SDC 25-4U 4-Door Electric Strike Controller
Overview
The SDC 25-4U is a wired 4-door electric strike designed for networked access control systems. It communicates via OSDP and TCP/IP protocols, enabling direct integration with modern credential readers and access control platforms without intermediate relay logic. Operating at 24VDC, the 25-4U accommodates up to 250,000 users in its credential database—a specification that matters for multi-tenant buildings, enterprise campuses, and distributed facilities where credential management scale is a real deployment constraint.
Key Features
- OSDP and TCP/IP Protocols: Direct command and control from compatible readers and panels eliminate the need for separate relay modules. This reduces panel-to-strike wiring complexity and lowers integration latency compared to legacy wired-relay designs.
- 4-Door Capacity: Single unit controls four strike assemblies. Useful for consolidating control in a small building or as a distributed node in multi-zone deployments. Each strike operates independently—one failed unit doesn't cascade to others.
- 24VDC Power: Standard access control voltage. If your facility already runs 24VDC to door frames, no additional power supply infrastructure is needed. Confirm your control panel has sufficient amperage capacity for all four strikes under load.
- HID Credential Support: Works with HID ProxCard, iClass, and compatible credential types. If your facility uses Salto, Dormakaba, or vendor-specific formats, verify integration before specifying.
- 250,000-User Capacity: Enterprise-scale credential roster. For sub-100-user deployments this is overkill, but for large multi-tenant or campus environments, it eliminates the need for credential compression or archiving strategies.
- Wired Connectivity: No wireless mesh or network congestion risk. The tradeoff: installation requires conduit runs to each door strike. Plan wire routing early—retrofitting is costly.
Integration and Compatibility
The 25-4U integrates with OSDP-compliant readers (Salto, HID, Dormakaba, and many others) and TCP/IP-based access control platforms. If you're deploying a new access control system, confirm your chosen platform supports OSDP command sets for door strikes—not all legacy panels do. TCP/IP integration allows remote strike control and audit logging from a central management console.
Pair the 25-4U with a networked reader and controller that speaks OSDP. Stand-alone operation (without a central server) is possible if your readers are hardwired to the strike unit; this scenario works well for standalone offices or small multi-door installations where centralized credential updates are not required.
Deployment Considerations
Each strike requires 24VDC wired back to a power supply and control signal routed from your reader or panel. In a 4-door setup, that's at least eight conductor runs (power and signal per strike, plus return). Underground or exterior conduit installations add cost and complexity. Indoor corridor or stair-well deployments are simpler.
Confirm the 25-4U (often searched as 25 4U) strikes meet your door frame and latch geometry before ordering. Electric strikes are mortise-specific—a 1200-series frame is not the same as a 6200-series.
When to Choose a Different Model
If you need wireless strike control or cellular fallback for remote facilities, consider alternative access control architectures that support wireless credentials or battery-backed strikes. If you're managing a single door, a 1-door strike will cost less and occupy less panel real estate. For high-traffic environments requiring audit-trail density, confirm your platform logs every strike activation—some basic panels do not.
Frequently Asked Questions
Q: Does the SDC 25-4U work with wireless readers?
A: No. The 25-4U is wired only. Your readers must be hardwired to the strike unit or to a control panel that commands the strike via OSDP or TCP/IP.
Q: Can I use the 25-4U with a legacy (non-OSDP) access control panel?
A: Only if your panel has TCP/IP output or relay outputs that can be wired to auxiliary inputs on an OSDP-compliant device. If your panel is relay-only, you'll need an OSDP gateway or a different strike model.
Q: How many users can the 25-4U store?
A: Up to 250,000 credential records. This is useful for enterprise deployments; smaller installations will never need this capacity.
Q: What is the typical power draw per strike?
A: Not specified in available documentation. Contact the manufacturer or your integrator for current and duty-cycle data to confirm your 24VDC supply can handle all four strikes simultaneously.
Q: Can I mix strikes from different manufacturers on the 25-4U?
A: The 25-4U controls four door strikes via 24VDC solenoid commands. As long as your strikes are 24VDC electromagnetic or solenoid-actuated, they should be compatible. Verify latch type and frame fit with your installer before purchase.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The SDC 25-4U is a straightforward wired strike controller for integrators building OSDP or TCP/IP-enabled door control across multiple access points. The 4-door consolidation is useful in small-to-mid-size deployments, but the real value is in the protocol support—OSDP eliminates proprietary relay logic and gives you a clean, auditable command path from reader to strike.
Technical Highlights:
- OSDP and TCP/IP Command Sets: Direct protocol support means no intermediate relay modules or custom wiring logic. This reduces integration latency and improves audit-trail density—every strike command is logged by the access control platform.
- 4-Door Multiplexing: Single unit controls four independent strike circuits. Useful for consolidating cabling in a stairwell, vestibule, or small multi-tenant floor. Failure of one strike does not affect the others.
- 250,000-User Credential Capacity: For large campuses or multi-tenant buildings, this eliminates the need to manage separate credential subsets or archiving. Small deployments will never hit this limit; don't use it as a selling feature for a 10-door office.
Deployment Considerations:
- Wired-Only Architecture: Every strike requires a dedicated 24VDC power and signal run. In a retrofit or exterior multi-door setup, conduit and labor costs can exceed the controller cost. Plan your routing early.
- OSDP Reader Requirement: The 25-4U commands strikes only via OSDP or TCP/IP. If your site has legacy relay-only panels, you need either a gateway device or a platform migration. This is not a backward-compatible retrofit for old installations.
- Power Supply Sizing: No peak wattage is published in the datasheet. Every strike draw amperage on 24VDC when energized; you must confirm your PSU can deliver peak current for all four solenoids simultaneously. Under-sizing the supply will cause nuisance de-energization under load.
Deploy the 25-4U in new-build or major renovation projects where OSDP readers and TCP/IP control platforms are already specified. It's a solid fit for warehouse automation facilities, multi-tenant office builds, and campus card-access systems. Avoid retrofitting into relay-dependent infrastructure without a full platform upgrade.
