User manual

General Concepts 12
Doc.Id. HMSI-27-205
Anybus Wireless Bridge - Ethernet to WLAN
Doc.Rev. 1.30
2.2.2 Reset to Factory Defaults
It is possible to reset to the factory default settings in 4 different ways:
• Enter and confirm SMART mode 2.
• Issue AT&F.
•Hold the Mode button while the Wireless Bridge is starting. Note: Ensure that the Ethernet ca-
ble is disconnected, and that any firmware update program has been stopped.
• Press the Restore Device button in the AT-commands section.
2.2.3 Wireless LAN Modes
A Wireless LAN network can be set up in two main connection modes:
• Ad-hoc mode
This is typically used when two WLAN devices connect to each other without going via a WLAN
Access Point. In ad-hoc mode, only 802.11b transmission speeds are used, i.e. a maximum of 11
Mbit/s. The only encryption method supported is WEP.
• Managed (or Infrastructure) mode
This is typically used when a group of devices are connected through a common WLAN Access
Point. In this mode, all available transmission speeds can be used, up to a maximum of
54 Mbit/s. This also allows for user selection of encryption and authentication methods to use.
This means that use cases supporting Managed mode normally have higher throughput.
2.2.4 Wireless Bridge Modes
There are three main Wireless Bridge modes supported by the Wireless Bridge, and these are referred to
in all the use cases described later in this document.
1. Ethernet Bridge mode
In this mode, which is supported only between two Wireless Bridges, the Ethernet packages are
encapsulated in UDP packages and transferred transparently between the two modules. Devices
on both sides of the wireless link are completely unaware of the wireless connection.
2. Client mode
In this mode the Wireless Bridge acts as a wireless extension of the wired Ethernet device it is
connected to. The module is configured to take over (clone!) the MAC address of the connected
device. This means that only ONE Ethernet device can be connected to each module, and not
an Ethernet network with several devices connected through an Ethernet switch or hub. In
"Client Mode", the Wireless Bridge cannot be accessed over the Wireless LAN interface. How-
ever, if the Ethernet link is lost, the module will temporarily enter "Multiclient mode" and can
then be accessed again. When the Ethernet link is re-established, the module will revert to "Client
Mode".
3. Multiclient mode
In this mode, the Wireless Bridge acts as in Client mode, but with the addition that multiple de-
vices using the IP layer can be connected.
Ethernet Bridge mode will introduce an extra overhead (because of the encapsulation) and will have a
significantly lower throughput than Client/Multiclient mode.