Read DALI through its gateway or controller at a sensible interval. Never bypass the controller, and confirm which data points the gateway actually exposes.
Why a Gateway Sits in the Middle
A DALI line runs at 1200 bit/s and is managed by an application controller that owns addressing, groups and scenes. A DALI gateway connects that controller to an IP or building network. An outside system should read through the gateway, because only an application controller can command control gear and a second master would disturb the bus.
What the Gateway Can Expose
Typical interfaces are BACnet, Modbus, KNX and MQTT. Common data points are group and luminaire status, dim level, lamp failure and driver failure. Energy, power and operating hours are available only where the drivers support DALI-2 D4i data (IEC 62386 parts 252 and 253), and only if the gateway passes them on.
DALI, DALI-2 and D4i
DALI version 1 covered control gear. DALI-2 adds certified control devices such as sensors and application controllers and requires independently verified certification. D4i extends DALI-2 with luminaire, energy and diagnostics data. DALI-2 is designed to be backward compatible with earlier equipment.
Polling Without Overloading
Because the bus is slow, query the gateway cache rather than every address in turn, and choose an interval that matches the use. Fault alerts need minutes, energy trends need longer. A short interval on a large installation can keep the gateway busy and slow down real lighting commands.
Commissioning Checklist
Confirm the gateway interface and its object list, note the addressing of each group, test one luminaire fault by removing a lamp and checking the alert, and compare one reading with the gateway display. Record firmware versions, because object lists can change between releases.
Common Questions
How many DALI devices can one gateway read?
A DALI line supports up to 64 control gear and 64 control devices. A gateway may serve several lines. Check the gateway datasheet for the number of lines and objects it exposes.
Does IoTServa dim or switch DALI lights?
Pilots start read-only. IoTServa reads status, faults and, where available, energy data from the gateway. Commands are a separate permission and are sent through the gateway or controller.