Intruder Test: Risco RWT74

Traditionally, two product groupings that have been ignored by many installers and integrators are wireless devices and external detection. However, recent advances have seen both enjoying something of a renaissance, and crime trends have pushed wireless external detection to the fore. Benchmark looked at the Risco RWT74 to see what it offers.



t is sometimes hard to understand why some involved in the design and installation of security systems are quick to resist wireless technology and/or external detection devices. More often than not, the reasons lie in the past. In the late 1980s and early 1990s, both technologies faced issues as some products didn’t achieve what was expected from them.

Over the years many technological advances have been made, and credible manufacturers have not only addressed the problems, but have further enhanced the products so that today most solutions offer reliability, credibility and high levels of performance.

Whilst the benefits of wireless technology are increasingly well documented, as are the positive elements of external detection, it is probably wireless external detection devices that have seen a higher degree of interest from the market-place. The devices not only eliminate issues with cabling in open areas, but also introduce the ability to protect temporary or remote applications.

With crimes such as metal theft and attacks on vacant properties becoming increasingly common, the devices have seen a significant take-up from the systems installation and integration sector.

Risco Group now offers wireless external detection devices, in the form of the RWT74 Grade 2 active infrared beam sensors.

The RWT74 is available in a range of sizes; the Benchmark test unit was 1 metre in height and included four twin-beam units. The devices are made up of a transmitter and receiver pair, and have a quoted range of up to 5 metres in external applications, or 8 metres for internal use. This is relatively short for IR beams, but the units are designed to create a barrier coverage pattern across portals or windows.

The units require simultaneous interruption of two beams to generate an alarm condition, and the interruption time is variable from 225 to 900 milliseconds; this is adjustable to suit site requirements.

The beams feature two channels to eliminate cross-talk where units are stacked or installed back to back. Again, two channels might seem limited compared to other systems, but because of the intended use of these devices it should be enough.

The units use CR123A batteries, and battery life is claimed to be three years. It should be noted that there is a battery compartment in each detection head, at both the transmitter and receiver unit: more about that in the Installation section.

Other adjustments include beam strength (dependent upon distance, detection sensitivity and supervision time. Wall tamper can be enabled or disabled; cover tamper protection is standard.

The physical units are sealed to IP65, and the beams themselves can be rotated through 180 degrees, allowing a full range of adjustment during mounting.

Our test units were supplied with mounting screws and rawlplugs, along with wall tamper plug-ons and four batteries. There is also a single sheet instruction document which is slightly cramped as it’s a multi-language offering.

The beams are compatible with Risco’s Agility and WisDom wireless systems as well as ProSys hybrid systems.

The instruction sheet is fairly sparse on information, but the step-by-step guide does include all the details required.

Each unit is made up of one master unit and three slave units. Initial set-up is via the master units, which at least means that each head does not require individual configuration.

There are a few settings to be initialised via the DIP switches prior to fitting the batteries. This ensures the units start up in installation mode. The DIP switch arrays are very small, so care will be needed when setting them. Once the batteries are inserted you can commence alignment. A note about the batteries: there is a battery compartment for each head, which made a total of 8 for our test unit. It was supplied with four cells. There is also a conflict in Risco’s information about the number of batterys, and the manual is vague, telling you to insert batteries into both master units to initialise the beams, then it simply states, ‘Insert remaining batteries’. We used the four supplied (rather than eight) and the units worked as specified. Obviously, we cannot verify the three year battery life!

Beam configuration is fairly simple, partially aided by the limited distances achievable which makes visual alignment fairly straightforward. There is no need for a viewfinder as often used by longer range units. The Transmission master unit has a three bar LED to indicate signal strength, and an audible bleeper can also be used. It has three differing tones, and when all are sounded in a rapid succession the units are optimally aligned; the latter isn’t explained well in the instructions, but it soon becomes obvious!

The final task is to walk-test the unit and finalise settings, again via those tiny DIP switches, before setting the panel (certain Risco models only) to ‘learn’ the detector.

Active infrared detectors are, essentially, very simple devices, albeit with advanced technology to ensure credibility. With regard to detection, the units were accurate with genuine beam breaks where two beams were blocked. It must be noted that the two beams that are blocked need to be on the same detector head.

The only adjustment required was with regard to beam obscuration time; otherwise the unit was stable and reliable.

The installation of nearby active beams of other brands didn’t affect the performance of the Rico units; white halogen lights sources had no detrimental effect, even when close to the beams.

Catch performance remained high, and the unit behaved as expected throughout the test. Even attempts to defeat it with a knowledge of the unit’s configuration were detected.

Active infrared beam detectors are typically used over longer distances to form perimeter protection systems. The Risco units, however, are intended for a slightly simpler application – the protection of doors and windows – and as such they do lack some of the functionality usually present with these devices.

That said, they work well, but the overall package could be improved. A better manual would be good, with clarification about batteries, and the small DIP switches aren’t the best we’ve used.

The application is limited to short ranges, which isn’t an issue, but that the units can be used with certain Risco panels rather than a wide range of third party panels and/or transmitters might put some off.

Benchmark is the industry's only publication for installers and integrators which is dedicated to technological innovation and the design and implementation of smarter solutions. With an unrivalled level of experience in technology-based systems, Benchmark delivers independent and credible editorial content.

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