User's Manual

4.3.1Getting an IP address using Ethernet

Here is a general guide to the way Reader network

address assignment works:

The Ethernet interface is either served an IP address

via DHCP or is assigned a static IP address by the

user. If the Reader is set to use a DHCP assigned

address and no DHCP server is available it will

automatically use a link local address of

169.254.0.0/16.

The Reader must be powered up with the Ethernet

connected to get a DHCP assigned IP address.

By default, the Readers are set to Obtain an IP address automatically,

which means they look for a DHCP server. If one isn't present, for example

when a crossover cable is used to connect to a single PC, the Reader will

choose a Link Local address.

A Link Local address (also known as Automatic Private IP Addressing -

APIPA) is one chosen at random in the range 169.254.0.1 to

169.254.255.254 with a netmask of 255.255.0.0.

Windows PCs and most other computers by default will use the same

system, which allows an ad-hoc network of computers and Readers to

automatically pick unique addresses. This can work for a crossover cable

between a single Reader and a computer or a more complex setup involving

multiple Readers and multiple PCs using a normal Ethernet cable and

Ethernet hub/switch.

This system is very good to use because it requires no expertise or

intervention from users.

The below process has been discussing automatic address negotiation only.

In order to successfully connect a Reader via a crossover cable follow these

steps:

Step 1. In Windows, open the Start -> Settings -> Control Panel -> Network

Connections window

The PC's Ethernet connection should be marked as disconnected

Step 2. Plug in the crossover cable. Turn the Reader on. The user should instantly

see the state of Ethernet change to Looking For An Address.

This process may take up to a minute.

Step 3. Eventually it should go to the state Limited Or No Connectivity. In the

desktop icon tray, the Ethernet will be marked with a yellow triangle.

What this means is that Windows was looking for a DHCP server, but was

unable to find one, so it used a Link Local address (169.254.X.X)

instead. Even though it looks like an error, this is what we would expect to

see.

Step 4. Left click on the Ethernet connection and look in the Details box on the

bottom of the left hand side pane of the Network Connections window. You

should see the IP address in here.

MARS-24 USER MANUAL 63-70-006-DOC ver.1