User's Manual
Siemens PLT 111 · 1999
6/3
Bus communication
Design
If e.g. automation systems are to be connected together via a
local bus, the following are required for
n
participants:
•
n
interface modules for 20-m local bus
(cf. table on page 6/5)
•
n
-1 cables 6DS8 201-8..
• 1 front plug 6DS9 200-8AA.
2 interface modules N-AS are required for the AS 235 H system.
These are handled as one participant, i.e. the same bus address
is set on both interface modules.
Up to nine CS 275 modules can be coupled together as a local
bus island via the 20-m local bus. If this local bus island is con-
nected to the remote bus, each of the bus converters UI (max.
2) is also counted as a participant (cf. Figs. 6/3 and 6/4).
The cable connectors are provided at one end with a front plug
for connection to the interface module for 20-m local bus, the
other end of the cable is prepared for the connection and is sol-
dered to the front plug of the next interface module. Only one
front plug is required for the n-th local bus participant. This is sol-
dered to the free end of the cable. The single front plug is not
required with an additional remote bus coupling. It is replaced in
this case by the front plug of the cable 6DS8 204-8..,
6DS8 205-8.., 6DS9 201-8CA or -8FC.
With a remote bus connection, the AS 235 H is always delivered
with a cable 6DS9 201-8FC with 5 plugs instead of a combina-
tion of two connecting cables (6DS8 204-8../6DS9 201-8CA +
6DS8 201-8..).
The cable 6DS8 205-8.. with two plugs can be used for the point-
to-point connection of two local bus participants as an alterna-
tive to the combination of cable 6DS8 201-8.. and front plug.
Local bus cables which have to be routed more than 2.5 m out
of cabinets must be laid in a separate, screened/earthed cable
duct.
The various interface modules for 20-m local bus are listed in the
following table. Catalog PLT 130 contains a detailed description
of the individual modules.
Remote range
Transmission takes place via a coaxial cable at distances up to
4 km. The coupling to the remote bus is non-reactive.
Remote and local buses can be connected by bus converters.
In this way, individual AS or OS systems or groups located in one
area and connected by a local bus can exchange information
with more distant individual systems or groups. The complete
plant bus carries the same information.
Two autonomous plant buses are connected together via a bus
coupler so that only the information intended for the other bus is
transferred.
Fig. 6/5 Connection of a single remote bus
(AS 235 / AS 235 K/ AS 235 H)
Single remote bus
An AS 235 or AS 235 K system is connected to a single non-
redundant remote bus via the interface module for 20-m local
bus N-AS and a bus conductor UI. Two coupled interface mod-
ules N-AS are used in the AS 235 H system.
A cable 6DS8 205-8MB is required in this case with the AS 235 K
system. This is provided with 2 front plugs for connection to the
interface module N-AS and the bus converter UI. The connection
distributor AV is omitted in the AS 235 K.
The cable 6DS8 204-8.. with 3 plugs is used for the single remote
bus with the AS 235, and connects the N-AS to the bus converter
UI and the connection distributor AV. An alternative is the cable
6DS9 201-8CA with 4 plugs which is provided for the redundant
remote bus. One plug remains unused in this case until a redun-
dant design is made if required.
The AS 235 H is also provided with the cable 6DS9 201-8FC with
5 plugs for a single remote bus connection. This connects both
N-AS modules to the bus converter UI and the connection dis-
tributor AV. One plug remains initially unused. An alternative is
a combination of cables 6DS8 204-8.. and 6DS8 201-8.. .
A connector board AF "Remote bus" is required to connect the
remote bus cable. The coaxial cable connection to the connec-
tor board AF has a fixed connection to the bus converter.
AF
AV
UI
or
N-AS N-AS
Remote bus
6DS8 204-8.. + 6DS8 201-8..
6DS8 201-8..
6DS9 201-8CA or
6DS8 204-8.. or
6DS8 205-8.. (without AV)
N-AS
AV Connection distributor
UI Bus converter
or
6DS9 201-8FC
with 5 plugs
This catalog is out of date, see note on page 1