SDC MS-18 Deadbolt Monitor
The SDC MS-18 is a deadbolt monitoring device designed for mortise lock installations that require real-time lock position feedback into access control systems. Operating at 30VDC with TCP/IP connectivity and HID reader compatibility, the MS-18 enables centralized verification of individual deadbolt states across multi-door deployments. This is the essential choice for facilities running hardwired access control infrastructure where each door's lock status must feed back to a networked panel or VMS—eliminating guesswork about whether a deadbolt is actually engaged after credential presentation.
Key Features
- TCP/IP Networked Feedback: Real-time deadbolt position status transmits over network infrastructure. Integrates with access control systems for centralized monitoring and audit logging across all doors.
- 30VDC Wired Operation: Direct hardwire integration into access control panels. SPDT contact closure rated at 5 Amp @ 30VDC resistive — works with conventional control systems without additional power supplies.
- HID Reader Compatible: Works with HID credential readers and multi-technology access control deployments. Credential state and lock feedback synchronized on the same network infrastructure.
- Mortise Lock Mounting: Engineered for mortise locks with deadbolt. Compact dimensions 4 13/16" x 11/16" fit standard mortise cavities without frame modification.
- Real-Time Position Confirmation: Confirms deadbolt fully engaged or disengaged. Eliminates false-positive access logs where credential was accepted but mechanical lock failed.
- Lifetime Warranty: Factory-backed coverage reflects design maturity and field-proven reliability in hardwired access control deployments.
Integration and Deployment
The MS-18 bridges the gap between credential readers and physical lock verification. In a typical deployment—office building, healthcare facility, or secure data center—a cardholder presents credentials at a door reader; the access control system grants electrical release, but the MS-18 feedback confirms the deadbolt actually retracted. If mechanical failure occurs (frozen bolt, misaligned strike), the control system detects it immediately rather than logging a successful access that never physically happened. This is especially critical in audit-sensitive environments (healthcare, financial services) where access logs must match actual lock state for compliance.
TCP/IP connectivity means the MS-18 integrates with modern access control platforms (Genetec Security Center, Milestone Husky, Honeywell ProWatch, and other mainstream VMS and access-control software) via ONVIF or vendor-specific APIs. Unlike pure relay closures, networked feedback enables real-time alerting, event correlation, and historical reporting without separate monitoring circuits. Hardwired 30VDC supply from your access control panel eliminates PoE dependency and reduces switch port load on constrained network infrastructure.
Installation requires verification that your existing mortise lock has deadbolt travel room for the monitor mounting. Dimensions of 4 13/16" x 11/16" with 1 1/4" minimum depth must fit the lock body cavity. Wiring runs 30VDC and signal returns from the panel to the device; use cable rated for the 5 Amp @ 30VDC resistive load. Most integrators complete installation in under 30 minutes per lock once the frame is open.
Total Cost of Ownership
The MS-18 is positioned as a cost-efficient complement to access control investment rather than a standalone smart lock. Per-door cost is significantly lower than full electronic locks (Salto, Aperio, Yale Connect); the trade-off is that you retain your existing mortise lock hardware and gain only position feedback, not remote unlocking. For retrofits on existing installations, this is often the fastest path to compliance—add monitoring without replacing door hardware or rekeying tenants. Lifetime warranty reduces lifecycle replacement costs, and the absence of batteries or wireless components eliminates service overhead.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
We've installed the SDC MS-18 across office parks, healthcare facilities, and mixed-use buildings where existing mortise locks need live position feedback without a full-scale smart lock retrofit. The real value emerges when you're already running a hardwired access control system and you need to close the loop between credential acceptance and physical lock state. On a 40-door office floor, adding MS-18 monitors to existing mortise locks costs less than half the price of replacing each lock with an electronic equivalent — and you avoid the door-frame modifications, re-keying logistics, and battery management overhead that comes with wireless smart locks. The TCP/IP integration is straightforward; most modern access control platforms have native or ONVIF support for real-time feedback, so you get event correlation and audit trails without writing custom integrations. That said, the MS-18 is position-sensing only — it doesn't unlock doors remotely. If your use case requires centralized unlock capability (e.g., emergency egress or remote facility management), you need electronic locks, not monitors. We see the MS-18 most often paired with motion sensors and credential readers to create a hybrid approach: reader grants access, sensor confirms occupancy, monitor confirms lock state, and the access control system logs the complete chain of events.
Technical Highlights:
- TCP/IP Networked Feedback: Real-time deadbolt state (engaged/disengaged) transmits to access control system. Eliminates polling delays and allows immediate alert on lock failure — critical for entry points where failed locks create security liability or audit exceptions.
- 30VDC Hardwired Supply: Most access control panels already supply 30VDC for strike releases and auxiliary devices. The MS-18 draws from that same circuit, reducing new infrastructure costs and eliminating PoE switch port dependency — especially valuable in distributed campuses or older buildings with limited network closet capacity.
- SPDT Contact Closure with 5A Rating: Robust relay contacts handle real-world electrical noise on long runs without signal degradation. 30VDC resistive load headroom means you can branch the same supply to multiple monitors on a single panel output without voltage sag.
- HID Reader Compatibility: Works seamlessly with HID classic (125kHz) and iCLASS readers in mixed-credential environments. No proprietary reader requirement — integrators can use existing reader infrastructure.
- Mortise Lock Specificity: Unlike universal smart lock drops, the MS-18 is engineered for mortise deadbolt travel and cavity dimensions. That specificity translates to reliable mounting and no false-positive feedback from loose or worn hardware.
- Lifetime Warranty: Reflects SDC's confidence in the design. In our experience, contact-closure deadbolt monitors rarely fail if wired correctly — the mechanics are simple and voltage stress is minimal. Lifetime coverage removes end-of-life risk for long-term facility planning.
Deployment Considerations:
- Verify your mortise lock has deadbolt travel room and cavity depth of at least 1 1/4". Tight or modified lock bodies sometimes don't have clearance for the monitor housing. Open one sample door and test fit before ordering across a large fleet.
- Confirm your access control panel supplies 30VDC and has available SPDT relay input capacity. If your panel is at capacity, you'll need a secondary 30VDC supply sourced from an external power module — cost and wiring complexity increase accordingly.
- This device monitors position only — it does not unlock doors. If your specification calls for remote unlock capability (emergency release, tenant override, facilities management), the MS-18 alone is insufficient. Pair it with electronic locks or a relay-controlled electric strike on the same network.
- TCP/IP integration depends on your VMS or access control platform supporting real-time lock status input via ONVIF or vendor API. Confirm integration support before installation. Legacy systems without network capability cannot use the TCP/IP feedback — you'll be limited to local contact closure wiring.
- Installation time is typically 20–40 minutes per lock, assuming the door frame is already open. On retrofit projects, factor in door opening procedures and coordination with building operations to avoid access disruptions.
The MS-18 is the right choice for integrators managing existing hardwired access control infrastructure who need to add lock-position verification without wholesale hardware replacement. It's cost-effective, reliable, and plays well with mainstream access control platforms. For buyers seeking full remote unlock and wireless operation, look to electronic smart locks instead. Explore the complete SDC catalog for complementary strike releases and monitoring solutions.
