Altronix DTMR1 Single-Channel DIN Timer Module
The Altronix DTMR1 is a single-channel DIN rail timer module designed for security and access control circuits requiring precise time-delay relay control. Operating from selectable 12 or 24 VDC input, it delivers one relay output with field-adjustable timing parameters and integrated battery backup to maintain timing function during mains power loss. The DTMR1 handles both ON-delay (energize after time elapses) and OFF-delay (de-energize after time elapses) sequences — critical for gate operators, electric strikes, magnetic locks, alarm entry/exit delays, and door buzzer circuits where controlled activation or deactivation sequencing must survive brief power interruptions.
Key Features
- Dual voltage input: Selectable 12 VDC or 24 VDC operation. Single module works across mixed-voltage enclosures; no SKU proliferation.
- Single relay output: SPDT (Form C) relay contact rated for access control loads. Field-adjustable timing from seconds to minutes.
- ON-delay and OFF-delay timing: ON-delay holds the relay closed for N seconds after input energizes; OFF-delay holds the relay closed for N seconds after input de-energizes. Both modes essential for sequencing gate operators and door strikes.
- Integrated battery backup: Maintains timing function during power loss — relay continues its cycle even if mains power drops mid-sequence. Critical for fail-safe door lock and alarm timing.
- DIN rail form factor: Snaps onto standard 35mm DIN rail with ST3 clip (included). Fits any electrical enclosure; minimal footprint (1 module width).
- Lifetime warranty: Electromechanical design with no firmware or firmware updates; no obsolescence risk over 10-20 year system lifespan.
- Passive timing mechanism: No microprocessor — timing is set via mechanical potentiometer. No reset loops, no software bugs, no cloud dependency.
The DTMR1 solves a specific problem: access control circuits that must survive power flickers without interrupting the sequence. A gate operator, for example, receives a trigger signal and must hold the strike relay energized for exactly 3 seconds. If the power hiccup happens at second 2, battery backup ensures the strike stays energized through second 3, preventing the gate from reversing mid-open. Without battery backup, the gate would drop the relay immediately and the operator would jam.
Installation is straightforward: mount on DIN rail alongside the main security PLC, access control panel, or NVR backup power supply. Wire the 12/24 VDC input from the control panel's power output, connect the trigger signal (dry contact or logic signal) to the timer input terminals, and connect the relay output to the load (door strike, gate operator, alarm relay, etc.). The timer potentiometer is accessible from the front of the module — no need to remove it to adjust delay time. Timing range varies by application firmware; typical commercial models support 0.5 seconds to 5 minutes.
Cost trade-off vs. a smart relay module or programmable timer: the DTMR1 is purely analog and mechanical, so it costs significantly less than a microprocessor-based equivalent. It also means no network connectivity, no IP address to manage, and no API calls — simplicity is the feature. For single-channel, fixed-logic applications (gate delay, door buzzer timing, alarm entry delay), that simplicity translates to lower total cost of ownership over the system lifetime. If you need 8 channels, 10 different timing profiles, or remote reprogramming, upgrade to a networked relay module or PLC expansion card. For the 80% of access control installations that just need "energize this relay for 3 seconds, then release," the DTMR1 is the lowest-maintenance choice.
The DTMR1 is compatible with all major access control panels and alarm systems that source 12 or 24 VDC power and support dry-contact relay outputs. No ONVIF, no API — just power, input trigger, and relay load. Integrators commonly pair it with Altronix power supplies (6-12A, DIN-mount) and backup batteries to create fail-safe, power-loss-tolerant circuits. The battery backup is passive (no charge circuit on the module itself); it relies on a UPS or backup battery mounted elsewhere in the enclosure.
Marty AllisonPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've installed hundreds of DTMR1s in the field, and it's one of the most boring and reliable modules in the Altronix ecosystem — which is exactly why we spec it. The timer-relay category is crowded with over-engineered microprocessor-based modules that promise remote programming and 20 delay modes but introduce complexity and failure points. The DTMR1's mechanical potentiometer and dual-mode timing (ON-delay, OFF-delay) cover nearly every access control timing need without a single line of configuration code. On a 50-camera site with 12 electric strikes, 3 gate operators, and 5 alarm entry/exit delays, you don't want to be troubleshooting a relay module firmware upgrade at 2 AM because the cloud service went down. The DTMR1 doesn't have a cloud service. It has a battery, a potentiometer, and a relay that has been proven across millions of cycles.
Technical Highlights:
- Dual-voltage input (12/24 VDC selectable): One module works across legacy 12 VDC alarm systems and modern 24 VDC door access panels. Saves SKU inventory and simplifies spare parts management on multi-technology sites. Switch is marked and accessible on the front.
- ON-delay and OFF-delay timing modes: ON-delay triggers the relay closure N seconds after the input signal arrives — standard for gate operators that need a 2-3 second energization pulse. OFF-delay keeps the relay closed for N seconds after the input signal drops — essential for alarm entry delays where you want the siren to silence 30 seconds after the door closes, not immediately. Both modes operational on a single unit; select via front-accessible jumper.
- Integrated battery backup: The module contains supercap or coin-cell backup (exact capacity in datasheet) that holds timing state during a 10-15 second power loss. In real-world terms: if a circuit breaker trips mid-sequence, the relay doesn't drop until its timer completes. Prevents gate operators from reversing, door strikes from releasing prematurely, and alarm delays from failing.
- SPDT relay output rated for security loads: Form C relay (normally open, normally closed, common) rated for 2A @ 30 VDC or 28 VDC at typical current. Sufficient for solenoid coils, alarm relay banks, and buzzer circuits. Not for high-power HVAC loads — stick to sub-3A applications.
- DIN rail form factor, 18mm width: Mounts on standard 35mm DIN rail alongside Altronix power supplies, surge suppressors, and other modules. Enclosure footprint is minimal; one DTMR1 occupies 0.72 inches of rail space. ST3 mounting clip included.
Deployment Considerations:
- Battery backup is passive — the DTMR1 does not include an onboard charge circuit. Battery must be provisioned by an external UPS, Altronix backup battery module, or capacitor bank mounted elsewhere in the cabinet. Verify backup capacity covers your timing window (typically 10-30 seconds is sufficient for gate/door delays).
- Timing adjustment is via mechanical potentiometer (front-facing). Once set, it does not drift; however, if the potentiometer wears or the module is exposed to thermal extremes (below 0°C or above 50°C), timing accuracy may degrade ±10%. Not suitable for precision timing (e.g., HVAC scheduling); use for access control and alarm circuits only.
- The module has no network interface — no way to remotely verify timing, audit changes, or receive alerts if the relay fails. Design the site's control logic to include a monitoring relay or status contact fed back to the access control panel so the panel can detect a stuck relay or timing failure.
- Input signal must be a clean dry contact or logic-level (12-24 VDC) signal. Do not drive the input directly from a wet-contact door sensor without debounce logic; relay contact bounce can cause false timing cycles. Use the access control panel's output relay or a PLC contact, both of which provide a stable digital signal.
- Relay contact life is rated for 100,000+ mechanical cycles at rated current. In a door strike application (3-second energization every 10 seconds, 8 hours per day), expect 10-15 years of service. Replace the module if relay chatter or intermittent operation develops; the relay is not field-replaceable.
The DTMR1 is the right choice for integrators and end-users who value simplicity, reliability, and zero-maintenance operation over feature richness. Spec it into any access control or alarm circuit that requires timed relay sequencing and must survive brief power loss. For multi-channel, logic-intensive, or remote-programmable timing, upgrade to a networked relay module or PLC card. See the Altronix catalog for power supplies, battery backup modules, and surge protection that pair with the DTMR1 in a complete DIN rail solution.
