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February 2010
E client/station uses 3-address mode any Access Point that it is to communicate with may be
configured for
either
3 or 4 address mode (i.e. Access Point mode does not matter).
4-address mode allows a WI-MOD-E client/station to bridge traffic from devices connected to its
wired Ethernet port without acting as a proxy for their MAC address. This means that a WI-MOD-E
client/station in 4-address mode can bridge
any
Ethernet traffic – not just IP based traffic as with 3-
address mode. 4-address mode should also be used if the bridge Spanning Tree Protocol is required.
When a WI-MOD-E client/station uses 4-address mode any Access Point that it is to communicate
with
must
also be configured for 4-address mode.
Router Operation
A router joins separate Ethernet networks together. The router has different IP addresses on its
wired and wireless ports, reflecting the different IP addresses of the separate Ethernet networks.
All
the devices in the separate networks identify the router by IP address as their gateway to the other
network. When devices on one network wish to communicate with devices on the other network,
they direct their packets at the router for forwarding.
As the router has an IP address on each of the networks it joins, it inherently knows the packet
identity. If the traffic directed at the router can not be identified for any of the networks to which it
is connected, the router must consult its routing rules as to where to direct the traffic to. For details
on configuring routing rules see section “3.11 Routing Rules”.
3.8
Radio Configuration
The WI-MOD-E can be configured for different radio transmission rates. A reduction in rate
increases the reliable range (transmission distance). The factory-default data rate settings are
suitable for the majority of applications and should only be modified by experienced users.
The WI-MOD-E allows for configurable
fixed
or
fallback
radio transmission Data Rates. When a
fixed rate is configured the radio transmission rate is never altered, even under extremely poor
conditions. The fallback rates allow a maximum rate to be configured whilst enabling the unit to
automatically reduce the rate when transmit errors occur. When a radio transmission is unsuccessful
the WI-MOD-E will automatically drop to the next lowest data rate and enter
probation
. If
subsequent transmissions are successful at the lower rate, the WI-MOD-E will attempt to increase to
the next highest rate when probation has ended. This can occur when either a specified number of
data frames have been successfully transmitted at the lower rate, or when a specified amount of time
has elapsed whilst using the lower rate.
The WI-MOD-E also has a configurable “Basic Rate”. The difference between the Basic Rate and
the radio Data Rate is that it only applies to multicast radio transmissions and
management
frames.
The Basic Rate is generally set to a lower value than the Data Rate since multicast transmissions
have no inherent error correction mechanism.
Select the “Radio” Menu to change the following configuration parameters. If a change is made,
you need to select “Save Changes” to retain the changes. Changes will not take effect until the unit
is reset.
