BACnet explorer built in Elixir with Phoenix LiveView and bacstack.
Discover devices, browse Structured View hierarchies or create your own based upon object names, read and write properties, subscribe to COV updates, and monitor alarms - all in real time from the browser.
This project has been built with Grok Build and the Composer 2.5 Fast model.
- Network discovery - Who-Is / I-Am scan with live device list, filters, and optional limited instance / vendor ranges
- BBMD / Foreign Device - register with a remote BBMD so Who-Is is distributed via Distribute-Broadcast-To-Network; automatic re-registration
- Stack settings - transport (BACnet/IP or MS/TP), network interface / serial port, local device instance, APDU/timeout options; persisted to
runtime_settings.jsonand restartable from the UI - Device load & scan - full device object list scan with progress banner; scan recovery for validation failures (relaxed value/type skip modes)
- Hierarchies - Structured View tree with search and “reveal in flat list”; optional name-based hierarchy built from object-name separators when no Structured View exists
- Object explorer - property table with RPM (ReadPropertyMultiple) first, individual ReadProperty fallback, live load progress, status-flag icons, and COV badges
- Property writes - Present_Value (with priority where applicable), generic property write, and weekly schedule editor
- COV subscriptions - per-property or bulk Present_Value subscribe, auto-renewal, active-subscription overview, notification log, and COV history charts (CSV/JSON export)
- Alarms & events - GetAlarmSummary polling, live Confirmed/UnconfirmedEventNotification handling, active-alarm popups, notification-class recipient enrollment, JSON/CSV event export
- Trend logs - chart viewer for log buffer data, time-range navigation, CSV/JSON export
- File objects - AtomicReadFile / AtomicWriteFile transfer UI
- EDE export - generate BACnet Engineering Data Exchange files from a scanned device (
bacnet_ede) - Device services - time synchronization, DeviceCommunicationControl, and ReinitializeDevice
- i18n - German (default) and English via Gettext; locale switcher persisted in
localStorage(desktop: OS locale on first launch) - Keyboard shortcuts - press
?for help (/,r,1–4,0/ Escape on device pages)
- Elixir ~> 1.18
- Erlang/OTP 26+
- Node.js (asset bundling in dev)
- UDP port 47808 available for BACnet/IP (others choosable)
mix setup
mix phx.serverI recommend running mix deps.update --all before to get the newest versions and latest bacstack patches/improvements.
Open http://localhost:4000, click Scan network, then select a device.
To discover devices on a remote BACnet/IP network, register BacView as a Foreign Device with your BBMD (dashboard sidebar). Who-Is scans are then distributed through the BBMD.
Stack settings (transport, network interface, device instance, COV options, BBMD) are configured in the dashboard sidebar and persisted to priv/runtime_settings.json.
Copy .env.example to .env and adjust as needed (optional in dev).
BacView can also run as a native desktop app via ElixirKit and Tauri.
Desktop mode is selected at compile time with BACVIEW_DESKTOP=1. Run mix clean when switching between web and desktop builds.
The environment variable ensures that we only pull desktop dependencies when we need them and otherwise keep it clean.
Requirements: Some system packages are required for Tauri.
For recent Debian-based installations:
sudo apt update
sudo apt install libwebkit2gtk-4.1-dev \
build-essential \
curl \
wget \
file \
libxdo-dev \
libssl-dev \
libayatana-appindicator3-dev \
librsvg2-dev \
inotify-toolsStarting the desktop application:
BACVIEW_DESKTOP=1 mix desktop.setup
BACVIEW_DESKTOP=1 mix desktop.serveror
./scripts/desktop_dev.shWindows also has a batch with ending .bat.
Package a distributable installer (.{AppImage,deb,rpm} on Linux, .exe on Windows):
BACVIEW_DESKTOP=1 mix desktop.installeror
./scripts/desktop_release.shWindows also has a batch with ending .bat.
Desktop notes:
- Settings persist under
~/.config/bacview/runtime_settings.json - OS locale is detected on launch and applied; DE/EN can still be switched in the app
- MS/TP will be included if the dependency
circuits_uartis present or non-Windows OS - typically it will be omitted on Windows (due to NIF)
Verify desktop dependencies: BACVIEW_DESKTOP=1 mix bacview.desktop.check
| Variable | Default | Description |
|---|---|---|
PHX_SERVER |
- | Set true to start HTTP in releases |
PORT |
4000 |
HTTP port |
SECRET_KEY_BASE |
- | Required in production (see mix phx.gen.secret) |
BACVIEW_BACSTACK_DEBUG |
- | Enable verbose bacstack debug logs (1 / true) |
BACVIEW_ENABLE_MSTP |
- | Enable MS/TP transport regardless of platform (1 / true) |
BACVIEW_DESKTOP |
- | Set to 1 at compile time to build the desktop app (see above) |
BACVIEW_DESKTOP_LOCALE |
- | The locale to use on startup (automatically set by the desktop app) |
BACVIEW_LOG_PATH |
~/.config/bacview/bacview.log on desktop, tmp/bacview.log otherwise |
Location of the Logger logfile |
BACVIEW_PROPERTY_READ_CONCURRENCY |
8 |
Max parallel individual ReadProperty requests when loading object properties / scan fallback - lower (e.g. 1) if old devices are overwhelmed |
BACVIEW_READ_CONCUR_ENABLE_SHARED_RED |
- | Cap property-read concurrency to 1 when multiple devices share a transport address (e.g. router) (1 / true) |
BACVIEW_SETTINGS_PATH |
priv/runtime_settings.json |
Optional override for persisted stack settings |
BACVIEW_TIMEZONE |
Europe/Zurich |
IANA timezone for BACnet wall-clock timestamps, bacstack, and UI display |
mix assets.deploy
SECRET_KEY_BASE=$(mix phx.gen.secret) mix releaseStart the release:
PHX_SERVER=true PORT=4000 ./_build/bacview/rel/bacview/bin/serverOr use the release binary directly:
PHX_SERVER=true ./_build/bacview/rel/bacview/bin/bacview startPlace a .env file next to the release root to load environment variables at startup (see rel/env.sh.eex).
BacView.Application # strategy: :one_for_one
├── BacViewWeb.Telemetry
├── BacView.PubSub
├── BacView.Settings # runtime_settings.json
├── BacView.LogStore # in-app log ring buffer (+ optional file)
│
│ # when config :bacview, start_bacnet: true (default; tests set false):
├── BacView.BACnet.Cache # named ETS tables
├── BacView.BACnet.Stack # supervisor (see below)
├── BacView.BACnet.ForeignRegistration # BBMD foreign device re-registration
├── BacView.BACnet.Discovery # Who-Is / I-Am
├── BacView.BACnet.SubscriptionManager # COV subscribe / renew / notification log
├── BacView.BACnet.NotificationClassRecipient
├── BacView.BACnet.AlarmEvent # GetAlarmSummary + event notifications
├── BacView.BACnet.NetworkNumber # What-Is / Network-Number-Is (NPDU)
│
│ # always started (also when start_bacnet: false):
├── BacView.BACnet.DeviceRegistry # Registry :unique → DeviceSession
├── BacView.BACnet.DeviceSessionSupervisor # DynamicSupervisor → DeviceSession
│
├── BacViewWeb.Endpoint
└── # desktop only (BACVIEW_DESKTOP=1 compile):
├── ElixirKit.PubSub
└── Task (broadcasts ready:http://… to the desktop shell)
BacView.BACnet.Stack (child supervisor):
Stack
├── Stack.Boot # GenServer: start/restart/monitor runtime
└── Stack.Runtime # started later via Boot.start_runtime/0
├── Transport.* # IPv4 or MS/TP (named TransportLayer)
├── Segmentator # bacstack segmentation
├── SegmentsStore
└── Client # bacstack client (named ClientStack)
Notes:
- BACnet domain processes (Cache through NetworkNumber) start only when
config :bacview, start_bacnet: true. Tests setstart_bacnet: falseto avoid UDP. - DeviceRegistry + DeviceSessionSupervisor always start so session APIs stay available even with BACnet offline.
- The stack Runtime (transport + client) is not started inside
init/1. After the root supervisor is up,ApplicationcallsStack.Boot.start_runtime/0. Invalid settings leave the app running with BACnet offline; settings can be fixed and the stack restarted from the UI (Stack.restart/0). Stack.Runtimeuses:one_for_alland is registered as a temporary child ofStackso a crash does not loop forever; Boot monitors it and exposesstatus/last_error.- After the root supervisor starts,
LogStore.attach/0installs a:loggerhandler for the in-app viewer.
| Layer | Modules | Role |
|---|---|---|
| Settings / platform | Settings, LogStore, Platform, Timezone |
Persisted stack config, log buffer, desktop vs web |
| Stack / transport | Stack, Stack.Boot / Runtime, Transport.*, Client, TransportResolver |
bacstack client, IPv4/MS/TP, APDU segmentation |
| BBMD / foreign device | ForeignRegistration |
Register with remote BBMD; TTL re-registration |
| Network layer | NetworkNumber |
Local network number, What-Is-Network-Number / Network-Number-Is |
| Discovery | Discovery, IAmCollector |
Who-Is / I-Am, device list + share ETS |
| Per-device session | DeviceSession, DeviceSessionSupervisor, DeviceRegistry |
Load/scan device, object cache, property read/write, scan recovery |
| Property IO | PropertyLoad, Protocol.PropertyReader / PropertyWriter, ObjectScanRead |
RPM first, individual ReadProperty fallback, writes, scan fallback |
| Validation recovery | ValidationSkipStore |
Persist skip modes after scan recovery |
| Subscriptions / COV | SubscriptionManager, Subscription |
COV subscribe, auto-renew, notification log |
| Alarms / events | AlarmEvent, ActiveAlarms, NotificationClassRecipient |
Poll + live events, active lists, NC recipient enrollment |
| Hierarchy | HierarchyBuilder, NameHierarchyBuilder, NameHierarchyCache, HierarchySplit |
Structured View + name-split trees |
| Device services / files | DeviceServices, FileTransfer, EdeExport |
Time sync, DCC, reinit, AtomicRead/WriteFile, EDE |
| Protocol helpers | Protocol.* (formatters, charts, trend log, schedules, …) |
Display, export, chart payloads |
| Web | BacViewWeb.Live.*, components, helpers |
LiveViews, tables, popups, charts |
Primary UI routes:
| Path | LiveView |
|---|---|
/ |
DashboardLive |
/devices/:device_id |
DeviceLive |
/devices/:device_id/objects/:type/:instance |
ObjectLive |
Domain logic lives under lib/bac_view/bacnet/; UI under lib/bac_view_web/. Runtime BACnet state uses ETS (BacView.BACnet.Cache and a few owner-created tables) and JSON settings (BacView.Settings) - no Ecto for domain data.
Full device scan (DeviceSession load/reload): device object → object list → per-object scan → hierarchy. Progress on PubSub "device:#{id}:load_progress".
Single-object properties (DeviceSession.read_properties → PropertyLoad → PropertyReader):
- Prefer RPM (
read_object/ ReadPropertyMultiple withread_level: :all). - On segmentation/buffer-style failures → individual concurrent
ReadProperty(default concurrency 8,BACVIEW_PROPERTY_READ_CONCURRENCY). - Validation skip mode (from scan recovery) is applied via bacstack
object_optson the normal path - it does not force the scan path alone. - On certain hard failures →
ObjectScanReadfallback (same individual-read style as step 2).
Individual property progress is broadcast on "device:#{id}:properties_progress" and shown in the object detail UI.
Some properties are treated as heavy: large or expensive lists that can stall the UI for a long time if each element (or the whole list) is fetched with individual ReadProperty calls. The behaviour depends on the load path:
| Path | Heavy properties |
|---|---|
RPM success (read_object / :all) |
Included in the object property table. Values were already returned in the RPM response, so they are kept for display and debugging (e.g. object_list, bindings, COV subscription lists). |
| Any individual / fallback path | Not read at all — removed from the candidate list before ReadProperty is issued. They do not appear in the UI and are not requested from the device. |
This applies to:
- Object property view when RPM fails and BacView falls back to per-property reads
- Schema /
property_listfallback when the device has no usable property list ObjectScanRead/ scan-style map loads used during device scan and hard-error recovery
Examples of heavy identifiers (see PropertyReader.heavy_properties_for/1 for the full list):
- Device objects:
object_list,structured_object_list,device_address_binding,active_cov_subscriptions, slave/manual slave bindings, time-sync / restart notification recipient lists,configuration_files, andproperty_listitself - Trend Log / Trend Log Multiple:
log_buffer(andproperty_list) - All other object types:
property_listonly (used only to discover which properties exist; not shown as a row)
Practical effect: if a device supports RPM well, open the Device object (or any object loaded via RPM) and heavy lists show up like any other property. If the device forces the individual path, those rows are simply missing — BacView is not hiding a value it already has; it never asked for them, so discovery and object loads stay usable on limited devices.
Owned by BacView.BACnet.Cache at startup:
:bacview_devices, :bacview_device_share, :bacview_objects, :bacview_properties,
:bacview_subscriptions, :bacview_hierarchy, :bacview_name_hierarchy, :bacview_events,
:bacview_validation_skip_modes
Created by other processes (still cleared with device data via Cache.clear_all_device_data/0):
| Table | Owner |
|---|---|
:bacview_cov_notification_log / :bacview_cov_notification_seq |
SubscriptionManager |
:bacview_notification_log / :bacview_notification_seq |
AlarmEvent |
:bacview_nc_recipients |
NotificationClassRecipient |
Web code must not open subscription ETS directly - use SubscriptionManager APIs.
| Module | Status |
|---|---|
BacView.BACnet.Transport.IPv4 |
Production-ready (BACnet/IP UDP) |
BacView.BACnet.Transport.MSTP |
Available when circuits_uart / MS/TP stack is present; experimental |
BacView.BACnet.Transport.BACnetSC |
Stub for future BACnet/SC (WebSocket) |
Transport selection and network interface are configured in the dashboard sidebar (persisted settings).
mix precommit # unlock unused deps, compile -Werror, format, credo, dialyzer, testBACnet is disabled in test (config/test.exs: start_bacnet: false) to avoid UDP port conflicts.
See project license.