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Breaker Data Adapter (BDA)
WL Circuit Breaker
IP Addresses
The partner must have a unique
address so that it can be addressed
in the extensive Intranet/Internet
system. The IP address format is
used for this purpose, which, as of
Version 4, comprises four figures
from 0 to 255, separated by a
decimal point. Example:
146.254.245.62
The address is 32 bits long. Three
classes have been created to enable
the addresses to be structured on a
world-wide basis and to ensure that
the same address does not exist
twice. The IP address is comprised
of a small header, which describes
the class, a network number, and
a host number. The address of a
subnetwork (Intranet, for example) is
encoded in the network number. The
host number is basically the unique
address of a station in a network of
class X and subnetwork Y.
The first byte of class A IP addresses
contains a number from 0 to 127:
e.g. 98.x.x.x. This class can support
up to 128 subnetworks, each with
around 16 million connections.
Since class A networks are very
limited in number, these addresses
are only available for large global
companies and organizations. A
Network Information Center (NIC)
is responsible for assigning the
classes and network numbers.
Class B networks (these begin with
128.x.x.x to 191.x.x.x) support up
to 16,384 subnetworks, each with
up to 65,535 stations. The majority
of large companies and providers
have a class B address.
With around 2.1 million
subnetworks, each with up to
256 stations, class C addresses
are often used by smaller providers
and companies with no more than
256 connections in their corporate
network. The IP addresses start
from 192.x.x.x to 223.x.x.x
4/23
Subnet Mask
The subnet mask provides
information on the size of the
subnetwork (Intranet) and its
address band. In this way, each
station knows whether the IP
address to be addressed is located
in the same subnetwork or whether
it has to be addressed via a gateway.
Example:
IP address 1st BDA: 206.150.100.89
IP address 2nd BDA:
206.150.102.32
IP address gateway: 206.150.100.1
IP address browser: 206.150.100.50
Subnet mask: 255.255.255.0
Subnet mask 255.255.255.0 means
that all addresses whose first three
bytes are the same as the station
address are located on the line of
that station. These can be
addressed directly (in the example
above, from the browser of the first
BDA). A comparison of the address
of the second BDA with the subnet
mask shows that this address is not
on the same line as the station.
This means that the gateway must
be addressed, via which the request
is then forwarded to the second
BDA. The subnet mask is usually
255.255.255.0.
BDA IP Address
The BDA must be assigned its own
unique IP address that has not been
used before so that it can run on
the Ethernet. This address must
be in the same range as the other
addresses on this line.
WL PROFIBUS Communication and Electronic Accessories • July 2004
Gateway IP Address
If an address that is not located in
the subnetwork is addressed in the
browser, the request is forwarded
to the gateway. The gateway knows
the location to which the request
has to be forwarded on account of
the configuration. The IP address of
the gateway must be obtained from
the network administrator.
If 0.0.0.0 is set as the gateway IP
address, no access to a gateway
has been configured.
Operation
Once the addresses have been set,
it should be possible to call up the
BDA Plus via the Ethernet. This can
be checked using a test ping. To
do so, enter "ping x.x.x.x" in Start >
Execute (x.x.x.x is the placeholder
for the IP address of the BDA to be
addressed). The DOS box that then
appears tells you either that a reply
from the "pinged" IP address is
received, or that the request has
been timed out. In this case, no
connection has yet been established
from the BDA Plus to the target
system.
Note: You may have to include the
IP address of the BDA Plus in the list
of addresses that do not use a proxy
server. The use of a proxy server is
optional and depends on the
network.
Once a connection has been
established, start the browser and
enter the IP address of the BDA
Plus in the address line.
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