The CSIRO, with funding assistance from Japan Coal Energy Center (JCOAL) and The Australian Coal Association Research Program (ACARP), has developed, tested and secured IEC Ex.ia certification via Simtars for an Ethernet Switch and via TestSafe for a Serial To Ethernet Converter (STEC) and a Paging and Location System (PLS). The STEC provides translation between serial data and Ethernet packets. Any device with a wired (i.e. copper) serial interface can be connected to the STEC; the device then becomes part of an optical fibre-based Ethernet network and is controllable and addressable using standard Ethernet communication protocols. The PLS is comprised of two devices: tags and nodes. The tags, small portable units that communicate wirelessly, can be attached to personnel and/or equipment within a mine. The tags have a paging function, enabling two-way messaging between personnel and the remote server (control room operator). The tags communicate with the remote server via the nodes; fixed units that communicate with each other and the control room via optical fibre. Tag locations are continuously tracked within the mine, providing the control room with the locations of all tagged personnel, vehicles and equipment. Prototypes of the technologies developed by CSIRO were tested and demonstrated at three mines.