Instructions

UM-0085-B09 DT80 Range User Manual Page 207
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Subnet Mask
The DT80's Ethernet IP address actually consists of two parts:
• The network number, which identifies the network to which the DT80 and its neighbours are connected.
• The node number, which uniquely identifies this DT80. No two devices on the network may have the same
node number. Also known as a host number.
The subnet mask is a property of the network to which the DT80 is connected and specifies which part of the IP address
is the network number and which is the node number.
For example, the subnet mask 255.255.255.0 specifies that the first three parts of the IP address are the network
number, and the last is the node number within the network. So in this case the IP address 192.168.2.101 would
represent node 101 on the "192.168.2" network.
As with the IP address, the subnet mask can be set manually using a profile setting, or it can be assigned automatically
by a DHCP server.
Note: The subnet mask is not applicable to point-to-point connections; it is only relevant for Ethernet.
Gateway
The DT80 can communicate directly with any of the nodes connected to its local Ethernet network, or to the computer at
the other end of a point-to-point link. In some cases this is all the connectivity that is required.
If, however, the DT80 needs to be accessed from farther afield then it needs to know how to communicate with
computers on different
networks. This is done by assigning one of the computers on the DT80's local network to be a
gateway. The IP address of the gateway is then entered into the DT80.
Now, any time the DT80 wants to talk to a computer on a "foreign" network it will simply passes the data to the
designated gateway and let it sort it out. The gateway may then pass the data on to other gateways, until eventually the
data finds its way to its destination. See also Connection to a LAN (P231).
As hinted above, if you only want to connect your DT80 to one computer, or to a few computers which are all on the
same local network, then it is not necessary to specify a gateway. As with the IP address, the gateway IP address can be
set manually using a profile setting, or it can be assigned automatically by a DHCP server.
For a point-to-point serial or DtUsb connection, the gateway is not relevant because in these cases the network beyond
the computer at the other end of the link is not visible to the DT80.
For a mobile network connection using the integrated modem, the gateway will be set up automatically during the
connection process.
DNS Server
Most networks include a Domain Name System (DNS) server. This is responsible for translating names such as
ftp.datataker.com into numeric IP addresses. If the DT80 is configured with a valid DNS server address then the current
job will be able to access FTP servers by name rather than having to use a raw IP address.
As with the IP address, the DNS server IP address can be set manually using a profile setting, or it can be assigned
automatically by a DHCP server. Often two DNS server addresses are specified – a primary one and a backup.
For a point-to-point serial or DtUsb connection, the DNS server is not relevant because in these cases the network
beyond the computer at the other end of the link is not visible to the DT80. For a mobile network connection using the
integrated modem, the DNS servers will be set up automatically during the connection process.
Integrated Modem
Only applicable to DT8xM models
The DT80 'M' models (DT80LM/82EM/85LM/85GLM) include an integrated wireless (cellular) modem. This allows you to:
• connect the logger to the internet wherever there is mobile coverage
• configure and monitor the logger over the internet using dEX (if permitted by your mobile plan).
• wirelessly unload data to an FTP server or your email inbox
• send SMS alarm messages to a mobile handset
• send email alarm messages to your computer or smartphone
The DT82EM3, DT80LM3 and DT85LM3 variants support 2G and 3G networks (GSM/ GPRS/ EDGE/ WCDMA), while
the corresponding DT8xM2 models support 2G networks only (GSM/ GPRS/ EDGE).