Silvair occupancy sensing automatically activates lighting when presence is detected, while vacancy sensing requires a manual ON command before automatically reducing or switching off lighting after vacancy. Both strategies can use Occupied, Prolonged and Vacant states. Zone Linking allows occupancy or manual-control events to be shared between zones within the same Silvair Area.
How Does Silvair Occupancy Control Work?
Silvair occupancy sensing starts with a compatible sensor reporting an occupancy event into the lighting network. The control profile assigned to the receiving zone then determines how luminaires respond. A zone is a group of devices that follows a common profile, so the profile—not the sensor alone—defines the resulting level, timing, and transitions. This makes the system state-based rather than a simple on/off rule. A Silvair occupancy sensing design should document the required response before equipment is selected. [Silvair SN-211 Lighting Control]
Occupancy detected → Zone enters Occupied → Defined occupied level → No further occupancy → Prolonged state → Vacant state
In practical Silvair occupancy controls, each new valid occupancy event refreshes the timing logic. The zone can remain at a task level while activity continues, then reduce in stages after activity stops. This approach permits the light response to be designed around use, safety, and visual comfort. It also separates three decisions that should not be conflated: what the sensor detects, what the controller interprets, and what the luminaires do.
Bluetooth NLC Occupancy Sensors: Reporting Versus Lighting Control
The Bluetooth Occupancy Sensor NLC Profile v1.0 was published on 12 September 2023. It defines behavior for an occupancy-sensor product; it is not a complete lighting-control strategy. The profile supports Motion Sensed, Presence Detected, and People Count reporting. For Motion Sensed, the post-motion hold behavior is handled by the receiving control model rather than being a universal timer defined by the reporting sensor. [Bluetooth Occupancy Sensor NLC Profile v1.0]
Source: Bluetooth Occupancy Sensor NLC Profile v1.0 (12 September 2023)
A Bluetooth NLC occupancy sensor supplies the event information. The Basic Lightness Controller NLC Profile is the controller-side role that can use information from occupancy sensors, ambient-light sensors, dimming controllers, and scene selectors to adjust light output. A Bluetooth NLC occupancy sensor therefore should be evaluated with the compatible control model and target fixtures, rather than assumed to command luminaires by itself. [Bluetooth Basic Lightness Controller NLC Profile v1.0]
Source: Bluetooth Basic Lightness Controller NLC Profile v1.0 (12 September 2023)
Not every legacy Silvair-compatible Bluetooth mesh device should automatically be described as a Bluetooth NLC product. Silvair introduced Bluetooth NLC support with Firmware 2.30 NLC in January 2024; the exact device qualification, firmware version, and supported NLC Profile must be verified for a specific product. This check matters when a project mixes installed and new devices. Silvair occupancy sensing must be matched to verified device capabilities. [Silvair Firmware 2.30 NLC]
Silvair Occupancy Controls vs Silvair Vacancy Sensing
The central difference is initial activation. Silvair occupancy controls can turn lighting on automatically after a valid occupancy event. Silvair vacancy sensing requires a manual ON command from a configured wall switch, companion switch—formerly referred to as an EnOcean switch—or another supported control interface. Both approaches can later reduce output or turn it off automatically after vacancy, and both can use the same three-state logic when the assigned scenario supports it.
| Control behavior | Occupancy sensing | Vacancy sensing |
| Initial activation | Automatic after occupancy is detected | Manual ON command from a configured control interface |
| Occupancy sensor used | Yes | Yes |
| Manual switch required for initial ON | No | Yes—wall switch, companion switch, or supported interface |
| Automatic response to vacancy | Yes | Yes |
| Prolonged state available | Yes, when configured | Yes, when configured |
| Vacant level configurable | Yes | Yes |
| Manual override possible | Yes, when compatible manual control is installed and configured | Yes, when compatible manual control is installed and configured |
Silvair vacancy sensing is useful where unprompted activation is undesirable but automated vacancy response is valuable. Silvair occupancy controls fit circulation, access, and other spaces where lighting should respond without a manual first action. The selection should reflect how the space is actually used, not a generic preference for automatic operation.
How Occupied, Prolonged and Vacant States Work
Silvair occupancy sensing can use three states to convert a reporting event into a staged lighting response. The values below are project-defined. Sequences such as 100% → 30% → 10% or 100% → 20% → 0% are examples, not Silvair default values.
| State | Entry condition | Light level | Timer | Exit condition |
| Occupied | Occupancy detected | Project-defined occupied level | Occupied Timeout | No further occupancy |
| Prolonged | Occupied Timeout expires | Project-defined intermediate level | Prolonged Timeout | New occupancy or timeout |
| Vacant | Prolonged Timeout expires | Standby level or off | — | New occupancy or manual ON |
The Occupied state maintains the intended task or circulation level while valid activity is reported. When its timeout expires, the Prolonged state can provide background or orientation light instead of an abrupt move to the final condition. After the Prolonged timeout, the Vacant state can be off or a low standby level. New occupancy returns the applicable zone to its active response. This structure lets Silvair vacancy sensing preserve a deliberate path after a manual ON command as well.
Diagram: Occupied, Prolonged and Vacant states, timeout logic, and per-transition Fade Time.
How Levels, Timeouts and Fade Behavior Shape the Response
A wireless occupancy lighting control design should distinguish wait time from transition time. Occupied Light Level, Prolonged Light Level, and Vacant Light Level determine output setpoints. Occupied Timeout and Prolonged Timeout determine how long the zone waits before changing state. Fade Time determines how quickly the fixtures move from one defined level to the next. Each state transition can use its own Fade Time; it is inaccurate to assume that the entire profile uses one universal fade.
For example, a zone may operate at 100% while occupied, wait for the Occupied Timeout, fade to 30%, wait through the Prolonged Timeout, and then fade to 10%. A warehouse aisle, a stairway, and an office may need different timings and levels. Wireless occupancy lighting control should therefore be documented per zone or zone type. This keeps wireless occupancy lighting control tied to occupant experience rather than a universal preset.
How Manual Override Returns to Automatic Control
A manual input can select a temporary light state through a compatible control. The accurate logic is: Manual input → Manual Override active → the zone remains vacant for the configured Manual Override Timeout → automatic control resumes. The Manual Override Timeout is a continuous-vacancy interval, not simply a fixed countdown beginning when a user presses a switch. A new occupancy event resets the vacancy timer. Users can also restore automatic operation manually through an ON/AUTO action where that control is available.
If the Manual Override Timeout is disabled, the manual state can persist until the user restores Auto or another valid control event changes it. This behavior should be described only for applicable Occupancy/Vacancy scenarios, not as a capability that necessarily applies to every Silvair control scenario. A clearly documented return-to-auto condition avoids prolonged unintended light levels. [Silvair SN-200 Commissioning User Manual]
What Is Silvair Zone Linking and How Does It Work?
The linking function shares an occupancy or manual-control event from a source zone with a target zone. It does not require both zones to use identical light levels, timeouts, or fades; each target zone can retain its own profile parameters. In a uni-directional relationship, Source Zone A can influence Target Zone B, while activity in B does not automatically influence A. In a bi-directional relationship, both directions allow control influence.
Occupancy-driven linking requires related zones to use scenarios that support Occupancy/Vacancy behavior. A Manual Control scenario should not be described as responding to occupancy events in the same way. This scenario compatibility must be tested before commissioning. Silvair Zone Linking is particularly useful when an occupant needs light ahead of the local zone without making every neighboring zone behave identically. [Silvair FAQ and troubleshooting guidance]
Diagram: Source Zone A to Target Zone B uni-directional link and bi-directional Zone A to Zone B link.
Same-Area Limitation
Silvair Zone Linking works only between zones in the same Area. Zones in different Areas cannot be directly linked through the standard Zone Linking function. An Area is a logical subdivision of a Silvair project, commonly representing a floor, a large floor section, or another network segment. This limitation should be established during project planning, because it affects how movement paths and adjacent lighting responses are partitioned. [Silvair SN-213 Recommendations for Complex Lighting Installations]
Zone Linking and Network Scale
Area scale affects the engineering headroom for linked control. Silvair guidance commonly treats roughly 200 devices per Area as a design recommendation, not an absolute hard ceiling. Firmware 2.18 and later use a Replay Protection List (RPL) with 350 entries. Sensors, switches, and related devices consume relevant RPL capacity, so more complex linking can reduce available control-device capacity. Silvair also advises against configuring an Area to accept manual control from more than 28 Areas; that figure is not a universal maximum for all Zone Linking. Detailed calculations belong in project-specific mesh planning. Bluetooth mesh occupancy controls should be reviewed against this capacity early in design.
How Neighboring-Zone Control Supports Safer Movement
Linked-zone occupancy control can light the next corridor section before an occupant reaches it, maintain an illuminated route outside an occupied room, or coordinate adjacent aisle and cross-aisle behavior. A directional response is often appropriate where movement has a known direction. A full linked response may suit two corridor sections where activity in either section should create a coordinated result. The correct approach follows traffic flow, safety needs, and local-zone independence.
Bluetooth mesh occupancy controls should be planned as an occupancy-based control strategy, not as a blanket instruction to copy a local response everywhere. In practice, Bluetooth mesh occupancy controls work best when only relevant neighboring zones receive the event. The source event, target scenario, individual profile settings, and Area boundary all matter. This keeps sensor-driven lighting useful at the point of need while avoiding unnecessary activation in unrelated spaces. It is the practical objective of wireless occupancy lighting control across connected zones.
Sensor Placement, Missed Detection and False Triggers
Sensor placement must support both the local zone and any intended neighboring-zone response. Consider approach direction, entry and exit points, stationary activity areas, mounting height, furniture, shelving, partitions, walls, equipment, detection pattern, and obstruction. After commissioning, conduct a walk test with the real furniture, shelving, and equipment in place. A mounting location that is convenient electrically may not provide the coverage required by the control logic.
False triggers are only one risk. PIR motion sensing and true presence sensing are not the same: seated people, fine work, or people hidden by shelving and partitions may not create enough motion to maintain a motion-based signal. That can create false vacancy, even when a person remains in the space. Where quiet or stationary occupants must be detected, select a device that genuinely supports Presence Detected rather than relying solely on an ordinary PIR motion response. A Bluetooth NLC occupancy sensor should be assessed against this detection requirement, not only against its network compatibility.
Conversely, moving fans, trees, animals, doors, machinery, or nearby traffic can produce unwanted signals that keep local or linked zones active. Sensor coverage must match the movement that matters and reject movement that does not. This is particularly important where one sensor initiates a linked response in another zone. [Silvair Troubleshooting]
Where This Control Strategy Is Most Useful
Silvair occupancy sensing and linked-zone behavior are useful in warehouses, garages, corridors, stairways, offices, industrial facilities, and storage areas. A Silvair occupancy sensing specification should name the intended movement pattern for each linked condition. Warehouses can combine aisle detection, high-low levels, and linked cross-aisle response. Garages can coordinate drive lanes and pedestrian routes. Corridors can light the next section before a person approaches.
Offices can apply automatic occupancy response in selected rooms and Silvair vacancy sensing where a manual initial ON is preferred. Industrial and storage environments can combine access-route lighting with a prolonged low level and final vacant reduction. For each application, define activation, levels, timing, manual return-to-auto, link direction, same-Area condition, sensor coverage, and network scale before finalizing the profile.
Key Takeaway
Silvair occupancy sensing and Silvair vacancy sensing differ primarily in how lighting first becomes active: automatic detection versus a manual ON command. Both can use Occupied, Prolonged, and Vacant states to deliver measured reductions instead of an abrupt off response. Manual override should return to Auto only after the zone has remained vacant for its configured timeout or after a deliberate ON/AUTO action. Silvair Zone Linking can extend an event to a neighboring zone, but it is directional by design choice, scenario-dependent, and limited to zones in the same Area. Good results depend as much on sensor coverage and RPL-aware network planning as on the nominal control settings. A Silvair occupancy sensing plan should record both local and linked behavior.
Clickable Technical References
- Silvair SN-200 Commissioning User Manual — Use the current revision shown in Silvair’s public document library. Open source
- Silvair SN-211 Lighting Control — Use the current revision shown in Silvair’s public document library. Open source
- Silvair SN-213 Recommendations for Complex Lighting Installations, Rev. 3.3, 18 March 2024 — Complex project and Area planning reference. Open source
- Bluetooth Occupancy Sensor NLC Profile v1.0, 12 September 2023 — Occupancy reporting behavior. Open source
- Bluetooth Basic Lightness Controller NLC Profile v1.0, 12 September 2023 — Controller-side light-output behavior. Open source
- Silvair FAQ and Troubleshooting — Zone linking and sensor troubleshooting reference. Open source
- Silvair Manuals and Data Sheets — Use this library to verify the latest document revisions. Open source
Frequently Asked Questions
Does Silvair occupancy sensing always turn lights fully off?
No. The Vacant state can be set to off or to a project-defined standby level. The chosen level should reflect safety, orientation, energy, and operating needs. A Vacant state is a control condition, not automatically a requirement for zero output.
What is the difference between occupancy and vacancy sensing?
Occupancy sensing can activate lighting automatically after a valid event. Vacancy sensing begins with a manual ON command from a configured control interface, then automatically reduces or switches lighting off after vacancy. Both can use Occupied, Prolonged, and Vacant states.
Does the Bluetooth Occupancy Sensor NLC Profile control luminaires directly?
No. The profile standardizes how an occupancy-sensor product reports information such as motion, presence, or people count. A receiving controller, such as a Basic Lightness Controller NLC Profile implementation, interprets applicable inputs and adjusts light output.
Can one sensor affect more than one zone?
Yes. Silvair Zone Linking can let an event in a source zone affect one or more target zones when the linked scenarios and Area structure support the intended behavior. Target zones can keep their own levels, timeouts, and fade parameters.
Can Silvair Zone Linking operate between different Areas?
No. Standard Silvair Zone Linking works only between zones in the same Area. Areas are logical project subdivisions, so a designer should establish Area boundaries before relying on a linked response along a movement path.
Does Silvair Zone Linking require a gateway?
Basic local Zone Linking and automatic lighting behavior do not require a gateway to execute the event-sharing logic. Gateways are used for services such as monitoring, gateway scheduling, ADR, and related system functions, depending on the project configuration.
How does Manual Override Timeout work?
It is a continuous-vacancy interval. After manual control is active, the zone must remain vacant for the configured timeout before automatic behavior resumes. A new occupancy event resets that vacancy timer. If disabled, manual state can persist until Auto or another valid event changes it.
How many zones can be linked in a Silvair project?
There is no useful single hard number. Capacity depends on Area boundaries, device count, link direction, relevant source control devices, scenario compatibility, and Replay Protection List capacity. The 28-Area guidance applies to an Area accepting manual control from many Areas, not every linking case.
Are all Silvair Bluetooth mesh sensors Bluetooth NLC sensors?
No. Do not assume that a legacy Silvair-compatible Bluetooth mesh device is Bluetooth NLC qualified. Verify the actual product qualification, installed firmware version, and supported NLC Profiles. Firmware 2.30 NLC introduced Silvair’s Bluetooth NLC support; Bluetooth mesh occupancy controls still require device-by-device qualification.
What causes missed detection or false vacancy?
A motion-only PIR sensor may miss seated, quiet, or shielded occupants. Furniture, shelving, partitions, mounting choices, and detection pattern can all affect coverage. If stationary presence must be detected, select a sensor that supports Presence Detected and validate it through a post-installation walk test.
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