What B-ALCS Is
A BACnet device profile is a standardized capability level: a checklist of things a device must be able to do before it can wear the label. B-ALCS (BACnet Advanced Lighting Control Station) is defined in Annex L of ANSI/ASHRAE 135-2024 (clause L.10.1) as any device that needs to interact with Lighting Output, Binary Lighting Output, and Channel objects in other devices to monitor and control them. B-ALCS devices are not workstations or displays; they are more limited devices such as smart wall switches, dimmers, and scene-preset consoles, and they differ from a B-LCS in the ability to configure and command advanced lighting parameters.
The checklist items are BACnet Interoperability Building Blocks (BIBBs), each a named unit of capability such as “can send a read request” (DS-RP-A). B-ALCS is a control-station (client) profile: it initiates lighting commands to other devices while responding to discovery, communication-control, and time-synchronization requests about itself. A device documents its profile claim in its PICS (Protocol Implementation Conformance Statement); to verify a claim, ask for the PICS and check the profile line.
Where It’s Used
B-ALCS fits the fixed control device that commands lighting rather than a staffed console.
- Scene-preset consoles. A wall console that recalls lighting scenes by commanding Lighting Output and Channel objects in other devices.
- Smart switch and dimmer stations. A control device that writes lighting levels and issues group commands across a lighting network.
- Time-driven lighting controllers. A station that schedules output actions in itself and in other devices based on date and time.
Required Services
The table below is the service set required by the B-ALCS BIBBs. Initiates means the device sends the request or notification; Executes means the device receives and acts on it (responding, for confirmed services). BIBB codes encode the same split: a -A BIBB is the initiating side, a -B BIBB the executing side. A - means the profile does not require that direction; a device may still support it.
| Capability area | Service | Required by BIBB | Initiates | Executes |
|---|---|---|---|---|
| Data sharing | ReadProperty | DS-RP-A, DS-RP-B | Yes | Yes |
| Data sharing | ReadPropertyMultiple | DS-RPM-A | Yes | - |
| Data sharing | WriteProperty | DS-WP-A, DS-ALO-A | Yes | - |
| Data sharing | WritePropertyMultiple | DS-WPM-A | Yes | - |
| Data sharing | WriteGroup | DS-WG-A | Yes | - |
| Scheduling | WriteProperty (schedule write-out to other devices) | SCHED-E-B | Yes | - |
| Device and network management | Who-Is | DM-DDB-A, DM-DDB-B | Yes | Yes |
| Device and network management | I-Am | DM-DDB-A, DM-DDB-B | Yes | Yes |
| Device and network management | Who-Has | DM-DOB-B | - | Yes |
| Device and network management | I-Have | DM-DOB-B | Yes | - |
| Device and network management | DeviceCommunicationControl | DM-DCC-B | - | Yes |
| Device and network management | TimeSynchronization ¹ | DM-TS-B | - | Yes |
| Device and network management | UTCTimeSynchronization ¹ | DM-UTC-B | - | Yes |
The scheduling row requires a hosted object. SCHED-E-B requires the device to host a Schedule object whose List_Of_Object_Property_References names properties in other devices, so the station writes those values out with WriteProperty. The DS-ALO-A (Advanced Lighting Output) BIBB commands standard properties of lighting and value objects and folds onto the WriteProperty row.
¹ The profile requires one of the two time-synchronization services, not both. (Protocol_Revision is a readable property of the device’s Device object.)
Related Profiles
| Profile | How it differs from B-ALCS |
|---|---|
| B-LCS | Lighting Control Station: one step down. Commands Lighting Output objects but no WriteGroup, no advanced parameters, and no external scheduling |
| B-ALWS | Advanced Lighting Workstation: the staffed operator interface, with alarm, trend, and object-configuration capability B-ALCS omits |
| B-LS | Lighting Supervisor: the device side. It hosts Channel and Lighting Output objects that a B-ALCS commands |
What Chipkin Provides
B-ALCS is a control-station profile whose lighting-command initiation is implemented in Chipkin’s BACnet test tooling rather than the shipping device stack, which targets the server-side profiles. Talk to us about building or integrating a B-ALCS operator interface.