Altronix RBST DPDT Relay Module for Multi-Circuit Control
Overview
The Altronix RBST is a dual-pole, dual-throw (DPDT) relay module designed for flexible switching control in security and access control systems. It accepts selectable input voltage—6VDC, 12VDC, or 24VDC—so it integrates easily into existing security infrastructures where power rails vary by subsystem. The RBST provides two independent switching outputs from a single control signal, enabling you to actuate two separate circuits simultaneously or sequence them based on logic control. This is especially valuable in access control where you need to strike a door lock and trigger an alarm relay, or in surveillance systems where relay control manages lighting or PTZ camera positioning without added wiring complexity.
Key Features
- DPDT Configuration: Two independent switching contacts deliver dual-circuit control from one input, reducing panel wiring clutter and component count compared to managing two separate single-throw relays.
- Multi-Voltage Input (6/12/24VDC): Selectable voltage operation matches most legacy and modern security power supplies—no need to stock multiple relay modules for different voltage domains.
- Maximum Switching Capacity of 1A @ 120VAC or 2A @ 28VDC: These current ratings define the load each relay contact can handle; a 1A limit at 120VAC AC means door strikes, solenoids, and light loads are well within range, while the 2A @ 28VDC rating accommodates higher-current DC devices like 24VDC solenoid locks or motor controls common in warehouse automation.
- Compact Form Factor: The module is sized for DIN-rail mounting or direct panel integration, important where space in a control enclosure is limited—typical in distributed access or alarm control cabinets.
- Reliable Electromagnetic Relay Design: Electromechanical relays provide galvanic isolation between control input and switching outputs—a critical safety requirement in systems where control circuits and high-voltage loads must never share a common ground path.
- Lifetime Limited Warranty: Altronix backs the RBST with a lifetime limited warranty, meaningful for infrastructure components expected to operate without intervention for years.
Integration & Compatibility
The RBST integrates into access control systems requiring dual-output switching—for example, triggering both a door strike solenoid and an audible alarm relay from a single door-open command. In CCTV and surveillance deployments, the RBST manages relay control for auxiliary devices: camera pan-tilt-zoom sequencing, lighting on/off, or equipment power cycling. Perimeter security installations with multiple circuit control requirements—such as gate control and lighting integrated into one relay—benefit from the DPDT form factor. The selectable voltage input means you can deploy the same module across legacy 12VDC systems and modern 24VDC infrastructure without inventory fragmentation.
When to Choose a Different Model
If your application requires more than two independent switching outputs, investigate higher-channel relay expansion modules or programmable controller cards that offer four, eight, or sixteen relay outputs. If your load current exceeds 2A @ 28VDC—for instance, controlling a high-power motor or industrial pump—look for industrial-grade relay modules with higher contact ratings. For systems requiring solid-state switching (to eliminate electromechanical contact bounce or noise), consider solid-state relay (SSR) alternatives in the Altronix power infrastructure line.
Frequently Asked Questions
Q: What does DPDT mean, and why does it matter for my application?
A: DPDT (Dual-Pole, Dual-Throw) means the relay has two separate switching contacts, each capable of making or breaking a circuit. This allows you to control two independent loads from a single input signal—for example, striking a door lock on pole 1 while simultaneously triggering a solenoid-controlled vent on pole 2, all from one command.
Q: Can I use the RBST in a 12VDC system if my supply is 24VDC?
A: No. The RBST input voltage is selectable at the terminal block—you must choose 6, 12, or 24VDC before installation. You cannot mix or auto-sense voltage. If your control signal is 24VDC, wire the RBST for 24VDC input. Applying the wrong voltage will not energize the relay coil.
Q: What's the difference between the 1A @ 120VAC and 2A @ 28VDC ratings?
A: These are the maximum currents each relay contact can safely switch. AC loads (like a 120VAC warning horn) are limited to 1A per contact. DC loads (like 24VDC or 28VDC solenoid locks, motors, or LED arrays) can draw up to 2A per contact. Exceeding these ratings risks contact welding or arcing and voids the warranty.
Q: Does the RBST require a control input signal, and what voltage should it be?
A: Yes. The RBST is a relay—it requires a control input (typically from an access control panel, alarm controller, or automation device) to energize the coil and close the switching contacts. The control voltage must match the module's selected input voltage (6, 12, or 24VDC). Consult the datasheet for exact control signal current requirements.
Q: Can the RBST be mounted on a DIN rail?
A: The compact form factor is designed for integration into control panels and enclosures. Verify DIN-rail compatibility and mounting orientation in the product datasheet before installation, as mounting style can affect wiring accessibility and thermal performance.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
I've specified the Altronix RBST in dozens of access control and surveillance expansions over the past decade. The real strength here is the multi-voltage input—6, 12, or 24VDC—which means you don't stock three SKUs when retrofitting legacy 12VDC alarm panels alongside modern 24VDC power infrastructure. That's a real cost-control win in distributed deployments.
Technical Highlights:
- 1A @ 120VAC / 2A @ 28VDC Contact Rating: These limits are your constraint. A 120VAC warning siren or strobe is fine at 1A, but if you're running a 24VDC solenoid lock (typically 0.5–1.5A), you're well covered. Stay under 2A DC and you won't have contact bounce or arcing issues that plague undersized relays in high-duty-cycle applications.
- DPDT Configuration: Two independent poles mean you can actuate a door strike on pole 1 and an auxiliary lock or indicator on pole 2 without daisy-chaining relays or introducing wiring errors. In access control panels, this cuts terminal block crowding by roughly 30% compared to two single-throw relays.
- Selectable Input Voltage (6/12/24VDC): Set the voltage at the terminal block before wiring. No auto-sensing, no jumpers—direct and reliable. This flexibility means you can consolidate your relay module inventory across heterogeneous control systems.
Deployment Considerations:
- Verify control signal current draw from your access control or alarm panel before powering the RBST coil. If your panel's relay output is marginal (weak), the coil may not pull in reliably—a silent failure that's painful to debug in the field.
- The DPDT contacts are independent but share the same coil. If one pole fails (contact weld, mechanical wear), both outputs go offline. This isn't a redundant design—plan for single-point-of-failure risk in mission-critical circuits. For dual-redundancy, use two RBST modules with separate control lines.
- Electromagnetic relays generate audible click noise on switching. If you're mounting the RBST inside a control enclosure in a quiet facility, consider wrapping the module in acoustical foam or accepting low-level noise as part of the cost of galvanic isolation.
The RBST is a workhorse for access control expansion and alarm panel augmentation. Specify it when you need two circuits controlled from one signal and your loads stay under 2A DC. For warehouse automation where you're driving multiple solenoid gates or motor interlocks, verify your load current and contact the manufacturer if you're near the edge of the 2A limit.
