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Before Operation Section 3-1
3-1 Before Operation
In order to connect the Ethernet Unit to an Ethernet network, it is necessary to
set the IP address. This section explains the process of address conversion,
which is required information for determining the Ethernet Unit’s IP address.
Address Conversion (for
FINS Communications
Only)
When using the FINS communication service, it is necessary to specify the
nodes according to the FINS address system. Even in this case, data must be
sent and received on the Ethernet network using IP addresses. Therefore, IP
addresses are converted from FINS addresses.
There are three ways to convert addresses. For each method, there are
restrictions on the maximum number nodes at the same network level for
which communications is possible. The methods and the maximum number of
nodes are shown in the following table.
Use the CX-Programmer to select the address conversion method in the Sys-
tem Setup. For an explanation of how to make the setting, refer to 4-2 CPU
Bus Unit System Setup.
3-1-1 Automatic Address Generation
Automatic address generation converts addresses using the FINS node num-
ber as the host number of the IP address. The network ID of the local IP
address is used for the network ID. The IP address of a remote node is calcu-
lated from the local Ethernet Unit’s IP address, the subnet mask, and the
remote node number (Fins node number), as follows:
Remote IP address =
(local IP address AND subnet mask) OR remote FINS node number
Example
The remote IP address is calculated for the node using the following settings:
Local IP address: 130.25.36.8 (decimal)
Subnet mask: 255.255.255.0 (decimal)
Remote FINS node number: 5
Ethernet Unit
Ethernet Unit
IP address: 153.211.32.114
Node number: 23
CS/CJ-series
CPU Unit
User program
Network address: 5
Node number: 23
Data
Address conversion
To 153.211.32.114
To
To 153.211.32.114
Data
Address conversion method Maximum number of nodes
(including local node)
Automatic generation (the default) 126
IP address table 32
Combined method
(using both automatic generation
and IP address table)
126