Specialist terms clearly and briefly explained

Acoustic Sensor

Some B.E.G. detectors have an additional acoustic sensor. These mean that after automatic switch-off, the light can be switched back on again by sound. This is particularly useful for rooms where motion detectors do not have a direct line of sight to all areas (e.g. in toilets).

Analogue Time Switch

Analogue time switches work on mechanical principles. Generally, analogue time switches have one switch, with which the clock can be set permanently on, off or in automatic mode. Setting of switching times takes place on the unit using slides.

Annual Time Switches

Annual time switches can be individually configured for each calendar day. This makes it possible to have different settings, e.g. for holidays.

Anti-creep zone

Exterior motion detectors often have sensors pointing forwards. So that no unauthorised persons can creep along the wall under the detector, an area beneath the detector is covered by a so-called anti-creep zone.

Astronomical Time Switch

In an astronomical time switch, sunrise and sunset times are stored in the device. The device automatically calculates these times daily according to installed location.

Bidirectional Remote Control

Bidirectional devices are controlled with bidirectional remote controls. These remote controls can not only send commands and settings to the device, but also receive data. This means you can retrieve device data and settings.


are for adjustment of the detector’s detection area to local conditions as required. They are clipped to the detector’s lens.

Colour Temperature

The colour temperature describes the inherent colour of the light emitted by a light source. This is given in kelvins (K). The most common colour temperatures are warm white (approx. 3000K), neutral white (approx. 4000K) and daylight white (approx. 5600K).

Constant Light Regulation

For constant light regulation, a desired brightness value is set on the detector. If there is too little natural light in the room, the detector adds enough artificial light until the total of daylight and artificial light reaches the desired brightness.

Corridor Function

When the corridor function is active, full automatic mode (see: Full Automatic) is deactivated after switching off the light via a push button for only 10 seconds – instead of the follow-up time that was set.

Corridor Occupancy Detector

B.E.G. has developed special lenses for corridors, which perfectly tailor the detection area of these detectors to long hallways. These detectors are denoted with a “C” in the product name.


see: Colour Rendition

Daily Time Switch

A daily time switch repeats its switching program in a 24 hour cycle.


DALI technology is a bus system which was originally developed for lighting. The term DALI stands for “Digital Addressable Lighting Interface”, and is the definition for a standardised digital lighting device interface. This standard ensures interoperability of lighting devices from different manufacturers in one lighting system.

Detection Area

The detection area is a value in metres, describing the area which can be covered by motion detection. With occupancy detectors using PIR technology, three values can be given here (movement across the sensor, movement towards the sensor and very small movements), as there are big differences in detection area according to the direction in which a person is moving.

Digital Time Switch

A digital time switch displays the switching program and much more information via an LCD screen. Compared to an analogue time switch, it offers many more options for programming and control. Switching programs can be programmed for a defined number of locations, which are then automatically carried out by the time switch.

DIM / 1 – 10 V

DIM is also known as 1-10 V technology. The technology is a predecessor of DALI, but is still widespread today. DIM occupancy detectors can dim lights with a 1-10V electronic ballast.

DIP Switches

A DIP switch enables easy and quick basic settings to be set on a product (e.g. the choice between DALI and DSI on B.E.G. DALI/DSI occupancy detectors).

Double Lock

see: Tamper Protection


The abbreviation “DSI” stands for Digital Serial Interface, and is a proprietary, unidirectional bus system for lighting control. DSI is a predecessor to DALI (see: DALI).

DUO Occupancy Detector

DUO is how B.E.G. describes occupancy detectors which control two lighting groups. Two integrated directable light sensors independently measure light levels in two different zones of the room (e.g. zone near the window/zone away from the window), to regulate the light as needed.

Efficiency (LED)

The efficiency of LED lights is given by how much light (lumens) is produced per watt. It is given in lm/W. The higher this value, the higher a light’s energy efficiency.


ETS is the manufacturer-independent software used to set up KNX systems. Manufacturers always make the relevant product database for their products available to ETS.


The abbreviation “FC”, in B.E.G. motion and occupancy detector product names, means (false) ceiling mounting.


The abbreviation “FM”, in B.E.G. motion and occupancy detector product names, means flush-mounting.

Follow-up Time

Once the detector no longer registers motion, the follow-up time begins. After it finishes, the light is switched off. For each detector, this can be set by the installer (within certain limits). The follow-up time ensures that people who do not move for a while are not suddenly plunged into darkness.

Full Automatic

In full automatic mode, the detector reacts to motion and switches the light on or off automatically. The light can also be switched on or off through a switch.

Guided Light / Guided Light PLUS

Guided Light is the description of a function which can only be implemented with the DALISYS® lighting control solution from B.E.G. Motion detection in a particular area can be installed for automated control of the light on one DALI loop (Guided Light) or in the entire building (Guided Light PLUS). Using this function, the safety and convenience aspects are maintained (all visible areas have at least orientation lighting switched on), while energy is also saved (non-visible areas are switched off).

HF (high frequency)

Unlike PIR sensors, HF sensors actively emit high frequency signals. The signals hit an object, are reflected back to the sensor, and then evaluated for use in detection of moving objects.


HVAC (= Heating, Ventilation and Air Conditioning) identifies B.E.G. detectors which have a special channel for control of heating, air conditioning and ventilation devices.

IK Classification

The IK code or impact resistance level is used to classify mechanical impact protection. This can also be given as a value in joules. The higher the IK rating or joule value, the higher the impact resistance.


Illuminance is the luminous flux falling on a surface per unit area. Illuminance is given in lux (lx). It is the most important measurement for the user, as it describes the brightness on the floor or work surface.

INI Light

The INI-ON and INI-OFF functions determine whether the main light is switched on (INI-ON) or off (INI-OFF) during the self-test cycle. The factory setting is usually light on during self-test cycle.

IP Classification

The IP classification denotes the product’s protection rating. The first figure denotes protection against dust, and the second against water. The higher the figures, the higher the protection rating.

IR Adapter

When using the B.E.G. smartphone app, the infrared connection to the detector is made via the B.E.G. IR Adapter. This simply plugs in to the headphone socket of a smartphone.


KNX is a worldwide standard bus for building automation. The KNX standard is an open standard, to which currently over 400 companies worldwide are affiliated.


see: Luminous Flux

Luminous Flux

Luminous flux is the light energy radiated from a light source or a light fitting. The luminous flux from a light fitting is always less than that from a light source, due to losses in the fitting. Luminous flux is given in lumens (lm).


see: Illuminance

Master/Slave Devices

Master devices control the lighting, and give switching and control commands to the system to which they are connected. A master device’s detection area can be extended by a slave device.

Mixed Lighting Detection

Mixed light is the term for a combination of natural light and artificial light. In mixed lighting detection, the occupancy detector measures the total of artificial light plus daylight, so that the artificial light can be switched off as daylight increases.

Motion Detector

Motion detectors react to movement in the immediate area. If movement is registered by the detector and the light level is below the lux value set, the lighting is switched on. If movement is no longer registered, the detector switches the light off again after a selected follow-up time. Motion detectors measure the light level only during the switch-on process. This means that if new movements continue to be detected, the artificial light remains switched on even if daylight levels increase. Therefore motion detectors are primarily suited to installation outside, or in transit areas such as hallways and stairways. Most motion detectors use PIR technology (see: Passive Infrared). There are also motion detectors that use HF technology (see: HF).

Occupancy Detector

Occupancy detectors work using PIR or HF technology and contain one or more light sensors. If movement is detected and the light level is below the lux value set, the lighting is switched on. Occupancy detectors have highly sensitive sensors and can capture even the smallest movements perfectly, such as typing on a keyboard or moving a mouse. Unlike motion detectors, occupancy detectors measure light levels continuously. This means that if there is sufficient light from daylight, the artificial light is switched off, even if the detector continues to detect movement. For this reason, occupancy detectors are best for rooms in which people stay for long periods.

Orientation Light

A dimming value is set in the detector as a percentage for orientation lighting. The light can be dimmed to this value once no more movement is detected. This means that areas with a safety requirement are not completely dark, but energy is still saved compared to having the main light on.

Orientation Light Plus

The same as “Orientation Light”, but with more flexible settings (5% to 90%)

Party Function

The party function deactivates automatic lighting control for 12 hours. When activated, the light can be switched on or off.

Passive Infra Red (PIR)

Passive infrared sensors capture heat emissions given off by warm moving objects. They emit nothing themselves, and are therefore described as passive.


PC-Tools is a Windows application package specifically for the B.E.G. DALISYS® lighting control system. The applications enable the addressing, grouping, setup and maintenance of all components on a DALI circuit.

Peak (light fitting)

The peak is the point on a light fitting where the brightness is highest. For this, the light fitting is considered from all sides. Too high a brightness on the light fitting can lead to dazzle.

PF (Power Factor)

The power factor describes the relationship between effective power (P) and apparent power (S). As high a power factor as possible is sought in electricity supplies to avoid transmission losses. In an ideal case, it is exactly 1.


The basic parameters of switch-on threshold, follow-up time and desired brightness can be set directly on the detector by using a screwdriver to adjust the potentiometers.

Projector Mode

If the light is switched off manually via a connected switch, the light remains off for as long as motion is detected, plus the delay time that was set.

Radar detector

see: HF

RC Suppressor or arc extinction kit

RC suppressors provide any necessary suppression for the lighting installation. For technical reasons, voltage spikes when switching inductive loads (e.g. conventional ballasts), especially combined with long wiring runs, can lead to unexpected operation of ceiling or motion detectors. For large installations where many electronic ballasts are controlled in parallel, the use of RC suppressors is recommended. The best suppression can be achieved using an installation close to the source of interference.

Reed Relay

A reed relay is a particularly quiet kind of relay, from which no switching noise can be heard.

Reflection Factor

The brightness at a work surface differs from the brightness measured by the occupancy detector at the ceiling. The reflection factor is the relationship between the brightness at the ceiling and that at the work surface. Under normal room conditions, the reflection factor is around 2. This value is set as a factory setting in B.E.G. detectors. To equalise differences in the room, the reflection factor can be changed.

Regulation Mode

In regulation mode, the detector regulates/dims the artificial light according to the amount of natural light.

Reserve Power

In time switches with reserve power, there is a backup battery. This is for covering power cuts.


In semi-automatic mode, the lighting is not activated by movement, but has to be switched on manually at a push button. Once movement is no longer detected, the selected follow-up time begins, after which the light is automatically switched off.

Set Value

The set value describes the illuminance (lux value) desired by the user in that room.


The abbreviation “SM”, in B.E.G. motion and occupancy detector product names, means surface mounting.

Smartphone App

All B.E.G. remote control-capable B.E.G. detectors, lights, emergency lights and photo electric switches can be adjusted with the B.E.G. smartphone app. Data can also be retrieved from bidirectional devices. The app replaces all previous remote controls. To use the app, you need a compatible smartphone and the B.E.G. IR adapter. User-friendly navigation makes controlling B.E.G. devices easy.

Soft Start

Soft Start is a function which can be activated or deactivated in all DALI products. If activated, the light is regulated to 10% of its full intensity at the moment that it is switched on. After that, the artificial light is automatically regulated to the defined set value. If the function is deactivated, regulation starts from 100% when the light is instructed to switch on.

Soft Start PLUS

The same as “Soft Start” but with more flexible switch-on values (10% to 90%) and additional “calculated switch-on value” algorithm.

Status LEDs

Status LEDs are for displaying and indicating various states/functions of occupancy and motion detectors.

Switching Mode

In switching mode, the detector switches the light on or off.

Switching Threshold

The switching threshold denotes the illuminance (lux value) at which the artificial lighting should be activated or deactivated.

Switch-on Threshold

With switching detectors, the brightness level at which the lighting is switched on is described as a switch-on threshold. Only below this level is the light switched on by movement.

Tamper Protection

Tamper protection deactivates the infrared interface for the remote control in the detector, to prevent accidental or deliberate changing of the settings without the consent of the owner.

Test Mode

Test mode is for determining the size of the detection area (range). For this purpose, when each movement is detected, the detector switches on the main light for two seconds, then off for two seconds.


see: Colour Rendition

TRIO Occupancy Detector

TRIO is how B.E.G. describes occupancy detectors which have three channels. Depending on the product, these three channels can be switch contacts or DALI interfaces.

Unidirectional Remote Control

A unidirectional remote control allows commands and settings to be sent to a remote control-capable device. However, the remote control cannot receive data from the device.

Vandalproofing/Vandal Protection

B.E.G. offers accessories for some products, which protect them from unauthorised access, e.g. a securely screwed-down potentiometer cover.

Weekly Time Switch

Weekly time switches allow individual switching times to be set for each day of the week.

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