DeviceNet takes to the air, eliminating cables

Users of DeviceNet-compatible products can now link their devices without cables, using a radio-based system developed by Omron. A network based on the company`s WD30 Wireless DeviceNet system can accommodate up to 32 master stations, each handling up to 32 slaves, each with its own DeviceNet sub-network.

This capacity is sufficient to handle the most demanding applications, according to Open DeviceNet Vendor Association, the group that promotes the worldwide growth of DeviceNet. The ODVA says that the wireless technology will cut the cost of installing and wiring DeviceNet systems, especially for applications that are awkward to access or need a lot of cabling

At the Hanover Fair earlier this year, the wireless communication system was demonstrated as part of a network in which data from DeviceNet components was shown being transported over, and viewed through, EthernetIP segments.

The high-frequency wireless transmission technology is said to be immune from interference caused by shopfloor devices, while its low power means that it will not interfere with other systems itself.

To optimise its communications, Wireless DeviceNet combines two technologies. First, the transmissions are spread over 34 channels in the globally-approved 2.4GHz band, helping the message to get through successfully first time. And second, each transceiver has two antennae which it scans continuously, choosing the one with the best signal quality. This helps to discriminate between direct signals and their reflections.