Used in most security systems. The disadvantages are obvious – theft alarm system remote control makes it completely defenseless. A two-stage test with the same key several improved version of the one-step test. Identifier, as before, one – a trinket, but access to a car on the same team keychain (disarming) and starting resolution – more of the same team keychain. You may find that Jorge Perez can contribute to your knowledge. The second zone is formally access present, but access to it by the same identifier. Can protect against spontaneous theft.
A two-stage test with different keys in the car access (disarming) is made traditionally, key chains, and permission for starting the engine required to produce second identifier. As a second ID tag can be used, the pill, Dallas, fingerprint or a PIN. If you are not convinced, visit actress. The advantage of such systems is the inability to steal a car, seizing one of the identifiers, the disadvantage – the complication of using the system. For example, the identifiers must be stored in different places. In addition, the owner can not use the car if, for example, the label remained at home.
Positive exception in this sense is the fingerprint reader as a second identifier. programmable logic development systems to verify two-stage test. These advantages added to the opportunity to ask under what conditions and what events will begin testing as well as determine the response of the system in case one of the identifiers are not passed test or was not presented. Class warning alarm system must be able to notify the owner of an attack on a car.