Camden CM-331 Wired Touchless Switch with Built-in Door Control
The Camden CM-331 is a line-powered touchless switch engineered for hands-free door activation in access control installations. Unlike battery-dependent wireless switches, the CM-331 operates on 12–24 VAC/DC power, eliminating battery replacement maintenance cycles and delivering reliable motion-triggered access across building entries, loading docks, and healthcare facilities. The integrated Form C relay output (3 amps @ 30VDC) controls up to three magnetic locks or electric strikes per unit without requiring a separate door-control relay — a significant labor and cost savings in retrofit projects where panel space is constrained or new wiring runs are cost-prohibitive.
Key Features
- 12–24 VAC/DC Line Power: Eliminates battery replacement cycles and compatibility issues with older 30VDC legacy systems. Single unit draws 40mA, leaving adequate headroom on standard access control supplies.
- Built-in Form C Relay (3A @ 30VDC): Controls up to 3 doors per switch without external relay modules. Wire multiple CM-331 units in parallel to expand capacity beyond three doors.
- IR Motion Sensing (1–28 inches standard; up to 72 inches in auto-range mode): Detects hands and bodies through standard glass and acrylic enclosures. Mount height 36–48 inches above floor for optimal detection reliability.
- Three Motion Modes: Momentary activation (pulse), Momentary with Alarm (timed alert on non-activation), or Maintained/latching operation for extended door-hold scenarios.
- REX and Door-Position Inputs: Integrates with existing door-status sensors and request-to-exit circuits. Wiring harness supports chaining with magnetic locks, electric strikes, and monitoring contacts.
- Mounting Flexibility: Wall-, pendant-, or recessed-mount options. Black polycarbonate standard; stainless steel faceplate available for food-processing, healthcare, or corrosive-environment installations.
- Optional Wireless Transmitter (CM-TX99): Retrofit touchless activation to existing wireless access control systems without running new power or signal lines. Pair with CM-TX99 for temporary or emergency egress routes.
- Manufacturer Warranty: Factory-backed coverage on switch mechanism and relay contacts.
The CM-331 solves a widespread retrofit problem: integrating touchless activation into older access control panels without major rewiring or panel upgrades. In healthcare and food-processing environments, hands-free operation reduces cross-contamination risk during entry and exit cycles. The built-in relay means one less piece of hardware in the cabinet — a real advantage when panel real estate or power-supply amperage is tight. The switch accepts door-position feedback, so you can log activation events and detect prop-open conditions within your access control software.
Deployment scenarios include ADA-compliant egress in offices and retail (motion triggers automatic unlock for wheelchair and mobility-device users), hands-free entry at loading docks and warehouse receiving (operators carry packages or pallets), emergency-egress routes in hospitals and long-term care (reduces contact surfaces during pandemics), and food-prep areas where gloved workers need tool-free door passage. Relay hold time is configurable (momentary pulse or 1–60 second maintained), so you can tune activation duration to match your door-closer and strike-release cycle.
Integration is straightforward on any access control system with 12–24 VDC power and 40mA capacity. The switch outputs Form C contacts (Normally Open, Normally Closed, and Common), allowing you to wire it as a simple NO momentary for electric strike release or as part of more complex door-state logic. ONVIF-style integration is not applicable (this is not an IP device), but event logging through door-sensor circuits is compatible with Genetec, Milestone, and proprietary NVR event inputs if your access control panel bridges to video.
The CM-331 is factory-new, genuine hardware with a manufacturer warranty covering relay contacts and motion-sensing electronics. Stainless steel models are available for environments where galvanized steel or aluminum housings corrode or are aesthetically unacceptable. If your existing wiring infrastructure is wireless or you need retrofit activation without adding new 24VDC runs, pair the CM-331 with the optional CM-TX99 wireless transmitter — this unlocks temporary or emergency egress scenarios without permanent installation.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
In our experience, the CM-331 fills a critical gap in retrofit access control: most integrators we know have sat in a pre-bid meeting where the customer says, "We need hands-free doors for ADA compliance, but we can't tear open walls for new wiring." The CM-331 solves that without infrastructure redesign. Because it's line-powered on the same 24VDC bus as the rest of the panel, there's no battery-swap maintenance nightmare — a real advantage in multi-door installations where you might be servicing 40+ switches across a campus. The built-in relay is the hidden win: instead of speccing a separate door-control relay module, you just wire the switch output directly to your strike or magnetic lock. On a 20-door retrofit, that's tangible labor and parts cost savings. We've also found that healthcare facilities especially appreciate the hands-free germ-reduction story — but the operational benefit is that motion sensing eliminates the "button push" failure mode; fewer service calls means lower TCO.
Technical Highlights:
- Form C Relay (3A @ 30VDC): Supports up to three magnetic locks or electric strikes per unit without external amplification. Most standard 30VDC strike releases draw 1–2A, so you can confidently wire three of them to one CM-331 relay. Holding power is maintained for 1–60 seconds (configurable), so door-closer cycles complete before the relay drops.
- IR Motion Sensing (adjustable 1–28 inches or 6–72 inches auto-range): Detects through glass and transparent acrylic, but not through opaque barriers. In our installations, standard 1–28 inch range covers most door openings when mounted at 42–48 inches; auto-range mode is useful for high-traffic areas or recessed mounting where detection distance varies with approach angle.
- 12–24 VAC/DC Input (±10%): Works on legacy 30VDC panels and modern 24VDC supplies without jumpers or converters. 40mA draw is negligible on any commercial access control power supply, even older 2–3 amp units.
- Momentary, Momentary with Alarm, and Maintained Modes: Momentary is standard for electric strikes (pulse opens the strike, door closer pulls it shut). Maintained (latching) is useful for magnetic locks on heavy doors or for accessibility scenarios where you want to hold the lock open for 5–10 seconds. Alarm mode sends a local buzzer signal if no activation is detected within a timeout window — valuable for detecting sensor failure.
- REX and Door-Status Integration: The switch accepts wired REX and magnetic door-position inputs, allowing you to interlock it with existing door-monitoring circuits. If your access control system logs events through dry-contact inputs, the CM-331 can feed activation and fault events upstream.
- Optional CM-TX99 Wireless Transmitter: For temporary egress routes or areas where you can't run new 24VDC, the plug-in wireless module converts the CM-331 to a wireless transmitter. Useful for emergency exits or load-dock seasonal access where permanent wiring isn't justified.
Deployment Considerations:
- Mount height and approach angle matter: motion detection is most reliable when the switch is 42–48 inches above the floor and the user approaches perpendicular to the faceplate. Test your detection range before finalizing mount location, especially if the switch will be recessed into a wall or mounted on a pedestal.
- Relay contact rating is 3A @ 30VDC — standard for magnetic locks and strikes, but verify your specific lock or strike draws within that spec. If you're controlling high-current loads (heating elements, LED illuminators, or multiple heavy-duty strikes), you'll need to add an external relay or power amplifier.
- Wire gauge for power and output should be 18–16 AWG for runs under 50 feet; if your panel is more than 50 feet from the switch, use 14 AWG to minimize voltage drop, especially on 12VDC systems. Voltage drop on 40mA is minimal, but the output relay contacts are sensitive to supply sag.
- Outdoor or high-humidity mounting: stainless steel faceplate is essential in salt-spray, food-processing, or frequently hosed-down environments. Polycarbonate is fine for typical commercial interiors but can degrade in direct sunlight or harsh chemicals.
- False activations are rare, but auto-range mode (6–72 inches) can pick up movement in hallways adjacent to the door. If nuisance triggers occur, dial back to standard 1–28 inch range or adjust motion sensitivity — most panels allow switch-level tuning in the access control software.
The CM-331 is the right choice for integrators and end-user facilities teams who need retrofit hands-free activation without infrastructure rebuild, healthcare providers focused on cross-contamination reduction, and any multi-door environment where battery maintenance cycles are unacceptable. For more options and integration guidance, explore the Camden catalog.
