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The iWISE intruder detector series features Rokonet's Anti-Cloak Technology (ACT), and uses a new patent pending processor designed to ensure no burglar can fool the detector and pass undetected. The ACT system is criteria driven, automatically switching from dual-channel PIR/MW mode to single-channel MW mode, should the infrared capability become compromised.

The proprietary technology will cope with an attempt by a burglar to conceal his IR radiation using camouflage techniques, or should the ambient temperature reach that of normal body heat, when the PIR element is unable – even with 'temperature compensation' techniques – to differentiate between the intruder and his background.

ACT identifies these situations by utilising pattern recognition algorithms within the microprocessor of the sensor and automatically switches the detector to trigger alarms based solely on detection from the microwave channel for a predefined window of time.

This 15m range detector is expected to be specified for the upper domestic/lower commercial market where a high level of stability is required to cope with expected environmental problems, such as RF interference, rapid temperature changes or draughty locations.

The unit is CE marked for European compliance and comes with a reasonable two-year guarantee.

N.B. The ACT should not be confused with anti-masking technology, designed to give a trouble output if the PIR or MW detection sensors are blocked at source by a physical barrier of some kind.

The two-part case is constructed from a very rigid ABS plastic in a soft white finish, with a single white-headed screw on the underside to secure the cover. The Rokonet series of dual technology and passive infrared detectors has been on the market for many years now, and installers will be familiar with the visual design. Overall, the detector is professional and looks the part. Customers are also known to be fond of the three different coloured LEDs! These represent activations by each technology – green for MW, yellow for PIR, and red for both together.

The whole case, including the optical section, is sealed against insect and dust intrusion, so the cable entry and wall mounting holes need to be created in the usual 'knock out' positions for either flat or corner mounting.

Inside the case, the printed circuit board is secured by a small 'posi' head screw holding it firmly in place. This PCB design allows a small amount of vertical movement within the case to increase or decrease the working range of the PIR detection. The operational mounting height is fairly flexible, between 2.1m and 3.3m.

It should be noted however, that increasing the mounting height above 2.7m creates an operational blind spot beneath the unit that cannot be corrected by sliding the PCB fully up inside the case. This may or may not be a problem depending on the situation. Microwave range adjustment is achieved via the potentiometer on the face of the PCB.

The wiring connections are via a six-way terminal block along the top edge of the PCB. Connections are printed on the PCB using conventional terminology, thus negating the need to consult the technical literature. A six-core cable is the minimum requirement to provide for 12v DC supply, one normally closed anti tamper pair and one normally closed alarm output pair.

There is now more space inside the detector case for wiring along the top edge of the board. This is a distinct improvement over the existing RK 115 DT, where wiring space inside the top of the case is at such a premium that it is commonplace to pinch the feed wiring when snapping the board into place (not to mention the difficulty of including an 'ADE' biscuit with point ID configuration).

Two pairs of jumper pins are provided on the face of the PCB, one to select the 'anti cloak technology', the other to disable/enable the on board traffic lights, sorry, walk test LEDs!

The iWISE DT has no memory latch, and no pulse counter for the passive infra red detector, which uses only a single dual pyro head (unlike the very popular Rokonet Cosmos 'Quad' type sensors that uses twin dual heads).

Although the front case is slightly different to the existing range of Rokonet Quad PIRs, single element PIRs, pet detectors and standard DTs, it is still similar enough to be able to mix and match detectors within the same installation without causing an aesthetic problem. Customers are very unlikely to notice the slight difference, much less create a fuss.

The back case is uniform throughout the range, giving installers the luxury of a swift retro fit should the need arise for a different type of detector. The whole concept of a uniform range of very similar detectors is thoughtful and clever, and is surely a model for other manufacturers to follow.

We found the current consumption to be more or less as per the quoted specification at 20mA, rising to 40mA when all three LEDs are illuminated. And though the detector is designed to operate at a nominal 12v DC, the voltage range is said by Rokonet to be usable from 9v – 16v DC. The relay output gave a reading of less than 1 Ohm for a changeover period of around two seconds. The technical literature gives an impressive operational temperature range, from –20 to + 55 degrees C. That should just about cover it for most situations!

The lens is segmented into 62 zones divided into four horizontal layers, plus an additional look down or 'creep' zone immediately beneath the detector. The horizontal spread of the detection pattern was close to 90 degrees, though by observing the green LED, it is obvious the microwave technology exceeds the PIR coverage in every way, including length, width and speed of catch.

We mounted the RK iWISE DT at 2m height for the duration of the test, where it performed very well during our series of standard tests (see perfor-mance panel). In a further test, the unit reverted to MW only operation in a confined, heated environment and continued to give good results.

It has to be said the microwave detection is very 'lively' and careful consideration needs to be given to positioning and MW range adjustment. Installers should always bear in mind that microwave energy can readily penetrate low density brickwork, woodwork, plaster board and glass. That means MW detectors are prone to trigger in situations that a PIR would tolerate, such as running water through pipes, slight movement of surfaces and movement on the outside of the premises.

Instructions & technical support
The accompanying instructions are provided on a single printed A2 sized sheet with schematic diagrams for identification of parts and coverage patterns for the PIR detection area. The instructions are methodical with installation guidelines in text and picture form, including explanations of the ACT technology. A specification is included with all the information required by an installer, i.e. current consumption, operating voltage, operating range and temperature requirements.

The telephone number supplied for technical support is on the instruction sheet, together with telephone numbers and instructions in Francais, Espanol, Italiano and Portugues, should you find yourself in those parts of the world. The English instructions are well translated into good English, which is always welcome. We were also able to obtain the telephone number using directory enquiries, whereupon we were treated efficiently and courteously by one of the Rokonet team who was willing to chat at length about ACT. N.B. Do not try to telephone this company between 1 and 2pm. It shuts for lunch.

What the manufacturer says ...
The iWise with Anti-Cloakâ„¢ technology is the first true breakthrough in detector technology since the introduction of dual technology. Providing the benefits of DT while avoiding its drawbacks, this patent pending innovation is expected to set a new standard for the security industry. The benefits of combined PIR and microwave detectors are of course false alarm immunity: both channels have to detect to generate an alarm.

However in a growing number of burglary cases, unexplained misdetection occurs when detectors fail to raise an alarm. This is due to vulnerability of PIR technology in two specific cases:

When ambient temperature is close to body temperature the infrared energy emitted from an intruder is similar to the IR emitted from the room background, therefore PIRs cannot detect any signal difference. In this case the PIR channel is ineffective, because no matter how advanced the temperature compensation mechanism is, there is just not enough signal difference to analyse and detect an intruder.

It is easy for an intruder to elude PIR detection by camouflaging himself with an umbrella or other IR emission blocking screen or canvas, in a "cloaking" attempt.

So Rokonet has developed ACT™ – a revolutionary anti-cloak solution, a milestone in motion detector technology. Offering significantly higher detection capabilities as well as immunity from false alarms, ACT™ thwarts even sophisticated burglars. The concept of ACT is identifying cases in which PIR detection is problematic, and automatically switching to microwave-only detection.

Anti-Cloakâ„¢ Technology measures the ambient temperature and switches to microwave-only detection when the temperature is close to body temperature. False alarm immunity is not compromised because in microwave-only mode the microwave sensitivity is reduced.

This is accomplished by increasing the threshold of the Doppler pulse required for triggering an alarm and by increasing the number of Doppler pulses required for triggering an alarm.

Anti-Cloakâ„¢ Technology concentrates only on the shape and frequency of the signal and disregards signal strength. Using complex pattern recognition algorithms ACTâ„¢ is able to identify a camouflage attempt by a moving intruder. When ACTâ„¢ identifies a camouflage attempt in the PIR channel and microwave detection is present, it switches to microwave-only mode for a short window of time. False alarm immunity is not compromised because the ACTâ„¢ algorithms filter out all causes of false alarms in the PIR channel.

Reader Service No 101