Didactum Indoor Radar Motion Sensor

Function and Purpose

The Didactum Radar Motion Sensor is a high-performance detector that utilizes advanced microwave radar technology for precise detection of motion and objects. It serves as an energy-efficient and highly sensitive motion sensor for indoor use and ensures reliable operation even under varying environmental conditions. The sensor responds to even the slightest movements, providing a high level of security and efficiency for monitoring applications.

Unlike conventional infrared sensors, the radar motion sensor operates on the basis of electromagnetic waves that actively propagate within the monitored area. When these waves encounter a moving object or person, the reflected frequency is altered by the so-called Doppler effect. This signal variation is detected by the sensor’s electronics and transmitted in real time to the Didactum Monitoring System. Based on this data, predefined actions can be triggered, such as alarm notifications, lighting activation, or video recording.

A key advantage of microwave technology is its high penetration capability. The emitted signal can pass through materials such as plastic, glass, ceilings, wooden doors, or thin walls. This allows the sensor to be discretely installed behind surfaces—ideal for applications where hidden monitoring is desired or where sensors must be placed in hard-to-reach areas.

The Radar Motion Sensor is connected directly to a Didactum monitoring unit via an analog port (A1…A8). Thanks to its plug-and-play functionality, no additional software configuration is required: once connected, the sensor is automatically detected and can be immediately integrated into the monitoring logic. Individually adjustable thresholds and logic rules enable event-based control—for example, triggering alarms, ventilation systems, or security lighting.

For larger installations, the maximum number of connected sensors and the total cable length can be flexibly expanded by using a Sensor Expansion Unit or a DIN Extension Unit. This scalability makes the system ideal for comprehensive building automation and security solutions where multiple motion zones need to be monitored simultaneously.

With its high sensitivity, energy efficiency, and discreet design, the Didactum Radar Motion Sensor offers an advanced solution for demanding monitoring applications. It significantly contributes to enhanced operational safety, energy savings, and the protection of critical infrastructure.

Application Areas

The microwave radar sensor or detector is used for a wide range of security and automation purposes across various environments. Its precision, sensitivity, and ability to penetrate non-metallic materials make it suitable for both commercial and industrial applications.

Motion Detection: Ideal for detecting human presence or movement indoors, making it perfect for integration into security systems, intelligent lighting control, and energy-saving automation. The sensor ensures fast and reliable response to changes in activity within the monitored area.
Object Detection: Capable of identifying objects even in environments where the signal must pass through materials such as glass, plastic, or thin walls. This feature makes the sensor particularly suitable for concealed installations in offices, residential spaces, storage areas, or production facilities where discreet monitoring is required.
Energy-Efficient Automation: Frequently used in systems that automatically control lighting, ventilation, or heating and cooling equipment based on the presence of people or objects. This contributes to significant energy savings while maintaining comfort and safety in the monitored environment.

The sensor is highly flexible and can be expanded for larger installations using sensor expansion units or a DIN extension module. This scalability allows comprehensive multi-zone monitoring and seamless integration into complex building automation or security solutions.

Microwave Radar vs. PIR

Why choose a microwave motion sensor?
The microwave motion sensor offers faster response times and higher accuracy compared to conventional PIR (Passive Infrared) sensors. The emitted microwave signal can penetrate materials such as plastic, glass, ceilings, wooden doors, and thin walls. This makes it one of the most advanced technologies available for modern motion detection.

Unlike PIR sensors, which rely on infrared radiation to detect body heat, microwave radar sensors detect motion based on changes in reflected electromagnetic waves. This allows them to perform reliably even in environments with challenging conditions—such as strong air circulation, temperature fluctuations, or obstructed lines of sight.

Example:
Air conditioning systems can be problematic for PIR sensors, particularly in server rooms where strong airflow may cause false alarms. In such environments, the use of microwave radar detectors provides a far more stable and dependable solution for accurate motion detection and system control.

By combining robustness, precision, and environmental resistance, microwave radar sensors represent a new level in motion detection performance, making them ideal for both industrial and commercial monitoring applications.

Dimensions

Installation:

Recommended installation height: 3 m
Detection angle: 120°
Detection distance: 4, 6 or 8 m
Induction radius: approx. 5–6 m
Maximum induction radius: 6 m at a mounting height of 3 m
Cable length: 2 m
Mounting options: wall or ceiling mounting
Output connection: 1 × RJ11 (6P4C)

Induction Area

The graphics below show the detection range in meters. The darker area in the illustrations indicates zones of high sensor sensitivity, while the lighter area represents lower sensitivity.

For microwave radar sensors, the induction area is particularly important, as the microwave signal can penetrate various materials such as plastic, glass, or thin walls, allowing flexible placement. The high sensitivity in the dark area means that movements or objects in these zones are reliably detected, while detection in the lighter area is less certain.

Typically, the maximum range of such a sensor is between 3 and 12 meters, depending on the model. The detection zone usually extends in a 360-degree viewing angle in front of the sensor, with the highest detection accuracy found in the center (i.e., the dark area). The visualization of the induction areas helps optimize installation and planning to minimize false alarms and ensure the desired coverage.

For scaling larger systems, the sensors can also be connected via expansion units to cover multiple zones with appropriately adjusted induction areas and ensure comprehensive monitoring.

Installation

The sensor consists of the following parts:

RJ connector for connecting the sensor to the Didactum monitoring unit or to the expansion unit or DIN expansion unit.
A socket for the ball mount for wall installation. The ball mount can be connected to the wall bracket.
A wall bracket that can be connected to the ball mount.
Side view of the fully mounted sensor.
A window through which the sensor transmits and receives signals.

Step 1:

Attach the wall bracket to the wall using the supplied dowels and screws. The recommended installation height is 3 meters.

Step 2:

Use the RJ11/RJ12 6P4C cable and connect the sensor to the Didactum monitoring unit or to the expansion unit or DIN expansion unit. The sensor is "plug-and-play".