The Didactum RS485 Expansion Module is a high‑performance component for modern access control and security monitoring systems. Supporting the secure OSDPv2 protocol (Open Supervised Device Protocol Version 2) and integrating seamlessly with Didactum monitoring systems 100T, 300T, 500T, and 550T, the module unlocks new capabilities for secure access control—from server rooms to sensitive enterprise areas.

By combining monitoring and access control, the system can instantly react to physical events, trigger alarms, and centrally record security status.

Protecting sensitive IT and enterprise areas

Server rooms, technical centers, and data centers are among the most security‑critical zones in any organization. The RS485 Expansion Module enables direct connection of OSDP‑compatible card readers, keypads, or biometric devices to the Didactum monitoring system.

In real time, the system controls and logs who gains access, when, and where. In case of unauthorized access attempts, it can respond immediately—by sending alerts via email, SMS, or SNMP trap, or by automatically locking the door through connected relay modules.

Access events are recorded alongside environmental parameters such as temperature, humidity, smoke detection, or motion in the central monitoring system. This ensures full correlation between access control and environmental monitoring.

Advantages of the OSDPv2 protocol

• End‑to‑end encryption protects communication between reader and controller from tampering or interception.
• Bidirectional communication provides real‑time status updates and diagnostics.
• Compatible with a wide range of OSDP devices including smart card readers, fingerprint scanners, and facial recognition systems.
• Standardized—future‑proof integration into existing access control systems via open interfaces.

Integration with Didactum monitoring systems

The RS485 Expansion Module is simply inserted into the housing of the Didactum monitoring device—no system restart required. After installation, the web interface automatically detects all connected OSDP peripherals. From here you can:

• Create access rights and user profiles
• Define access times and security zones
• Set up alarm rules and actions

Configuration is carried out via the system’s browser‑based web interface without installing additional software.

Easy installation and flexible wiring

Connection to access readers is via standard RS485 bus wiring, enabling long distances between reader and controller—ideal for large buildings or industrial sites.

• Simple integration via slot‑in connection in the monitoring system
• Built‑in termination resistor, optionally disabled for long bus runs
• Compatible with existing RS485 networks

Application examples

• Server room: Access monitoring with OSDP readers, logging of access data, and alerting on unauthorized entry.
• Data center: Managing multiple security zones, integrating with climate control and fire protection systems.
• Research laboratory: Access control via smart cards or biometric systems, with complete event logging.
• Technical centers: Tamper protection and alerting on sabotage attempts.
• Office building: Integration with time tracking and visitor management via OSDPv2‑compatible devices.

Centralized security management via web interface

All access events and security statuses can be viewed in the central web dashboard. Combined with the system’s monitoring functions, this creates a unified security platform where both IT and physical security aspects are monitored in real time.

Future‑proof access control with OSDPv2

The Didactum RS485 Expansion Module with OSDPv2 support combines security, scalability, and ease of integration. It ensures protected communication, precise access control, and full logging of all access events—making it the ideal solution for enterprises, data centers, and industrial sites with the highest physical security requirements.