Showing posts with label intrusion Alarm System. Show all posts
Showing posts with label intrusion Alarm System. Show all posts

Thursday, July 15, 2021

Before Buying Intrusion Alarm System

Before Buying Intrusion Alarm System 

This is a short note on Intrusion or Burglar alarm system. A burglar alarm system is not something you shop for regularly. That’s because it’s an important purchase for your business that is meant to last — so make sure you have the best. While you can always upgrade as new technology is released, you still need to trust that your alarm system will work when it needs to.

In terms of cost, a high-quality alarm system can be expensive but it is an investment that provides peace of mind.

The system charges are generally separate from the monthly subscription costs besides the installation fees. While there is a lot to learn about alarm systems, it’s important to first learn which one would be the best fit for your home by reaching out to the professionals and asking the right questions.

Here are three questions you need to ask before deciding on which home alarm system is right for your home or your small offices:

Question #1: Accreditation?
The first question you should ask is to make sure that the company has the required accreditations to perform the service. There are a lot of companies who claim they have all the required levels of accreditations, but that might not be true. If they are able to produce some level of documentation that could authenticate that, it can’t get much better than that.

Question #2: Type of System?
The second question to ask is the type of system that is best for your business. Some homes are configured for both wired and wireless security systems while some are not. Hence, you need to be sure about it and avoid settling for a type of connection that is not already configured at your facility.

Question #3: How Much?
The most important question to ask is the cost associated with the total installation. Some companies offer incentives like free installation while others may offer discounts on monthly subscriptions.

Since there are so many types of commercial alarm systems available on the market, that suits your needs and your budget; just because a provider promises you the best, doesn’t mean and could be more effective doesn’t mean you necessarily need it.

Question #4: Installation by whom?
This is another most important questing to ask installation, testing & training of system that is best for your business. Both wired and wireless security systems recommended to involve certified installer. Non-certified experienced person may share password and backdoor entry details with hacker and connection that is not already configured correctly as per your needs.

Hopefully, this post has provided you with the information you can use to determine if you going to install. If you’re not sure, SSA Integrate can help. We have Texecom Certified (Level 3) Intrusion experts that can help you determine the best solution to meet your security needs while keeping you compliant with all the relevant codes. Contact SSA Integrate today to learn more.

Wednesday, December 16, 2020

Intrusion Alarm Circuits Guide

Intrusion Alarm Circuits Guide 

Intrusion alarm circuits are a fundamental element of wired intrusion / burglar systems. Designing the intrusion alarm circuit greatly affects its performance. In particular, more efficient circuit designs introduce less resistance and cause fewer false alarms.

Alarm Circuits Overviewed

Intrusion alarm circuits use wires between an Intrusion alarm panel and various sensors. When the circuit / connection of those wires is broken (e.g., an alarmed window opens), the alarm is triggered if the system is armed / enabled.

How an Alarm Circuit Works

An intrusion alarm circuit consists of a pair of wires running from an intrusion alarm panel to a sensor, such as a magnetic contact. Electrical charge flows from the positive terminal, down one wire, and into the sensor. When something causes the sensor to close, it completes the circuit, allowing the charge to flow down the other wire and back to the negative terminal on the panel.

In the case of the contact, the circuit is complete because the magnet causes the reeds to touch, allowing current to flow from the reed on the positive side of the circuit to the reed on the negative side.

Using a pair of wires to connect both sides of the sensor to both terminals on the panel creates a large circle, which is where the word circuit comes from. The electrons flow freely all around this circuit, from the positive terminal on the panel, through the sensor, and back to the negative terminal. Opening the window will cause the reed to separate, which will break the circle and stop the flow of electrons. In other words, opening a window will create an open circuit. It is this open circuit that causes an alarm condition.

Loops vs Splices

The two most common ways to add multiple sensors to circuits is to use loops or splices.

Loops are preferred because it creates a short pathway, which means less resistance, fewer points of failure and faster to install. However, loops can only typically be used in new construction where the technician has the ability to run wires and loops through the window frames before the drywall is installed. Prewiring requires coordination with the general contractor or the carpenter. The alarm company needs to be able to schedule a technician to complete the wiring before the drywall crew is scheduled to begin installing drywall, and the carpenter should be told where to drill holes on the moulding or window frame.

Splices should be minimized because they add resistance and are more time consuming to install. However, adding alarms to exiting homes or businesses typically require this since it is not feasible to open the drywalls to run a looped circuit.

Two types of splicing exists: field splice and ITB (in-the-box) splice. The benefits of field splices are lower total circuit resistance and using less wire, but it requires a more skilled technician to hide the splice. By contrast, ITB splices are easier to troubleshoot, have fewer potential points of failure and they can be done by a less experienced installer, but they have higher total circuit resistance and require an installer to home run a wire to each individual window.

Loops Explained

The image below shows an example of a loop that allows two windows to share a circuit. Opening either the top sash or the bottom sash of either the right window or left window will cause the same zone to open. To accomplish this, a technician runs a single wire from one contact to another, allowing the current to travel around the windows in a circle. The technician leaves a loop at every window, which will bring the circuit in one side of the contact and out the other.

One wire of the pair runs to the window on the right, and the other runs to the window on the left. The technician has run loops of wires from one side of the contact to the other. One side of the contact on the top right window has a loop running to one side of the contact on the left (shown in black below). The loop between the top left contact and the bottom left contact (shown in RED) completes the circle, as long as all the windows are closed.

Field Splices

A field splice is one that is made at the device end of the wire, usually at the device itself. A skilled technician can make a field splice if the conditions are right. Splices must be accessible for future troubleshooting, so a field splice can only be made if there is someplace to hide them away from casual view. For example, when wiring windows, a technician can staple the wire to the underside of the frame or moulding, out of sight but easily found by an experienced / certified intrusion alarm troubleshooter. Intrusion alarm installers commonly wire all sirens and strobes in a location to a single circuit, and make field splices inside the siren box.


In this example, a pair of wires (green) is running to the alarm panel. Red wires are running to magnetic contacts on the bottom sash and the top sash of the right window, and blue wires are running to the top sash and the bottom sash of the left window. One red wire is spliced to one blue wire, leaving one red wire and one blue wire to be spliced to the green wires.

ITB Splices

ITB splices, or in-the-box splices, are those made inside the alarm can. Separate wires are run to each individual contact, and they are then joined up at the panel using a splice.

ITB splices are much easier for inexperienced technicians, and much faster to wire up. Making ten splices, one after another, to add ten devices to five zones, is faster than making a splice at every entranceway and then figuring out how to tuck them away. They are also much easier to troubleshoot if properly labeled in the can, because a troubleshooter can quickly isolate the circuit branch causing the issue, and does not have to first find and identify the splice. However, running individual wires is more more labor intensive, and uses more wire.

Circuit Electrical Specifications

All devices in an alarm, including unpowered devices such as contacts, require a specific amount of charge flowing through the wires at a specific speed and pressure or it will not work.

Every circuit has a voltage, current, and resistance value:

  • Voltage is measured in volts (V).
  • Current is measured in amps (A).
  • Resistance is measured in ohms (Ω).

Voltage is a measurement of how much electricity is available for use. Every device lists the amount of voltage it requires to operate.

  • If given too few volts, the device will either not power up or will work erratically.
  • If given too many volts, it will either shut down or overheat.

Current is the pressure at which the charge flows. All devices consume, or draw, electricity at a predetermined rate.

  • Not enough amps may cause the device to work harder to draw voltage, which could cause it to either shut down, overheat, or work erratically.
  • Too many amps is not harmful as the device cannot draw more current than it can use.

Resistance is anything that slows the current. Factors that increase resistance are

  • Number of connected devices
  • Wire length
  • Splices
  • Time
  • Copper oxidization

Too much resistance on a circuit will lower the current, making it more difficult for the alarm to monitor the zone properly. Since resistance increases in all circuits as time goes on, improperly designed circuits have a high probability of causing false alarms years after being installed. Therefore, every effort should be made to keep the resistance as low as possible.

Parallel Versus Series

The two methods of joining multiple sections to a single circuit are parallel and series. Devices can either be wired in parallel or in series with each other. Circuits using parallel splices are called parallel circuits, and circuits using series splices are called series circuits.

In a series splice, one of the pair of wires is spliced to one the next pair of. This way, no matter how many pairs of wires are added, the end result is two wires that are simple to connect to two screw terminals. In between, lots of wires are spliced to each other. This makes troubleshooting simpler, because a technician can simply test a single branch of the circuit at a time. Series is typically best for connecting a small number of devices to a circuit. It is faster and easier to wire up. The downside is that series introduces a lot more resistance if too many devices are connected.

In a series circuit, the wires from each branch of the circuit will be spliced together until two wires not spliced to anything are left. These single conductors will be connected to the screw terminals, while the splices 'hang' in the air, not connected to anything but each other. No matter how many devices and wires are connected to the circuit, there will always be only one wire to connect to the positive and one to connect to the negative.

Parallel splices are typically best for connecting a large number of devices to a single circuit, or for circuits that draw lots of power. It greatly reduces the amount of resistance, allowing those large numbers of devices to be connected. However, it is harder / more complicated to implement, will not work if done incorrectly, and is more difficult to troubleshoot later on.

In a parallel circuit, all the matching sides of the wire pairs are simply spliced together, with the end result being two thick wire twists. This can be a challenge to connect to screw terminals. In order to troubleshoot the wire going to a branch of the circuit, a technician must first undo the entire splice.

Experienced alarm technicians develop a 'feel' for when to splice devices in parallel and when to splice in series. However, the key determinate is this: when a series splice will result in too much resistance, a parallel splice must be used. Before splicing anything, technicians can test a circuit in order to determine the amount of resistance present.

Measuring Resistance

Resistance is measured using a digital multimeter, or DMM. To measure resistance, turn the function dial of meter to the Ω (ohms) symbol, and touch the leads to the bare wires of the circuit. Technicians measure resistance in order to

  • Test that all devices on a circuit are functioning normally
  • Decide whether to keep devices on a zone or to split them up among multiple zones
  • Decide whether a circuit should be wired in series or in parallel
  • Record a baseline resistance at the time of installation
  • Troubleshoot, as a zone with a resistance reading well over baseline can indicate a broken wire or defective sensor

How Much Resistance Is Too Much?

There is no clear answer to the precise amount of devices, and consequently the precise amount of resistance, that should be allowable on a single detection circuit. As a general rule of thumb, many installers try to keep the baseline resistance on a single circuit to ~40Ω. Remember that the resistance will inevitably creep up over time, depending on the number and nature of sensors connected to the circuit, the number and nature of splices on the wire, the exact composition of the wire, and even the environment, which could cause the wire to oxidize faster or slower. The following animation shows the current slowing the more devices are added to the circuit:

Different alarm panel manufacturers have different standards for what constitutes an alarm condition, but all those standards are based on the panel reading the resistance on a zone circuit. If a circuit has a reading significantly higher than 40Ω, consider either using a parallel splice or splitting the zone, removing some devices from one zone and wiring them to a new zone.

Some installers prefer ITB splices because it allows them to decide to split the zone later on. If devices have been wired together using wire loops or field splices, this is not possible.

How Many Devices Is Too Many?

In theory, an installer can connect all the doors on a single zone, all the windows on another zone, all the motion detectors on a third zone, and so forth. However, this is quite an inefficient way of using an alarm. The more devices are on a single zone, the harder it will be for the user to figure out which device is causing the zone to be open.

If all the windows in a room are on a single zone, the user will have to check all of them before being able to arm the system. If a user wants to keep a single window open while arming the rest of the system, they would have to bypass all the windows in the room, which is a higher security risk than simply bypassing a single window. If central station needs to dispatch police or fire to the user's site, they will only be able to give a vague description of the location of the problem, not a specific location.

Most panels can only handle a limited number of zones out of the box. Using additional zones requires purchasing and installing zone expanders, which add to the overall cost of the installation. Using multiple zone expanders may require adding a second can, which likewise adds to the cost. The question of when to combine devices on a single zone and when to separate devices into separate zones has no easy answer, but becomes clearer with experience.

Wiring Sirens

Wiring sirens is slightly different than wiring other alarm devices.

  • Sirens are rated in watts, not volts like all other alarm devices
  • Watts are a measure of how much a power a device outputs
  • Volts a measure of how much power a device uses
  • Most sirens are rated to 30 watts

Most panels only have a single siren output. However, many applications call for the volume to be lower on some sirens than on others. For example, a siren mounted indoors would cause hearing damage if sounding at a full 110dB, but 110dB is necessary for notification outdoors. In order to have different volumes from a single output, installers can choose to wire sirens in either parallel (for louder volume) or in series (for lower volume). They can even choose to wire some sirens in parallel and other sirens in series. The sirens in series have more resistance than the sirens in parallel, so that there is more resistance, and therefore fewer watts, forcing the siren to sound at a lower volume.

Intrusion alarm siren wiring is a perfect illustration of Ohm's Law.

Ohm's Law

Understanding Ohm's Law makes alarm troubleshooting much easier. Ohm's Law states that there is a direct relationship between volts, amps, and ohms, specifically that volts equals amps times ohms. Amps is ohms divided by volts, and ohms is volts divided by amps. Adding resistance (ohms) makes the current (amps) go down, and adding current (amps) makes the resistance (ohms) go down.

The simplest way of lowering or raising the power available to the siren is by raising or lowering the resistance. This raises or lowers the amount of available power, which in turn affects the operation of the siren.

Understanding Ohm's Law can help a technician diagnose and repair power supplies, sensors, circuits, and sensors. Changing a splice from series to parallel, replacing a power supply for one that outputs the same voltage at a higher amperage, or adding a resistor are all repair options that an installer has once they understand how Ohm's Law works.

Source: IPVM.com & circuitstoday.com

Sunday, February 9, 2020

Burglar or intrusion Alarm System Component Details

Burglar (or intrusion) Alarm System Component Details

Burglar (or intrusion), fire, and safety alarms are electronic alarms designed to alert the user to a specific danger. Sensors are connected to a control unit via low-voltage wiring or a narrowband RF signal which is used to interact with a response device. The most common security sensors are used to indicate the opening of a door or window or detect motion via passive infrared (PIR). New construction systems are predominately hardwired for economy. Some installations often use wireless systems for a faster, more economical installation. Some systems serve a single purpose of burglar or fire protection. Combination systems provide both fire and intrusion protection. Systems range from small, self-contained noisemakers, to complicated, multi-zoned systems with color-coded computer monitor outputs. Many of these concepts also apply to portable alarms for protecting cars, trucks or other vehicles and their contents (i.e., "car alarms"). See also fire alarm control panel for specific fire system issues. Burglar alarms are sometimes referred to as alarm systems, see burglar alarm control panel for a discussion of hard-wired burglar alarm system design.
Burglar alarms (or perimeter detection systems, Perimeter protection, intrusion detection systems and many more terms for the same thing) are divided to two main fields: home burglar alarms and industrial burglar and perimeter intrusion detection.

Intruder Panel

These are reliable and easy to use and offers enhanced fire detection and external lighting control facilities, conforming to CE specification directives and BS4737 standards. 

The salient features are:

Zones - Each zone is separately identified on the keypad and provides ample security detection for most domestic properties. Typically 4zone. 8zone, 16 zone panel in market. Currently some hybride panel also there (eg: 4 Hardware Zone + 8 wireless Zone)
3 Part Set Programs - Allows three programmed setting levels dependent on the people in the property or the level of protection required. 
Simple Set Readers for Ease of Operation - Up to 4 stylish readers can be used to set/unset the system using a proximity keyfob. 
Personal Attack Facility - Any number of PA buttons may be set to activate the system in an emergency. 
Remote Keypads for added Flexibility - Up to four keypads can operate the system from any point in the property. 
Input for Remote Keyswitch or Push to Set Switch - A remote keyswitch or push can be used to set or unset the system. 
Fire Zone - Any number of zones can be programmed as a fire zone. Two types are available: Standard Fire - operated only whwn system has been set; 24 hour - operates all the time. 
Lighting Control Feature - Full manual and automatic control over security lightng. 
Duress Code - Allows the user to unset the system and silence the alarm under duress, using a second code that will communicate an alarm to an alarm receiving center. 
Chime - Can be used to select a low security chime alarm for various areas of the protected area, even when the main alarm is turned off. 
Built-in tamper control.
Indoor

These types of sensors are designed for indoor use. Outdoor use would not be advised due to false alarm vulnerability and weather durability.

Motion detector

A motion detector is a device that contains a physical mechanism or electronic sensor that quantifies motion that can be either integrated with or connected to other devices that alert the user of the presence of a moving object within the field of view. They’re a vital component of comprehensive security systems, for both homes and businesses.
An electronic motion detector contains a motion sensor that transforms the detection of motion into an electric signal. This can be achieved by measuring optical or acoustical changes in the field of view.
A motion detector connected to a burglar alarm that is used to alert the home owner or security service after it detects motion. Such a detector may also trigger a red light camera.
An occupancy sensor is a motion detector that is integrated with a timing device. It senses when motion has stopped for a specified time period in order to trigger a light extinguishing signal. These devices prevent illumination of unoccupied spaces like public toilets.
There are basically three types of sensors used in motion detectors spectrum.
  • Passive Infrared sensors (PIR)
    • Looks for body heat. No energy is emitted from the sensor.
  • Ultrasonic (Active)
    • Sensor sends out pulses and measures the reflection off a moving object.
  • Microwave (Active)
    • Sensor sends out microwave pulses and measures the reflection off a moving object. Similar to a police radar gun.

Passive infrared detectors

The passive infrared detector (PIR) is one of the most common detectors found in household and small business environments because it offers affordable and reliable functionality. The term passive means the detector is able to function without the need to generate and radiate its own energy (unlike ultrasonic and microwave volumetric intrusion detectors that are “active” in operation). PIRs are able to distinguish if an infrared emitting object is present by first learning the ambient temperature of the monitored space and then detecting a change in the temperature caused by the presence of an object. Using the principle of differentiation, which is a check of presence or nonpresence, PIRs verify if an intruder or object is actually there. Creating individual zones of detection where each zone comprises one or more layers can achieve differentiation. Between the zones there are areas of no sensitivity (dead zones) that are used by the sensor for comparison.

The salient features of the range of movement detectors are as follows:

Look Down Technology - Dual lookdown zones are employed to ensure that even the most determined intruder will be detected. 
NC/NO Selectable Outputs - Products are fitted with changeover relays to ensure compatibility with all requirements. 
White Light Filter Lens - To minimize any possibility of problematic alarms due to fluorescent / environmental conditions. 
Intelligent Pulse Counts - Reduces the possibility of false alarms caused by environmental and power line interference. 
Sealed Optics - The sensor element is sealed, to prevent unwanted small insects form accessing the sensor area.

Dual-technology motion detectors

Many modern motion detectors use a combination of different technologies. These dual-technology detectors benefit with each type of sensor, and false alarms are reduced. All companies have the option to use PIR/Microwave Motion Detectors that have "Pet-Immune" functions which allow the detector to ignore pets that weigh up to 80 pounds. Placement of the sensors can be strategically mounted so as to lessen the chance of pets errantly activating alarms.
Often, PIR technology will be paired with another model to maximize accuracy and reduce energy usage. PIR draws less energy than microwave detection, and so many sensors are calibrated so that when the PIR sensor is tripped, it activates a microwave sensor. If the latter also picks up an intruder, then the alarm is sounded.n it is also used in burglar alarm. As interior motion detectors do not ‘see’ through windows or walls, motion-sensitive outdoor lighting is often recommended to enhance comprehensive efforts to protect the property.

Panic Button

Panic buttons are targeted and rapid mode of contact used primarily by sick and old people to contact their care takers at times of distress or during emergency situations. It offers either visual or acoustic signaling. The signals can also be routed to the wireless devices carried by their caregivers, enabling a fast and quick response. This system typically consists of a main communicator panel and the multiple points connected to it.


Ultrasonic detectors

Using frequencies between 25 kHz and 75 kHz, these active detectors transmit ultrasonic sound waves that are inaudible to humans. The Doppler shift principle is the underlying method of operation, in which a change in frequency is detected due to object motion. This is caused when a moving object changes the frequency of sound waves around it. Two conditions must occur to successfully detect a Doppler shift event:
  • There must be motion of an object either towards or away from the receiver.
  • The motion of the object must cause a change in the ultrasonic frequency to the receiver relative to the transmitting frequency.
The ultrasonic detector operates by the transmitter emitting an ultrasonic signal into the area to be protected. The sound waves are reflected by solid objects (such as the surrounding floor, walls and ceiling) and then detected by the receiver. Because ultrasonic waves are transmitted through air, then hard-surfaced objects tend to reflect most of the ultrasonic energy, while soft surfaces tend to absorb most energy.
When the surfaces are stationary, the frequency of the waves detected by the receiver will be equal to the transmitted frequency. However, a change in frequency will occur as a result of the Doppler principle, when a person or object is moving towards or away from the detector. Such an event initiates an alarm signal. This technology is considered obsolete by many alarm professionals, and is not actively installed.

Microwave detectors

This device emits microwaves from a transmitter and detects microwaves at a receiver, either through reflection or reduction in beam intensity. The transmitter and receiver are usually combined inside a single housing (monostatic) for indoor applications, and separate housings (bistatic) for outdoor applications.
By generating energy in the microwave region of the electromagnetic spectrum, detector operates as an active volumetric device that responds to:
  • A Doppler shift frequency change.
  • A frequency phase shift.
  • A motion causing reduction in received energy.

Photo-electric beams

Photoelectric beam systems detect the presence of an intruder by transmitting visible or infra red light beams across an area, where these beams maybe obstructed. To improve the detection surface area, the beams are often employed in stacks of two or more. However, if an intruder is aware of the technology’s presence, it can be avoided. The technology can be an effective long-range detection system, if installed in stacks of three or more where the transmitters and receivers are staggered to create a fence-like barrier. Systems are available for both internal and external applications. To prevent a clandestine attack using a secondary light source being used to hold the detector in a ‘sealed’ condition whilst an intruder passes through, most systems use and detect a modulated light source.

Glass break detectors

A glass break detector is a device that detects a break in a pane of glass, alerting a burglar alarm. If it detects broken glass, and the alarm is set, then it sets off the alarm.
It used for internal perimeter building protection. When glass breaks it generates sound in a wide band of frequencies. These can range from infrasonic, which is below 20 Hertz (Hz) and can not be heard by the human ear, through the audio band from 20 Hz to 20 kHz which humans can hear, right up to ultrasonic, which is above 20 kHz and again cannot be heard. Glass break acoustic detectors are mounted in close proximity to the glass panes and listen for sound frequencies associated with glass breaking. Seismic glass break detectors are different in that they are installed on the glass pane. When glass breaks it produces specific shock frequencies which travel through the glass and often through the window frame and the surrounding walls and ceiling. Typically, the most intense frequencies generated are between 3 and 5 kHz, depending on the type of glass and the presence of a plastic interlayer. Seismic glass break detectors “feel” these shock frequencies and in turn generate an alarm condition.
Acoustic Glassbreak Detectors employ a microphone, which "listens" for the sound(s) created by breaking glass. These sounds are typically recorded, digitized and then compared to a library of other sounds/events to determine if in fact glass was broken or a false alarm occurred.
There are several types of window break detectors, one kind detects the vibrations of the window, and if the vibrations get too high/ the window breaks the alarm goes off. Basically the device tells whether or not the window is broken by measuring the vibrations. Another kind detects the noise of glass breaking.

Magnetic Door Contact
Magnetic Door Contact detectors identify intruders by using a magnet and reed switch mechanism. The reed switches are electrical contacts held open by the presence of a magnet. When a magnet attached to an opening door moves away from the reed switches in the alarmed sensor, the switches make contact with each other and trigger a radio frequency (RF) transmission to the system control panel. Information in the RF transmission identifies the type and location of the sensor.

Magnetic Door Contact Detectors can be surface-mounted or recessed. Absence of any external wiring provides the installer with unlimited scope to place the device in positions where it is hidden from view. The detector is a truly stand alone module containing the low power viper integrated circuit, identification and encoding electronics, scantronic transmitter, integral aerial and battery. 


Salient features include: 
Simple calibration 
Exclusive double knock facility at point of attack 
Wire free 
Scantronic 4600 series compatible 
Adjustable detection sensitivity 
Fully approved transmitter 
Integral magnetic door contact


LPG Gas Detector


LP gas (butane or propane) is the most common type of fuel used for cooking and heating worldwide. LPG leak can cause devastating explosions and consequences of a gas leak in both domestic and commercial situations are every bit as disastrous as those of a fire and can be avoided with the fitting of easy to use and cost effective detection equipment. 


Feature and Benefits are as follows:
Officially approved to BS7348 (The British Standards for Domestic Gas Detectors). 
Proven semiconductor sensor technology. 
230Vac or 12Vds versions. 
Relay output models are available. 
Suitable for home, caravan and commercial use. 
Easy to install and use with no maintenance.

Smoke, heat, and carbon monoxide detectors

Smoke Detectors provide the earliest practicable fire detection and warning. This system consists of smoke or heat detectors at designated locations, to detect smoke or heat at the earliest during any outbreak of fire. The various types of detectors used in this system are Photoelectric, Heat and Multisensing. The detectors are selected based on certain pre-determined parameters. On sensing fire the system initiates a warning alarm, thereby alerting the occupants.
Most systems may also be equipped with smoke, heat, and/or carbon monoxide (CO) detectors. These are also known as 24 hour zones (which are on at all times). Smoke detectors and heat detectors protect from the risk of fire and carbon monxide detectors protect from the risk of carbon monoxide.

Auto Dialer

The communicator / auto dialer is pre programmed to place 4 automatic calls to any pre set destinations, which could include the owner, other two important numbers and one to the Central Monitoring System (CMS). 


The salient features are:
Up to four keypads per control panel 
Full LCD status indication 
Illuminated keys 
On-board PA facility Entry / exit tones 
Programmable user strings 
Programmable backlight options for keypad and LCD display.

Outdoor

These types of sensors would be found most of the time mounted on fences or installed on the perimeter of the protected area.

Vibration (shaker) or inertia sensors

These devices are mounted on barriers and are used primarily to detect an attack on the structure itself. The technology relies on an unstable mechanical configuration that forms part of the electrical circuit. When movement or vibration occurs, the unstable portion of the circuit moves and breaks the current flow, which produces an alarm. The technology of the devices varies and can be sensitive to different levels of vibration. The medium transmitting the vibration must be correctly selected for the specific sensor as they are best suited to different types of structures and configurations.
More sophisticated sensors use piezo-electric components rather than mechanical circuits, which can be tuned to be extremely sensitive to vibration. These sensors are more durable and more resistant to tampering.
  • pros: Very reliable sensors, low false alarm rate and middle place in the price range.
  • cons: Must be fence mounted would be the main con. Its rather high price deters many customers, but its effectiveness offsets its high price.
The Salient feature are as follows: 


Removable Electronics 
Non gravity dependent 
Dual memory LED and relay 
Walk test facility 
Remote rest 
Dual stage sensitivity 
Sensitivity potentiometer 
LED lens relay auto resets 
Surface mount technology 
Anti condensation base 
Door contact option 
Double knock link

Passive magnetic field detection

This buried security system is based on the Magnetic Anomaly Detection principle of operation. The system uses an electromagnetic field generator powering with two wires running in parallel. Both wires run along the perimeter and are usually installed about 5 inches apart on top of a wall or about foot buried in the ground. The wires are connected to a signal processor which analyzes any change in the magnetic field.
This kind of buried security system sensor cable could be buried on the top of almost any kind of wall to provide a regular wall detection ability or be buried in the ground.
  • pros: Very low false alarm rate, can be put on top of any wall, very high chance of detecting real burglars.
  • cons: Cannot be installed near high voltage lines, radars, or airports.

E-field

This proximity system can be installed on building perimeters, fences, and walls. It also has the ability to be installed free standing on dedicated poles. The system uses an electromagnetic field generator powering one wire, with another sensing wire running parallel to it. Both wires run along the perimeter and are usually installed about 800 millimetres apart. The sensing wire is connected to a signal processor that analyses:
  • amplitude change (mass of intruder),
  • rate change (movement of intruder),
  • preset disturbance time (time the intruder is in the pattern).
These items define the characteristics of an intruder and when all three are detected simultaneously, an alarm signal is generated.
The barrier can provide protection from the ground to about 4 metres of altitude. It is usually configured in zones of about 200 metre lengths depending on the number of sensor wires installed.
  • pros: concealed as a buried form.
  • cons: expensive, short zones which mean more electronics (more money), high rate of false alarms as it cannot distinguish a cat from a human. In reality it doesn't work that well, as extreme weather causes false alarms.

Microwave barriers

The operation of a microwave barrier is very simple. This type of device produces an electromagnetic beam using high frequency waves that pass from the transmitter to the receiver, creating an invisible but sensitive wall of protection. When the receiver detects a difference of condition within the beam (and hence a possible intrusion), the system begins a detailed analysis of the situation. If the system considers the signal a real intrusion, it provides an alarm signal that can be treated in analog or digital form.

Microphonic systems

Microphonic based systems vary in design but each is generally based on the detection of an intruder attempting to cut or climb over a chainwire fence. Usually the microphonic detection systems are installed as sensor cables attached to rigid chainwire fences, however some specialised versions of these systems can also be installed as buried systems underground. Depending on the version selected, it can be sensitive to different levels of noise or vibration. The system is based on coaxial or electro-magnetic sensor cable with the controller having the ability to differentiate between signals from the cable or chainwire being cut, an intruder climbing the fence, or bad weather conditions.
The systems are designed to detect and analyse incoming electronic signals received from the sensor cable, and then to generate alarms from signals which exceed preset conditions. The systems have adjustable electronics to permit installers to change the sensitivity of the alarm detectors to the suit specific environmental conditions. The tuning of the system is usually accomplished during commissioning of the detection devices.
  • pros: very cheap, very simple configuration, easy to install.
  • cons: some systems has a high rate of false alarms because some of these sensors might be too sensitive. Although systems using DSP (Digital Signal Processing) have largely eliminated false alarms.

 Taut wire fence systems

A taut wire perimeter security system is basically an independent screen of tensioned tripwires usually mounted on a fence or wall. Alternatively, the screen can be made so thick that there is no need for a supporting chainwire fence. These systems are designed to detect any physical attempt to penetrate the barrier. Taut wire systems can operate with a variety of switches or detectors that sense movement at each end of the tensioned wires. These switches or detectors can be a simple mechanical contact, static force transducer or an electronic strain gauge. Unwanted alarms caused by animals and birds can be avoided by adjusting the sensors to ignore objects that exert small amounts of pressure on the wires. It should be noted that this type of system is vulnerable to intruders digging under the fence. A concrete footing directly below the fence is installed to prevent this type of attack.
  • pros: low rate of false alarms, very reliable sensors and high rate of detection.
  • cons: Very expensive, complicated to install and old technology.

Fibre optic cable

A fibre-optic cable can be used to detect intruders by measuring the difference in the amount of light sent through the fibre core. If the cable is disturbed, light will ‘leak’ out and the receiver unit will detect a difference in the amount of light received. The cable can be attached directly to a chainwire fence or bonded into a barbed steel tape that is used to protect the tops of walls and fences. This type of barbed tape provides a good physical deterrent as well as giving an immediate alarm if the tape is cut or severely distorted. Other type’s works on the detection of change in polarization which is caused by fiber position change.
  • pros: very similar to the Microphonic system, very simple configuration, easy to install. Can detect for distances of several km on a single sensor.
  • cons: high rate of false alarm or no alarms at all for systems using light that leaks out of the optical fiber. The polarization changing system is much more sensitive but false alarms depend on the alarm processing.

H-field

This system employs an electro-magnetic field disturbance principle based on two unshielded (or ‘leaky’) coaxial cables buried about 10–15 cm deep and located at about 2.1 metres apart. The transmitter emits continuous Radio Frequency (RF) energy along one cable and the energy is received by the other cable. When the change in field strength weakens due to the presence of an object and reaches a pre-set lower threshold, an alarm condition is generated. The system is unobtrusive when it has been installed correctly, however care must be taken to ensure the surrounding soil offers good drainage in order to reduce nuisance alarms.
  • pros: concealed as a buried form.
  • cons: affected by RF noise, high rate of false alarms, hard to install.

Hooter
The hooters offered are sophisticated, stylish and highly featured solution to external sounder requirements.
The features are: 

Easily mountable 
Rugged strobe with panaromic lens 
Sound output - 108 db - 113 db 
Selectable timer 
Dual ring mode 
Alternating comfort Leds 
Selectable sounder cut-off timer

System connections

The trigger signal from each sensor is transmitted to one or more control unit(s) either through wires or wireless means (radio, line carrier, infrared). Wired systems are convenient when sensors (such as PIRs, smoke detectors etc) require power to operate correctly, however, they may be more costly to install. Entry-level wired systems utilize a Star network topology, where the panel is at the center logically, and all devices "home run" its wire back to the panel. More complex panels use a Bus network topology where the wire basically is a data loop around the perimeter of the facility, and has "drops" for the sensor devices which must include a unique device identifier integrated into the sensor device itself (e.g iD biscuit). Wired systems also have the advantage, if wired properly, of being tamper-evident. Wireless systems, on the other hand, often use battery-powered transmitters which are easier to install, but may reduce the reliability of the system if the sensors are not supervised, or if the batteries are not maintained. Depending on distance and construction materials, one or more wireless repeaters may be required to get the signal reliably back to the alarm panel. Hybrid systems utilize both wired and wireless sensors to achieve the benefits of both. Transmitters, or sensors can also be connected through the premises electrical circuits to transmit coded signals to the control unit (line carrier). The control unit usually has a separate channel or zone for burglar and fire sensors, and better systems have a separate zone for every different sensor, as well as internal "trouble" indicators (mains power loss, low battery, wire broken, etc).

Alarm connection and monitoring

Depending upon the application, the alarm output may be local, remote or a combination. Local alarms do not include monitoring, though may include indoor and/or outdoor sounders (e.g. motorized bell or electronic siren) and lights (e.g. strobe light) which may be useful for signaling an evacuation notice for people during fire alarms, or where one hopes to scare off an amateur burglar quickly. However, with the widespread use of alarm systems (especially in cars), false alarms are very frequent and many urbanites tend to ignore alarms rather than investigating, let alone contacting the necessary authorities. In short, there may be no response at all. In rural areas (e.g., where nobody will hear the fire bell or burglar siren) lights or sounds may not make much difference anyway, as the nearest responders could take so long to get there that nothing can be done to avoid losses.
Remote alarm systems are used to connect the control unit to a predetermined monitor of some sort, and they come in many different configurations. High-end systems connect to a central station or responder (eg. Police/ Fire/ Medical) via a direct phone wire (or tamper-resistant fiber optic cable), and the alarm monitoring includes not only the sensors, but also the communication wire itself. While direct phone circuits are still available in some areas from phone companies, because of their high cost they are becoming uncommon. Direct connections are now most usually seen only in Federal, State, and Local Government buildings, or on a school campus that has a dedicated security, police, fire, or emergency medical department (in the UK communication is only possible to an Alarm Receiving Centre - communication direct to the emergency services is not permitted). More typical systems incorporate a digital telephone dialer unit that will dial a central station (or some other location) via the Public Switched Telephone Network (PSTN) and raise the alarm, either with a synthesized voice or increasingly via an encoded message string that the central station decodes. These may connect to the regular phone system on the system side of the demarcation point, but typically connect on the customer side ahead of all phones within the monitored premises so that the alarm system can seize the line by cutting-off any active calls and call the monitoring company if needed. Encoders can be programmed to indicate which specific sensor was triggered, and monitors can show the physical location (or "zone") of the sensor on a list or even a map of the protected premises, which can make the resulting response more effective. For example, a water-flow alarm, coupled with a flame detector in the same area is a more reliable indication of an actual fire than just one or the other sensor indication by itself. Many alarm panels are equipped with a backup dialer capability for use when the primary PSTN circuit is not functioning. The redundant dialer may be connected to a second phone line, or a specialized encoded cellular phone, radio, or internet interface device to bypass the PSTN entirely, to thwart intentional tampering with the phone line(s). Just the fact that someone tampered with the line could trigger a supervisory alarm via the radio network, giving early warning of an imminent problem (e.g., arson). In some cases a remote building may not have PSTN phone service, and the cost of trenching and running a direct line may be prohibitive. It is possible to use a wireless cellular or radio device as the primary communication method.

Broadband Alarm Monitoring

Increasing deployment of voice over IP technology (VoIP) is driving the adoption of broadband signaling for alarm reporting. Many sites requiring alarm installations no longer have conventional telephone lines (POTS), and alarm panels with conventional telephone dialer capability do not work reliably over some types of VoIP service.
Legacy dial up analog alarm panels or systems with serial/parallel data ports may be migrated to broadband through the addition of an alarm server device which converts telephone signaling signals or data port traffic to IP messages suitable for broadband transmission. But the direct use of VoIP (POTS port on premises terminal) to transport analog alarms without an alarm server device is problematic as the audio codecs used throughout the entire network transmission path cannot guarantee a suitable level of reliability or quality of service acceptable for the application.
In response to the changing public communications network, new alarm systems often can use broadband signaling as a method of alarm transmission, and manufacturers are including IP reporting capability directly in their alarm panel products. When the Internet is used as a primary signaling method for critical security and life safety applications, frequent supervision messages are configured to overcome concerns about backup power for network equipment and signal delivery time. But for typical applications, connectivity concerns are controlled by normal supervision messages, sent daily or weekly.

Listen In Alarm monitoring

Monitored alarms and speaker phones allow for the central station to speak with the homeowner and/or intruder. This may be beneficial to the owner for medical emergencies. For actual break-ins, the speaker phones allow the central station to urge the intruder to cease and desist as response units have been dispatched.

Alarm monitoring Services

The list of services to be monitored at a Central Station has expanded over the past few years to include: Access Control; CCTV Monitoring; Environmental Monitoring; Intrusion Alarm Monitoring; Fire Alarm & Sprinkler Monitoring; Critical Condition Monitoring; Medical Response Monitoring; Elevator Telephone Monitoring; Hold-Up or Panic Alarm Monitoring; Duress Monitoring; Auto Dialer tests; Open & Close Signal Supervision & Reporting; Exception Reports; and PIN or Passcode Management. Increasingly, the Central Stations are making this information available directly to end users via the internet and a secure log-on to view and create custom reports on these events themselves.

Alarm response

Depending upon the zone triggered, number and sequence of zones, time of day, and other factors, the monitoring center can automatically initiate various actions. They might be instructed to call the ambulance, fire department or police department immediately, or to first call the protected premises or property manager to try to determine if the alarm is genuine. They could also start calling a list of phone numbers provided by the customer to contact someone to go check on the protected premises. Some zones may trigger a call to the local heating oil company to go check on the system, or a call to the owner with details of which room may be getting flooded. Some alarm systems are tied to video surveillance systems so that current video of the intrusion area can be instantly displayed on a remote monitor, not to mention recorded.

Access control and bypass codes

To be useful, an intrusion alarm system is deactivated or reconfigured when authorized personnel are present. Authorization may be indicated in any number of ways, often with keys or codes used at the control panel or a remote panel near an entry. High-security alarms may require multiple codes, or a fingerprint, badge, hand-geometry, retinal scan, encrypted response generator, and other means that are deemed sufficiently secure for the purpose.
Failed authorizations should result in an alarm or at least a timed lockout to prevent "experimenting" with possible codes. Some systems can be configured to permit deactivation of individual sensors or groups. Others can also be programmed to bypass or ignore individual sensors (once or multiple times) and leave the remainder of the system armed. This feature is useful for permitting a single door to be opened and closed before the alarm is armed, or to permit a person to leave, but not return. High-end systems allow multiple access codes, and may even permit them to be used only once, or on particular days, or only in combination with other users' codes (i.e., escorted). In any case, a remote monitoring center should arrange an oral code to be provided by an authorized person in case of false alarms, so the monitoring center can be assured that a further alarm response is unnecessary. As with access codes, there can also be a hierarchy of oral codes, say, for furnace repairperson to enter the kitchen and basement sensor areas but not the silver vault in the butler's pantry. There are also systems that permit a duress code to be entered and silence the local alarm, but still trigger the remote alarm to summon the police to a robbery.
Fire sensors can be "isolated", meaning that when triggered, they will not trigger the main alarm network. This is important when smoke and heat is intentionally produced. The owners of buildings can be fined for generating False alarms that waste the time of emergency personnel.

False / no alarms

System reliability can be a problem when it causes nuisance alarms, false alarms, or fails to alarm when called for. Nuisance alarms occur when an unintended event evokes an alarm status by an otherwise properly working alarm system. A false alarm also occurs when there is an alarm system malfunction that results in an alarm state. In all three circumstances, the source of the problem should be immediately found and fixed, so that responders will not lose confidence in the alarm reports. It is easier to know when there are false alarms, because the system is designed to react to that condition. Failure alarms are more troublesome because they usually require periodic testing to make sure the sensors are working and that the correct signals are getting through to the monitor. Some systems are designed to detect problems internally, such as low or dead batteries, loose connections, phone circuit trouble, etc. While earlier nuisance alarms could be set off by small disturbances, like insects or pets, newer model alarms have technology to measure the size/weight of the object causing the disturbance, and thus are able to decide how serious the threat is, which is especially useful in burglar alarms.

False-Alarm Reduction

Home and business owners can now choose a new type of keypad control panel designed to help reduce false alarms.
Based on a standard called CP-01-2000, developed by the American National Standards Institute (ANSI) and Security Industry Association (SIA)) , the new generation of keypad control panels takes aim at user error by building in extra precautions that minimize unwarranted dispatch of emergency responders.
Some of the features of CP-01 keypads include a progress annunciation function that emits a different sound during the last 10 seconds of delay, which hastens exit from the premises. Also, the exit time doubles if the user disables the pre-warning feature.
Other "rules" address failure to exit premises, which results in arming all zones in Stay Mode and a one-time, automatic restart of exit delay. However, if there is an exit error, an immediate local alarm will sound.

Cross zoning reduces alarms

Cross zoning is an innovative alarm-system strategy that does not require a new keypad. Using multiple sensors to monitor activity in one area, advanced software analyzes input from all the sources.
For example, if a motion detector trips in one area, the signal is recorded and the central-station monitor notifies the customer. A second alarm signal - received in an adjacent zone in close time proximity, is the confirmation the central-station monitor needs to request a dispatch immediately. This builds in increased protection and a fail safe should a door blow open or a bird rattle an exterior window.

Enhanced Call Verification

Enhanced Call Verification (ECV) helps reduce false dispatches while still protecting citizens. ECV requires central station personnel to attempt to verify the alarm activation by making a minimum of two phone calls to two different responsible party telephone numbers before dispatching law enforcement to the scene.
The first alarm-verification call goes to the location the alarm originated. If contact with a person is not made a second call is placed to a different number. The secondary number, best practices dictate, should be to a telephone that is answered even after hours, preferably a cellular phone of a decision maker authorized to request or bypass emergency response.

Video verification

Video verification documents a change in local conditions by using cameras to record video signals or image snapshots. The source images can be sent over a communication link, usually an Internet protocol (IP) network, to the central station where monitors retrieve the images through proprietary software. The information is then relayed to law-enforcement and recorded to an event file, which can later be used as prosecution evidence.
An example of how this system works is when a passive infrared or other sensor is triggered a designated number of video frames from before and after the event is sent to the central station.

A second video solution can be incorporated into to a standard panel, which sends the central station an alarm. When a signal is received, a trained monitoring professional accesses the on-site digital video recorder (DVR) through an IP link to determine the cause of the activation. For this type of system, the camera input to the DVR reflects the alarm panel’s zones and partitioning, which allows personnel to look for an alarm source in multiple areas.

SSA Integrate is Certified installer for Texecom Intrusion product in India.