Research: Wireless use in industry
Wireless in industrial applications has been around for a number of years. Its use has mainly been in areas where a traditional networking solution of industrial Ethernet or fieldbus has not been feasible, either through problems with distance, cost, or lack of existing infrastructure. Wireless technology has had to overcome a number of barriers in the past: A perceived lack of reliability, its suitability for control, and its ability to transmit in a busy environment have all hindered its adoption. However, as the technology has matured, user acceptance has grown.
Wireless communications used in factory and process automation are currently driven by three main technologies. In 2011, IHS estimated that almost one quarter of all new wireless connections made were made by wireless LAN. This can be in the form of 802.11a, b, g, and n. Modes a, b, and g are more popular, but n mode is beginning to make headway as it moves from the consumer market into the industrial space. Common use of multiple antennae means it has built-in redundancy should a single antenna be damaged or fail.
Bluetooth is also widely used within industry and is estimated to account for over one-fifth of total new wireless connections in 2011. Classic Bluetooth is relatively low bandwidth, but the newer Bluetooth high-speed variant is designed to improve this. Bluetooth can be suitable for battery-powered solutions, although Bluetooth Low Energy has been designed specifically with this in mind.
Cellular technology has been in used in wireless communication for some time now and is estimated to make up 15% of new connections. It is very suitable for long-distance transmission due to the existing cellular infrastructure in remote locations. This makes it very suitable for SCADA systems.
Many proprietary and “other” solutions exist in the wireless space. These include unlicensed bands such as the sub-GHz range as well as long haul communications. These are popular in the process industry and, like most wireless solutions, do not require any existing network infrastructure. The lower cost of installation can make them an appealing prospect to those looking to install wireless. WirelessHART and ISA100.11a have, until recently, been working toward a single standard. This, however, has not been successful and is unlikely to occur in the near future. The lack of convergence means these two technologies will continue to vie for new connections in the industrial space.
– Tom Moore, B.Sc, is analyst for industrial automation, IMS Research (Part of IHS Inc.). Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering and Plant Engineering, firstname.lastname@example.org.