50
Connection
50
Echochange - Manual / Connection
Change Connection Timeout
Using this setting, you can specifically change the timeout setting for connection monitoring that will
end a connection when parameterizing a station remotely. This makes sense in cases where you
disabled the transmission of life data acks for an Internet connection, for example. Please note that
increasing this value will also increase the response time in case of connection problems (such as a
broken cable).
Change Connection Memory
This setting allows you to change the memory size reserved for a connection. The minimum memory
size for a connection is 1460 bytes (maximum number of payload for Ethernet connections). For a
broadcast Receive connection (UDP), this setting might not be sufficient. If the partner station sends
data faster than the PLC can accept it, the data will be buffered in this memory. The UDP data will
only be discarded if this memory overflows.
8.2.3.2 IP Address
Basics
To establish the communication between two technical devices, each device must be capable of
sending data to the other device. This data can only be received by the intended remote station if it
has been addressed properly. In IP networks, this is ensured by specifying an IP address.
An OPC server is able to address a PLC directly by its IP address. Example: 192.168.1.20
It is also possible to address a PLC by its name. For this purpose, specify the name of the PLC and
the corresponding IP address and enter the domain server in the TCP/IP settings of the server. For a
domain name (e.g. “PLC1”), the server queries the name server to get the IP address and then
addresses the PLC directly using its IP address (192.168.1.20).
IP Address
Each IP data packet starts with an IP header. This is an information section used for transmission on
the IP layer. This header also includes two fields where the IP addresses of both the sender and the
receiver are entered before transmitting the data packet. Routing is done on layer 3 of the OSI model,
the network layer.
Structure
IPV4
The IPv4 addresses that have been used predominantly since the introduction of Internet Protocol
Version 4 consist of 32 bits, i.e. 4 octets (bytes). This means that it is possible to represent 2
32
=
4,294,967,296 addresses. In dotted decimal notation, the four octets are written as four integers,
from 0 to 255, in decimal format, separated by dots.
Example: 192.168.1.20.
IPV6 – new version with a bigger address space
Due to the rapidly increasing IP address demand, it was foreseeable that the usable address space
provided by IPv4 would soon be exhausted. The IANA address pool was depleted on February 03,
2011. This was the main reason for developing the IPv6 protocol. IPv6 uses 128 bits to store
addresses. This means that 2
128
= 256
16
(=
38
) addresses can be represented.
This number is sufficient to provide each square millimeter of the surface of the earth with at least
665,570,793,348,866,944 (= 6.65 · 10
17
) IP addresses.
Since a decimal representation with
ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd.ddd would neither be very
transparent nor handy, IPv6 addresses are usually represented in hexadecimal format. To further
simply this representation, every two address octets are grouped and separated by colons.
To Next Page
Loading...
