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
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
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.
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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WL MODBUS Communication and Electronic Accessories • January 2005
