Siemens ST PCS 7 User Manual
Communication
PROFIBUS DP
Introduction
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Siemens ST PCS 7 · November 2007
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Application
The PROFIBUS DP fieldbus enables the SIMATIC PCS 7 auto-
mation systems (controllers) to communicate with distributed
I/Os from the ET 200 range (remote I/Os) as well as with
field/process devices, CPUs/CPs and operator terminals that
have a PROFIBUS DP interface. It is possible to route the
PROFIBUS DP into Ex zone 1 by using a fieldbus isolating trans-
former (RS 485-iS coupler) and the RS 485-iS transmission tech-
nology. Connection of the intelligent, distributed field/process
devices and operator terminals on PROFIBUS PA to the automa-
tion system takes place likewise through PROFIBUS DP.
Depending on the type of automation system and the number of
Depending on the type of automation system and the number of
available slots, up to 4 PROFIBUS DP lines can be connected to
a SIMATIC PCS 7 automation system through internal interfaces
in the CPU, and up to 10 PROFIBUS DP lines through additional
CP 443-5 Extended communications processors. On a
PROFIBUS DP line it is possible to operate up to 125 devices,
and on a bus segment up to 31 devices with PROFIBUS DP in-
terface (32 stations).
Electrical and optical transmission technologies offer many dif-
Electrical and optical transmission technologies offer many dif-
ferent configuration options for PROFIBUS DP networks. Electri-
cal networks can span up to approx. 10 km. With optical trans-
mission systems, the total size of the network is governed
primarily by the cycle times as a result of the almost loss-free
transmission.
With SIMATIC PCS 7, PROFIBUS DP topologies are always im-
With SIMATIC PCS 7, PROFIBUS DP topologies are always im-
plemented through the standard electrical PROFIBUS DP con-
nection on the automation system in the form of electrical or
mixed (electrical/optical) networks. In the case of mixed net-
works, the transition between the two media is implemented by
an optical link module (OLM). As regards communication be-
tween the stations, there is no difference between electrical two-
wire technology and fiber optic technology.
Electrical networks can be configured with a line or tree topol-
Electrical networks can be configured with a line or tree topol-
ogy. Mixed electrical/optical networks with OLMs as routers can
be configured with a line, ring or star topology.
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Technical specifications
1)
According to PROFIBUS installation guideline 2.262
PROFIBUS DP
Data transmission
RS 485
RS 485-iS
Fiber-optic
Transmission rate
9.6 kbit/s ... 12 Mbit/s
9.6 kbit/s ... 1.5 Mbit/s
9.6 kbit/s ... 12 Mbit/s
Cable
2-wire shielded
2-wire shielded
Plastic as well as multi-mode and
single-mode glass-fiber
Type of protection
EEx(ib)
Topology
Line, tree
Line
Ring, star, line
Nodes per segment
32
32
1)
–
Nodes per network (with
repeater)
repeater)
126
126
126
Cable length per segment depen-
dent on transmission rate
dent on transmission rate
1200 m at max. 93.75 kbit/s
1000 m at 187.5 kbit/s
1000 m at 187.5 kbit/s
400 m at 500 kbit/s
200 m at 1.5 Mbit/s
100 m at 12 Mbit/s
1000 m at 187.5 kbit/s
1)
400 m at 500 kbit/s
1)
200 m at 1.5 Mbit/s
1)
Max. 80 m (plastic)
2-3 km (multi-mode glass-fiber)
>15 km at 12 Mbit/s (single-mode
2-3 km (multi-mode glass-fiber)
>15 km at 12 Mbit/s (single-mode
glass-fiber)
Repeater for signal refreshing
with RS 485 networks
with RS 485 networks
Max. 9
Max. 9
1)
Not relevant
© Siemens AG 2007