Context
License Plate Recognition (LPR) lets a gate or garage open automatically when a registered vehicle approaches. This article explains what the system does, what hardware it needs, and what residents and staff can expect.
How it works
- A vehicle approaches the gate or garage.
- The LPR Bullet Camera detects the vehicle and captures its license plate.
- The AI Camera Gateway reads the plate characters locally, on-site, and sends the result to the controller.
- The controller checks the plate against the vehicles authorized for your property, including residents, staff, and active visitor passes.
- The controller grants or denies entry, and the event is logged in Door Releases with a snapshot and a one-minute video clip.
Access decisions typically happen within seconds of a successful read.
Required hardware
| Component | What it does |
|---|---|
| LPR Bullet Camera | Captures the vehicle and plate. Available in short-range (0 to 50 ft) and long-range (50 to 100 ft) models. |
| AI Camera Gateway | Processes plate recognition locally. Supports up to 10 cameras. |
| Two-door controller | Makes the access decision, triggers the gate, and sends the event log to the ButterflyMX OS. Required for every LPR installation, including logging-only setups. |
All three components must be on the same local network. Hard-wired Ethernet is required, with at least 6 Mbps of dedicated bandwidth per camera.
What you can do with LPR
- Authorize resident vehicles. Add plates individually, in bulk by CSV, or let residents manage their own vehicles.
- Give visitors vehicle access. Add a license plate to a visitor pass so an approved guest, contractor, or delivery driver drives straight in.
- Search and review activity. Search by full or partial plate number and view the captured image and video for each event.
- Use the cameras as security cameras. LPR cameras record continuously and stream live in the ButterflyMX OS, the same as any other ButterflyMX camera.
Good to know
- LPR continues to work during an internet outage as long as the local network remains operational, because the camera, gateway, and controller communicate over the local network. Event logs sync once connectivity is restored.
- If a plate cannot be read, residents can still use Swipe to Open in the ButterflyMX app.
- Camera placement has a direct effect on read performance. See the LPR Access Implementation Guide for placement, angle, distance, and site requirements.
- Third-party ONVIF cameras may be compatible, but they have not been tested for plate capture and read performance cannot be guaranteed. The ButterflyMX LPR Bullet Camera is strongly recommended for any camera capturing plates.