What Is RDM?
Have you ever been setting up lighting for a concert or event, started programming, and noticed that one of your stagehands or volunteers (or let’s be honest, it was probably YOU who screwed the pooch on this one) has set a DMX address or mode incorrectly on a fixture? Now you have to find a way to get to a light that is now more than likely impossible to access, just to change one small setting that you should have noticed earlier!!
Well, let me introduce you to Remote Device Management, otherwise known as RDM. RDM is a lighting protocol that works alongside the DMX protocol that you are already using and allows bi-directional communication between a lighting controller and a fixture. In a nutshell, RDM allows you (among other things) to access, change, and monitor certain settings on your DMX lighting fixtures, such as the fixtures’ address, mode, or temperature from your lighting console/software or handheld tester.
While RDM is an exciting advancement in entertainment lighting, just like most newer technologies, it's not something that is currently available on all lighting controllers and fixtures. You need to have BOTH an RDM compatible controller AND fixtures to take advantage of these features. To take it one step further, if you have a lighting system using DMX splitters, those also have to be RDM compatible.
If you are using a network-based lighting protocol such as ART-NET or sACN, RDM will work for you as well. You just need to make sure you have the RDM compatible controller and fixtures, and if you're using a node or gateway, those need to be RDM compatible too.
Once you have the correct hardware and lighting fixtures, using RDM is a pretty straightforward process. On your console (or lighting software, tester, ect.), you have to turn RDM on to use it. Once it's on, your console will discover any RDM compatible fixtures and populate them in your patch window. RDM can take awhile to discover all your fixtures, especially if you have a decent amount of fixtures. Don't be worried if everything doesn't pop up immediately, it's normal for it to take several minutes to find every fixture. If you have many of the same model of fixtures, it can be hard to tell which fixture in your patch window is which physical light in your rig. Fortunately, beside each fixture in the patch window is usually an “Identify” button which, when pressed, will flash the corresponding fixture in your rig so you know which one you will be working with. From there, you can assign or change the address and/or modes of the fixture right from the console. Once you have made the changes you need to make to your fixtures, I always recommend turning RDM back off. While there is generally not an issue keeping it on all the time, it can occasionally cause anomalies with some fixtures, so turning it off when not in use is good practice. It helps keep your DMX data stream cleaner during showtime. When possible, I still like to do most of my addressing and mode setting on my fixtures from the ground, because I feel it takes less time, but when my rig is in the air and I need to make changes to a fixture, RDM can be a lifesaver!
What's great about RDM is that you can use the same 3 or 5-pin DMX cabling that you already have. Yes, even if you are using a 3-pin DMX cable, you can still use RDM. A common misconception is that if you want to use RDM, you need a 5-pin DMX cable. This is NOT the case. The RDM signal runs on the same 3-pins as the DMX signal, it just fits itself between the gaps of the DMX signal, leaving pins 4 and 5 still unused.
RDM even has a strong foothold in the architectural side of lighting. A vast number of churches, high school/college theaters, and many other types of venues are installing architectural DMX lighting that is RDM capable. On many of these new architectural fixtures, you can ONLY change settings via RDM. A lot of these fixtures no longer have any way to make address or setting changes physically on the fixture.
Even professional/industrial garden grow lights are jumping on the RDM bandwagon! I just finished working on a project at a college where they are using DMX-controlled grow lights, and the settings are only accessible through RDM.
The RDM revolution is constantly growing, and as more lighting manufactures are adding this technology to their products, it will become ever more accessible to smaller, more budget-conscious venues. So if RDM capable technology interests you, or you have further questions on what RDM is or how you can implement it in your next project or lighting upgrade, please comment below or give us a call. We would love to geek out with you!
