Automation unplugged

Wireless automation technologies enable a seamless flow of real-time information to utility providers.

Automation technology has come a long way in the past 30 years and with the arrival of wireless communication the sector is taking another giant leap forward.

Wireless technologies present compelling opportunities for the utility sector to implement applications that they simply could not justify with traditional wired technology.

Wireless networks can provide real-time accurate data and visibility into equipment performance, field workforce, consumer consumption and the whereabouts and utilisation of other assets, from trucks on the road to spare parts on warehouse shelves.

Wireless process automation, meanwhile, enables information to be gathered from remote sensors at hard to reach or even dangerous unmanned sites, which would otherwise be measured infrequently. The opportunity now exists to take readings from rotating or moving plant equipment. The obvious attraction of wireless is the major cost savings compared with wired installations. For example, installing additional wired measurements within hazardous areas of a plant is often cost prohibitive.

Wireless reduces the expense of installation by as much as 90%. Installation is simplified since it is not necessary to plan and run conduit and cables to every device. Users are also relieved of the complexities and limitations of physical wiring.

By adopting wireless communication techniques, operators, maintenance and IT personnel, and management gain convenient access to information that would previously have been unobtainable. On top of that, wireless technologies can help to improve productivity and safety, and, ultimately, reduce operational costs.

Mesh networks

There are various wireless technologies available for industrial applications, but not all are suitable for the harsh environments found at plants, including the inevitable "canyons of steel" that can present problems for wireless signals. However, self-organising wireless mesh networks overcome these obstacles to deliver reliable, secure communications.

Mesh networks combine smart monitoring devices with wireless transmitters, networked together using Time Synchronised Mesh Protocol (TSMP) communications technology. The networks use IEEE 802.15.4 radios with channel hopping as the physical layer.

They are designed and tested to be tolerant to almost all interference and can co-exist with other wireless networks in the plant.

The transmitters have a maximum range of 150-400m, depending on the location, and as many as 100 devices can relay information back to one gateway. Wireless upgrade modules can even be fitted onto existing wired devices.

As new wireless devices are added, they connect automatically to the self-organising network. New nodes beyond the range of a gateway pass their messages through other wireless devices until they reach the destination.

This wireless mesh technology is easily scalable, since repeated extensive site surveys are unnecessary and new devices can be online within 30 minutes of installation. With this plug-and-play functionality, plant or grid coverage can easily be expanded as requirements change.

Traditional point-to-point wireless networks require a site survey to ensure that every node in the system has a line-of-sight path. This survey work is expensive and also tends to require up to three times as many infrastructure nodes than a self-organising network.

Another advantage of self-organising networks is that they are dynamic. If something disrupts communication between transmitters, such as scaffolding, new equipment, or moving vehicles, the self-correcting system recognises the problem and automatically re-routes the data traffic along the next best path.