GPS
The presence of a
GPS satellite navigation module in the alarm design.
By itself, such a module is only responsible for determining the current geographical coordinates of the alarm (and, accordingly, the car in which it is installed), but the further use of such data depends on the alarm model and the capabilities that it provides. GPS data can be used, in particular, for classic navigation (via the on-board computer, advanced radio, etc.), as well as for searching for a stolen car (in beacon mode).
Autorun
Features for automatic start and shutdown of the engine, provided in the alarm. In some cases, using automation is much easier, more convenient, and even more reliable than starting and stopping the engine manually.
— Autostart
by timer. Alarms with this function are able to automatically start the car engine at a certain time set by the driver. This feature allows, in particular, to provide additional comfort and save time on warming up: since the owner does not need to be in the car to start the engine, he can come later, get into an already warmed up car and drive right away.
— Autostart
by temperature. The ability to use an alarm to automatically start the engine for warming up — in the event that its temperature drops below certain values. This function is intended for the cold season, when the machine has to stand outdoors for a long time (for example, all night). Starting a cold, and even more “frozen” engine is associated with a number of problems: the oil becomes thicker, and the battery can “sit down” and produce a weaker current than expected. To avoid such problems, some car alarms are equipped with an auto start function based on temperature: when the engine temperature drops below a certain level, the system automatically starts it to warm up. This ensures that the temperature is maintained sufficient for a comfortable start of the engine at any time. On the other hand, fuel
...is spent on regular warming up of the engine, and in enclosed spaces and other places where exhaust gases are undesirable (and even dangerous), this function is poorly applicable. Thus, most alarms with this feature have limitations related to fuel economy — for example, starting less than a certain number of times during one idle time, or the maximum engine warm-up time.
— According to the voltage of the on-board network. Automatic start of the car engine in the event of a voltage drop on the on-board network (in fact, the car battery) to a certain level. By using this function, you can avoid a decrease in battery charge and related troubles — including not only starting “with a pusher” or “lighting up”, but also completely turning off the alarm (if it does not have an autonomous power supply). Of course, the operation of autorun requires additional fuel costs, but usually such alarms have a number of restrictions aimed at minimizing such costs. But when parking a car in a closed room, this function should be used with caution — it requires good ventilation, otherwise the periodic engine start will lead to the accumulation of exhaust gases.
— Turbo timer mode. Possibility of operation of the alarm as a shutdown timer for an engine equipped with a turbocharging system. During driving, the turbocharger can reach high temperatures, and the oil circulation necessary for effective cooling is ensured by the operation of the engine. If you immediately turn off the car after driving, the heated compressor will actually lose the main cooling system, which can lead to damage and even failure. Therefore, the rules for operating turbocharged engines prescribe, after stopping, to allow the engine to idle for a while to cool the turbocharging system. However, the driver does not always have time to wait for the compressor to cool down. The turbo timer "simplifies life" for drivers of turbocharged cars: it keeps the engine running for some time after the ignition key is removed, after which it automatically turns off the engine. This eliminates the need to wait without removing the key from the ignition and manually control the idling time.
— Webasto support. Car alarm support for Webasto equipment, more precisely, the proprietary W-bus protocol. Webasto is known primarily as a manufacturer of starting heaters for cars, however, in addition to this, the company produces many other components, mainly for “climatic” purposes — air conditioners, sunroofs, etc. Accordingly, Webasto support allows you to connect an alarm to equipment under the W-bus and control this equipment through it. Note that W-bus controllers are also available separately, but it is usually easier and more reliable to buy a compatible signaling right away. — Support of the signaling of the Start/Stop function. This function is mainly intended to give the driver the ability to start the engine without using a key, simply by pressing a special button. At the same time, some models are designed for installation in a car where such a button was originally provided, and we are only talking about compatibility with a keyless start system; others are equipped with their own button and can even be installed in cars that were initially started only with a key.
In addition, models with the "Start / Stop" function can have the function of remote engine start on command from the key fob. This can be useful, for example, to save time on warming up the car before driving in cold weather: you can start the engine without leaving your home, and then get into an already warm car.
— Automatic transmission support. Signaling compatibility with automatic transmissions.
Such systems are structurally more complex than traditional mechanical boxes, they are closely related to the electronics and controls of the car. Therefore, for the correct operation of the autorun functions on a car with automatic transmission, it is necessary that this type of transmission is initially supported by the alarm system. If the “signaling” covers only locks and other functions that are not actually related to the engine, this feature is not mandatory.
— Support for diesel engines. This feature is indicated for car alarms that have a specialized mode for starting diesel engines. One of the differences between such engines and gasoline engines is that they use the so-called. glow plugs. For normal operation of the diesel engine, it is necessary that such candles warm up to operating temperature; heating starts immediately when the ignition is switched on, but it takes time. These moments are taken into account in the "diesel" mode: the alarm first turns on the ignition, and gives the start command only after the candle warm-up indicator goes out.Control distance
The maximum distance at which the ability to control the alarm from the standard key fob remains. In other words, this is the greatest distance from which the driver can give the system a control signal. This parameter should be distinguished from the reception range (see below): due to their small size, transmitters in key fobs are made relatively low-power, and the control range from the key fob inevitably turns out to be less than the signal reception range on the key fob (if the latter is provided at all in this model).
When choosing by this parameter, note that the control range is indicated for perfect conditions — that is, line of sight with a minimum of interference. The actual “range” of the key fob will inevitably be less, especially in the face of an abundance of obstacles. At the same time, modern car alarms most often have quite impressive range indicators. Thus, a distance of
less than 500 m is considered rather small in this sense;
500 – 750 m is the average value,
750 – 1000 m is above average, and in some models a range
of more than 1 km is claimed.
Max. range
The maximum range at which a regular key fob in a two-way system (see "Type of communication") can receive signals from the central signaling unit. In other words, this is the greatest distance at which the driver can receive notifications from the alarm in the car on the key fob.
When choosing according to this indicator, note that the control range is indicated for perfect conditions — that is, line of sight with a minimum of interference. The actual "range" of the system will inevitably be less, especially in the face of an abundance of obstacles. At the same time, the main signaling units can be equipped with fairly powerful transmitters that can effectively “reach” key fobs over long distances. Thus, the claimed receiving range usually turns out to be on average twice the control range (see above), and even in relatively simple models it can exceed 1 km.
Screen
The display is one of the most convenient ways to display various notifications; it can work with almost any kind of visual information that is relevant for modern car alarms. Simply put, the display can show both numbers (for example, data from the autorun timer, see "Functions"), and text (for example, the inscription "Call"), and graphic data (such as a car diagram showing the status of each zone protection). Thanks to this, key fobs with screens are well suited for even the most versatile and advanced alarm systems; However such versatility also affects the price.
Note that this feature is found only in models with a two-way type of communication (see above) — it simply does not make sense to equip a one-sided key fob with a display.
Anti-scan
Availability of alarm
protection from scanning ; if the characteristics specify the type of such protection, it is also given in this clause.
Scanning is used by attackers to intercept the control signal from the key fob; by forging such a signal, the hijacker can safely open the car. Accordingly, this protection is aimed at preventing such hacks. And its main types nowadays are
dynamic code and
dialog code, here are the features of each of these methods:
— Dynamic code. The general principle of dynamic coding is that each time you press the button to turn on or turn off the alarm, the key fob gives a new, unique signal. Most often, the Keelog algorithm is used for this; it assumes that the signal from the key fob contains data on the serial number of the device, the number of clicks and the secret code that the central unit also “knows” (this code is written at the factory and is unique for each alarm). Based on the serial number, the system performs general identification of the key fob, the click counter confirms that the signal has not been sent before, and the secret code acts as an encryption key. Thus, even if an attacker intercepts and copies the signal from the key fob, this signal will be outdated and, accordingly, useless; and it is impossible to decipher this signal and reproduce the desired version without a secret code.
The main advanta
...ge of systems with dynamic coding is simplicity and, accordingly, low cost. However, this method in itself is less perfect than the dialog code, it provides a lower degree of protection against interception and hacking — with the help of the so-called dynamic code grabber with a jammer, an attacker can still intercept the control code under certain conditions and open the machine. However this procedure is quite complicated and does not give a guarantee; so in general, dynamic code is a good option for inexpensive cars that are not particularly attractive to professional crackers. But for maximum protection, it is still better to use dialogue systems.
— Dialogue code. Protection operating on the principle of “friend or foe” recognition: before giving a control signal, the key fob and the central unit exchange service data, identifying each other and making sure that the signal comes from the rightful owner. This is done in the following way. When you press a button on the key fob, it sends a connection request with data about its serial number. The central unit checks the serial number and, if the result of the check is positive, sends a randomly generated number to the key fob. The keyfob processes this number according to a certain algorithm and sends the result (together with a request for action) to the central unit, which performs calculations according to the same algorithm; if the results agree, the defense gives the go-ahead to execute the command. The algorithm used for calculations is unique in each individual signaling, and so-called hash algorithms are used to encrypt the transmitted data. Due to this, the dialogue code is almost impossible to crack: for this, the attacker must intercept 3 data packets (request, riddle, guess) and decrypt 2 of them, while without knowing the key (embedded in the alarm itself and inaccessible without physical access to the device), such a decryption nowadays is inaccessible even to the most powerful computers.
Dialogue systems are naturally somewhat more expensive than dynamic ones, but this is more than offset by a high degree of security.Vibration
This function is completely similar to the
vibration signal used in modern mobile phones. Its purpose is to give signals in conditions in which sound notifications are undesirable or ineffective. As an example of such conditions, in particular, lectures and other events where it is supposed to turn off the sound, or noisy environments (concert halls, clubs, etc.), where the vibration of the key fob in your pocket is felt better than the squeak of its dynamics, can be cited.
Number of tags (keyless)
The number of tags provided in the delivery set of keyless alarms (see "Type of connection"). For more information on tags and their purpose, see "Functions -
Hands Free Function (Tag) ". And the presence of several tags in the kit allows you to provide access to the car to several people at the same time - for example, if the driver and passenger need to go about their own business, and it is not known who will return to the car earlier, you can give the passenger a second tag. In addition, a spare can be useful in case of loss or damage to the main tag.
Most modern keyless alarms with the appropriate capabilities are equipped
with two or more tags. This is considered the best option given that it is not often that there is a real need to distribute additional tags, but a margin is highly desirable in any case.
Delivery set
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.