BACnet B-LCS Lighting Control Station Profile

B-LCS is the BACnet Lighting Control Station profile (Annex L): what it is, where it's used, and the services it requires.

What B-LCS 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-LCS (BACnet Lighting Control Station) is defined in Annex L of ANSI/ASHRAE 135-2024 (clause L.10.2) as any device that needs to interact with Lighting Output or Binary Lighting Output objects in other devices to monitor and control them. B-LCS devices differ from workstations and displays in that their interaction with people is more limited; examples include smart wall switches, dimmers, and scene-preset consoles.

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-LCS 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-LCS is the simplest fixed lighting-command device.

  • Wall switches and dimmers. A control device that writes the Present_Value of Lighting Output objects in other devices.
  • Scene-preset consoles. A station that recalls preset lighting levels by commanding lighting objects across the network.
  • Local control stations. A device that commands lighting while answering queries about its own status.

Required Services

The table below is the service set required by the B-LCS 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 areaServiceRequired by BIBBInitiatesExecutes
Data sharingReadPropertyDS-RP-A, DS-RP-BYesYes
Data sharingWritePropertyDS-WP-A, DS-LO-AYes-
Device and network managementWho-IsDM-DDB-A, DM-DDB-BYesYes
Device and network managementI-AmDM-DDB-A, DM-DDB-BYesYes
Device and network managementWho-HasDM-DOB-B-Yes
Device and network managementI-HaveDM-DOB-BYes-
Device and network managementDeviceCommunicationControlDM-DCC-B-Yes
Device and network managementTimeSynchronization ¹DM-TS-B-Yes
Device and network managementUTCTimeSynchronization ¹DM-UTC-B-Yes

The DS-LO-A (Lighting Output) BIBB writes the Present_Value of Lighting Output, Binary Lighting Output, and standard value objects and folds onto the WriteProperty row, so the profile adds no new wire service beyond it.

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.)

ProfileHow it differs from B-LCS
B-ALCSAdvanced Lighting Control Station: a step up. Adds WriteGroup commanding, advanced lighting parameters, and external scheduling
B-LODLighting Operator Display: a display that also views lighting data and issues WriteGroup commands
B-LDLighting Device: the device side. It hosts the Lighting Output objects a B-LCS commands

What Chipkin Provides

B-LCS 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-LCS operator interface.