Industrial wireless blackout warning
30 May 2014
Negotiations over a European standard for industrial wireless devices threaten to render vital plant control sensors useless, trade body Gambica has warned.
The trade body, which serves the instrumentation, control and automation sectors, has criticised a proposal by the European Telecommunications Standard Institute (ETSI) to amend the existing rules for all devices using the publicly available radio band that includes WiFi and Bluetooth.
Gambica technical executive Andrew Evans said the proposed ETSI standard, EN300328 V1.8.1, requires wireless devices to wait for periods before transmitting – a move that could create a blackout for industrial continuous monitoring devices.
“The new version, 1.8.1, was written a couple of years ago [and it] introduces ‘listen before talk’ (LBT) as a way of preserving bandwidth,” said Gambica technical executive Andrew Evans.
We can’t live with a listen before talk mechanism
Gambica technical executive Andrew Evans
Using LBT, transmitters would have to listen first if something else was emitting and then wait for a clear signal before being able to transmit.
“The problem is that you might have a wireless pressure transmitter on top of a tank and you wouldn’t necessarily know if that is saying the pressure is going too high, the reading is going too high etc.,” Evans told Process Engineering.
“The basic process control system is not necessarily going to know what the readings are, so we can’t live with a listen before talk mechanism.”
According to Gambica, industry attempted 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 such as refineries.
However, these compromises were not included in the new revision of the standard EN 300 328 V1.8.1.
Having been unsuccessful in its attempt to revise EN 300 328 V1.8.1, industry drafted a new standard via the International Electrotechnical Commission (IEC), called the EN62657-2 industrial wireless co-existence standard.
“Standards organisation Cenelec had voted EN62657-2 to become an EN standard, so the next step was to get that harmonised under the radio and telecommunications terminal equipment (R&TTE) directive,” said Evans.
“But ETSI blocked that harmonisation.”
Gambica is now urging all 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,” Evans said.
Firms wishing to lobby on this issue must do so before 1st January 2015, when the new EN 300 328 V1.8.1 standard comes into full effect.
