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Master Your CRMX Linking Key: The Complete Guide
If you've ever found yourself in a linking marathon, resetting dozens of fixtures, clicking the link button over and over and wishing you had a better system, you're not alone. CRMX linking keys exist to solve exactly this problem, but they come with some quirks that aren't always obvious. Let's break down everything you need to know to use linking keys like a pro.
What is a CRMX Linking Key?
A CRMX linking key is an 8-digit code that automatically pairs your CRMX receivers with your transmitter, eliminating the manual linking dance. Think of it as a password that both your transmitter and fixtures share, once they're on the same key, they connect instantly.
This becomes invaluable when you're managing multiple universes or working with rotating crews. Studio owners can set up overhead fixtures once and let different teams walk in ready to work. Pre-lighting crews can handle all the pairing, then hand off to the main team with their own DMX kit without missing a beat.
Here's the best part: linking keys work with both CRMX Classic and CRMX². Despite common misconceptions, you don't need the CRMX² update to use this feature, they're completely separate functionalities.
The Stardust Exception You Need to Know
Here's where things get interesting. The LumenRadio Stardust handles linking keys differently than most other transmitters, and understanding this difference will save you headaches on set.
Stardust approach: One linking key for the entire unit. In CRMX Classic, its 4 universes sit on outputs A, C, E and G; in CRMX², its 8 universes use outputs A to H. You select the output manually on each receiver.
Standard approach (Cerise, TimoTwo devices, Moonlite, Aputure Sidus, Ratpac Satellite): One unique linking key per universe, with only universe A usable per key.
This is a design choice by LumenRadio, not a limitation of the technology. The Stardust can't generate several keys, and the other transmitters can't share one key across separate universes. Your fixtures might let you select different outputs even when not connected to a Stardust, but with transmitters like Cerise, only output A will actually work.
To keep things simple, stick to one transmitter family for a shoot. If you move a rig from a Stardust to Cerise, an Aputure Sidus or any other transmitter, only fixtures on output A can follow, and only if you set the new transmitter to the Stardust's Linking Key. Every fixture on another output has to be relinked with a new key, one per universe, on output A, which cancels out most of what the Linking Key saved you. The same is true the other way round. Single-universe transmitters that support CRMX², such as the LumenRadio Aurora, Luna or Moonlite, are no exception: they only use output A, so they can only clone or replace the Stardust's first universe. If you'll switch transmitters between prelight and the shoot, link the rig with the one you'll use on the day, or plan time to relink the fixtures.
Another critical point: if you're using a multi-chip transmitter like Cerise, each output needs a different linking key. Setting the same key on multiple outputs causes them to fight over the same receivers, resulting in bugs, glitches, and unwanted flashes.
Choosing Secure Linking Keys
Your linking key is essentially a password: anyone who knows it can take control of your fixtures. Avoid obvious choices like 12345678 or 11111111. Treat it like you would any other security credential on set.
There's also a technical consideration: until recently (fixed in firmware 1.1.1.0), linking keys with four or more consecutive zeros (like 00000000 or 00001111) caused issues where some receivers would link correctly while others wouldn't. If you're running older firmware, avoid these patterns.
Using Linking Keys with Non-Supporting Fixtures
What if your DMG DASH or generic CRMX receiver doesn't officially support linking keys? There's a simple workaround.
Set your desired linking key in the transmitter first, then manually link your fixtures using the link button. The manual linking process essentially sends the key to the receivers, which memorize it until they're reset or unlinked. Problem solved.
Advanced Technique: Transmitter Cloning
Here's an experimental but potentially useful trick: two transmitters can use the same linking key to create seamless coverage across large areas. While having them close together causes conflicts, placing transmitters at intervals allows receivers to jump smoothly between them as they move in and out of range.
This works beautifully for car chases, actors with props on expansive sets, or any situation where maintaining continuous wireless coverage is challenging. Just remember this is advanced territory: test thoroughly before show time.
Setting Linking Keys on Cerise
Using linking keys with Cerise couldn't be simpler. Open the Cerise WebUI and locate the linking key button next to the link and unlink buttons of the universe you want. Enter your 8-digit key and press "Confirm." (Cerise beta fw 1.8.1 and later will also display the key in that popup, even after a reboot, so no need to write it down or memorize it).
Keep in mind:
- Entering a new key disconnects every receiver already linked, so you'll need to relink them.
- Each output on a 2U or 4U Cerise needs a different linking key.
- Receivers must use output A (or 1) for each linking key.
- If the option doesn't show up, update Cerise (firmware 1.5.1 or later) and, if needed, its TimoTwo modules (CRMX firmware 1.0.7.2 or later).
The linking key system transforms how you work with wireless DMX, especially on complex productions. Once you understand the Stardust exception and the one-key-per-universe rule for standard transmitters, you'll wonder how you ever managed without it.
Sources :
https://lumenradio.com/support-materials/user-manual/