What to do when your fixture isn't in the library

Patching is where most people give up on lighting software. If the profile for your light does not exist, nothing else about the app matters — you cannot build a scene, you cannot rehearse a look, and the 3D stage shows you a fixture that behaves nothing like the one in your hand. There are three ways out of that, and only one of them involves giving up.

Why does patching stop so many people?

Patching is the step where software stops being a demo and starts being your rig. It asks for four exact answers — fixture model, DMX mode, universe and start address — and it does not tell you when one of them is wrong. It just produces a light that ignores you, or does the wrong thing at the wrong moment. That reads as a broken app, when it is almost always a mismatch.

The fixture profile is the part people least expect to be a problem. A fixture profile is a description of what each DMX channel on a light actually does — channel 1 dimmer, channel 2 red, channel 7 gobo wheel — so that software can turn "warm amber at 40%" into the right bytes on the right channels. Without one, the app is sending numbers to a device that means something completely different by them.

How should you search the fixture library first?

Search on the manufacturer name printed on the fixture, the model exactly as printed, and the channel count of the mode you intend to use. Those three together find a profile far more often than the name you have in your head does, because the name in your head is usually the retailer listing, an abbreviation, or the model one revision either side of the one you own.

What do you do when it genuinely is not there?

If your fixture is not in the library, point HitLight at the PDF that came with the light — or a photo of the DMX chart — and it drafts a working profile in seconds. The chart is the page in every manual that lists channel 1, channel 2, channel 3 and what each one does, usually with value ranges for the wheels. That page is all the drafting needs.

A usable source has four things in it. Check for these before you upload:

• The mode header. Charts are printed per mode. A photo that starts at "CH1" and omits the heading above it loses the one piece of context that decides which layout you are looking at.
• Every channel number, legibly. A blurred row in the middle is worse than a missing page, because it produces a plausible profile with one channel silently shifted.
• The value ranges. Colour wheels, gobo wheels and macro channels do different things at different values. Ranges are what turn "channel 7 is gobos" into a usable control.
• Both pages, if the chart runs over two. Long charts split across a page break constantly, and the second half is where the effect and reset channels live.

No manual? Try the manufacturer's support site for the exact model, then the printed chart on the fixture's own body — many moving heads and bars have an abbreviated one silkscreened near the DMX sockets. Failing both, the on-unit menu will at least tell you the mode names and channel counts, which narrows the search back at the library.

Why does the generated profile arrive marked as a draft?

Generated profiles stay marked as drafts because a manual is not a fixture. You test the channels on the real light and confirm them before they are used in a show. This is deliberate friction: a profile that says it is verified when nobody has verified it is worse than no profile at all, because it moves the failure from patching night to show night.

Manuals are wrong more often than people expect. Charts get printed for a firmware revision that never shipped, modes get dropped in a later production run, and channel lists get translated twice on the way to the PDF. None of that is detectable from the document — only from the light.

It also matters because of how the assistant works. HitLight's assistant never invents your fixture's channels; it works from the profile you patched and the values actually on the wire. That is the right design, and it has a direct consequence: if the profile is wrong, the assistant will be wrong with total confidence. The draft flag is what stops that from being a surprise.

How do you verify a profile channel by channel?

Bring channels up one at a time, at low values, in numeric order, and compare what the light does against the chart. This takes about ten minutes per fixture type and it is the only step that turns a draft into something you can trust. Do it once, on one unit, and the rest of that model inherits the result.

1. 1

   Isolate one fixture where you can see it

   One unit, patched at a start address you have read off its own display, in a mode you have read off its own display. Not the whole rig. You are testing the profile here, not the show.

2. 2

   Open the dimmer at a low value first

   If the fixture has a shutter or strobe channel it may need opening too. Until something lights up at all, every other test is ambiguous.

3. 3

   Walk the channels in order, low

   Channel 2, then 3, then 4. Ten or twenty per cent is enough to see a response. You are looking for one thing: does the light do what the chart says this channel does?

4. 4

   Watch for the off-by-N symptom

   If red appears on the channel the chart calls green, and green on the channel it calls blue, you have an offset — a wrong mode or a wrong start address, not a wrong profile. Stop and re-read the fixture's display before changing anything in software.

5. 5

   Test the wheels at several values

   Colour wheels, gobo wheels and macro channels are where charts are least reliable. Step through a handful of values across the range rather than checking one and assuming the rest follow.

6. 6

   Leave hazardous channels until last, deliberately

   Flame ignition, pyro, laser and smoke channels get verified last, with the unit in a safe state and nobody standing in front of it. HitLight's automatic paths never drive those channel types, but manual verification is you, and the rules of the room apply. See lighting safety.

7. 7

   Press Blackout and watch the rig go dark

   Before you trust any of it. Blackout is immediate, and the only way to know it is wired correctly is to use it.

How do you confirm the model, mode, universe and address?

Walk to each light and read all four off its own display. Do not trust the patch sheet — trust the fixture. A patch sheet records what someone intended; the display records what the unit is currently doing, and those two drift apart every time a light gets swapped, borrowed or re-addressed by someone who did not write it down.

• Start address is usually the first menu item and the one people check. It is also the one that is usually right.
• DMX mode is usually a separate menu item, and it is the one people forget. Changing the address does not change the mode, and changing the mode does not warn you that the addresses of everything downstream have just shifted.
• Universe matters if you are running more than one. A fixture fed from a node outputting universe 2 will never respond to universe 1, no matter how correct the patch is.
• Model and revision from the rating label, so the profile you picked is actually the profile for the thing in front of you.

What is a DMX mode, and why does the wrong one break everything?

A DMX mode is a channel layout that a fixture can be switched between, changing how many channels it occupies and what each one does. The same moving head might offer an 8-channel mode for basic control and a 16-channel mode with fine pan, fine tilt and effects. Both are correct. Only one of them matches what the unit is currently set to.

Picking the wrong one makes every channel after the first one wrong, and it does so in the most misleading way possible: channel 1 is the dimmer in nearly every mode of nearly every fixture, so the first test passes, everyone relaxes, and the divergence starts at channel 2. You end up sending colour to a gobo wheel and pan to a strobe.

The second effect is worse in a full rig. Channel counts decide where the next fixture starts. A 16-channel fixture patched as 8 channels overlaps the eight channels belonging to its neighbour, so two lights fight over the same addresses and both behave unpredictably. If a rig misbehaves the moment you add a fixture, suspect the mode before you suspect anything else. The DMX glossary covers universes, addresses and modes if any of that vocabulary is new.

None of this is unique to HitLight. Every lighting console on earth needs a profile, a mode and an address, and every one of them will do something baffling if you get one wrong. What changes is how long you are stuck when the profile does not exist yet — and that is the part worth fixing. More on how patching works in HitLight is on the fixture library page.