Access Sensor

Reliable access control for doors and windows

The Didactum door contact sensor monitors the status of doors, windows, or server cabinets (open or closed) and is therefore a key component of any access control system. It connects to an analog port (A1–A8) of a Didactum Monitoring System, is ready to use immediately, and supports daisy chaining of multiple sensors, making it easy and scalable to monitor larger installations with multiple access points.

Whether it is a server room, archive, or executive office: the door contact sensor reports every unauthorized opening of an access point to the monitoring system in real time and can be combined with additional components such as a siren to trigger an immediate alarm in an emergency.

Two-component principle: reed contact and magnet

The door contact sensor consists of two separate components that work together to detect status changes.

As long as the magnet is in close proximity to the sensor unit, the internal reed contact closes and reports the status "closed." When the magnet moves away as the door or window opens, the reed contact opens and the sensor reports "open." Because the magnet operates completely passively and requires no power supply, the entire design is especially low-maintenance and durable.

How the sensor detects door status

The reed contact in the sensor unit responds to the magnetic field of the associated magnet. When the door is closed, magnet and sensor are close together, the contact closes, and the monitoring system shows the status "Normal" (closed). When the door opens, the magnet moves away from the sensor, the contact opens, and the system reports "Alarm" (open).

If needed, the logic can be reversed directly in the web interface, so the sensor is also suitable for applications where an open state is normal and a closed state should trigger an alarm.

Connection and daisy chaining of multiple sensors

The door contact sensor is connected via a standard RJ11/RJ12 sensor cable (6P4C) to one of the analog ports (A1 to A8) of a Didactum Monitoring System and is automatically detected there using plug-and-play. Thanks to the input and output ports (both RJ11/RJ12), multiple door contact sensors can be connected in series using daisy-chain wiring. All sensors in a chain appear as a single shared element in the web interface; if any sensor in the chain is triggered, this is reported as one combined status change.

Mounting on doors, windows, or rack cabinets

The sensor unit is mounted on the fixed frame, while the magnet is placed directly opposite on the moving door leaf, window sash, or rack cabinet door.

Depending on the construction of the access point, the sensor can be attached with the included screws, adhesive strips, or the supplied mounting bracket. The bracket is especially suitable for clean installation in 19-inch IT racks and control cabinets. It is important that the magnet and sensor are precisely aligned with each other when the door or window is closed so that the reed contact closes reliably.

Monitor more access points

For larger installations with numerous access points, the number of connectable door contact sensors and the overall system range can be increased using a Didactum sensor expansion unit (8× analog, connected to the monitoring system via CAN bus). This makes it possible to centrally and comprehensively monitor large buildings, multiple floors, or many server cabinets without replacing the central unit.

Applications for the door contact sensor

• Server room security: Monitoring all doors and server cabinets with real-time status updates and logging of door openings.
• Access control in data centers: Monitoring all access points, including documentation of access events.
• Securing archives and storage rooms: Monitoring doors outside business hours with automatic alerting.
• Building automation: Linking with air conditioning or lighting control when opened or closed.
• Protection of sensitive office areas: Securing development departments or executive offices.
• Window and emergency exit monitoring: Early detection of unauthorized open windows or emergency exits.

Performance data at a glance

What is included in the package

Please check the contents for completeness upon receipt and report any missing or damaged parts to your supplier immediately.

• Door contact sensor (reed contact) with magnet1 each
• RJ11 sensor cable, 6P4C, 2 m1 piece
• Mounting bracket1 piece
• Mounting screw1 piece
• Screws, nuts & washers2 each
• Adhesive strips for mounting2 pieces

Why this door contact sensor is the right choice

More about the door contact sensor

Frequently asked questions