Industrial wireless blackout looms
19 August 2014
Andrew Evans, technical executive at GAMBICA – the UK trade body for instrumentation, control, automation and laboratory technology industry – is calling for the harmonisation of the new EN62657-2 industrial wireless co-existence standard, which otherwise could lead to a major industrial wireless failure.
With the intention of preserving bandwidth, the telecommunications industry has written a harmonised standard that does not allow industrial wireless control systems to function. The European Telecommunications Standard Institute (ETSI) is now blocking the harmonisation of a European standard, which facilitates co-existence management of Industrial communication networks under the R&TTE directive. This restriction is likely to make Europe lose significant competitive ground in the industrial wireless field.
ETSI is officially recognised by the European Union as a European Standards Organisation and has written the harmonised standard: EN 300 328 V1.8.1 – a standard that amends the existing rules for all devices using the publicly available radio band. The band includes millions of devices using WiFi, Bluetooth and Zigbee technologies. This means it will have a major impact on manufacturers from all sectors once it comes into force, in January 2015.
It is a harmonised EN standard covering the essential requirements of article 3.2 of the R&TTE Directive, which states that in addition, radio equipment shall be constructed so that it effectively uses the spectrum allocated to terrestrial/space radio communication and orbital resources so as to avoid harmful interference.
With the intention of effectively using the spectrum, the telecommunications industry has produced a harmonised standard, which does not allow industrial wireless control systems to function. The problem with the standard is that it introduces the concept of Listen Before Talk (LBT). LBT requires each radio device to first check whether another device is transmitting, in which case it must hold back until the channel is free. This causes random and unpredictable communication delays.
A nonviable idea
The entire idea is simply nonviable. At times of heavy use, the result is 'graceful degradation of service'. Unfortunately, the real problem for an industrial site is that key wireless devices can never be relied upon to report their alarm or status messages in a timely fashion.
Industry has tried to work with ETSI by submitting comments on the revision of EN300328 V1.8.1 including suggestions for exemption or optional use of LBT within defined industrial automation areas. These solutions have not been included in the new revision of the standard. V1.8.1.
Industry has also worked hard via technical committee SC65C to develop an IEC standard: 62657-2 (2013) ‘Industrial Communication Networks – Wireless Communication Networks – Pt 2: Coexistence Management’. This has been voted positively by CENELEC to become EN62657-2, but the harmonisation of this standard under the R&TTE directive has been blocked by ETSI.
GAMBICA has urged all its member companies providing industrial wireless equipment, or whose services rely on these systems, to contact their UK trade association or other organisations on the continent. The industry needs to make further efforts to explain the possible consequences of LBT to the European Commission and call for the harmonisation of EN62657-2 under the R&TTE directive as soon as possible.
Wireless process control technology is in its infancy still, but widely seen across the process industry as a huge growth area. One only needs to glance at trade publications to see the plethora of wireless marketing material. It is a significant growth area which provides major cost savings in wiring and installation time. Many sites have wireless systems installed and more are in the pipeline. At a stroke, these investments are put at risk and the future growth of industry will be gravely harmed.
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