ANPR questions & answers
Answers for the systems around number-plate recognition.
Practical, vendor-neutral guidance for cameras, NVRs, VMS platforms, access control and metadata integrations.
These are general industry answers, not product support. Setting up ANPR Edge? Read the camera connection guide.
145 answers
Why is my Milestone XProtect LPR server CPU usage hitting 100%?
Check the installed LPR release, the camera workload and the recognition settings before changing codecs. High LPR server CPU usually means the server is decoding and analysing more video than it can handle, and the codec advice depends on the release: the 2024 R2 manual recommends JPEG, while the 2025 R2 manual recommends H.264, advises against JPEG and does not support H.265 for LPR.
XProtect LPR Administrator Manual 2024 R2 (page 29); XProtect LPR Administrator Manual 2025 R2 (pages 38 and 41)
Why does my Hikvision ANPR camera show video on a third-party NVR, but no license plates?
Video feeds and ANPR metadata are transmitted using completely different network protocols. While your third-party NVR can receive the standard video feed via ONVIF Profile S or RTSP, Hikvision transmits its license plate text and vehicle metadata using proprietary ISAPI or ISUP payloads that non-Hikvision NVRs cannot decode.
Hikvision ISAPI Event Notification Integration
Why does my ANPR camera capture plates perfectly during the day but fail completely at night?
Nighttime ANPR failures are overwhelmingly caused by "IR blooming" and slow shutter speeds. The camera's infrared light reflects too intensely off the retro-reflective coating of the license plate, turning it into a solid glowing white rectangle, while slow shutter speeds cause moving vehicles to severely blur in low light.
ANPR Watch: Minimising False Positives
Why is my Avigilon ACC/Unity LPR watch list CSV import failing?
Avigilon Unity and ACC require a very specific CSV formatting structure to successfully import a database of watch list plates. The most common cause of complete import failure is omitting the mandatory "Minimum Confidence" column, which tells the VMS how strict the OCR match must be before triggering a security rule.
Avigilon Unity Video Client User Guide - LPR Watch Lists
Can a Uniview (UNV) NVR perform Smart Plate Search with a third-party ANPR camera?
Check the exact recorder and how plate search is integrated. On the NVR516-64E-R-IM, the model whose specifications were checked, Uniview restricts Plate Comparison to UNV LPR cameras. The same specifications list NVR-generated video metadata for third-party cameras, but that is not proof that the recorder can search plate text from a third-party camera.
Uniview: NVR516-64E-R-IM specifications (Plate Comparison and Video Metadata)
How do I get Hikvision ANPR plate data via the HTTP API?
Use the event interface documented for your exact model and firmware. Hikvision's 7-series ANPR integration guide describes two routes: a persistent GET event stream from the camera, and camera-initiated delivery to a listening server you run. It is a historical guide and does not settle support in every newer firmware build, so confirm the route in the ISAPI documentation for your camera.
Hikvision: ANPR Camera Integration Solution for 7 series (sections 4.1.2 and 4.2); Hikvision: product-specific ISAPI documentation finder
Why did my Dahua ANPR HTTP API stop working after a firmware update?
Diagnose the exact device, firmware and request before assuming the API was removed. There is no documented evidence that Dahua removed local HTTP/CGI access from its ANPR cameras across the board: its Access ANPR camera manual documents a CGI Service setting, and a November 2024 ITC413-PW4D datasheet still lists CGI, HTTP and HTTPS. Neither guarantees every endpoint on every firmware.
Dahua: Access ANPR Camera Web Operation Manual V1.1.0 (System Service); Dahua: DHI-ITC413-PW4D series datasheet, 2024
Why does Avigilon LPR Performance Mode disable Face Recognition on AI NVRs?
Activating high-performance LPR heavily taxes the AI NVR's computational resources. To prevent frame dropping and maintain accurate plate reads on fast-moving vehicles, the system redirects all available processing power to the OCR engine, intentionally disabling conflicting analytics like Face Recognition.
Avigilon Unity Video - Setting up License Plate Recognition
Why are Wisenet WAVE LPR bookmarks playing back at the wrong time?
If clicking an LPR event bookmark in the Wisenet WAVE client jumps the video playback to a timestamp completely devoid of a vehicle, you are experiencing a severe clock synchronization mismatch. The VMS server and the edge cameras are operating on different clocks.
Hanwha Vision: Synch issue between playback time and camera time
Why does the Wisenet WAVE AI Plugin freeze or drop streams?
When utilizing the WAVE AI Plugin, adjusting the "AI Tracking Speed" too high exponentially increases the computational burden on the server. Setting the tracking speed to "Very Fast" for vehicles can severely reduce the number of AI streams the server can handle, leading to dropped frames and system freezing.
WAVE: How to Setup the AI Plugin
How do I configure Vaxtor VaxALPR events with Axis cameras?
To send license plate data from a Vaxtor on-edge application to third-party systems or local relays, you must utilize the Axis VAPIX/ONVIF event framework. This bridges the gap between the Vaxtor OCR engine and the Axis OS action rules.
VaxALPR On-Camera Axis Integration Guide
Why is my Nedap ANPR Lumo Wiegand output failing to open the barrier?
Check the Lumo's output mode, how plates map to credentials and the format the controller accepts. The ANPR Lumo has three Wiegand modes: Wiegand 26 sends a truncated value derived from a SHA-1 hash of the plate, Wiegand 64 encodes the characters, and Wiegand Matchlist sends an ID configured in the match list. A format mismatch is a common cause, but parity is not the only thing to check.
Nedap: ANPR Lumo Installation Guide v1.16 (sections 7.3.11 to 7.3.13)
Why is the ZKTeco LPR camera relay not opening a boom barrier?
When a ZKTeco camera detects a whitelisted plate but the boom barrier fails to open, the issue often lies in the wiring architecture. If you are integrating via Wiegand to a ZKTeco Security Relay Box (SRB) instead of direct GPIO wiring, you must ensure the camera is outputting an encrypted signal.
ZKTeco Security Relay Box Specifications
How many pixels are required for accurate license plate recognition?
Follow your recognition engine's documented plate-width and character-size requirements; 100 pixels across the plate is not a universal guarantee. Plate widths differ too: a US plate is exactly 12 inches (0.3048 m) wide and a standard EU plate is 520 mm, so the same camera density puts very different pixel counts across each.
NIST: SI units, length; Axis: License plate capture white paper
Can ONVIF Profile S send ANPR metadata?
Not as a standard way to deliver plate text. Profile S covers video streaming and basic events, not analytics metadata such as plate text or bounding boxes. ONVIF Profile T includes metadata streaming and Profile M standardises analytics metadata, but neither guarantees that the camera recognises plates or that the receiver understands and indexes the plate fields.
ONVIF: Profile T; ONVIF: Profile M
Does ONVIF Profile M guarantee that every camera can recognize plates?
No. It standardizes analytics interfaces rather than adding an OCR engine.
ONVIF Profile M
Can ONVIF Profile T carry metadata without Profile M?
Yes. Profile T includes metadata streaming.
ONVIF Profile T
Why does ANPR fail on crossing traffic but work on cars approaching the camera?
Sideways image motion produces more blur.
Axis: License plate capture white paper
Why are number plates blurred even on stationary vehicles?
Check focus before changing OCR settings.
AXIS Q1700-LE user manual
Can barrel-distortion correction change the area used for ANPR?
Yes. Image correction can change resolution and field of view.
AXIS P3265-LVE-3 user manual
Why does increasing camera gain make plate recognition worse?
Gain can add noise that obscures character edges.
XProtect VMS Administrator Manual 2019 R2
Why does extra sharpening make readable plates harder for OCR?
Artificial enhancement can distort character boundaries.
XProtect VMS Administrator Manual 2019 R2
Why does external strobe illumination create inconsistent images on another camera?
The other camera may need synchronized capture.
AXIS P1486-LE Global Shutter Camera user manual
Why does AXIS License Plate Verifier accept a plate that is not on the allowlist?
Character-tolerant matching can accept a similar plate.
AXIS License Plate Verifier user manual
Why does AXIS License Plate Verifier miss short personalized plates?
The configured minimum character count may exclude them.
AXIS License Plate Verifier user manual
Why does one Axis plate read produce New, Update and Lost events?
These are stages of one tracked vehicle, not necessarily separate visits.
VAPIX License plate verifier API
Why is vehicle direction missing from the first Axis LPR event?
Direction is undefined in the New event.
VAPIX License plate verifier API
Why can’t I install License Plate Verifier on my Axis camera?
Installation depends on the supported device and firmware combination.
AXIS License Plate Verifier product support
Does one AXIS License Plate Verifier license cover several cameras?
The support page specifies one analytics app license per camera.
AXIS License Plate Verifier product support
Why is the Axis license-plate tab missing in XProtect Smart Client?
The Axis search tab may be hidden.
AXIS Optimizer for XProtect user manual
Why does an Axis plate search stop at 5,000 results?
Optimizer documents a 5,000-result display limit.
AXIS Optimizer for XProtect user manual
Why does an AXIS Camera Station plate search result have no linked video?
The external data source needs a configured view to link data with recordings.
AXIS Camera Station Pro user manual
Why have old plate records disappeared from AXIS Camera Station Pro?
External data has its own retention setting.
AXIS Camera Station Pro user manual
Why does Axis Scene Metadata detect vehicles but contain no plate text?
The plate-text feature depends on License Plate Verifier being installed.
Axis Scene Metadata: Fusion tracker
Why does XProtect LPR ignore plates that look readable on screen?
The character-height range may exclude them.
Milestone: Configuring cameras for LPR
Why does XProtect recognize only fragments of a number plate?
Obstructions and an insufficient partial-recognition time span can cause incomplete results.
Milestone: Configuring cameras for LPR
Why does XProtect LPR reject a foreign plate but read local plates?
The relevant country or region module may not be active.
Milestone: Country modules
Why does XProtect’s generic country module fail to identify a plate’s country?
Generic symbol recognition is not equivalent to country identification.
Milestone: Country modules
Why does an XProtect match-list alarm fail after the plate is recognized?
A list match needs an associated event to trigger the intended workflow.
Milestone: Match lists, 2026 R1
How do I watch for an XProtect plate when one character is unknown?
Match lists support question-mark wildcard patterns.
Milestone: Match lists, 2026 R1
Why can’t I add another LPR camera even though XProtect records its video?
LPR needs its own camera license.
XProtect LPR licenses, 2026 R1
Why can’t I enable another XProtect country module?
You may have used the available country-module licenses.
XProtect LPR licenses, 2026 R1
Why are known XProtect LPR events missing from my search?
Search filters may exclude the events.
Milestone: Viewing LPR related content, 2026 R1
Why did importing a new XProtect match list remove existing plates?
The import may have used Replace instead of Add.
Milestone: Viewing LPR related content, 2026 R1
Why did an old XProtect LPR component stop writing logs after a Log Server upgrade?
A historical authentication change can block older components.
Milestone: Managing server logs
Why does a Hikvision entrance camera reject my allowlist spreadsheet?
Use the template exported by that camera.
Hikvision Intelligent Entrance ANPR Camera user manual
Why does a Hikvision allowlisted plate still fail to open the barrier?
Check the entry’s validity and its event linkage.
Hikvision H8 ANPR installation and configuration guide
Why does a Hikvision ANPR allowlist stop accepting more vehicles?
A model-specific list capacity may have been reached.
Hikvision H8 ANPR installation and configuration guide
Why is the same plate missing when it returns within a few minutes on an older Hikvision camera?
A repeat-plate filter may suppress the second read.
Hikvision IPC-H7 firmware release notes
Why does a Hikvision ISAPI request work on one ANPR model but fail on another?
Check the integration documentation for the exact product.
Hikvision model-specific ISAPI developer guide finder
Should I use HikCentral OpenAPI or camera ISAPI to retrieve ANPR events?
Choose the interface for the system holding the events.
Hikvision Integration Center
Why can my ANPR integration reach a local Hikvision camera but not one behind a changing remote address?
The connection method may not suit the deployment.
Hikvision Open Capabilities
Why does DSS show a Dahua camera online but omit its ANPR functions?
Check the device category and series used when adding it.
DahuaWiki: Add LPR camera to DSS Pro V8
Why does an ITC431 camera capture vehicles outside the intended lane?
Its default lane geometry may still be active.
DahuaWiki: ITC431-RW1F-IRL8 initial setup
Why is the live ANPR result panel empty even though my ITC431 is detecting plates?
Check whether the live result receiver is enabled.
DahuaWiki: ITC431-RW1F-IRL8 initial setup
Why do Dahua plate recordings exist but blacklist alarms never fire?
Recognition and list-alarm linkage are separate settings.
Dahua Network Video Recorder user manual
Why does my older Dahua recorder show plate results in different colours?
The colours can indicate regular, blacklist and whitelist classifications.
Dahua Network Video Recorder user manual
Why does a vehicle added to DSS still lack permission to enter a car park?
A vehicle record alone may not complete the parking authorization.
DahuaWiki: Parking Lot Entrance Management
Why are Dahua ANPR snapshots unavailable after a network outage?
Check whether local storage was configured and writable.
Dahua Access ANPR Camera user manual
Why does a Dahua access ANPR camera recognize an authorized vehicle but leave the barrier closed?
Check the barrier permission assigned to the vehicle or group.
Dahua Access ANPR Camera user manual
Why do Milesight MQTT plate notifications fail while HTTP notifications work?
Check MQTT support and topic settings for that model.
Milesight: Troubleshooting LPR Data Push Failure
Why does a Milesight camera’s ONVIF video work but its plate metadata never arrives?
Check the firmware and metadata transmission switch.
Milesight: Troubleshooting LPR Data Push Failure
Why did changing a Milesight camera to HTTP posting break plate search on its NVR?
The recorder expects the camera’s TCP posting mode.
Milesight: Causes of LPR Data Not Received by NVR
Can a Milesight camera send plates to an NVR and also notify an external HTTP service?
Use the separate HTTP notification mechanism described for events.
Milesight: Causes of LPR Data Not Received by NVR
Does a Milesight ANPR camera need an SD card to recognize plates?
Not for recognition, list matching and live posting.
Milesight: Answers to common LPR questions
Why does a plate added to a Milesight NVR allowlist not appear in the camera’s list?
The lists are separate stores.
Milesight: Answers to common LPR questions
Why does Milesight VMS Enterprise receive no plates until an external sensor is triggered?
The camera may be configured for alarm-input detection.
Milesight: VMS Enterprise ANPR Solution
Why are Milesight VMS Enterprise plate events visible but their playback clips missing?
Check recording and event-triggered channel settings.
Milesight: VMS Enterprise ANPR Solution
Why does enabling VMS analytics fail to produce camera-side Milesight ANPR results?
Confirm which device performs recognition.
Milesight: How to Set ANPR Solution
Why does my Milesight NVR omit a plate when the same vehicle returns shortly afterwards?
Repeat Plate Checktime can suppress it.
Milesight NVR user manual: ANPR
Why does a Milesight system alter or reject plate text with an unusual character count?
Inspect the plate-format rules.
Milesight NVR user manual: ANPR
Why can’t I install Wisenet Road AI on an ordinary Hanwha camera?
Road AI requires supported cameras supplied with the application.
Hanwha: Configure Road AI and integrate with WAVE
Why does a new Wisenet Road AI camera struggle with plates outside the USA?
Check its selected recognition region.
Hanwha: Configure Road AI and integrate with WAVE
Why does only one of several Road AI cameras send plate text to a Wisenet NVR?
Check each text integration’s port and channel mapping.
Hanwha: Road AI camera event setup for NVRs
Why do Road AI plate records appear under the wrong Wisenet NVR camera?
Check the text receiver’s channel assignment.
Hanwha: Road AI camera event setup for NVRs
Why do WAVE Road AI bookmarks contain plate numbers but no vehicle details?
Automatic bookmarks and Generic Events carry different information.
Hanwha: Generic events, bookmarks and rules with RoadAI
Why does a Road AI whitelist event arrive in WAVE without triggering the expected action?
Check the Generic Event description filter.
Hanwha: Generic events, bookmarks and rules with RoadAI
Why did Road AI or RoadWatch bookmarks stop after upgrading WAVE to 5.1?
An older integration may use the previous bookmark API.
Hanwha: Bookmarks no longer created after WAVE V5.1 upgrade
Why does changing the camera’s relay pulse duration fail to keep an ANPR barrier open longer?
The ANPR application can override the camera setting.
Hanwha: Increase pulse time for barrier operation
Why does RoadWatch fail to send LPR data to WAVE when the camera name contains spaces?
Check the documented RoadWatch camera-name issue.
Hanwha: RoadWatch LPR data in WAVE
Why does RoadWatch connect to WAVE video but fail to deliver plate events with my credentials?
Check the authentication configuration used by the application.
Hanwha: RoadWatch LPR data in WAVE
Why does a SharpV G3 fail when powered by an older SharpV PoE injector?
Verify its power source against the G3 requirement.
Genetec: SharpV cannot read plates at night
Why do SharpV HTTP events work but HTTPS events fail?
Check TLS certificate validation and endpoint trust.
Genetec: Configure SharpV HTTP/HTTPS extension
Why did SharpV anonymized plate identifiers change after a configuration change?
Check whether the anonymization salt changed.
Genetec: Configure SharpV HTTP/HTTPS extension
Why are only high-confidence SharpV reads reaching my HTTP receiver?
The extension may apply a confidence filter.
Genetec: Configure HTTP/HTTPS extension
Why did queued SharpV HTTP reads disappear when I disabled offline retention?
That setting can delete retained reads.
Genetec: Configure HTTP/HTTPS extension
Why does SharpV 14.5 Multi extension resend stored reads to Security Center but not to my HTTP server?
The documented Multi extension has different outage behaviour for its destinations.
Genetec: Configure multiple SharpV extensions
Can a SharpV 14.6 camera send different recognized plate datasets to different extensions?
Its extensions share the same ALPR data.
Genetec: About SharpV extensions
Why does AutoVu record NOPLATE events even though vehicles are being counted?
A vehicle trigger can occur without a readable plate.
Genetec: Investigating NOPLATE reads
Why does editing an AutoVu NOPLATE read change its confidence to 100?
That is the documented behaviour of a manual correction.
Genetec: Investigating NOPLATE reads
Why does SharpV read parked vehicles beyond my intended capture lane?
Check character-height limits and the recognition area.
Genetec: Low ALPR read rates or poor quality reads
Why did a legacy Patroller hotlist stop updating after its USB drive or source location changed?
The configured source path may no longer exist.
Genetec: Hotlist or permit list does not update automatically
Why does replacing a legacy Patroller hotlist file with new content fail to refresh the list?
Check the incoming file’s modification timestamp.
Genetec: Hotlist or permit list does not update automatically
Why does adding a plate to a Security Center hotlist fail to create hits for older reads?
Hotlist edits affect new reads; retrospective matching is separate.
Genetec: Editing hotlists
Why are AutoVu hotlist hits live on my map but ordinary plate reads are not?
The Web App displays them differently.
Genetec Web App: Monitor ALPR events on maps
What should I collect before reporting an AutoVu component connection failure?
Capture the component’s status and diagnostics.
Genetec: Checking AutoVu component status
Why does Patroller ignore older reads after I add a new wanted plate?
Past read matching may be disabled or its look-back period too short.
Genetec: Operation — Hotlists tab
Why doesn’t Patroller generate a second consecutive hit for the same plate?
Allow consecutive hits may be switched off.
Genetec: Operation — Hotlists tab
Why does UniFi recognize a plate but fail to unlock my gate?
Check the complete Protect-to-Access pairing and permission chain.
Ubiquiti: Configure License Plate Unlock
Why can a UniFi plate unlock the gate again sooner than its cooldown suggests?
Another unlock method can reset the relevant cooldown behaviour.
Ubiquiti: Configure License Plate Unlock
Why do UniFi AI Key results arrive minutes after the vehicle has passed?
The AI Key processes queued detection events.
Ubiquiti: AI Key setup and FAQs
Why are UniFi AI Key results missing during very busy periods?
Its event queue can reach capacity.
Ubiquiti: AI Key setup and FAQs
Why does changing a third-party camera’s stream resolution not change the streams used by UniFi AI Port?
The AI Port selects streams during adoption.
Ubiquiti: Protect AI Port FAQs
Why can’t I pair more third-party ANPR cameras with one UniFi AI Port?
Capacity depends on camera type and resolution.
Ubiquiti: Protect AI Port FAQs
Why does a G4 or G5 camera show vehicle detections but no plate recognition in Protect?
Vehicle detection and LPR have different hardware requirements.
Ubiquiti: Protect AI detections and recognition
Why does my UniFi AI 360 camera lack the plate-recognition option shown for other AI cameras?
The capability table excludes 360 models from that recognition feature.
Ubiquiti: Protect AI detections and recognition
Why does a Uniview HC121 camera miss plates viewed at a steep angle?
Check the model guide’s installation-angle limits.
Uniview: 2MP LPR Bullet Camera solution guide
Why does a short-focus Uniview HC121 entrance camera struggle with fast road traffic?
The lens and deployment may suit an entrance rather than a road.
Uniview: 2MP LPR Bullet Camera solution guide
Why do multiple unknown plates produce the same access-control ID from ANPR Lumo?
A configured No Match or No Plate ID may be in use.
Nedap ANPR Lumo installation guide
Why doesn’t a Nedap Lumo access-list pattern match plates such as NEDAP1234?
Enable regex processing and use the intended pattern syntax.
Nedap: Working with regular expressions
Why does VaxALPR on i-PRO read Latin plates but miss plates with small Arabic characters?
Check the character size against the manual’s format-specific guidance.
Vaxtor VaxALPR On-Camera i-PRO configuration manual
Why does VaxALPR on i-PRO fail to retain unsent plate messages locally?
Check its supported SD-card and extended-software storage setup.
Vaxtor VaxALPR On-Camera i-PRO configuration manual
Why does VaxALPR’s TCP connection close after sending one plate?
That can be the documented sender behaviour.
VaxALPR On-Camera Axis Software Developer’s Guide
Why do non-ASCII plate characters become corrupted in a VaxALPR integration?
Check the reporting template and receiver encoding.
VaxALPR On-Camera Axis Software Developer’s Guide
Why does VaxALPR merge two similar plate reads into one vehicle event?
Check repeat suppression and string-distance settings.
VaxALPR On PC user manual
Why does VaxALPR accept incomplete or low-quality plate text?
Inspect size and confidence thresholds.
VaxALPR On PC user manual
Why does VaxALPR produce no results when vehicles pass an otherwise clear camera view?
Check whether triggered recognition is waiting for an input.
Vaxtor VaxALPR On-Camera capabilities
Why does VaxALPR report approaching vehicles but ignore departing vehicles?
Check the direction filter.
Vaxtor VaxALPR On-Camera capabilities
Why does an HTTP Generic Event reach Nx Witness without triggering my alarm rule?
Event reception and rule matching are separate.
Network Optix: Create HTTP Generic Events
Why does a plate event create a bookmark on the wrong Nx Witness camera?
Check the device association sent with the event.
Network Optix: Create HTTP Generic Events
Why is Nx Witness plate or analytics search slow even when video playback is smooth?
Analytics metadata has its own storage workload.
Network Optix: Analytics usage limitations
Why does moving a camera between Nx Witness servers complicate historical analytics search?
Its metadata can span servers.
Network Optix: Analytics usage limitations
Why doesn’t a partial plate wildcard search behave as expected in Nx Witness?
Search syntax depends on the search area and field.
Network Optix: Search syntax guide
Why does a recognized plate fail to match an Nx Witness attribute search?
Check the attribute name and query syntax.
Network Optix: Search syntax guide
Why does my Nx analytics plugin create hundreds of duplicate objects for one vehicle?
The plugin may create a new object for every frame.
Network Optix: Metadata SDK implementation best practices
Why can my Nx plugin draw a plate box but users cannot search the plate text?
A bounding box alone does not supply searchable plate attributes.
Network Optix: Metadata SDK implementation best practices
Why do Plate Recognizer Stream webhooks stop arriving during an endpoint outage?
Check retry handling and cached delivery.
Plate Recognizer Stream configuration
Why can an old Stream plate event arrive after the network recovers and reopen a barrier?
Queued webhooks may be delivered later.
Plate Recognizer Stream configuration
Why does my Stream webhook parser fail when it expects a plain JSON request body?
The documented request is multipart.
Plate Recognizer Stream webhooks and output formats
Why is the plate bounding box misplaced when I overlay Stream results on the original image?
Check which image the coordinates refer to.
Plate Recognizer Stream webhooks and output formats
Why does Plate Recognizer Stream return plates a few seconds after the vehicle passes?
Processing and delivery can add delay.
Plate Recognizer Stream FAQ
Why does Stream lose incoming work when my webhook receiver is slow?
The processing queue can fill.
Plate Recognizer Stream FAQ
Why does Stream report STR0008 even though the camera plays in VLC on my computer?
Test camera reachability from Stream’s actual runtime.
Plate Recognizer Stream error messages
Why does Stream report STR0010 while recognizing plates?
Check access to its output or webhook-cache storage.
Plate Recognizer Stream error messages
Why is plate recognition unavailable on my Alta panoramic camera?
The cited Alta setup guide excludes panoramic cameras.
Avigilon Alta: configure an LPR camera
Why does Alta detect vehicles but miss plates when several cars occupy one LPR zone?
The zone may cover too much traffic.
Avigilon Alta: configure an LPR camera
Why does my H4 LPC scene look very dark even during daylight?
This dedicated capture camera is sensitive to IR rather than visible light.
Avigilon H4 LPC / ACC LPR 6 site design guide
Why does increasing my ACC LPR analysis rate fail to improve recognition?
Check the camera’s actual frame rate.
Avigilon H4 LPC / ACC LPR 6 site design guide
Why does Avigilon Player return no results for a partly remembered plate?
Check the search’s Match percent.
Avigilon Player 7 user guide
Why does my ACC watchlist generate too many false plate alerts?
Review the per-entry Minimum Confidence and its version-specific meaning.
ACC integration guide for Gallagher Command Centre
Why did Bosch IVA Pro LPR become inaccurate after I changed the camera position?
Reset the LPR calibration.
Bosch IVA Pro License Plate application note
Why does changing Bosch IVA Pro’s plate country fail to improve results immediately?
Reset calibration after changing the plate region.
Bosch IVA Pro License Plate application note
Why are cars following close together missed by a low-mounted Bosch LPR camera?
Check the installation geometry.
Bosch IVA Pro License Plate application note
Why does an E-LPRC500 return repeated reads while a vehicle waits over its virtual loop?
Stable recognition can output periodically while the vehicle remains present.
ZKTeco E-LPRC500 user manual
Why does an E-LPRC500 fail to recognize a vehicle until a ground loop activates?
External triggering may be selected.
ZKTeco E-LPRC500 user manual
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