- Zhaga Book 18 defines the interface for outdoor luminaire controllers (OLCs), including the connector, pin arrangement, supply voltage, luminaire-to-node communication and permitted power budget. The node’s external network protocol to a gateway or CMS is outside its scope.
- Zhaga specifies interoperability between a Zhaga-D4i-certified luminaire and a certified node. This covers more than connector shape, but not the node’s CMS connection. Verify both product records, the power budget and support for the central platform.
- Compatible sensing and communication nodes can add functions within the interface power budget. A camera or other accessory is not automatically compatible merely because the luminaire has a Book 18 socket.
- DALI signal lines are included, enabling the node to control driver dimming directly over DALI-2 without additional control wiring.
What Is Zhaga Book 18?
Zhaga is an international consortium that standardises mechanical and electrical interfaces for LED lighting components. Its Books cover interfaces ranging from LED modules to drivers and control systems.
Book 18 defines the interface between outdoor luminaires and sensing or communication nodes, on the top or underside. Edition 4 was published in October 2025. The interface covers: Zhaga Book 18
- Connector mechanics, dimensions and sealing
- Pin allocation for DC supply, DALI and reference potential; the reference is not the mains neutral
- Supply voltage from the luminaire to the node
- The node’s maximum electrical load
- Mechanical locking so the node can be fitted and removed without tools or opening the housing
The OLC node can therefore be replaced independently of the luminaire. A local authority can change control supplier or adopt new radio technology without replacing the luminaire.
Control Standards — What Book 18 Covers
| Interface element | Defined by Book 18 | Note |
|---|---|---|
| Mechanical connector | Yes — pins, position and locking | Verify the IP rating of the assembled socket, seal and node or cap |
| Supply voltage | Yes — 24 V DC auxiliary supply from luminaire to node | Maximum current is limited by the profile |
| DALI signal lines | Yes — DALI-2 bus signals are available through the connector | Allows the node to control the driver |
| External communication to gateway/CMS | No | May use Zigbee, LoRaWAN, NB-IoT, Bluetooth Mesh, Wi-Fi or a proprietary protocol |
| CMS platform | No | Nodes from different manufacturers are not necessarily compatible |
| Data rights | No | Must be governed by contract |
Book 18 ≠ Complete Supplier Independence
Zhaga specifies interoperability between a Zhaga-D4i-certified luminaire and a certified node. This covers more than connector shape, but not the node’s CMS connection. Verify both product records, the power budget and support for the central platform. Zhaga
What Can Be Connected?
The table lists functions that a project may request. It is not a compatibility list: verify the exact node, power budget and interface. The Comlight example is a documented radar node.
| Node type | Function | Example |
|---|---|---|
| Presence sensor | Radar or PIR motion detection for adaptive dimming. | Comlight Eagle Eye Zhaga |
| IoT gateway | Forwards luminaire and sensor data to a cloud platform or CMS. | Platform-specific gateways |
The Link to DALI-2 and D4i
The interface provides DALI-2 signal lines. An OLC node can send dimming commands directly to the driver, read status data, and — where supported by the selected driver — retrieve luminaire data (Part 251), energy reporting (Part 252), and diagnostics and maintenance data (Part 253). Full D4i certification for an LED driver also requires Part 207 and Part 250 for integrated DALI bus power. DALI Alliance — D4i
This requires a DALI-2-certified driver, a node that supports DALI communication and a CMS able to interpret the forwarded commands and data. See DALI-2, Zhaga and D4i — How a Smart Street Luminaire Communicates.
RF Transparency and Wireless Communication
Metal can attenuate radio signals; an external antenna, external node or RF window can provide a solution. SMC can permit internal radio integration, but does not guarantee a particular range or zero attenuation. Verify the antenna, frequency, placement and assembled construction. An external Zhaga node has different conditions from a radio inside the housing. Casambi
Questions to Ask in Procurement
- Certification and system support: Are both the luminaire and node listed in the relevant certification registers, is the power budget sufficient, and is the selected CMS platform supported?
- Node compatibility: Which OLC nodes have been tested with this luminaire model?
- Communication protocol: Which radio protocol does the node use, and is it open or proprietary?
- CMS dependency: Which central platform does the node require, and what happens to the data if the supplier ceases trading?
- DALI support: Can the node communicate through the interface’s DALI-2 lines?
- Power demand: How much current does the node require, and can the luminaire supply it?
VALDUR — Technical Note
VALDUR can be ordered with Zhaga Book 18 sockets for sensor and communication nodes. The socket can be on the top (ZH1), bottom (ZH2) or both (ZH3), depending on the ordered configuration, and allows an OLC node to be fitted without opening the housing. The dielectric SMC housing is RF-transparent. Philips Xitanium LP S1 with 1–10 V is the standard driver. DALI-2 is available with a selected FP, SR or CR driver; the specified SR/CR drivers are D4i-certified. See POLAB Controls. CLO is included as standard in every VALDUR luminaire.