CPD PROGRAMME | LIGHTING installations to control systems could be an expensive and time-consuming task. Traditionally, luminaires have been linked through wired networks that are connected to each tting to achieve overall control. While the benets of such networks often controlled using the digital addressable lighting interface (DALI) protocol can be considerable, they can also lead to signicant additional cabling requirements, with the attendant cost implications. Extensive cabled networks can also be challenging to amend when luminaires fail or need to be updated. This position has recently changed with the advent of the standard DALI wireless protocol (see DALI panel). Lighting networks that use wireless DALI connections enjoy the same benets as a typical DALI system, but without the set-up and maintenance of largescale wired solutions. In a wireless system, integrated wireless nodes are housed within the luminaire and communicate with each other, eradicating the need for a physically connected network with its associated cabling requirements. Inevitably, safety and security are priority concerns with all building systems, and lighting control is no exception. As highlighted in CIBSEs recent cyber security publication, CIBSE DE6.1: Cyber security in building services design, when considering the security of such systems, a traditional wired system with tamper-evident protection is generally preferable to the use of wireless connectivity. Wireless is inherently less secure; a malicious or simply inadvertent interruption, or interception, of network trafc can take place in the vicinity of a system, and standard encryption protocols may be insufcient to prevent such an attack. The majority of the recently developed wireless lighting-control systems occupy a frequency outside of the spectrum occupied by Wi-Fi or Bluetooth systems (typically 868MHz). This makes them less susceptible to disruption, allowing the wireless network to operate in a more secure and reliable way, which is a particular requirement if there are multiple remote sites. It is prudent to assess the risks and evaluate opportunities, as deemed necessary for the particular application, for enhanced security, system redundancy and provision for fallback in case of failure. With the extra cabling needs removed, networks can be scaled up with minimum disruption, while additional spaces or even separate buildings can be brought under the control of the same system. For designers and consultants, this means that lighting installations are not rigidly xed at the time of commissioning. Instead, they can Basic comfort, trade-offs? Manageable conicts? Rapid? Taken seriously? Effective? Efcient? Integration of control zones for heating, cooling, lighting,ventilation, noise and privacy Fine-tune Speed of response to complaints, and so on Actual control Perceived control No window seat? Random disturbances? Stuck at desk? Deep-plan space? Open environment? Hot? Dirty? Perceived productivity, comfort and health Personal factors? Lifestyle? Management attitudes? Workgroup? Task? Usable? Working? Effective? Efcient? Feedback? Manual overrides? Plus signs show positive effects (that is, an increase in one normally produces an increase in the other); minus signs are decreases or Figure 1: Control strategies: three routes for better occupant satisfaction (as illustrated in the recently updated CIBSE TM403) be adjusted as the occupancy and usage patterns of individual spaces or entire buildings develop. The simplied scalability of the wireless system makes it practical for operators to control entire estates, and even manage multiple sites. In conjunction with building management software, this allows luminaires to be assessed for repair or maintenance without the need to be on site to check for ttings that are in need of repair. The lighting-control system allows building operators to make system-wide assessments of, and changes to, the lighting function. Luminaires can be managed on an individual or group basis, depending on the requirements. This enables the simple, but functionally important, parameters for each xture to be amended quickly and easily. The nodes can be readily addressed with an app or online portal, and entire systems can be monitored, controlled and managed remotely, with nodes passing the commands between each other. Sensors can be applied to groups or to individual ttings, with the settings for these sensors altered and adjusted depending on the needs of the facility. This also allows maximum outputs to be set for luminaires and illumination for spaces to be reset with reference to outdoor conditions, or time of day, so as to keep lighting levels and energy costs under control. A room can be programmed to have several different scenes, each equipped with different lighting levels and DALI Digital addressable lighting interface (DALI) systems protocol can be used to broadcast typically to groups of luminaires in zones to activate and maintain on/off, scene setting and dimming control. DALI-addressable systems, which are able to communicate with individual devices and luminaires, provide additional functionality, such as lamp-status feedback, lamp colour temperature shift, and automatic test and monitoring of emergency lighting. Each eld device and luminaire has an individual address for control and identication purposes. The recently updated DALI standard IEC 62386-104:2019 species the use of DALI with wireless instead of a wired bus system. (The underlying transport protocol differs from the conventional wired DALI bus system that is described in part 101 of the standard.) 52 October 2020 www.cibsejournal.com CIBSE Oct20 pp51-54 CPD169 Tamlite Supp v2.indd 52 25/09/2020 16:47