The presence of a
GSM mobile communication module in the alarm design.
Such equipment gives the alarm the ability to send notifications and various data (for example, about the location of the car) to the user's mobile phone and receive commands from this phone via the cellular network. GSM modules, by definition, provide two-way communication, however they can be found in both "pure two-way" and
keyless alarms (see "Type of communication"). The main advantage of GSM over direct communication over a radio channel (through a key fob) is its practically unlimited range: the car can be at least on the opposite side of the globe, the main thing is that it stays in the GSM coverage area. In addition, such a signal cannot be scanned. On the other hand, the use of mobile communications is associated with additional costs — payment for data transfer services, and when the funds on the account are exhausted, this function may become useless. In addition, in close proximity to the car, a key fob or other device with a direct connection is more convenient than a mobile phone: it takes a certain time for commands to pass through the cellular network, while the alarm responds instantly to the key fob. Therefore, this function is used mainly as an auxiliary one, supplementing the main control tool (key fob, label, etc.).
The way of working through GSM networks can be different: some alarm models use vo
...ice communication (usually with control of tone signals from the phone buttons), others work through special mobile applications. The first option is less convenient, but very versatile: it allows you to work from any mobile device, even the simplest one. The second method provides more advanced features, but requires a smartphone with a suitable operating system.The delivery set includes, in addition to the main alarm unit, it can also include additional elements, including a
CAN bus, a
LIN bus,
a blocking unit, an
immobilizer,
a limit switch,
a volume sensor, an interior temperature sensor, an inclination sensor, a movement sensor, a
boot opening relay,
siren. More details about them:
— CAN bus. The ability to connect the alarm to the car's electronic CAN bus. Many modern car models are equipped with such a tyre (and their number is constantly increasing); it allows you to receive information from the car's own built-in sensors about the status of its various parts, from the opening of the doors and boot to the position of the gear knob and the readings of the speedometer and tachometer. To date, connecting a car alarm to the CAN bus is the most convenient option, because. does not require intervention in the standard wiring of the car and greatly simplifies the process. Note that the module itself can be either built-in (in such cases, the CAN connection is standard) or external. In the absence of a CAN module in the kit, usually, it can be purchased separately, but
...this is more difficult and troublesome than immediately acquiring a CAN-compatible signaling.
— LIN bus. The alarm can be connected to the vehicle's LIN bus. Integration with the LIN machine interface allows the security system to control and interact with some of the car's original functional systems. This can be an engine preheating system, a climate control system, etc. The LIN (Local Interconnect Network) interface combines the peripheral and secondary functional systems of the car, but it is impossible to control the operation of the engine or transmission through it. The main systems of the car are controlled via the CAN (Controller Area Network) interface.
— Lock block. Availability of the block of blocking of the engine in a complete set of delivery of the alarm system. Such a module, when triggered, blocks the engine or another element of the car (for example, the starter), preventing the attacker from leaving the car. Activation can occur by triggering an alarm or by pressing the "Anti-Hi-Jack" button (see "Security and Protection"). There are two main types of blocking block — with normally closed contacts (NC) and normally open (NO). In the first case, the blocking relay is de-energized in the normal state, and when the alarm is triggered, it becomes energized and opens the circuit. This option is convenient in that if the alarm fails, the machine will not be blocked, but the reliability of the NC from the point of view of safety is somewhat lower than that of HP. In turn, the blocker with normally open contacts is switched on if the voltage on the control relay is lost. Disabling such a system is somewhat more difficult (especially if the control is carried out via the CAN bus), however, in the event of a failure in the auto or alarm electronics, the car remains stationary. Some alarms provide universal blocking blocks that allow the owner to choose the format of operation — NO or NC — at his discretion.
— Immobilizer. Immobilizers are electronic devices designed to prevent the movement of a car in the event of illegal entry into it. Immobilizers can have different designs and areas of influence: for example, some open the starter or ignition circuit, others turn off the fuel injection controller, others send a control signal via the CAN bus (see CAN module), putting the entire system into an “inoperative” state. The immobilizer can be disabled by the driver using a key, tag, secret button, code, etc. Such devices, in fact, insure the main alarm in case of its failure or hacking: even if an attacker manages to get into the car, he will not be able to steal the vehicle. This is the difference between immobilizers and the blocking systems described above — they can work even when the alarm is "silent". Note that immobilizers are distinguished by a high degree of secrecy. So, a well-installed module is carefully hidden from prying eyes, its operation is often disguised as a malfunction (for example, a dead battery is simulated), and some models do not work immediately, but some time after the start of movement. The latter increases the likelihood that the attacker will be in a stalled car in the open and hide without trying to complete the theft. Immobilizers are installed in many cars as standard equipment, directly at the factory, however, the degree of safety of such equipment is low, and many motorists prefer to supplement it with non-standard devices. Of course, in the absence of an immobilizer, you can buy it separately, but this is more troublesome than buying a ready-made kit.
— Antenna module. The presence in the delivery set of the signaling of a separate block containing an active antenna. Such a unit greatly enhances the range of the transmitter, allowing you to receive notifications from two-way alarms (see "Type of communication") at a distance of 1 km or even more. Also, a driver call button or sensor is often installed on the antenna module (see "Functions").
— Limit switch. The presence of a limit switch (one or more) in the car alarm delivery set. The most popular application of limit switches is as sensors that monitor the opening of doors, boot, hood, gas tank cap, etc.: in the closed position, the door or lid presses the switch, and when opened, it releases it, to which the alarm reacts. Note that many modern cars are equipped with their own limit switches — for example, in the doors; they are normally responsible for turning on the lighting in the cabin, but alarms can also be connected to such switches. At the same time, firstly, attackers usually know the location of standard "limit switches" and can block them without any problems, and secondly, there are car models without such switches. Having separate limit switches, you can install them at your discretion, including in non-standard and most unexpected places for the hijacker.
— Volume sensor. The presence of a volume sensor in the delivery set of car alarms. Such a sensor works on the principle of a sonar: it periodically emits an ultrasonic signal and analyzes its reflection, thus “observing” objects in the cabin, and when the situation changes, it gives an alarm. In this way, protection is provided against "silent" penetration into the car — for example, with cutting glass, to which shock sensors and limit switches do not respond: the volume sensor will detect an intruder not noticed by other systems. There are also external sensors that monitor the situation around the car; when triggered, they do not turn on the main alarm, but give a relatively quiet signal, designed mainly to warn a person who has approached close that the car is on an alarm. The ability to connect such sensors is available in many modern car alarms, however, sensors are rarely included in the delivery set. So if you want to immediately get a system with such a function, without buying additional equipment, you should choose among the models that are initially supplied with volume sensors.
— Temperature sensor in the cabin. The presence of a sensor that monitors the temperature in the cabin, in the alarm package. This feature provides additional information to the driver, allowing him to assess the conditions in the cabin directly from the alarm key fob, without opening the car or approaching it, and take action if necessary — for example, leave the house a few minutes earlier to warm up the interior for a comfortable ride. In addition, the temperature sensor can also serve as an intrusion warning: for example, in cold weather, opening doors or windows leads to a sharp decrease in the temperature in the cabin, which can be noticed even if the intruders were able to open the car without triggering an alarm.
— Tilt sensor. As the name implies, the tilt sensor detects changes in the slope of the car body. Thus, for example, the system "takes care" that the wheels are not removed from the car. After all, to do this, you need to slightly raise the body. If a car thief decides to do this, then the tilt sensor will instantly detect manipulations with the body and immediately raise the alarm. The tilt sensor is one of the main sensors in many security systems for cars and motorcycles. Such a sensor can be found both in low-cost car alarms and premium security systems.
— The displacement sensor captures any mobility of the car: the car drives on its own, it is moved by a loader or in tow, it shifts from impact or rolls back due to a weak hand brake, etc. Having fixed the fact of the car’s mobility, the sensor activates the alarm. Often used in conjunction with a tilt sensor.
— Boot opening relay. The presence of a boot opening relay in the car alarm delivery set. If the car has an electric boot drive, you can connect it to this relay and control the opening / closing of the boot through the alarm key fob — this is much more convenient than pressing the button in the cabin every time.
— Relay with block. The presence of a relay with a block in the car alarm delivery set. This relay is used to connect additional external equipment to the alarm system — for example, a limit switch under the gas tank cap; the block also serves to attach the relay to the body of the car.
— Siren. The presence of a siren in the car alarm delivery set. The siren in this case is a sound warning unit that provides for the supply of characteristic sound signals. Note that such a unit is not always included in the delivery set, and if it is not available, you either have to buy the siren separately or connect the alarm to the horn. So if you want to immediately buy an alarm with your own sound signal, you should clarify the configuration of the selected model.
