Design
Siemens PLT130
.
1994
3/3
Remote range, bus components
The following therefore applies:
In the case of electrically isolated local bus inter face modules,
the ground potential of the bus inter face is decoupled from the
ground potential of the subrack system. In addition, the 0-V
level of the interface l ogic is matched to the potential of the cou -
pling partner via the local bus cable. This prevents equaliz ing
currents from flowing via the l ocal 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 b us traffic.
In this manner, it is possible e. g. to extend a local bus is land
(0-V island) consisti ng of basic and extension cabinets by
means of external, electricall y isolated local bus participants
(N-AS/N-AT). Any local bus inter face modules can be linked
together within this local bus island since they are powered from
the same power distribution s ubrack. The following conditions
apply: max. length 20 m, max. 9 participants, where each bus
converter UI also counts as one participant.
It is not permiss ible to mix non-floating part icipants with differ-
ent earthing concepts, e. g. SIMATIC S5 or SICOMP M with
OS265-3 systems or interface moduleN-V.24in the same local
bus island.
The interface modules for the l ocal bus have a redundant local
bus interface. They are each connected to one anot her by only
one cable which contains the redundant local bus.
The cables are fitted at one end with a front pl ug for connection
to the local bus interface modul es, the other cable end is pre-
pared for the connection and is soldered t o the front plug of the
cable of the next interface modul e. A single front plug is re-
quired for the n-th local bus participant. This i s not necessary
for standard connections, e. g. to the bus converter UI f or 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 coaxi al cable up to distances of
4 km. The signals are self-t iming bipolar square-wave pulses.
The coupling to the remote bus is reaction -free.
Up to 100 bus participants can communi cate with one another
via the remote bus. The remote bus and local bus are connected
together via inductive bus conv erters UI. The complete bus
systemtherefore has thesame information.
Twoautonomous bus systems are connected together via a bus
coupler so that only the infor mation intended for the other bus is
transferred. The bus coupler is counted in each of the two au-
tonomous bus systems asone bus participant.
Bus components
Local bus interface modules
Interface
modulefor
20-m localb us
Type
Requiredto connect the following systems and
devicesto the CS 275 bus system
floating
non-floating
N-AS
(-8AC)
AS215, AS 235 and AS 235 K
automationsystem
x
N-AS
(-8AA)
AS235 H automationsystem x
N-BK Buscoup ler x
N-AT OS520 operationand monitoring system,
AT-compatiblepersonal computers,
SICOMPindustrial PCs and
PG 770 programmer
x
N16-M OS 265-3 operation and monitoring systems
SICOMPM minicomputers
x
N-V.24 SICOMPindustrial PCs and non-Siemens com-
puters via V.24or 20-mA current loop interface
x
N-S5 SIMATICS5-155U programmable controllers x
Cable connectors for local bus
Toconnect the int erface 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 t he 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 v acant plug connection to the
redundant 20-m local bus for the connection of configuring aids
(SICOMP industrial PC with PRO GRAF program package) and
bus diagnostic aids. It mus t be connected to the local bus via a
separate cable connector for this purpose.
Inductive bus converter (bus conver ter unit UI)
A bus converter is required to connect individual partici pants or
a local bus with several par ticipants to a remote bus. It per -
forms continuous signal conversion between the local bus and
the remote bus or vice versa wi thout intermediate storage. The
coupling is inductive and non-reacti ve.
Standard locations:
Basiccabinet of the AS 235and AS 235 H automationsystem
Basicsystem of the AS 235 K automationsystem
OS265-3 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