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NOVATEK-ELECTRO
ЕТ-485
APPENDIX A
(recommended)
SWITCHING TO ETHERNET
WARNING! Switching the unit to Ethernet network requires mutual coordination of settings on the
connected devices. Connecting the misconfigured unit to the network may affect the
communication level of other units on the network. As a rule, all connections to a network of more
than 2 units are carried out by the qualified personnel (network administrator) only.
1. IP-ADDRESSING
When units are communicating over Ethernet network using TCP/IP protocol, every unit is using a set of IP-
addressing settings to identify the sender and receiver of the data. The unit memory contains a personal and
unique, within a single subnet, IP-address (four bytes are written as four integers, separated by dots, in the range of
0-255), subnet mask, which is the same for all units within the subnet (written similar to IP-address), and IP-address
of the gateway, which is used to communicate with other networks. Proper communication between units of a
subnet is possible under several conditions:
1)All units of a subnet have similar mask. Most of small LANs are using 255.255.255.0 mask.
2)Mask starts with a group of bits set to 1, followed by a group of bits turned to 0.
3)All bits set to 1 in the mask are similar for all the IP-addresses of units in subnet and indicate the subnet
address. 192.168 is most frequently used address in LANs for the mask 255.255.255.0. The third byte may be used
as a subnet number in a complex LAN. In smaller LANs, the third byte is usually equal to 0.
4)A set of bits in IP-address of the unit, which is set to 0 in the mask, is unique to each unit within the same
subnet .
5)In most cases, the unit like router, which is already communicating with other networks, is switched to the
network. This unit often gets the following address 192.168.0.1, 192.168.0.100, or 192.168.0.101. In this case, other
units in the network shall have this IP-address of the unit as the gateway address. This address is not necessary for
communication between units in a subnet, and is only used to connect units of one subnet to units of other networks.
Factory addressing settings for ET-485 Interface Converter are listed in Table A.1.
Table
А.1
– Factory settings for ET-485 addressing
Parameter
Value
IP-address
192.168.0.111
Subnet mask
255.255.255.0
Gateway
192.168.0.1
In order to communicate with ET-485, which is set to factory settings, the client unit (or any other units on the
same subnet) should have 255.255.255.0 as a mask and address starting with 192.168.0. The fourth byte of the
address can take any value in the range from 1 to 255, except for 111. If the connection between ET-485 and a client
unit is not provided directly but via a network with a number of units, the mentioned address can not be equal to any of
the addresses of other units on the subnet . If network has several units with the mask and the first three bytes of the
IP- address, which are different from those specified in Table A.1, or the ET-485 factory IP-address is already taken,
the configurable unit should be temporarily removed from the network to avoid addressing conflicts and establish a
communication between this unit and ET- 485 directly. This will allow to configure the unit and ET-485 for direct
communication or switching ET-485 to the network.
2. CONFIGURING THE CLIENT UNIT
The unit addressing is set according to documents and software it uses.
Below is an example of configuring the personal computer (PC) on Windows XP or Windows 7 to communicate
directly with the ET-485 on factory settings.
Open the list of OS network connections to configure the network address in Windows. To do this, follow the
steps below (mind the OS version):
For Windows XP:
1)Log in as administrator.
2)Select Start-Control Panel.
3)If control panel items are divided into categories, select "Network and Internet Connections".
4)Go to "Network Connections".
For Windows 7:
1)Log in as administrator.
2)Select Start-Control Panel.
3)If control panel items are divided into categories, select "Network and Internet".
4)Go to "Control Center Network and Sharing Center".
5)In the task bar (on the left), select "Change adapter settings".
