Festo SBOC-M-R1B-H, Manual

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4. Commissioning
4-6
Festo GDCS-SBOC-EN en 1602a
4.2 Addressing in the Ethernet (basic principles)
Due to the separation into logical and physical protocol layers
(Ethernet and TCP/IP ), there are two types of addresses in a
network:
– a fixed Ethernet address (MAC-ID) for each device and
– an IP address which is assigned to every device in the
network.
Before the application, data are always sent to or received
from an IP address. In order that the data reach the receiver,
a correlation must be created between the logical IP address
and the physical Ethernet address. The address resolution
protocol ARP does this: An ARP table is saved in each net­
work PC. This table lists the relevant physical Ethernet ad­
dress for each IP address in the network. If an Ethernet ad­
dress is not listed in the ARP table, the IP driver can ascertain
it with the aid of an ARP request.
Ethernet address (MAC-ID) The unalterable worldwide unique Ethernet address (MAC-
ID) of the Compact Vision System can be found on the name
plate. Through this, you can uniquely distinguish the differ­
ent Compact Vision Systems.
IP address An IP address as per standard IPv4 is usually specified with
4 decimal numbers separated by points (per 1 byte).
Example for an IP address: 192.168.2.10
An IP address is used to address a network as well as an indi­
vidual station in the network. The IP address therefore con­
tains:
– the net ID (specifies the address of a network) and
– the host ID (specifies the address of an individual station
in this network).