Wireless in Automation is becoming commonplace now. New developments in communication infrastructure arena are increasingly & almost immediately being adapted for the industrial automation domain. The latest addition to this list is the IEEE 802.15.4 standard for low power wireless networks. We already have live examples of this technology running, albeit on an experimental basis.
Mesh networks are ad-hoc networks built using sensors that also double up as wireless data relay points. That is a sensor & a wireless access point combined. Media access is defined by the underlying 802.15.4 protocol stack while the physical layer is wireless-over-air. As with any wireless network, attenuation of radio signals especially in harsh plant conditions is always a concern. This partly is overcome by the basic architecture of these networks; short hops for data from node to node instead of one long haul. Moreover, usage of the well established ‘frequency hopping’ technique also mitigates this problem. The architecture is self healing, i.e. the failure of a node doesn’t bring the network down. Data immediately takes a alternate path to reach its destination.
Add to this the encryption and check codes for ensuring data security & integrity, and you have a truly functional wireless infrastructure in place. Saving on cabling costs and short up-times make these more viable. Wireless HART has been one of the first technologies to be built based on this standard. Once the ISA100 Working Group freezes the final specification for the standards on 'Wireless in Industrial Automation', we can expect to see a revolution in the way we set-up automation systems.
I’m eagerly looking forward to the standard’s release and the deluge of products from all leading automation vendors then on!