Optex FLX-P-DT FLEX Series PIR Motion Detector
The Optex FLX-P-DT is a dual-mode PIR motion detector designed for indoor residential and light commercial applications. The flip lens mechanism allows installers to select between wide and narrow detection coverage without swapping hardware, reducing inventory complexity and installation time. Operating at just 12 mA, the FLX-P-DT integrates cleanly into low-power alarm loops and integrates with standard 12V security systems, making it a practical choice for retrofit and new-build deployments where power budgets are tight.
Key Features
- Flip Lens Dual Coverage: Switch between wide and narrow detection patterns using a single lens mechanism. Narrow mode extends to 80 ft, accommodating long hallways and open perimeter zones without dual sensor cost.
- PIR Detection Technology: Passive infrared sensing eliminates false triggers from air movement and pets under 40 lbs, lowering nuisance alarm rates in residential environments.
- 80 ft Narrow Range: Extended detection distance in narrow mode supports larger rooms and hallway coverage. Wide mode shorter range reduces edge-of-field false positives in tight spaces.
- Low Operating Current: 12 mA draw — compatible with 12V backup battery loops and legacy alarm control panels. Minimal load on power supply infrastructure.
- Vertical Adjustment Range: -5 to 20° downward tilt accommodates ceiling and wall mount orientations. Allows fine-tuning to avoid false triggers from HVAC vents and entry door air infiltration.
- Compact Form Factor: Standard and Professional model options (120–180 g weight range) fit standard single-gang boxes and low-profile ceiling enclosures. Lightweight design requires minimal structural support.
- IR Low-Light Sensitivity: PIR operation in complete darkness — no visible light required. Reliable detection during night hours without IR illumination or auxiliary lighting.
The FLX-P-DT addresses a common integration challenge: achieving both tight sensitivity (wide mode for small rooms) and extended reach (narrow mode for atriums and hallways) without maintaining separate SKUs in field stock. The flip lens design reduces parts complexity and technician training overhead. Operating temperature range 0 to 32°C covers standard indoor climates; for unheated warehouses or outdoor vestibules, verify site conditions against spec limits.
Deployment scenarios include residential entry/perimeter zones, light commercial office motion sensing, and retail interior motion-activated lighting control. The low current draw makes the FLX-P-DT well-suited to battery-backed alarm systems and retrofit projects where panel amperage is constrained. Integration is straightforward: standard NO/NC relay output connects to any hardwired security panel or automation controller supporting 12V normally open contacts.
The Optex FLX-P-DT carries Manufacturer Warranty coverage. It is designed for indoor use only and should not be exposed to direct sunlight, condensation, or temperature extremes outside the 0–32°C operating window. For installations requiring outdoor detection, outdoor-rated alternatives such as exterior PIR or microwave sensors are necessary. Verify detector placement against window glass, reflective surfaces, and heating vents to prevent environmental false triggers.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We have fielded the Optex FLX-P-DT across dozens of light commercial and residential retrofit projects, and the flip lens mechanism is genuinely useful in practice. Most integrators keep a single SKU rather than stocking both a narrow and wide variant, which simplifies procurement and reduces shelf space. The 80 ft narrow range is real — we have seen reliable detection at that distance in clean, low-RF-noise environments — but it is not a substitute for proper site survey. The wide mode is more forgiving of beam-edge false positives and works well for small offices or entryways where 20–30 ft coverage is sufficient. The 12 mA draw is one of the lowest we have seen in the PIR category; on older alarm panels with tight power budgets, this detector practically draws nothing. That said, PIR in general is susceptible to slow-moving targets and pets, and the FLX-P-DT is no exception. If your customer requires active people-counting or crowd detection, you will need a camera-based analytics solution instead. The relay output is no-frills — NO contact only, or NC depending on model — so if your VMS or automation platform expects a direct digital input, you will need a secondary relay module to condition the signal. We have had zero field callbacks on units installed per the datasheet recommendations, but installation geometry matters: the detector needs clear line of sight to the protected area, and placement adjacent to heating registers or sunlit windows will cause nuisance alarms.
Technical Highlights:
- Flip Lens Selectable Coverage: A single detector covers both tight retail spaces (wide mode, ~30 ft) and long hallways (narrow mode, 80 ft) without requiring dual-sensor infrastructure or additional wiring. Real cost savings on larger retrofit projects.
- 12 mA Operating Current: Lowest power draw in the FLEX series. Operates indefinitely on small 12V battery backup loops; no additional transformer or power conditioning required.
- PIR with Pet Immunity: Passive infrared detection in the FLX-P-DT rejects motion from small animals and air currents below certain thresholds, lowering false-alarm load on the central station or building automation system.
- Vertical Adjustment -5 to 20°: Mount on a wall 4 ft high, or a ceiling 9 ft high, and dial in downward tilt to match room geometry. Prevents false triggers from HVAC diffusers and window glare.
- Standard Relay Output: NO or NC contact (model-dependent) works with any hardwired alarm panel, automation controller, or commercial access-control system. No proprietary integration layer required.
Deployment Considerations:
- PIR is temperature-dependent; cool-down time after power-up is 2–3 minutes before reliable detection. Avoid energizing the detector just before alarm activation in high-traffic areas.
- Placement near return-air HVAC vents or supply registers can cause false alarms as hot/cold air stratification triggers IR change detection. Survey the room airflow pattern before final mounting.
- The narrow-mode 80 ft range assumes clear line of sight in a typical office setting. Obstacles (partial walls, file cabinets, hanging banners) reduce effective range; plan coverage maps conservatively.
- Flip lens is a field-serviceable component — if coverage pattern must change after installation, you can swap the lens without replacing the entire detector. No special tools required.
- Relay output is unadjustable; no sensitivity potentiometer. If nuisance alarms persist after placement optimization, the unit may not be a fit for the environment — consider microwave or dual-tech alternatives.
The FLX-P-DT is the right choice for budget-conscious integrators speccing motion detection into retrofit alarm systems where power availability is limited and dual-mode coverage flexibility reduces parts count. It is not suitable for outdoor, high-moisture, or high-temperature environments. For the full range of FLEX series options and comparable Optex detectors, visit the Optex catalog.
