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Rugged radio networks quit the control cabinet

01 December, 2003

Rugged radio networks quit the control cabinet

One of the many developments on show on the vast Siemens stand at the recent SPS/IPC/Drives Show in Germany was a second generation of IWAN (industrial wide area network) products using new methods to ensure reliable data transmission and to protect access. The components have rugged IP65 housings allowing them to be used directly in a plant rather than in control cabinets.

The IWAN components are used to create radio networks to IEEE 802.11b/g with data rates up to 54 Mbits/s, and transmission ranges of 30m indoors, or 100m outdoors. There are four main components:

• "robust access points" (RAPs) that create the network and are equipped with Ethernet interfaces for connecting the radio network to standard Ethernet systems;

• similar devices with two radio cards that allow simultaneous connections to a mobile local terminal and to a remote location;

• "robust client modules" (RCMs) which link Ethernet-equipped nodes such as PCs or PLCs to the radio network; and

• a communications processor in a PC-card format that allows mobile programming devices and PC-based devices to be linked to the IWAN.

Siemens says that its new IWAN technology goes beyond the requirements of IEEE 802.11 to ensure safe, deterministic data transmission and to protect against unauthorised access. Commercial and industrial data can be carried on the same network but a fixed bandwidth can be reserved for selected equipment to ensure that a central controller will receive alarm data from its remote terminals, even when there is a high volume of traffic on the radio network.