What B-AACC 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-AACC (BACnet Advanced Access Control Controller) is defined in Annex L of ANSI/ASHRAE 135-2024 (clause L.6.1) as the fuller access controller: like the B-ACC it makes access decisions and generates events, and it adds the client-side ability to read credential readers and command door controllers in other devices.
The checklist items are BACnet Interoperability Building Blocks (BIBBs). B-AACC is a B-role device that also acts as a client toward the readers and doors it coordinates. A device documents its 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-AACC fits a head-end access controller that coordinates separate reader and door devices across a site.
- Distributed access control. A controller that subscribes to credential events from reader devices and commands door devices, rather than wiring readers and doors directly to itself.
- Multi-panel coordination. A controller reading and writing access objects across other panels.
- Integrated security head end. An access controller that both serves its own decisions and drives downstream access hardware.
Required Services
The table below is the exhaustive service set required by the B-AACC 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, DS-ACUC-B, DS-ACSC-B | Yes | Yes |
| Data sharing | ReadPropertyMultiple | DS-RPM-A, DS-RPM-B | Yes | Yes |
| Data sharing | WriteProperty | DS-WP-A, DS-WP-B, DS-ACAD-A, DS-ACCDI-A, DS-ACUC-B, DS-ACSC-B | Yes | Yes |
| Data sharing | WritePropertyMultiple | DS-WPM-B | - | Yes |
| Data sharing | SubscribeCOV | DS-COV-A, DS-COV-B, DS-ACCDI-A | Yes | Yes |
| Data sharing | ConfirmedCOVNotification | DS-COV-A, DS-COV-B | Yes | Yes |
| Data sharing | UnconfirmedCOVNotification | DS-COV-A, DS-COV-B | Yes | Yes |
| Alarm and event management | ConfirmedEventNotification | AE-AC-B | Yes | - |
| Alarm and event management | UnconfirmedEventNotification | AE-AC-B | Yes | - |
| Alarm and event management | AcknowledgeAlarm | AE-ACK-B | - | Yes |
| Alarm and event management | GetEventInformation | AE-INFO-B | - | Yes |
| Alarm and event management | ReadRange (event log access) | AE-EL-I-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 |
| Device and network management | ReinitializeDevice | DM-RD-B, DM-BR-B | - | Yes |
| Device and network management | AtomicReadFile (backup) | DM-BR-B | - | Yes |
| Device and network management | AtomicWriteFile (restore) | DM-BR-B | - | Yes |
The access model lives in hosted objects. The device hosts the access-control object family, Access Point, Access Zone, Access Rights, and Access Credential, plus an Event Log (AE-EL-I-B) and Schedule and Calendar objects (SCHED-I-B, no outbound service). The -A data-sharing rows are what let it read and command the reader and door devices it coordinates.
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-AACC |
|---|---|
| B-ACC | Access Control Controller: a step down. No client-side access services |
| B-ACDC | Access Control Door Controller: the downstream door-operating device |
| B-ACCR | Access Control Credential Reader: the downstream credential-reading device |
What Chipkin Provides
The CAS BACnet Stack implements the access-control object family and the services the B-AACC profile requires; the client-side coordination services are exercised through Chipkin’s BACnet test tooling. Talk to us about building or integrating a B-AACC device on the stack.