Devices
Tags
A Tag is a small wearable device carried by a person on site. Tags emit a signal that is detected by nearby base stations, enabling the system to track proximity events. Each tag has a unique serial number and can be assigned to a person (staff or visitor). Tags are categorized into two roles:- Pedestrian — A person on foot near a machine (the most common safety concern)
- Operator — A person operating a machine (tracked for acknowledgment metrics)
Base Stations (PWS)
A Base Station, also called a Proximity Warning System (PWS), is a unit installed on a machine (excavator, crane, truck, etc.). It detects tags in its vicinity and reports incursion events. Base stations track:- Proximity events (incursions) with nearby tags
- GPS location of the machine
- Ignition state and runtime hours
- Video feeds from connected cameras (where installed)
Safety events
Incursions
An incursion occurs when a tag enters the detection zone of a base station. This means a person has come within a defined proximity of a machine — a potential safety hazard. Incursions have two acknowledgment states:- Acknowledged — The machine operator acknowledged the proximity warning (pressed a button)
- Unacknowledged — The warning was not acknowledged, indicating higher risk
- Total incursions — All proximity events in a period
- Acknowledgment rate — Percentage of incursions that were acknowledged
- Incursions per runtime hour — Normalized safety rate accounting for machine usage
Testing
Tags must be tested regularly to ensure they are functioning correctly. A tag test simulates an incursion to verify the tag and base station communicate properly. The system tracks days since last test for each tag.Organizational structure
Projects
A Project is the top-level organizational unit. It groups related worksites together, typically representing a construction contract, client, or geographic region.Worksites (Sites)
A Worksite is a geographic area defined by a polygon or circle drawn on a map. Worksites belong to a project and define where safety monitoring is active. Incursions are associated with the worksite where they occur.Brands
A Brand represents a customer organization in SensorZone. Each brand has its own set of users, devices, projects, and worksites. Data is isolated between brands.People and assets
People Assets
A People Asset is a personnel record (name, employee ID, company, email). People assets are managed independently from tags, so you can:- Reassign a tag to a different person without losing history
- Track a person’s safety record across multiple tags
Machine Assets
A Machine Asset is a vehicle or equipment record (serial number, manufacturer, year, number plate). Like people assets, machine records are separate from the base station hardware.Data flow
- A tag enters the detection zone of a base station
- The base station reports the incursion through the data pipeline
- The event is processed, enriched with location and device metadata, and stored
- The dashboard displays the data in real time across all pages