Directed 508D Dual-Zone Field Disturbance Sensor

The Directed 508D is a dual-zone field disturbance sensor designed to add proximity and interior-intrusion detection to a compatible vehicle security system. It creates adjustable sensing fields that react to moving high-density objects near and within the protected area. This makes it a practical security accessory for vehicles where conventional door and shock triggers do not provide perimeter coverage.

The 508D is especially suited to convertibles, removable-top vehicles, and other applications where open-cabin protection is useful. Its outer field can provide a pre-warning response before an object reaches the inner protected field. The inner field is intended to activate a connected system's full alarm response when intrusion is detected closer to or inside the vehicle.

Detection is based on RF field-disturbance technology operating at 2.4 GHz rather than ultrasonic sensing. The sensor responds to movement by high-density objects and is designed not to react to wind or rain. Its field can extend through upholstery, glass, plastic, and wood, while metal blocks the field.

Separate negative-trigger outputs support two stages of security-system response. The green wire provides a short pre-warning output for the outer field, while the blue wire provides a longer full-alarm output for the inner field. Built-in status LEDs indicate which field has detected motion during setup and testing.

The 508D fits into an alarm upgrade path for compatible Directed systems and other security systems able to accept appropriate trigger connections. It can interface with a Directed system that offers a multiplex input for perimeter-intrusion response, or with an optional 516U Vocalarm module. Field size is adjustable, allowing the installer to tune coverage for the vehicle and installation location.

Key Features

• Dual-Zone Detection: Provides separate outer warning and inner alarm sensing areas.
• 2.4 GHz RF Technology: Detects moving high-density objects using field disturbance.
• Convertible-Friendly Coverage: Adds protection where open-cabin security is needed.
• Adjustable Fields: Lets the installer tailor outer and inner coverage.
• Separate Trigger Outputs: Supports pre-warning and full-alarm system responses.
• Status LEDs: Green and red indicators assist with adjustment and testing.

Design & Installation

The 508D uses a compact wired sensor module with separate power, ground, pre-warning, and full-alarm connections. Its RF sensing field is designed to pass through common non-metal cabin materials, including upholstery, glass, plastic, and wood, but is blocked by metal. The unit can be mounted directly to metal when required.

Mount the sensor along the vehicle centerline, commonly beneath a center console or armrest, while keeping its adjustment controls accessible. Connect red to constant +12V, connect black to ground or an armed-output ground as appropriate, and connect the green and blue negative-trigger outputs to the compatible security system. Adjust the combined outer/inner field first, then adjust the inner field; the sensor has a 10-second activation delay after power is applied.