When Programming Takes on a Life of Its Own

The Self-Directing Light Show

The lighting designer sat at their grandMA3 console, confident that fourteen hours of programming had created a perfectly synchronized show. The first cue fired flawlessly. The second cue—supposed to be a subtle color shift—instead triggered the finale sequence complete with strobes, full-intensity washes, and every moving head whipping to center stage. The console had decided to skip ahead approximately forty-seven cues, transforming the opening ballad into an epileptic nightmare that left the performer shielding their eyes and the audience wondering if this was intentional avant-garde staging.

Understanding Cue Triggering Mechanics

Modern lighting consoles execute cues through complex software interpreting multiple input types. The ETC Eos family responds to button presses, MIDI triggers, SMPTE timecode, OSC commands, and network messages—each representing potential failure points where unintended signals can fire cues. The Hog 4 series adds internal timers and conditional triggers that can execute cues based on programmed logic rather than human intervention.

The timecode synchronization that enables tightly coordinated multimedia shows creates particular vulnerability. When a media server sends SMPTE timecode through MIDI interface to the lighting console, any glitch in that stream can cause cue jumps. A frame dropout that causes the console to receive timecode value ’01:23:45:00′ followed immediately by ’01:24:12:15′ will trigger every cue mapped between those values—potentially dozens of cues firing in milliseconds.

Historical Console Evolution

The journey from manual preset boards to intelligent control surfaces spans decades of incremental improvement. The original Strand Light Palette in the 1970s introduced computer memory to theatrical lighting, enabling cue storage that previously existed only in electricians’ notes. Electronic Theatre Controls refined this approach through the Expression and Obsession series, building the foundation for modern console architecture.

The introduction of moving light control in the 1980s required fundamental rethinking of console design. Vari-Lite’s proprietary Artisan console demonstrated that controlling hundreds of parameters per fixture required interfaces beyond traditional intensity faders. Flying Pig Systems’ work on the original Wholehog created the programming paradigms—palettes, effects engines, programmer tracking—that still dominate console design three decades later.

Software Bugs and Their Manifestations

Every lighting console runs software containing bugs that manufacturers continuously patch. The grandMA2 achieved legendary reliability, yet even this workhorse exhibited quirks—the famous ‘delete crash’ that could corrupt show files when attempting certain operations, fixed only after years of user reports. MA Lighting’s transition to grandMA3 introduced an entirely new software platform with its own learning-curve bugs that early adopters discovered through painful field testing.

The firmware update process itself creates risk windows. Installing new software versions before shows has caused countless disasters when updates introduced unexpected behaviors. The industry consensus recommends never updating mission-critical systems without thorough testing—advice that production schedules frequently force crews to ignore. The ETC Eos family’s generally conservative update cycle reflects lessons learned from competitors’ more aggressive release practices.

Network-Induced Chaos

The transition from DMX512 hardwiring to network-based control introduced failure modes previous generations never imagined. Art-Net and sACN protocols route lighting data through Ethernet infrastructure shared with video, audio, and production communication systems. A network storm caused by misconfigured switches can flood consoles with data that triggers unintended responses.

One touring production traced self-firing cues to multicast traffic from a media server that the lighting network should never have received. Improper VLAN configuration at a festival patch point allowed video NDI streams to reach the lighting console’s network port, where the console interpreted certain packet sequences as OSC triggers. The solution required network reconfiguration that delayed show start by ninety minutes.

Prevention and Recovery Strategies

Protecting against self-playing cues begins with understanding and controlling every trigger path into the console. Disabling unused external triggers—MIDI, timecode, OSC—when they’re not specifically required eliminates accidental activation routes. The grandMA3’s comprehensive network management tools allow precise control over what data the console accepts, but only if operators configure these protections.

Maintaining backup show files on separate media enables rapid recovery when console behavior becomes unpredictable. The ETC family’s automatic backup features create versioned show histories that can restore previous states within minutes. Productions that verify backup integrity before shows—actually loading the backup file to confirm it works—avoid discovering corrupted files during the crisis that made restoration necessary.

When Automation Becomes Adversary

The sophisticated automation features that make modern consoles powerful also create complexity that can behave unexpectedly. Effect generators that smoothly vary parameters can interact with timing engines to produce outputs nobody programmed. Conditional execution logic that seemed elegant during programming may trigger incorrectly when show conditions vary from expectations.

The lighting designer who understands their console’s underlying logic can predict and prevent most self-firing scenarios. Building show files with explicit trigger requirements—cues that require physical button presses rather than automatic advancement—creates manual checkpoints that prevent runaway execution. This approach sacrifices some convenience for reliability that harried operators often appreciate during high-pressure performances.