Blood on the Southern Cross is a "son et lumiere" which tells the story of the Eureka Stockade uprising in 1854 during Australia's gold rush. A protest against the cost of gold mining licenses and their corrupt supervision by the colonial authorities, Eureka is the only civil uprising ever to have taken place in Australia. Located at Sovereign Hill in Ballarat, one hour north of Melbourne, the production has been seen by over half a million people, which according to the show's producer Brian Shirley, is more Australians than have attended Phantom of the Opera, which has played in every major city.

Originally set up in 1992 to run once per night, and then only in the summer months, demand for tickets for the production was so strong that the show ran for the entire 12 months of its first year and now operates two to four performances per night, year-round. This placed more stress on the production equipment than was initially envisioned, and in mid-1998, a program to progressively replace the equipment and revamp the production was devised. Unfortunately, nature, in the form of a severe electrical storm, made a mockery of the plans by destroying a significant portion of the control system, necessitating a complete redesign.

After careful consideration of the requirements of the production, Lightmoves Pty. Ltd., the systems contractor, decided to use WinCommander as the DMX512 controller for the system with a minimally configured AMX show controller for the main control logic operations. The primary consideration with the upgrade to the show control system was to transfer the running show over to the new system before attempting any additions and enhancements. Accordingly, a "snapshot" of each existing lighting cue was taken and transferred over to the new WinCommander system, a process that went quite smoothly until it was discovered that WinCommander could not actually fade correctly from cue to cue. Emails and updates were frantically exchanged between the UK and Sovereign Hill until finally the Lightmoves team realized that the time had come to cut their losses and move the production onto a tried and trusted, if theoretically less sophisticated, ShowCAD system.

Project engineer Andrew Sherar had specified a pair of Pentium II 233MHz computers to form a dual-redundant system with plenty of processing power for the job, but discovered that there is a memory mapping clash between the ISA bus ShowCAD DMX output card and the new AGP video system on the latest generation of Pentium II motherboards. The Pentium II systems were replaced by Pentium 75MHz systems, which don't support AGP video, although they still have power to spare for running MS-DOS-based ShowCAD.

The show control system, which is now in place and runs the 55-minute main sequence of Blood on the Southern Cross uses an AMX controller. This is locked to SMPTE timecode coming from an Akai DR16 hard-disk recorder, which also holds all narration and effects audio, including the Korean, Mandarin, Cantonese, Japanese, and German versions, which are broadcast via a Philips LBB 3020 infrared transmitter to patrons' headsets.

The AMX controller also receives inputs from three other locations: a weather station in order to provide interactive adjustment for smoke machines and the artificial wind which blows the Southern Cross flag if the breeze isn't strong enough; an in-house-designed watchdog device that monitors the health of the ShowCAD controllers; and a motorcar alarm remote controller, which enables the people-transporter driver to start the otherwise operator-free show.

The main outputs from the AMX controller are the dual-identical MIDI streams to the dual-redundant ShowCAD systems, which control virtually every other device used in the production, ranging from pyrotechnics (in conjunction with a deadman's switch) and smoke machines to campfires, the movement of the actual stockade battlements, the burning of the Eureka Hotel, moving mirror heads, strobes, and even the animation of an image in a linnebach projector.

DMX was chosen for virtually all show control applications, as there appeared to be little reason to duplicate the lighting control distribution network for a second control protocol, particularly in view of the decision to use DMX over optical fiber to the subsidiary dimmer and control locations to reduce the risk of further lightning damage. Device control is implemented through Lightmoves' in-house-developed DMX interface units; a 16-channel, DMX-controlled relay box, and a five-channel, mains-powered interface card, which has one proportional mains output, two switched mains outputs, and two relay contacts. DMX feeds to all devices outside the dimmer locations are fed via individual cable runs from an LSC 20-way Multisplit DMX splitter to provide lightning protection on every feed.

In addition to 216 channels of 2.5kW dimmers, eight of the proprietary five-channel mains cards are used for proportional control of what were originally non-proportional smoke machines, and five of the 16-way relay boxes are used to control all other devices. Relay control is used for: pyrotechnics, the blower on the flag, hydraulic winches to animate the stockade, control valves for water, and LP gas flows for campfires and the burning hotel, the 45-degree rotating solenoids that animate a projected image and oxy-acetylene gas guns for battle sound effects. A measure of proportional control has been retrofitted to several of the flame effects used for campfires and the battle aftermath. Motorized valves with a five-second closure time have been installed to control the LP gas flow, which in combination with a few judiciously timed relay cues, allows flames to slowly dwindle and die rather than simply be extinguished.

There's a traditional belief that an Aussie farmer can do just about anything with a length of fence wire and some ingenuity. This would appear to have its show control equivalent in the use of DMX for show control on Blood on the Southern Cross.