System Sensor PR-2 Multi-Voltage Dual Form C Relay Module
Overview
The System Sensor PR-2 is a multi-voltage dual Form C relay module engineered for networked access control deployments where remote strike and lock sequencing must operate reliably across mixed-voltage facility environments. TCP/IP communication means you control relay switching from your access control software without proprietary wiring protocols—that simplifies integration when you're deploying across multiple buildings or integrating third-party readers into an existing access control system architecture. The PR-2 (often searched as PR 2) supports NFC and 13.56 MHz credential readers, positioning it for modern card-based authentication workflows where you need relay logic triggered by wireless card presents.
Key Features
- Dual Form C Relay Configuration: Two independent Form C relays give you flexibility to control a magnetic strike on one relay while sequencing a door lock release on the second—or wire both relays in parallel for higher-current loads. Form C (changeover) contacts handle both normally-open and normally-closed logic, so you don't have to work around relay limitations when designing your unlock sequence.
- TCP/IP Communication: Network-based relay control eliminates the need for dedicated hardwired control runs from your access control panel to remote doors. Standard IP networking means lower installation labor and easier troubleshooting—you can monitor relay state and command lock/unlock operations from your access control software's dashboard without field service calls to toggle local switches.
- Multi-Voltage Operation: Accepts multiple supply voltages in a single unit, reducing the need to stock separate modules for 12VDC, 24VDC, or AC installations. In facilities with legacy and modern wiring mixed together, this cuts your spares inventory and simplifies field replacement—one model covers multiple voltage domains.
- NFC/13.56 MHz Credential Support: Compatible with proximity and NFC card readers operating in the 13.56 MHz ISM band. This positions the PR-2 for deployments where you've standardized on contactless credential technology—no mechanical key exposure, faster throughput at high-traffic entry points, and auditable card presents in your access logs.
- Third-Party System Integration: TCP/IP architecture means the PR-2 integrates with access control platforms beyond the System Sensor line. If you're running Milestone, Genetec, or other third-party access control software that can issue TCP/IP relay commands, the PR-2 becomes a universal relay endpoint across your network—valuable when you're consolidating multiple legacy systems into one platform.
- Compact Modular Form Factor: Relay modules are designed for DIN-rail mounting in control cabinets or distributed wiring closets. This keeps your access control hardware organized and protected from facility dust, moisture, and accidental tampering—compared to loose relays soldered into panels.
Integration & Compatibility
The PR-2 integrates directly with System Sensor access control platforms and third-party systems leveraging TCP/IP-based relay control. Multi-voltage operation means you can deploy the same module across facilities with different electrical infrastructure—12VDC switching in newer installations, 24VDC in legacy industrial environments, or AC in facilities where DC conversion isn't practical. Dual Form C relays provide the flexibility to control strike plates, magnetic locks, door holders, and auxiliary devices (gate operators, camera triggers, intercom signaling) from a single module, reducing the number of separate relay units you need to install and manage.
When to Choose a Different Model
If your access control network requires four or more independent relay outputs, or if you need specialized relay modules with signal isolation, opto-isolation, or surge suppression built-in, evaluate higher-channel relay modules in the System Sensor product family. If your deployment operates entirely on a single fixed voltage (e.g., exclusively 24VDC in a modern facility), a single-voltage relay module may offer cost savings, but multi-voltage flexibility typically justifies the minimal cost premium during the system lifetime.
Frequently Asked Questions
Q: Can the PR-2 work with third-party access control software like Milestone XProtect?
A: Yes. The PR-2 communicates via TCP/IP, so any access control platform or integration engine that can issue TCP/IP relay commands can trigger the PR-2 remotely. Specific integration depends on your software's relay control API and network architecture, so confirm compatibility with your software vendor before final procurement.
Q: What voltage supply does the PR-2 require?
A: The PR-2 supports multiple voltage inputs (12VDC, 24VDC, and AC). Refer to the product datasheet for exact voltage ranges and current requirements for your specific application.
Q: How many doors or strikes can one PR-2 module control?
A: Each PR-2 has two Form C relays. Each relay can independently control one strike, magnetic lock, or auxiliary device. If your load requires more current, two relays can be wired in parallel. For facilities requiring more than two outputs, multiple PR-2 modules can be networked together.
Q: Is the PR-2 suitable for outdoor access points?
A: The PR-2 itself is a cabinet-mounted relay module and is not rated for direct outdoor exposure. It should be installed in a protected enclosure or control cabinet. If you require relay control at an outdoor reader location, house the PR-2 indoors and run dry contact wiring (or use wireless relay nodes) to the outdoor hardware.
Q: Does the PR-2 require a separate power supply?
A: Yes. The PR-2 requires an external power supply matched to your facility voltage. Confirm power supply sizing with your System Sensor integrator or the product datasheet to ensure adequate current capacity for your load.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The PR-2 is a straightforward relay module built for access control integrators who need networked switching in mixed-voltage facilities. Its strength is simplicity—dual Form C relays, TCP/IP control, and multi-voltage acceptance eliminate the need for voltage-specific variants or custom relay wiring. In practice, this cuts your parts count and field configuration time when you're scaling across multiple locations.
Technical Highlights:
- Dual Form C Relays: Two independent changeover contacts mean you can wire strike and lock sequencing from a single module without stacking multiple single-relay boards. Form C contacts also support both NO and NC logic, so unlock sequences that require energize-to-unlock or energize-to-lock both work without relay-type substitution.
- TCP/IP Networking: Unlike hardwired relay modules, the PR-2 eliminates long control runs from your access control panel to remote door hardware. Network-based commands reduce installation labor, simplify diagnostics (you can monitor relay state in your access control GUI), and avoid the cable routing overhead of distributed relay cabinets.
- Multi-Voltage Support: Single module accommodates 12VDC, 24VDC, and AC supply. In facilities where legacy and modern wiring coexist—common in older warehouses retrofitting automation—this eliminates the need to maintain separate PR-2 inventory for each voltage domain. Swapping a failed module becomes a drop-in replacement, no spec cross-reference required.
Deployment Considerations:
- The PR-2 is a cabinet-mounted relay module; it is not an outdoor-rated device. If you need relay switching at outdoor readers, house the PR-2 indoors in a protected control cabinet and run dry contact wiring or wireless relay signaling to the outdoor hardware. This design keeps the module away from weather and simplifies maintenance.
- TCP/IP relay commands depend on your access control software's API and network path. Confirm that your VMS or access control platform supports remote relay triggering before assuming seamless integration. Some legacy systems require gateway devices or custom integration middleware.
The PR-2 is well-suited for multi-building campuses, mixed-voltage industrial environments, and integrations where TCP/IP relay control simplifies wiring versus traditional hardwired relay cabinets. Its modularity and voltage flexibility make it a practical choice for system growth and retrofit scenarios where you're consolidating legacy hardware.
