English
The ESS detectors (PIR, glass break detectors, and such like) generally available on the market are equipped with relay or contact outputs (ALARM, TAMPER etc.) suitable for a connection to the CFox or RFox binary inputs.
The connection (and evaluation) to the system can be done in several basic ways (processed with the help of some support Jablotron):
NC contacts
This type of connection is mostly used for fire detectors, where there is probably no danger of sabotaging the loop. This type of simple connection is also common for ESS detectors in household alarm systems. Basically it is O.K, even though a malfunction of a detector (or the whole group of detectors) cannot be ruled out if a short circuit occurs in the cables or in the terminal block. Therefore it is advisable to use rather balanced loops.
A single balanced loop
It is mostly used where there are a number of detectors in one loop. The contacts are connected in series. The connection is simple and transparent. The disadvantage is precisely that there are many detectors in series and thus the place of activation cannot be accurately identified. The contacts (ALARM and TAMPER) are always NC (normally connected), which means that the switched contact represents the idle status. For more detailed information see Chapter 13.8.3. Single balanced inputs – voltage levels, evaluation.
A double balanced loop
Each detector mostly transmits two information items: activation (motion, opening the door etc.) and disruption of the cover – a sabotage. By using two resistance values, the idle state and the activation of the detector are transmitted. The idle state is determined by the basic value of resistance, and doubling this value results in activation. A short circuit or disconnecting the loop is considered as a sabotage of the loop or opening the cover of the detector. The resistance values have a tolerance range of about 10 % to avoid wrong evaluation due to resistance fluctuations caused e.g. by temperature changes.
The contacts (ALARM and TAMPER) are always NC (normally connected), which means that the switched on contact represents the idle status.
For detailed information see Chapter 13.8.4. Double balanced inputs – voltage levels, evaluation.
Subsequent chapters describe specific modules suitable for connecting alarm detectors as well as recommended types of detectors for each area of security, including examples of connection and basic technical information.