© 2009 AtlasGroup GmbH

Frequently Asked Questions

1. Fields of application

2. Energy saving

3. Installation

4. Interoperability/compatibility

5. Range

6. Technology

7. Sources

1. Fields of applicationWhat applications is EnOcean technology suitable for?

The applications are already very different, and are likely to expand very much in future. The focal use is in building automation. Functional areas for EnOcean sensors are for example: temperature, brightness, presence, dampness, gas, current, contact, flow and pressure. Functional areas for switches are for example: wall switches, remote controls, industrial switches, multiple switches, dimmers, blinds. In addition to the typical switching and control purposes, EnOcean technology can be used in quite different areas.

see application notes for EnOcean modulessee list of products based on EnOcean technologyCan I integrate EnOcean switches in furniture?

EnOcean technology is just made for this purpose. If a new cabinet or wall unit obstructs an existing light switch for instance, a wireless switch can easily be adhered to the side of it. Direct invisible integration in items of furniture is also conceivable, and a first manufacturer has already accomplished this: the company Funktechnik developed an office chair with an integrated presence detector that can form part of a workplace control system.

Are there EnOcean products for more convenience in sanitation and plumbing?

EnOcean switches are excellent for attachment to the tiles in a bathroom. A further example is that of the company Aqualisa in England. It created a switch module for a shower system (digital shower) that increases water pressure by remote control, and is suitable in particular for old housing or regions with a run-down water supply system.

Are there wireless motion detectors?

The new presence detectors SENSOLUX from Flextron or Eagle PM101 from Omnio are absolutely energy-autonomous, and need neither cabling nor batteries. This is made possible by highly optimized electronic circuitry and an innovative indoor solar cell, allowing operation for days in complete darkness.

Is EnOcean technology suitable for hydraulic applications?

In 2004 MD engineering GmbH developed a telemetry system that can detect hydraulic pressure up to 600 bar and signal it wirelessly. The system is suitable for mobile hydraulic plant on ships, construction and agricultural machinery.

Is EnOcean technology also suitable for efficient energy consumption metering?

Wireless heat cost allocators promote energy-conscious and economical consumption, and are already in use in millions of buildings. In the meantime about 20% of all heat cost allocators in Germany are wireless-based, 80% are currently going wireless. The wireless heat cost allocator means that nobody has to enter a home to read a meter, and tenants no longer have to wait for someone to come and read their meter. Landlords appreciate wireless units because they cut the administrative effort and cost: no rearrangement of appointments for meter reading, no on-the-spot readings, no reading errors, less trouble with tenants.

A huge market: the total inventory of heat cost allocators in Germany is 31 million (classic evaporators and wireless, 2006), and of these 6.2 million are wireless heat cost allocators (up from 5.1 million the year before; source: Techem).

Thermal generators to produce energy from the difference between the temperature on radiators and room temperature are currently being developed at EnOcean. These will be the basis for absolute servicing freedom of wireless heat cost allocators, because it will be possible to do away with the bothersome replacement cycles of expensive, miniaturized high-power batteries.

Will EnOcean technology let me integrate windows in an automation solution?

EnOcean technology is ideal for the use of room security and climate control systems. The STM 250 and STM 3xx window/door contact (868 MHz) works with a tiny solar cell for instance, and can signal by means of a magnet whether a window is closed or open. Periodic presence detection is also possible. Windows can also be integrated in automation solutions by a wireless window handle marketed by Hoppe. When a window is opened for example, the mechanical turning generates energy to send a wireless telegram. This automatically cuts back the heating of a room while a window is open.

Door handle switches with EnOcean technology have been developed by Steute.

Is it possible to dim halogen low-volt lamps by EnOcean switches? Yes, matching the Touch DIM wireless receiver from Osram there is the 150 VA HTi DALI dimmer for low-volt lamps, also from Osram.

Are EnOcean sensors also suitable for use in damp locations? EnOcean technology is absolutely service-free, so it allows partner companies to develop fully hermetically tight switches and sensors for use outdoors or in damp locations.

Are there radiator thermostats with EnOcean technology?

Oventrop markets in cooperation with Hoppe (window handle switch) the Uni LHZ thermostat head with timed temperature regulation and automatic cutout when windows are opened.

Is EnOcean technology suitable for implementing wireless foot switches?

The Steute company has used EnOcean technology to create wireless foot switches. Depending on the application you find foot switches with a solar cell and energy accumulator, or foot switches that derive their energy from movement of the tappet.

Can I use self-powered EnOcean switches to drive a blinds motor?

Yes, because the wireless switches generate energy for wireless transmission by the EnOcean principle both when pressed and when released. Plus, an EnOcean wireless switch can send a telegram indicating that it is pressed or released. Using an appropriate blinds receiver, a blinds motor can start moving when the switch is pressed, and keep moving either until it reaches the end position or the blinds switch is released and sends a stop telegram.

Will self-powered EnOcean switches drive a dimmer?

Yes, EnOcean switches are suitable for continuous regulation of lamps by a dimming actuator. The wireless switches generate energy for the wireless telegram both when pressing the up or down switch or releasing it. In this way the dimming actuator can increase or reduce the brightness in fine steps after receiving the "Switch pressed" telegram either until the final level is reached or the switch sends the "Switch released" telegram.

Are EnOcean sensors also suitable for use in rooms where explosion proofing specifications apply?

EnOcean technology is absolutely service-free, so it allows partner companies to develop fully hermetically tight switches and sensors for use in sensitive environments with readily flammable objects, gases or fluids.

What possibilities of self-powered temperature detection are there with EnOcean technology?

Thermokon Sensortechnik GmbH cooperated with EnOcean to develop the first self-powered room thermostat with temperature sensor and setpoint control. The sensor module obtains its energy from a tiny solar cell that works reliably even in poor light conditions. An ideal solution for modernizing heating plant is the SR65 self-powered outside temperature sensor – it can be simply screwed to the outside wall of a building without any cabling at all.

The company Wurm-Systeme has developed E-link pro, a self-powered temperature sensor for integration in the commodities compartments of commercial refrigerators. This is suitable for supermarkets and can continue working in up to four days of darkness.

Are there self-powered position switches for integration in electric machines?

Balluff GmbH has developed rugged position switches and multi-position switches for detecting position and switch-off at limits on machine tools, transfer lines, conveyor devices, etc. These derive their energy solely from the switching operation on a tappet.

Can door handles be combined with a wireless sensor?

Door handles with an integrated switch to operate machines have been around for some time, but they required an elaborate cable trailing device. So in 2004 the Steute company developed a door handle switch using EnOcean technology. Window handles with EnOcean technology have also been developed by Hoppe for example.

2. Energy savingHow big is the energy saving potential of building automation?

Buildings chiefly need energy in the form of heating and hot water (approx. 25 to 33% of the overall primary energy household in Germany) and electrical power, part of it for lighting (approx. 2% of Germany's overall primary energy consumption). Combining building automation and intelligent sensor concepts can produce energy savings of up to 30%.

How much energy can be saved by shade installations?

Inside blinds are anti-dazzle protection. But unlike outside blinds they cannot prevent a room from heating up in summer. Outside blinds and shutters reduce the energy need for air-conditioning, but require flexible operation direct from the workplace or a living room couch for instance. Wireless controls are consequently becoming more attractive. Currently 25% of all electric roller blinds and 60% of all shutters in Europe are controlled wirelessly (source: IO Homecontrol).

How much energy can be saved by lighting control on demand?

In the average office building a third of the power consumed is for lighting. People are always forgetting to turn off lights during the day. Lights are left on in many corridors and staircases, even outside of business hours. In banks and insurance corporations the average power consumption per head is more than 5000 kWh. That is more than in most households.

There is major potential for saving of 500 kWh per year and worker if lights were left on all day until now. 350 kWh per year in a 10-meter-long corridor with windows if light is only turned on when needed (communicating routes and siderooms occupy 30% of the area in office buildings).

250 kWh per year in a toilet room if lights are only turned on during someone's presence.

By using the right kinds of light and intelligent light control, it is possible to both enhance personal comfort and convenience and to cut energy consumption. Halogen lamps produce about twice as much as light as conventional filament lamps for the same electric power. Fluorescent and energy-saving lamps only take about 20% of the energy of a conventional filament lamp, but they are more expensive to manufacture and consequently cost more. So energy-saving lamps should only be used where light is needed for a sufficiently long, single period. But there is enormous further potential for saving: By lighting with fluorescent lamps and using motion and light sensors together with electronic (dimmable) control gear, it is possible to save as much as 70% compared to conventional control gear (source: Wikipedia). EnOcean enables service-free and wireless switches, motion detectors and light sensors to be placed where they are of optimum benefit. For example on flexible room partitions, furniture and other objects, on concrete ceilings and walls, and in renovations and conversions.

How much energy can I save by using wireless window contacts?

Reducing average room temperature is one of the most effective ways of saving heating energy (source: Wikipedia). Corridors and hallways, siderooms and bedrooms can all be heated to just 15°C without any loss of comfort. A temperature of 20 to 22°C is adequate for offices and living quarters. Energy consumption can be very much reduced if a system lowers the heating temperature as soon as users leave a room for a longish period. An interesting option in this context is central temperature regulators for single rooms. These are systems by which the temperature in different rooms can be regulated from a central point according to different time and temperature presettings. The saving through central temperature regulation of single rooms is put at 20 to 30% (source: Bremen Energy Institute). Cost reductions in microelectronics and through innovative wireless technology mean that solutions are possible today that would have been confined to the upper price segment just a few years back.

Simple thermostat valves open when cold air drops because of the anti-frost safeguard. So constantly tipped windows over radiators should by all means be avoided, especially in winter. Only open windows briefly for ventilation. According to a study by IFE Krefeld, the daily room heat energy need can be reduced 40% by using window contacts. When a window is opened, the heating in the room immediately cuts out. Calculation was based on daily airing for one hour with a difference between inside and outside temperature of 10°C. The considerations are identical when it comes to air-conditioning. Each degree more of room temperature means more than 4% less power for cooling (source: LfU). The right energy-saving and environment-friendly approach is by controlling sensors placed correctly as a function of place, time and use (temperature, humidity, presence).

3. InstallationCan EnOcean switches be attached to smooth surfaces?

Yes, many of the wireless sensors and switches offered by partner companies as well as the universal easyfit PTM 250 switch insert from EnOcean are easily adhered to smooth surfaces, and even to panes of glass. Delivery usually includes a special two-sided adhesive pad matched to the size of the switch.

How can I measure the receiving level of EnOcean sensors where I want to use them?

For these purposes EnOcean offers its EPM 100 level meter and EPM 200 wireless test set.

4. Interoperability/compatibilityWhy is EnOcean technology not compatible with other wireless switches? '

EnOcean intentionally opted for an extremely short wireless telegram, because this is the only way to ensure that several hundred wireless switches can work reliably in a tight space. Conventional wireless switches take 70 to 100 milliseconds to send a wireless telegram, while an EnOcean telegram is delivered in less than a millisecond. A description of the EnOcean Equipment Profiles (EEP) can be found here. Furthermore there exists the EnOcean Alliance to formalize the interoperable wireless EnOcean standard that is used across a wide range of products (see here for further information)

Can EnOcean technology be integrated in building automation?

Yes, in the meantime there are more than 60 manufacturers offering EnOcean components for building automation. Wireless receivers are already available for automation systems from GTE, Beckhoff, Phцnix Contact, Siemens, Wago and Wieland. Wireless gateways allow integration into all common building bus systems such as EIB/KNX, LON, TCP/IP and BACnet.

Are EnOcean switches also compatible with conventional ranges of flat switches?

EnOcean delivers the technology for self-powered wireless switches to very different manufacturers of installation switches, for instance PEHA (with its aura switch range) or Jдger-Direkt (with its Opus switch range). There is also the universal easyfit PTM 250 switch insert. This is compatible with designs with a 55 x 55 mm rocker from the manufacturers Berker (S1, B1, B3, B7 glass), Gira (Standard55, E2, Event, Esprit), Jung (A500, Aplus), Merten (M-Smart, M-Arc, M-Plan). This switch insert comes as a single or serial rocker in the colors white, aluminum and anthracite.

Is there EnOcean technology to match flat switches from Busch-Jдger?

The self-powered PTM 200 wireless module was integrated in the switch ranges Carat, Future, Future Linear and Solo from Busch-Jдger. Wireless flat switches are available through the manufacturer Thermokon.

Can EnOcean technology be used together with DALI terminals?

Yes, together with a wireless terminal from Wago for example, it is possible to drive room boxes by the digital addressable lighting interface (DALI) without extra cabling.

How can an EIB/Konnex automation system work with the EnOcean world?

Wieland Electric, for example, has developed gesis RC as a wireless gateway to the flexibly programmable EIB/KNX (European installation bus/Konnex) building automation system. The gateway was certified by the Konnex Association, and comes in a flatpack with the connectors usual with gesis components.

Thermokon offers the SRC-KNX/ENO, a wireless gateway with 32 individually assignable channels.

How can EnOcean technology be integrated in an Ethernet architecture?

In the SRC-Ethernet, Thermokon has developed a wireless receiver that can convert telegrams from EnOcean sensors.

5. RangeWhat is the range of EnOcean components?

In the open the range is typically up to 300 meters and in buildings up to 30 meters. To enable a longer range to be covered, EnOcean can offer the TCM 110 and the TCM 3xx class of repeater modules.

Which wall and ceiling materials cause how much loss in EnOcean wireless transmission?

Wood, plaster and uncoated glass attenuate between 0 and 10%. Brick and pressboard produce attenuation of between 5 and 35%. Concrete with iron reinforcement must be expected to attenuate between 10 and 90%. Metals and aluminum laminate show attenuation between 90 and 100%.

Will an EnOcean switch let me pass through a wall? Given the physical propagation conditions in the frequency band that is used, it is even possible to penetrate a number of walls of normal material. Even thin structural steel concrete walls can be penetrated. In this frequency band, wireless waves reflected on walls may also penetrate through smaller openings.

In the case of walls of wood or gypsum plasterboard the typical range of EnOcean sensors is 30 meters or as many as five walls. For brick and aerated concrete walls the typical range is 20 meters or maximally three walls. For structural steel concrete walls and ceilings the typical range is 10 meters or maximally one ceiling.

How can I nevertheless increase range if necessary?

To cover a long range or pass through thick structural steel concrete walls, EnOcean has developed bidirectional components that automatically retransmit a received wireless telegram (TCM 110 repeater, TCM3X0 repeater class).

How can I check wireless coverage in my building?

For electricians and building planners, EnOcean offers the handy EPM 100 level meter. A LED display indicates the signal quality of EnOcean transmitters at the intended location of a receiver. The device also enables location of possible sources of interference. Alternatively the level meter comes in the EPM 200 wireless test set, additionally including an easyfit PTM 250 switch and a rugged plastic case for protection during transport.

Are there likely to be problems if I want to integrate an EnOcean receiver in a control cabinet or fuse box of metal? Of course the basic principles of electromagnetic shielding through metal walls and the resulting, substantial reduction in range also apply to EnOcean receivers. If a receiver nevertheless has to be installed in a heavily shielded enclosure, EnOcean offers prefabricated packages for fast and simple installation of an external antenna.

6. TechnologyHow secure is EnOcean technology against manipulation?

Basic methods for security against manipulation are already implemented in the EnOcean system architecture: Each transmitter has its specific 32 bit ID as a fixed part of its transmitted telegram. This ID cannot be copied with the bidirectional EnOcean module. Further measures for greater security such as rolling code and encryption are in preparation.

Why does not EnOcean use battery-backed wireless switches?

For EnOcean the reliability of products is an absolute must. The disadvantage of batteries is their self-discharge, meaning that they usually have to be replaced after a few years. That would involve removing a wireless switch or sensor from the wall or wherever to service it.

For reliable operation, especially in buildings with a large number of wireless switches for instance, you have to schedule the battery replacement cycle in good time so that those units with the most intensive duty always have sufficient energy reserves. As a result, with the majority of the batteries more than half the energy ends up unused in the refuse. And in terms of environmental protection that is simply a crime.

Can the EnOcean wireless module also be designed into a sensor with a battery as an alternative?

Yes, it is possible to power the STM 110 sensor module from a battery. You can find details of this in the user manual under "Appnotes". But in our experience, as soon as a planner gets to know the batteryless alternative, they will not want to build any more products with batteries.

Are EnOcean wireless modules capable of bidirectional communication?

The new EnOcean Dolphin modules (STM 3xx, TCM 3xx) are capable of bi-directional communication and can transmit information as well as receive it. Devices from different manufacturers can communicate through the EnOcean standard and cooperate with one another in one and the same system. Furthermore the new platform remains backward-compatible with all earlier unidirectional wireless switches, sensors and actuators in EnOcean technology.

Can I program my EnOcean module myself?

Matching the new EnOcean Dolphin modules (STM 3xx, TCM 3xx), EnOcean offers an operating system with a programming interface (API) that allows you to write application-specific software. In addition, the SMART ACK software library function allows feedback from energy harvesting wireless sensors from EnOcean. The EDK 300 developer kit gives the designer a fast and full overview of the Dolphin platform and contains the Dolphin API and the Dolphin Studio software for programming TCM3xx/STM3xx modules.

Can Bluetooth communication (GSM cellphone, etc) interfere with EnOcean components?

No, because Bluetooth works to standard 802.15.1, and in an entirely different frequency band at 2400 MHz.

What is the situation like with data collision and latency?

EnOcean technology was developed to enable several hundred sensors to work in one radio cell at the same time. This is made possible by the extremely short telegrams (only about one millisecond) and triple redundant transmission with a random time shift. The subtelegram repetitions are a few milliseconds, which is the latency time. In the worst case (if all three subtelegrams are lost), data integrity is restored by cyclic presence telegrams. The time is for the most part selectable by the user.

Why did EnOcean opt for the 868 MHz frequency band and not for the 433 MHz band that is also commonly used in telemetry systems?

EnOcean technology works in a wireless channel at 868.3 MHz with a bandwidth of 240 kHz that has been released in Europe exclusively for short data transmission. All users of the wireless channel may only operate with 1% duty cycle, meaning maximally 0.6 seconds transmission in one minute. In contrast to the 433 MHz telemetry band, here the transmitting power is also limited for all users to 10 mW. At 868.3 MHz there is neither walkie-talkie operation nor the often very strong interference from medical radiotherapy apparatus. Nor are there radio amateurs, who can cause a lot of interference to secure wireless transmission.

What happens if, quite by chance, two different EnOcean switches in a room are operated at exactly the same time?

In principle the two wireless telegrams would interfere with one another of course, or the signal further away could be lost. But unlike in other wireless switch technologies, each EnOcean telegram is repeated twice within about 30 milliseconds for greater data security, the delay between the transmitted bursts being random controlled. This very fast and short multiple transmission enables very many transmitters to work in parallel in tight confines on the same frequency and with an extremely low error rate. Statistically seen, even with 200 wireless sensors each transmitting once per minute, the possibility of a data collision is every 10.000th transmission.

Could an EnOcean sensor accidentally trigger an incorrect switching pulse?

Each EnOcean module already has an individual 32 bit identification ex works, which is transmitted in each telegram – so 4.3 billion different modules can be addressed. Even if more modules are produced in future, the likelihood that two modules with exactly the same ID could be used in the same application is most extremely low.

Can I use several EnOcean switches to operate a light or a motor, and can I activate several loads simultaneously with one switch?

Naturally an EnOcean receiver can learn several switches or sensors – the single-channel RCM 250/255 switching actuator receiver for instance can learn as many as 30 wireless switches from the PTM product family or one or two wireless window contacts of the type STM 250/ STM 3xx. Reversely, EnOcean transmitters can be teached to any number of receivers.

How much electrosmog does an EnOcean switch produce?

The transmitting power of EnOcean components, as for all other conventional wireless switches, is maximally 10 milliwatts. But much less energy is radiated because the wireless telegram is so extremely short. A scientific investigation by the Institute for Socioecological Research and Education (ECOLOG) even showed that the emitted radio frequency field of an EnOcean telegram is one hundred times less intensive than that of a conventional light switch produced by the characteristic sparking when it is turned on and off.

Are EnOcean switches compatible with Feng Shui principles?

The emitted radio frequency field of an EnOcean telegram is one hundred times less intensive than that of a conventional light switch produced by the characteristic sparking when it is turned on and off. For this reason a number of architects have chosen EnOcean technology when creating office buildings by Feng Shui aspects. In the Feng Shui certified aviva MUNICH office complex, the current corporate headquarters of Bosch Siemens Hausgerдte GmbH, numerous EnOcean sensors were installed in 2003.

What is the mechanical load of energy converters from EnOcean? Mechanical load is a subject with energy converters for linear motion. Converters for building automation are currently specified with 50,000 operations. But basically there is no reason why switching modules should not be constructed in future that satisfy typical industrial requirements of several million operations.

With what transmitting power does EnOcean technology work, and in what frequency band?

All EnOcean components, like many other conventional wireless switches, transmit a maximum 10 milliwatts. The frequency band used in Europe is 868.3 MHz. All users of this frequency - released in many countries for telemetry purposes - may only operate with 1% duty cycle, meaning maximally 0.6 seconds transmission in one minute.

In North America the technology operates in the less common 315 MHz frequency band.

For what kind of sensors does EnOcean technology work?

In principle this is of course a question of the energy balance. Basically EnOcean is suitable for all sensor elements that are only briefly operated. Typical times are 1 millisecond at a current of 2 milliamperes. On a 5 volt supply you then have a total energy need of about 10 microwatt seconds per measurement. This is of the order it takes to send a wireless telegram. A solar cell produces about 20 microwatts at 400 lux, a thermogenerator about 20 microwatts at 5 Kelvin temperature difference. So what is important is the ratio of measurement duration to the number of measurements in time (on/off ratio). Typically the measurement cycles should be in the range of seconds rather than milliseconds.

How secure is communication against noise fields in a rough industrial environment?

EnOcean technology is already used intensively in industrial environments, and has been successfully trialed in automobile engine compartments. EnOcean wireless transmission is in a high frequency band where the typical spark chopping energy is relatively small. Plus, the specially selected timing of the triple redundant telegrams ensures very high resistance to interference in the typical industrial 50 to 60 hertz range.

What spacing should be maintained between EnOcean components and other wireless transmitters?

EnOcean transmitters may easily be installed next to other transmitters. EnOcean receivers, however, should be positioned at least 50 centimeters away from other transmitters (e.g. GSM, DECT, WLAN) and high-frequency sources of interference (computers, audio and video equipment and the like).

Normal wireless transmitters really only need very little power, and the batteries only have to be replaced every few years – what is wrong with that ecologically?

5 million wireless transmitters were sold in 2006 for building automation alone. For the near future this figure can be expected to almost double annually. So in this sector alone, more than 100 million batteries will be in use in only 5 years, and consequently need replacement in due time. Another example is the automobile industry – there is hardly any new vehicle in which the central interlock does not work wirelessly. For each of these vehicles the service schedule would normally foresee replacement of the battery in both ignition keys every two years. Consistent use of batteryless EnOcean technology will take a huge load off the environment within a few years.

Is vibration suitable for producing energy for wireless sensors?

In 2004 already, EnOcean demonstrated the capability of a vibration energy converter on a laboratory mockup. The sensor was powered solely by the vibration of the bearing plate of a grinding tool, and was able to transmit measured values every second. No product of this kind has yet been manufactured however.

Can EnOcean components be disturbed by WLAN communication (wireless DSL adapter, audio transmission, etc)?

No, because WLAN components work to standard 802.11, and in entirely different frequency bands at 2400 MHz or higher.

Can EnOcean components be disturbed by ZigBee communication (short-range telemetry, etc)?

No, because ZigBee components work to standard 802.15.4, and primarily in the 2400 MHz frequency band. The ZigBee variant for the 868 MHz frequency band works in a different wireless channel. A further ZigBee variant for use in the USA works at 915 MHz.

7. SourcesWhat does EnOcean deliver?

EnOcean GmbH is the developer of the innovative basic technology - self-powered wireless sensor technology - and sells modules direct to OEM partners or offers them through an international network of distributors.

Where can I obtain products based on EnOcean technology? Products based on EnOcean technology can be obtained direct from the manufacturer (OEM partner) or from specialist retailers. For private customers there are also online shops.

What does EnOcean GmbH supply?

As hardware EnOcean GmbH supplies complete transmitter modules with energy converters, energy management, microcontrollers, wireless transmitters, antennas, receiver modules and wireless receivers. In addition EnOcean supplies detailed technical documentation, such as data sheets, manuals and application notes.

As design-in support there are various evaluation kits such as EVA 100 or EVA 120 (for 868 MHz modules) and the EDK 300(C) for EnOcean Dolphin modules.