User's Manual

Design
Siemens PLT 130
.
1994
3/3
Remote range, bus components
The following therefore applies:
In the case of electrically isolated local bus interface modules,
the ground potential of the bus interface is decoupled from the
ground potential of the subrack system. In addition, the 0-V
level of the interface logic is matched to the potential of the cou-
pling partner via the local bus cable. This prevents equalizing
currents from flowing via the local bus cable in the event of volt-
age differences > 0.2 V between the grounds of the coupling
partners. These currents would interfere with the bus traffic.
In this manner , it is possible e. g. to extend a local bus island
(0-V island) consisting of basic and extension cabinets by
means of external, electrically isolated local bus participants
(N-AS/N-AT). Any local bus interface modules can be linked
together within this local bus island since they are powered from
the same power distribution subrack. The following conditions
apply: max. length 20 m, max. 9 participants, where each bus
converter UI also counts as one participant.
It is not permissible to mix non-floating participants with differ-
ent earthing concepts, e. g. SIMATIC S5 or SICOMP M with
OS 265-3 systems or interface module N-V.24 in the same local
bus island.
The interface modules for the local bus have a redundant local
bus interface. They are each connected to one another by only
one cable which contains the redundant local bus.
The cables are fitted at one end with a front plug for connection
to the local bus interface modules, the other cable end is pre-
pared for the connection and is soldered to the front plug of the
cable of the next interface module. A single front plug is re-
quired for the n-th local bus participant. This is not necessary
for standard connections, e. g. to the bus converter UI for the
remote bus, since prefabricated cables are available with
looped-through wiring to up to 5 plugs.
The total length of the cables must not exceed 20 m.
Remote range
Transmission takes place via a coaxial cable up to distances of
4 km. The signals are self-timing bipolar square-wave pulses.
The coupling to the remote bus is reaction-free.
Up to 100 bus participants can communicate with one another
via the remote bus. The remote bus and local bus are connected
together via inductive bus converters UI. The complete bus
system therefore has the same information.
Two autonomous bus systems are connected together via a
bus
coupler
so that only the information intended for the other bus is
transferred. The bus coupler is counted in each of the two au-
tonomous bus systems as one bus participant.
Bus components
Local bus interface
modules
Interface
module for
20-m local bus
Type
Required to connect the following systems and
devices to the CS 275 bus system
floating
non-floating
N-AS
(-8AC)
AS 215, AS 235 and AS 235 K
automation system
x
N-AS
(-8AA)
AS 235 H automation system x
N-BK Bus coupler x
N-AT OS 520 operation and monitoring system,
AT-compatible personal computers,
SICOMP industrial PCs and
PG 770 programmer
x
N16-M OS 265-3 operation and monitoring systems
SICOMP M minicomputers
x
N-V.24 SICOMP industrial PCs and non-Siemens com-
puters via V.24 or 20-mA current loop interface
x
N-S5 SIMATIC S5-155U programmable controllers x
Cable connectors for local bus
To connect the interface modules for 20-m local bus to one
another and to the bus converter UI. A front plug is required for
the last participant on the local bus.
Front plug for local
bus
Metal front plug with 2 cable inlets and contact points. The
contact points must be used to connect the plug with a low
inductance to the subrack.
Connection
distributor
The connection distributor has a vacant plug connection to the
redundant 20-m local bus for the connection of configuring aids
(SICOMP industrial PC with PROGRAF program package) and
bus diagnostic aids. It must be connected to the local bus via a
separate cable connector for this purpose.
Inductive bus converter (bus converter unit
UI)
A bus converter is required to connect individual participants or
a local bus with several participants to a remote bus. It per-
forms continuous signal conversion between the local bus and
the remote bus or vice versa without intermediate storage. The
coupling is inductive and non-reactive.
Standard locations:
Basic cabinet of the AS 235 and AS 235 H automation system
Basic system of the AS 235 K automation system
OS 265-3 system cabinet
Remote bus connection unit
Bus coupler subrack
Remote bus connection subrack FAZ-S5.
Created with "Chameleon CMYK PDF Creator" for Wolfgang Strozyk at Siemens AG
This catalog is out of date, see note on page 2