What is RFC?
RFC is a buried detection system that uses the well known "leaky cable " principle. Two special cables are buried parallel to one another around the perimeter of the site and the area between the two cables forms a sensitive detection area.
Using the latest version, CHAIN, the system can identify the point of intrusion to within a few metres, using software programmable zones and a single, mono-cable option is also available.
CHAIN can be used in all types of topography and, being buried, the entire system is completely invisible.
CHAIN is an active system and it creates a sensitive area that extends above ground for between 1 and 0.5 metres.
CHAIN uses 2 specially manufactured underground cables which are normally buried 20 cms deep and 1.2 metres apart.
The cables are specially constructed with an incomplete screen which will allow radio frequency signals to pass through under certain conditions. One cable carries a radio frequency signal and is called the transmitter cable. The signal will pass through, or "leak" through the screen into the surrounding area. The other cable will allow the radio signal so created to pass through the screen and therefore act as a receiver.
The signal transmitted is continuously compared with the signal received. When a person enters the area of the radio field the received signal will vary due to the effect of the intruders body mass on the field.
The resultant signal is subjected to complex analysis by the processor to determine whether it has reached the alarm thresholds and also whether it matches particular signal patterns and where on the perimeter the intrusion is located.
When all the criteria are met the signal is passed to a central unit which will interface into most alarm control and monitoring systems.
The CHAIN system can be installed under most surfaces including sand, soil, gravel, paving slabs, asphalt etc.
The inherent flexibility of the cable allows the system to easily follow ground contours, without altering its performance.
Each CHAIN processor will have up to twenty zones of protection each of which are programmable to within a few metres. The maximum length of perimeter for a single processor is approximately 200 metres. Each processor will have two cables running along the perimeter and terminated at the remote end.
By linking multiples of this basic configuration any length of perimeter can be protected. The processors, up to a maximum of 64, are connected to a common 4 core cable. When more than 64 sensors are required, multiple control units are used accordingly
CHAIN Cable Installation
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Sensitive cable This is the underground cable used to transmit and receive the rf signal. A special screen construction allows the radio frequency signal to pass from one cable to the other.
Processor This unit generates the rf signal that is transmitted and compares it with the signal received. It can monitor up to 200m each of the perimeter, split into a maximum of 20 programmable length zones.
The processor also houses the micro-processor based electronics for the signal analysis and all the communication interfaces for linking into the MX2000 network.
It is supplied in a weather-proof field cabinet, with a fan, suitable or most environments.
Communications Cable This is a 4 core fully screened, cable with protective outer sleeving suitable for direct burial. It links the Processor to the central Universal Communications Processor of the MX2000 system.