Comelit 2738W Mini Handset Simplebus 2 Push Button
The Comelit 2738W is a compact two-button mini handset designed for Comelit Simplebus intercom systems. This wall-mounted unit (7.52" H × 4.13" W × 1.1" D) provides door-call and auxiliary function buttons in a form factor that fits tight entry-door installations, residential lobbies, and small commercial corridors where panel real estate is limited. Two-way audio and direct Simplebus wiring integration mean straightforward installation without system reconfiguration or additional gateways.
Key Features
- 2-Button Configuration: Call button for door entry audio and auxiliary button for secondary functions (gate opener, switchboard call, or custom logic). Each button is independently programmable via DIP switch user code assignment.
- Mini Form Factor: 7.52" H × 4.13" W dimensions fit tight doorway and lobby installations. Wall-mount surface or flush depending on frame and trim configuration.
- Simplebus Direct Integration: Terminal connector article 1214/2C hardwired to Simplebus bus — no reconfiguration of main system or handset firmware needed when adding or replacing units.
- Two-Way Audio: Full-duplex conversation between door entry and handset without dead-air delays or half-duplex switching overhead.
- Privacy Mode Toggle: 3-position selector controls call volume and privacy mode (LED indicator shows privacy active). Mutes incoming audio while allowing outbound talk.
- Bus-Powered Operation: Draws power directly from Simplebus 2 bus via 1214/2C connector — no separate power supply or outlet required at the handset location.
- DIP Switch User Code Assignment: 8-position DIP switch lets system recognize individual handset identity on the bus — up to 256 unique device addresses without collision.
- Compact Wiring: Single twisted-pair Simplebus connection simplifies rough-in — no separate audio, video, or control lines to route.
The 2738W is purpose-built for Simplebus 2 mixed audio/video intercom architectures where you need a secondary or expansion handset without adding panel complexity. Its compact size and direct bus integration make it ideal for retrofit installations where existing Simplebus controller and door hardware are already in place — you simply wire the 2738W into the nearest Simplebus junction and assign its DIP code.
Simplebus systems are widely deployed in European residential complexes, small commercial buildings, and multi-unit apartment entries. The 2738W fills the role of a lightweight, no-configuration call station that reduces intercom clutter at the entry door itself. Unlike full-featured video panels, it offers audio-only transparency — residents hear the door caller and can buzz the gate or door lock without visual confirmation. This is operationally acceptable in single-entry lobbies, service entrances, or secondary access points where video verification is handled by a main panel elsewhere in the building.
Installation is straightforward: verify your Simplebus 2 main panel and controller support standard handset protocol (nearly all Comelit Simplebus controllers do), identify an available Simplebus junction point or drop near the target location, run twisted-pair cable, crimp the 1214/2C connector, and set the DIP user code to match your system's address scheme. White housing (finished plastic, not custom anodize) blends into standard door frames. The unit draws approximately 2W at idle from the bus and <5W when in active call, so power budget impact on the main controller is negligible even with multiple handsets.
Comelit manufactures the 2738W in Vietnam and backs it with a 2-year warranty covering defects in materials and workmanship. It is ONVIF-agnostic (as a legacy Simplebus node, it does not expose IP endpoints) and requires no VMS integration — it is a pure intercom device. If your facility runs Comelit's IP-based intercom systems (KVM series, VIDS, or ViP cloud platform), the 2738W is not compatible; those deployments require IP handsets. Integrators should verify current manufacturer support status and spare parts availability before committing to stock, particularly in North American markets where Simplebus deployment has declined in favor of IP-based intercom.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've installed the Comelit 2738W primarily in retrofit scenarios — existing Simplebus 2 buildings that needed a secondary or replacement handset without replacing the main panel. The real operational advantage is simplicity: because it's pure Simplebus wiring with no IP stack, no firmware updates, and no network configuration, it just works once the DIP code is set. That said, Simplebus is a legacy protocol in North America, and the 2738W's market is essentially limited to European installations and aging mixed buildings where you're maintaining Comelit infrastructure rather than upgrading it. We've seen it spec'd into retrofit projects where the client wants to move the handset from one door to another door on the same bus — because there's no reconfiguration overhead, the labor is just cable run and DIP switch assignment. In new-build or comprehensive refresh scenarios, integrators are moving away from Simplebus entirely toward IP-based intercom (Comelit KVM or ViP), where you get video, mobile app integration, and cloud-based event logging. The 2738W doesn't compete on capability — it competes on "I already have Simplebus, I need a second handset, and I want zero system touching." That's a real use case, but it's shrinking.
Technical Highlights:
- DIP Switch User Code Assignment (8-position): Each 2738W gets a unique address on the Simplebus logical bus. No firmware flashing, no terminal command strings — flip DIP switches, power cycle, and the system sees it as a distinct device. Operationally, this means you can add or swap units on an existing Simplebus network without touching the main controller or any handset configuration files.
- Bus-Powered Design (2–5W draw): Single twisted-pair Simplebus connection supplies both signaling and power. Reduces cable runs to one pair per handset and eliminates need for PoE injectors or separate 12V DC supply at the door. On a 16-handset installation, that's 15 fewer power distribution points to maintain.
- Two-Way Full-Duplex Audio: Simplebus uses a time-division protocol that delivers simultaneous talk and listen without half-duplex gating. The 2738W's speaker and microphone are always live during an active call — no "over" button, no dead-air switching delay. Residents experience natural conversation pacing with the door visitor.
- Privacy Mode Toggle (3-Position Selector): Residents can mute incoming call audio while still being able to speak to the visitor. The red LED signals privacy is active. This is table-stakes for residential intercom, but the 3-position selector (off, normal, privacy) is straightforward and requires zero menu navigation.
- Compact Mini Form Factor (7.52" H × 4.13" W): Fits standard single-gang or narrow-frame openings at apartment doors and service entrances. Flush or surface mount. In multi-unit residential retrofits, this form factor reduces aesthetic clutter versus full-size panel units.
Deployment Considerations:
- Simplebus 2 is a closed proprietary protocol — it does not interwork with IP intercoms, IP surveillance, or modern VMS platforms. If your facility plans to migrate to IP-based security within 3–5 years, the 2738W is a stranded investment. Consider Comelit KVM IP handsets for new deployments or comprehensive refreshes.
- The 1214/2C connector is Simplebus-specific. Cable termination requires the correct connector; mis-terminated cable will not power or communicate the handset. Verify the cable and connector type match your existing Simplebus runs before installation.
- DIP switch user code assignment is permanent once set — there is no default or fallback ID. If you swap a 2738W into an existing position without matching the original DIP code, the system will see it as a new device and the old address space may remain orphaned in the main controller's address table. Document the user code for each handset location before installation.
- Simplebus 2 maximum cable run is typically 500–800 meters depending on wire gauge and bus loading. If your Simplebus drop is at the physical edge of the network, adding a 2738W may degrade audio quality on existing handsets due to impedance loading. Run a continuity and voltage test on the Simplebus pair before committing.
- White plastic housing is not UV-stabilized for outdoor use. If the handset is mounted in direct sunlight (e.g., exterior entry vestibule), expect yellowing and potential brittleness over 3–5 years. For outdoor doors, use a recessed or shaded mounting location.
The 2738W is the right choice for integrators and facilities maintaining existing Comelit Simplebus 2 installations and needing a compact, zero-configuration secondary handset. It's not suitable for new-build or facility-wide intercom upgrades — those deployments should evaluate IP-based Comelit systems or other modern alternatives. For more options across the Comelit portfolio, see the Comelit catalog.
