The integrated network, developed by Multiskilled Resources, extends across 6.5km and incorporates the versatile Preventa multi-function programmable compact safety PLC technology from Schneider Electric.

This technology offers both site-wide coverage and strong local area functionality, meaning the system can respond rapidly to local issues as well as initiating a total site-wide shutdown in the event of an emergency.

While standard safety systems typically employ one master controller, the Schneider system incorporates distributed input/output functions at both ends.

The new unloader off the Main Northern Rail line has a capacity of 4000 tonnes per hour and, with conveyers up to 5.5km long, gives access to remote coal supplies.

"The primary safety solution using Schneider technology is highly advanced and highly practical in that it meets multiple design challenges with one integrated package," said Multiskilled engineer Doug Lithgow.

The Antiene system uses a single XPS MF3022 to govern 12 distributed control boxes with a total of 240 input/output functions responding to particular areas and particular hazards.

The PLC provides dual redundancy fault detection, having dual port ram, dual processors and duality of all functions needed for the PLC to compare outputs and establish whether a fault has arisen.

It operates through its own non-integrated safety circuit, in which safety programming and hardware are completely separate from standard automation functions. This saves time and reduces operational complexity because the non-integrated safety functions do not have to be checked every time changes are made to standard automation features.

The PLC system provides a response time within 100 milliseconds from any point, and could even be programmed to respond twice as fast as that.