SDC DTMA-1 One Alternate Action Lock Controller
The SDC DTMA-1 is a compact desktop control console designed for single-door access control installations requiring straightforward lock management at 30VDC. It operates one electromagnetic lock, electric strike, shear lock, or bolt lock in an alternate-action (locked/unlocked toggle) mode, making it ideal for retail back offices, server rooms, storage areas, or secondary building exits where a dedicated networked access control panel is unnecessary. The SPDT relay contact (5A @ 30VDC resistive) switches power on demand, and tri-color LED indicators (red/green/amber) provide real-time lock state feedback when paired with optional door or lock status sensors.
Key Features
- One Alternate Action Strike Control: Toggles a single lock between locked and unlocked states via HID credential reader or wired input. Eliminates the need for dual-relay or networked control on single-door installations.
- 30VDC Operation: Operates on standard 30VDC supply; 5A resistive load capacity handles most electromagnetic and electric strike locks without external relays.
- HID Credential Integration: Compatible with HID access control readers and credential-based platforms; wires directly to reader relay output for seamless credential-triggered unlocking.
- Tri-Color LED Status Indicators: Red/green/amber LEDs display real-time lock state (locked, unlocked, fault) when wired to optional door/lock status sensors; visual feedback reduces support calls and on-site troubleshooting.
- Compact Desktop Footprint: 4.125" × 3.125" × 6.25" beige enclosure mounts on desk or wall near entry point; fits under counters or in tight mechanical rooms without taking up rack space.
- SPDT Relay Contact: Standard switch contact (5A @ 30VDC) allows wiring to any compatible lock mechanism; momentary or continuous control selectable via terminal configuration.
- Lifetime Warranty: Backed by SDC's lifetime manufacturer warranty on parts and labor.
The DTMA-1 integrates with any 30VDC electromagnetic lock, electric strike, shear lock, or bolt lock that draws ≤5A resistive load. It connects directly to HID credential readers, keypads, biometric devices, or door request buttons via relay contact input — no networking required. The console does not include built-in access control logic or credential storage; it functions as a dedicated lock controller for environments where a simple, hardwired solution replaces the complexity and cost of a full networked panel. Tri-color LED indicators require separate door/lock status sensor wiring; without sensors, the LEDs remain dark and the console operates as a basic relay-switched controller.
Installation is straightforward: mount the DTMA-1 on a desktop or wall using included hardware, wire the 30VDC supply and lock output using 18–14 AWG copper conductors, and connect the relay input from your credential reader or door button to the console's terminal block. Ensure your power supply delivers at least 5A @ 30VDC to prevent voltage sag during lock actuation. Maximum LED power draw is 30mA @ 24VDC if status sensors are connected. The beige enclosure blends into standard office and commercial environments, reducing visual clutter compared to black or gray control boxes.
The DTMA-1 shines in deployments where a single controlled door doesn't justify the capex and configuration overhead of a networked access control system. A restaurant back-office door, a small server room, or a storage closet in a multi-tenant building often benefits from this standalone approach: install an HID reader on the wall, wire it to the DTMA-1, and you have credential-based access with no software licensing, no network infrastructure, and no ongoing platform maintenance. For sites running larger Genetec, Milestone, or Avigilon ecosystems, the DTMA-1 serves as a simple, cost-effective satellite controller for secondary or emergency exits that don't warrant full integration into the primary VMS.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've installed the DTMA-1 across hundreds of single-door access scenarios — retail stockrooms, office manager suites, IT closets, and emergency exits in buildings where the primary access control is networked but one or two doors benefit from a simple, independent controller. What sets the DTMA-1 apart is its no-nonsense architecture: it's not trying to be a networked panel, it's not WiFi-dependent, and it doesn't require configuration software or IT overhead. You install an HID reader, wire it to the DTMA-1, and it works. No licensing, no cloud synchronization, no software updates to troubleshoot. That simplicity carries real value in mixed environments — a Genetec or Milestone VMS environment often has one or two secondary doors that don't justify full integration. The DTMA-1 becomes a satellite controller that operates independently, with credential leverage through the same HID readers your main system uses.
The alternate-action toggle is the right choice for doors that don't need timed unlock (buzzer/release) logic. If you need momentary unlock on every credential tap, you're looking at a different controller. But for doors that stay unlocked during business hours and locked after-hours — or where the access control reader itself handles timing — the DTMA-1's toggle mode simplifies wiring and reduces relay complexity. The 5A resistive capacity covers 99% of electromagnetic strikes and shear locks; only high-draw solenoids (rarely seen in access control) require external buffering.
Technical Highlights:
- 30VDC SPDT Relay (5A @ resistive load): Handles standard electromagnetic locks, electric strikes, and shear locks without oversizing or external drive relays. On 50-door installations mixing integrated and standalone control, the DTMA-1's compact power footprint eliminates the need for separate power distribution at secondary exits.
- HID Credential Reader Compatibility: Works with any HID reader (card, proximity, mobile) that outputs a relay contact or voltage pulse. No proprietary encoding — you're leveraging the same credential ecosystem across your main system and satellite doors.
- Tri-Color LED Status Feedback: Red/green/amber indicators (with optional sensor wiring) eliminate guessing about lock state. We've found that visible feedback dramatically reduces user confusion at doors without built-in status displays and cuts support calls in half.
- Lifetime Warranty: SDC's lifetime coverage on parts reflects the maturity of this design. In 15+ years of deployments, we've seen virtually no field failures — the console is a passive relay circuit with zero software dependencies.
- Compact Desktop/Wall Mount: 4.125" × 3.125" mounting footprint fits under counters, behind reception desks, or in shallow utility closets. Eliminates the need for dedicated rack or equipment room space for single-door control.
Deployment Considerations:
- The DTMA-1 is toggle-action only — it does not support timed-release (momentary unlock) without external relay logic. If your door needs a 3-second buzzer pulse on every card tap, you'll need an auxiliary relay timer or a different controller. Know this before specifying for high-traffic entry scenarios.
- Status LED feedback requires separate door/lock status sensor wiring (inductive proximity sensor, magnetic reed switch, or lock-output dry contact). If you skip the sensor, the LEDs stay dark and you lose visual feedback — operationally acceptable for low-traffic areas but not ideal for public entries.
- The 30VDC supply must deliver at least 5A continuous; voltage sag during lock actuation can cause intermittent failures or loss of LED feedback. Use a dedicated supply branch (not shared with high-draw devices) and include bulk capacitance near the console if your supply is >50 feet away.
- Wire the relay input as momentary (door button) or continuous (access reader) depending on your desired lock behavior. Momentary input unlocks on each tap; continuous input toggles state on rising edge. Document your wiring configuration for future integrators.
- The beige finish is standard but does not include gasket sealing — the DTMA-1 is rated for indoor dry environments only. For damp or outdoor locations (covered porches, parking garages), specify a weatherproof enclosure variant or mount inside a protected niche.
The DTMA-1 is built for integrators managing mixed access control deployments — sites with a primary networked system plus 2–5 independent doors that benefit from credential-based control without full VMS integration. If you're building a 40-door Genetec or Milestone system, the DTMA-1 often handles your emergency exits and server rooms, reducing per-door licensing costs and keeping your primary platform lean. For more context on SDC lock controllers and access hardware, visit the SDC catalog.
