BACnet B-ACWS Access Control Workstation Profile

B-ACWS is the BACnet Access Control Workstation profile (Annex L): what it is, where it's used, and the services it requires.

What B-ACWS 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-ACWS (BACnet Access Control Workstation) is the physical-access-control operator interface for user administration, defined in Annex L of ANSI/ASHRAE 135-2024 (clause L.3.2). It enrolls and manages users, credentials, and rights (creating, deleting, and configuring Access User, Access Credential, and Access Rights objects) and operates the access-control system, but it does not configure the door and reader object set that a B-AACWS does.

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-ACWS is an operator-side (client) profile: it initiates reads, writes, object creation, and device management against other devices, and it receives access-event notifications rather than generating them. 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-ACWS is the user-administration seat, targeted at an operator who enrolls and manages people in the access-control system.

  • Credential-enrollment workstations. A console where staff create and manage Access User, Access Credential, and Access Rights objects for the building population.
  • Security operator desks. A workstation paired with a head end (the central BMS server) that acknowledges access events and monitors doors.
  • Access-control front ends. A station that presents access events, event logs, and schedules for daily operation.

Required Services

The table below is the exhaustive service set required by the B-ACWS 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. A service can appear under two capability areas when two different BIBBs use it.

Capability areaServiceRequired by BIBBInitiatesExecutes
Data sharingReadPropertyDS-RP-A, DS-RP-B, DS-ACAV-AYesYes
Data sharingReadPropertyMultipleDS-RPM-AYes-
Data sharingWritePropertyDS-WP-A, DS-ACM-AYes-
Data sharingWritePropertyMultipleDS-WPM-AYes-
Alarm and event managementConfirmedEventNotificationAE-N-A, AE-AC-A, AE-ACAVN-A-Yes
Alarm and event managementUnconfirmedEventNotificationAE-N-A, AE-AC-A, AE-ACAVN-A-Yes
Alarm and event managementAcknowledgeAlarmAE-ACK-A, AE-AC-AYes-
Alarm and event managementGetEventInformationAE-AS-AYes-
Alarm and event managementGetAlarmSummaryAE-AS-AYes-
Alarm and event managementReadRange (event-log view)AE-ELV-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-AYes-
Device and network managementTimeSynchronizationDM-MTS-AYes-
Device and network managementUTCTimeSynchronizationDM-MTS-AYes-
Device and network managementReinitializeDeviceDM-RD-A, DM-BR-AYes-
Device and network managementCreateObjectDM-OCD-A, DS-ACUC-AYes-
Device and network managementDeleteObjectDM-OCD-A, DS-ACUC-AYes-
Device and network managementAtomicReadFile (backup)DM-BR-AYes-
Device and network managementAtomicWriteFile (restore)DM-BR-AYes-

The view, modify, and configuration BIBBs add no wire service beyond the rows above. DS-ACAV-A (Access Control Advanced View) and DS-ACM-A (Access Control Modify) read and write access-object properties; DS-ACUC-A (User Configuration) creates, deletes, reads, and writes Access User, Access Credential, and Access Rights objects; AE-ACVM-A adjusts access-event parameters; SCHED-VM-A views and modifies schedules and calendars; DM-ADM-A enumerates objects; DM-ANM-A adjusts alarm routing by writing Notification Class recipient lists. Each is carried by the ReadProperty, WriteProperty, and CreateObject rows above.

ProfileHow it differs from B-ACWS
B-AACWSAdvanced Access Control Workstation: a step up. Adds site-object configuration (doors, readers), event-log modification, and audit reporting
B-ACSDAccess Control Security Display: one step down. Monitoring and event handling with minimal configuration, no object creation
B-ACCAccess Control Controller: the device side. It generates the access events a B-ACWS handles and hosts the access objects it manages

What Chipkin Provides

B-ACWS is an operator-side profile: its initiating and notification-receiving behavior 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-ACWS operator interface.