> ## Documentation Index
> Fetch the complete documentation index at: https://docs.catenatelematics.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Electronic Logging Devices (ELDs)

> Understanding the hardware backbone of connected fleet data and HOS compliance

export const ProviderCountSnippet = () => <Callout icon="layer-group" color="#3b82f6" iconType="duotone">
    <p>
      Catena currently supports <strong>216 ELD providers</strong>. <a href="/get-started/supported-providers">See the list</a>.
    </p>
  </Callout>;

<Note>
  **Terminology:** You may see that we use "ELD" (Electronic Logging Devices) and "TSP" (Telematics Service Provider) interchangeably. While ELDs are the physical devices, TSPs are the companies that provide the platforms and services that collect and manage ELD data (like Samsara, Geotab, or Motive). In practice, when we refer to integrating with an "ELD provider," we mean the TSP that manages the ELD's data.
</Note>

An **Electronic Logging Device (ELD)** is a piece of hardware installed in commercial vehicles that automatically records key data about the vehicle's movement, engine activity, and driver behavior. While ELDs are best known for tracking [Hours of Service (HOS)](./hos) to meet regulatory requirements, they capture a wide range of telematics data that powers modern fleet operations.

<Check>
  **The Bottom Line:** ELDs are more than digital logbooks—they're full-fledged data devices that serve as the hardware backbone of connected fleet data.
</Check>

## Why Fleets Use ELDs

ELDs serve both regulatory and operational purposes, making them essential for modern fleet management:

<CardGroup cols={2}>
  <Card icon="gavel" title="Regulatory Compliance">
    Meet FMCSA ELD Mandate requirements and maintain accurate HOS records to avoid violations and fines.
  </Card>

  <Card icon="shield-check" title="Safety Monitoring">
    Track driver behavior, prevent fatigue-related accidents, and ensure compliance with driving hour limits.
  </Card>

  <Card icon="chart-line" title="Operational Efficiency">
    Monitor vehicle health, optimize routes, and automate reporting workflows like IFTA calculations.
  </Card>

  <Card icon="gauge" title="Real-Time Visibility">
    Track assets in real time, analyze driver performance, and improve dispatch efficiency.
  </Card>
</CardGroup>

<Info>
  **Regulatory Requirement:** The FMCSA ELD Mandate requires most commercial motor carriers and drivers to use ELDs to record driving time and duty status.
</Info>

## What ELDs Capture

Depending on the provider and device capabilities, ELDs capture comprehensive data from multiple sources:

<AccordionGroup>
  <Accordion title="Hours of Service (HOS)" icon="clock">
    * Driving time and duty status changes
    * Rest breaks and off-duty periods
    * HOS violations and warnings
    * Daily and weekly drive time totals
    * Available hours remaining
  </Accordion>

  <Accordion title="Vehicle Movement" icon="location-dot">
    * Real-time GPS location coordinates
    * Speed and acceleration data
    * Ignition status and engine state
    * Motion events and idle time
    * Trip start and end points
  </Accordion>

  <Accordion title="Engine Diagnostics" icon="engine">
    * Engine RPM and hours
    * Diagnostic trouble codes (DTCs)
    * Fuel consumption and levels
    * Odometer readings
    * Maintenance triggers and alerts
  </Accordion>

  <Accordion title="Driver Behavior" icon="user-check">
    * Harsh braking events
    * Speeding incidents
    * Rapid acceleration patterns
    * Idling duration
    * Seatbelt usage (some devices)
  </Accordion>

  <Accordion title="Trip & Stop Events" icon="route">
    * Trip summaries and duration
    * Stop locations and times
    * Geofence entries and exits
    * State-by-state mileage (IFTA)
  </Accordion>

  <Accordion title="Fuel Data" icon="gas-pump">
    * Current fuel level
    * Fill-up events and locations
    * Fuel consumption rates
    * Fuel card transaction integration
  </Accordion>
</AccordionGroup>

<Note>
  **Data Sources:** Some data points come directly from the vehicle's engine via the diagnostic port (OBD-II/J1939), while others are generated by the ELD firmware or cloud-based TSP services.
</Note>

## How ELD Data Flows

Understanding the data flow from vehicle to your application:

<Steps>
  <Step title="Data Collection" icon="microchip">
    The ELD device plugs into the vehicle's diagnostic port and continuously collects data from the engine computer, GPS module, and onboard sensors.
  </Step>

  <Step title="Cloud Transmission" icon="wifi">
    Data is transmitted via cellular connection to a Telematics Service Provider (TSP) like Samsara, Geotab, Motive, or Verizon Connect.
  </Step>

  <Step title="Provider Processing" icon="server">
    The TSP processes, stores, and makes the data available through their platform and APIs, often adding value-added analytics.
  </Step>

  <Step title="Catena Integration" icon="code">
    Catena aggregates and normalizes data from the ELD providers, making it accessible through a single, consistent API.
  </Step>
</Steps>

## ELD Data for Developers

If you're building tools for fleets—whether for compliance, safety, routing, or reporting—ELD data is often your most valuable source.

### Common Use Cases

<CardGroup cols={2}>
  <Card icon="clipboard-check" title="Compliance Management">
    Pull HOS records, track violations, and generate compliance reports for audits and inspections.
  </Card>

  <Card icon="truck-fast" title="Dispatch Optimization">
    Monitor driver availability in real time and optimize load assignments based on remaining drive time.
  </Card>

  <Card icon="triangle-exclamation" title="Safety Alerts">
    Trigger alerts based on driving behavior events like harsh braking, speeding, or HOS violations.
  </Card>

  <Card icon="file-invoice-dollar" title="IFTA Reporting">
    Automate fuel tax calculations using accurate state-by-state mileage data from ELDs.
  </Card>

  <Card icon="wrench" title="Maintenance Scheduling">
    Feed maintenance systems with live diagnostic trouble codes and engine hours for preventive service.
  </Card>

  <Card icon="chart-mixed" title="Performance Analytics">
    Analyze driver behavior, fuel efficiency, and vehicle utilization to improve fleet operations.
  </Card>
</CardGroup>

### Integration Benefits

With the right ELD integration through Catena, you can:

* **Track driver availability** in real time for better dispatch decisions
* **Access rich trip histories** with location, speed, and timing data
* **Monitor vehicle health** with live diagnostic codes and maintenance alerts
* **Automate compliance reporting** including HOS and IFTA calculations
* **Improve safety** with behavioral insights and violation tracking

## ELD Providers & Coverage

Catena integrates with the ELD and telematics providers, giving you access to the majority of the commercial fleet market:

<ProviderCountSnippet />

<Card icon="plug" title="View All Supported Providers" href="/get-started/supported-providers">
  Explore the complete list of ELD providers and available data fields for each.
</Card>

***

# Ready to Get Started?

<CardGroup cols={2}>
  <Card icon="rocket" title="Quick Start Guide" href="/get-started/quickstart">
    Get up and running in 10 minutes with our step-by-step integration tutorial.
  </Card>

  <Card icon="book-open" title="API Reference" href="/api-reference">
    Explore all available endpoints, parameters, and response formats.
  </Card>

  <Card icon="user-plus" title="Get API Credentials" href="/get-started/getting-access">
    Request access to start building with the Catena Telematics API.
  </Card>

  <Card icon="plug" title="Supported Providers" href="/get-started/supported-providers">
    Browse the telematics providers available through our platform.
  </Card>
</CardGroup>