You Asked, Gary Meshberg Responded
In the last quarter of 2024, LD+A asked readers on social media if they had any pressing lighting controlsrelated questions. Cristina M. Cornejo wrote in with four inquiries and LD+A’s resident Controls Columnist Gary Meshberg provided the answers.
Cristina M. Cornejo: What are the different types of languages I need to understand in lighting controls?
Gary Meshberg: When people in the industry say ‘languages,’ they usually mean ‘protocols.’ Protocols are standard or manufacturer-specific sets of rules that enable interoperability and communication between lighting control devices. There are two major protocol types: front-end and back-end, with additional protocols used in robust systems such as those integrated with BAS.
When a networked lighting control system is specified, the front-end protocol is used. The specifier must understand the protocol’s capabilities and limitations to know how it will affect performance. Generally, an appropriate protocol can be selected by asking basic questions about the control system, such as how many devices need to be connected, whether it will be wired or wireless, how devices connect and talk to each other, and so on.
The back-end protocol governs how the luminaire receives a control signal to dim (or advanced function such as CCT) from a lighting controller. Examples include 0-10-V and DALI. An appropriate backend protocol will depend on how sophisticated the control system is. Advanced control functionality, for example, can be served by 0-10- V. Still, with a potential trade-off of more powerful controllers and more infrastructure being required, a more robust protocol like DALI is more attractive for these applications.
Cornejo: How do you specify a lighting control design in a lighting design drawing? Is there a language in common with which to express this information?
Meshberg: The lighting community has not standardized the way lighting control systems are specified. Some specifiers may create a matrix listing space types and the control strategy for each space (occupancy sensing, plug load, daylight harvesting). This matrix may also include notes for the space (for example, occupancy sensing timeout shall be 15 minutes). Other specifiers may elect to specify in a text form like the sequence of operations (SOO). This information is typically shown on the eDrawings sheets. The specification usually includes a system one-line riser diagram showing the system networked components and the distributed devices in each space as a minimum and up to a one-line drawing per space type. In either case, the more information you include in your specification, the better the likelihood that the system will consist of all necessary hardware, software, and programming set points.
Cornejo: What do lighting control specifiers and constructors need from my lighting design to make a lighting control design?
Meshberg: The lighting control design would originate from the owner’s project requirements (OPR). From the OPR, a control intent narrative (CIN) is created, this is a written document outlining the objectives, design considerations, and operational strategies for a lighting control system. It communicates the designer’s vision and ensures all stakeholders understand how the lighting control system will function to meet the project’s needs. For designers, the CIN ensures the system aligns with the design vision and architectural intent. For installers, the CIN provides clear guidance on implementing the system correctly. For owners and/or end users, the CIN helps them understand the system’s functionality and benefits.
The SOO is also specified and goes hand-in-hand with the CIN. The SOO is a detailed step-by-step description of how a lighting control system should function under various conditions. It defines the system’s behavior in response to specific inputs, such as time schedules, occupancy, daylight levels, or manual overrides. The SOO provides a clear operational blueprint for system programming and installation, helps ensure the system meets energy codes and user requirements, and facilitates troubleshooting and system optimization post-installation.
Cornejo: Can luminaires without control specification be controlled?
Meshberg: All luminaires can be switched, and most LED luminaires are controllable for both on/off and intensity (dimming with 0-10-V). In other words, they are ‘controls ready.’ The lighting controls layer of the design and specification connects the lighting to devices and systems that enact manual and automatic lighting control strategies to enhance flexibility and minimize energy waste.
