This unit contains the micro-processor based electronics for the signal analysis and the communications interface for the MX2000 Multiplex bus system.
These two units house the balanced diaphragms used to detect the pressure differences between the tubes.
All materials used are suitable for direct burial and protected against chemical agents typically found underground.
This unit is used to fill and pressurise the system. The body of the valve is of a special material suitable for direct burial without deterioration.
This is the underground pipe used to transmit the pressure signals to the sensor unit. A special synthetic mix is used to provide the correct elasticity factor and underground durability.
The PPS (Perimeter Position System) represents an evolution of the traditional GPS buried tube system., based on the principle of pressure difference monitoring . Variations in pressure generated by attempts to cross the sensitive zone are detected by sensors in the field.
The operating principle of the PPS system is based on the detection of pressure difference signals generated by a target crossing the sensitive zone.
The signals are generated by two sensors, placed at the two ends of the buried tubes of the sensitive zone. These signals are evaluated by a concentrator, which can discriminate between attempted intrusions and atmospheric and environmental signals and determine the point of entry to the sensitive zone with a precision of 5 metres.
The heart of the system is a microprocessor using DSP technology, which offers exceptional capacity for the evaluation and analysis of signals. The signal provided by the sensors is digitised and then analysed in both the time and frequency domains, discriminating common interference signals from genuine alarm signals.
Simultaneously the analogue signal from the field is stored in an archive so that, in the case of an alarm, the information is saved for a predetermined time, before and after the alarm event.
The type of analysis carried out on the signals from the sensors guarantees a high immunity to environmental and atmospheric effects, making this system ideal for installation on sites with high levels of interference, like adjacent railways, roads with heavy or high volumes of traffic. It is of particular value where it is necessary to know the precise crossing point, for example where moveable cameras with presets are installed along the zone.
The PPS is based on the detection of pressure variations generated by a target that crosses the sensitive zone.
The system is directly compatible with the MX2000 sensor management system, which can monitor and control up to 64 PPS Peripherals on a single multiplex bus cable.