design
FastConnect Stripping Tool
FastConnect
PROFIBUS FastConnect is a system for fast and easy assembly
of PROFIBUS copper cables. The system comprises compatible
components:
• FastConnect Standard Cable for fast assembly
• FastConnect Stripping Tool
• FastConnect Standard Cable for fast assembly
• FastConnect Stripping Tool
with FastConnect Blade Cassettes (spare blade cassettes for
the stripping tool)
• FastConnect bus connector for PROFIBUS
Repeater for PROFIBUS
A repeater links the individual bus segments with RS 485 tech-
nology. Main applications are:
• Increase in number of nodes and distances
• Electrical isolation of segments
If diagnostics functions for physical cable diagnostics are re-
• Increase in number of nodes and distances
• Electrical isolation of segments
If diagnostics functions for physical cable diagnostics are re-
quired in addition to the standard repeater functionality, a diag-
nostics repeater can be alternatively used. It additionally per-
forms physical online monitoring of the copper bus cables. In the
event of a fault it sends a diagnostic message with detailed in-
formation about the type and location of the fault to the DP mas-
ter.
Active RS 485 terminating element
The active RS 485 terminating element is used to terminate bus
segments. The component supplied with 24 V DC independent
of the bus stations provides a defined RS 485 signal level, and
suppresses reflections on the line. Bus stations (e.g. ET 200S)
can be coupled and decoupled without feedback to/from
PROFIBUS networks terminated by active RS 485 terminating
elements.
RS 485-iS coupler
The RS 485-iS coupler is an isolating transformer with which the
PROFIBUS DP fieldbus can be routed intrinsically-safe into the
hazardous area.
The RS 485-iS coupler has the following functions:
• Connection of intrinsically-safe PROFIBUS DP stations, e.g.
The RS 485-iS coupler has the following functions:
• Connection of intrinsically-safe PROFIBUS DP stations, e.g.
ET 200iSP, ET 200iS or devices from other vendors with
Ex i DP connection
• Conversion of the electrical PROFIBUS DP RS 485 transmis-
sion technology into the intrinsically-safe RS 485-iS transmis-
sion technology with a transmission rate of 1.5 Mbit/s
• Suitable as a safety barrier
• Additional use as a repeater in the hazardous area.
The RS 485-iS coupler as an open unit can only be used in hous-
• Additional use as a repeater in the hazardous area.
The RS 485-iS coupler as an open unit can only be used in hous-
ings, cabinets or rooms for electrical equipment. It is assembled
on a SIMATIC S7-300 rail which can be positioned horizontally or
vertically.
The RS 485-iS coupler is integrated into the PROFIBUS as fol-
The RS 485-iS coupler is integrated into the PROFIBUS as fol-
lows:
• Connection to standard PROFIBUS DP via standard Sub-D
• Connection to standard PROFIBUS DP via standard Sub-D
socket (at the bottom on the RS 485-iS coupler, behind the
right front door).
• Connection of PROFIBUS DP with RS 485-iS transmission
technology via screw terminals (at the top of the RS 485-iS
coupler, behind the right front door)
• The last bus station on the intrinsically-safe PROFIBUS DP
segment (not further RS 485-iS couplers) must be terminated
by a selectable resistance using the connector, Order No.
6ES7 972-0DA60-0XA0.
© Siemens AG 2007