Gateway links Modbus to Zigbee

A US company has developed a gateway between Modbus and the emerging ZigBee wireless communications technology. The gateway will allow PLCs from a variety of suppliers to communicate with remote sensors and actuators over a ZigBee network using standard Modbus addresses and commands.

"Before now, no one had the pieces needed to add the benefits of ZigBee technology easily to an existing network," explains Tim Cutler, vice-president of sales and marketing for the developer, Cirronet. What the new gateway offers is "an off-the-shelf solution that enables companies to add ZigBee technology to their industrial automation systems without the cost and time of making changes to their network".

ZigBee is a low-cost wireless networking technology being developed by an alliance of more than 120 companies, including ABB, Danfoss, Eaton, Honeywell, Mitsubishi, Motorola and Omron. A report last year, by the market analyst On World, predicted that the number of industrial wireless sensor nodes would mushroom from 330,000 in 2004 to 85.9 million by 2010, representing sales worth $2.9bn. ZigBee nodes are expected to account for 85% of this business.

• Mitsubishi has announced that it intends to commercialise ZigBee-based sensor networks for location and positioning applications in 2007. It has developed software that will measure the distances between ZigBee sensors to an accuracy of 10% for applications such as monitoring the position of goods in warehouses.