System Integration: This involves the integration of the various sub systems of a security management system. This paper will give an overview of the various components of a security system and then trace the history of how the various sub systems are being integrated.

Site Integration: This discusses the communication technology being used to integrate the security systems at different sites for the same organisation. The types of monitoring that are available for integrated system will also be discussed.

Components of a Security System

The following are the different types of electronic security systems available:

• Alarms and Alarm monitoring
• CCTV
• Access Control Systems
• Fence Detection System
• Intercom Systems

There is a definite trend towards the integration of the above systems. It may be worthwhile to understand how and why this integration is taking place.

System Integration

First Generation
At the first generation stage, electronic systems were a new concept. Each of the systems had its own, independent control point. One can pity the role of the guard trying to master and control all the above systems.

Second Generation
To overcome the above problem and make the system more effective, there was a trend towards integration. Some of the advantages of integration are:

• to make the best use of resources
• to enable the most effective management of the site most effectively and keep the control room uncluttered
• to allow the electronics to do most of the work
• to integrate systems so that one system could respond to a particular activity on another system electronically consistently and without the requirement for human intervention or judgement.

The major problem over here is that each system is developed on different platforms by different manufacturers. The systems do not speak the same language. Stop-gap solutions were found to make these systems communicate.

The Next Generation
The next generation integration will be done in multimedia mode. Following are the different types of information sent by the different security systems:

• Alarms Data
• Access Control Systems: Data
• CCTV: Video and Data
• Intercom System: Video and Sound

As we know, a multimedia system can handle data, video and sound using the appropriate cards in a computer. Once this information is received by the computer, it then requires the skills of software engineers to display the information in formats which will meet the requirements of the customer.

Some of the advantages are:

1. from a single keyboard, the entire security system can be controlled, including CCTV. Upon an alarm, the floor layout can pinpoint the exact location of the alarm with flashing lights and the image from the local camera can be displayed in a window in the same computer screen
2. the use of Graphical Display (GUI) and mouse (point and click) makes the system operation very user-friendly
3. the building management system and fire alarm system can even be controlled from the same terminal
4. by using standard networking techniques, like LAN or WAN, the security system can be controlled by any terminal in the network.

Site Integration
In a local site, the cameras, alarms, readers etc. are easy to cable, and standard cabling styles can be used such as co-axial cable for CCTV and twisted pair cable for alarms and access control systems. If the site is remote (in the same town, same state or same country), or for a multi-site organisation the communication link plays a very important role. Therefore, multimedia technology is dependent upon communication technology. As expected a lot of changes are taking place in this area.

Integrated Services Digital Network (ISDN)
As the name implies, ISDN is a digital network using normal copper wires. The traditional network (PSTN) is an analogue network. It is very slow. In a PSTN network, using a modem, the maximum speed of transmission is 9.6Kb per sec. It may be adequate for data (used with alarms and access control) but is very slow for video pictures. In spite of using picture compression, it is only possible to send a video frame every 2 seconds.

In that respect, the base ISDN link comprises 3 channels

• Channel A 56 Kb per sec
• Channel B 56 Kb per sec
• Channel C 16 Kb per sec

If channel A is used for video, then one can send 6 video frames per second. The other channels can then be used to send alarm information from motion detectors, heat sensors and other information such as access control etc. If the current copper telephone lines are upgraded to fibre optics, then the capacity to send information will be unlimited. Many countries are taking the step and changing all the telephone cables to fibre optics.
Fibre optics has a band width of 1000Mhz. Transmission of real time video pictures would be possible. ISDN networks and multimedia are going to change how organisations set-up their control rooms. Multi-site organisations are using these trends to set-up a central monitoring station. From this central station, watch is kept on all the sites, which may be spread throughout the city, state or country.

Types of Monitoring Stations

The functions of centralised monitoring stations may vary from organisation to organisation, but can be classified under the following three areas :

1. After Hours Monitoring. During normal office hours a each site would monitors its own operation, but after normal hours it passes control to the central monitoring station. The central station accesses each site periodically by fast scan and views all cameras as a routine check. This is like a guard’s tour. An alarm from any site appears on the monitor and the operator can then take appropriate action. Saving manpower saving and continuous monitoring are the obvious benefits of this system.
2. Simultaneous Monitoring. Both the local site and the central monitoring station would function simultaneously. The central station accesses any site by fast scan and operates the camera network through its own switching system. For fixed cameras, the camera can be operated by the two locations at the same time, while in the case of pan tilt cameras a priority system needs to be set up. In an alarm situation, both the local and remote systems would be activated by an interface and the operator of each system would handle the switching network independently and differently. Despite the duplication of efforts the benefits of risk reduction and joint action between local and central stations  produces a more effective action in combating security breaches. Such a system is valuable for high security organisations.
3. Remote Monitoring. For small sites it may not be economical to have local monitoring. In such cases it is best to monitor the location from a central monitoring station. Saving manpower saving and security for small sites are the major advantages of such a strategy.

In a typical electric strike installation, there are two key components. The strike is fitted into the door jamb and has a bolt pocket that holds the latch securely. When the strike is opened, its pivoting lip, or keeper, rotates away from the pocket allowing the bolt to be pulled away. The latch is embedded in the door and has no moving parts or power demands. The strengths of electric locks include their ability to handle high traffic areas effectively (in really high traffic areas, magnetic locks can be better), and the fact that they cut down on manpower requirements. Strikes also allow timed opening, multi-functioning and interfacing with integral safety systems.

Strikes give positive door status and lock status indications, as well as allowing remote and automatic door control. They eliminate the costly suiting of mechanical locks and end the need for key cutting and copy controls. Using an overall access system with electric strikes allows administrators to reprogram locks remotely.

“Probably the fundamental question security managers and installers will face relates to whether or not the door is fire rated or simply an internal access point”

There are a number of things to consider when buying electric strikes. For a start, it’s important that solenoid bolts are continuous duty or CDR rated if they are fail safe. Of course, all fail-safe locks should be DC-powered. A CDR rating is necessary to ensure they don’t wear out prematurely due to being constantly energised against a spring.

Non-CDR rating would mean a large current draw and an unwelcome build up of heat that could slow the mechanism down. Installers and specifiers should also ensure any fail safe locks installed are intermittent duty rated (IDR). These locks need power to pull a bolt out of a lock or to open a strike plate. The periods of idleness these locks experience mean it’s vital that the right amount of magnetism is generated by the lock when needed. Too much current blows a fuse and too little causes the lock to open slowly or not at all.

Choosing a strike

One of the challenges faced when choosing an electronic locking device is the enormous range that’s available. Along with this, different types of lock are often generally suitable for a range of applications, making it hard to work out which option is going to be best. When you’re making your selections, think about the realities of your own site.

Something to consider early on is the preload of an electric strike – in specifications this force is often measured in Newtons, which are a value of force rather than weight or pressure. Essentially 1 Newton is the force required to accelerate a mass of 1kg at the rate of 1 metre per second, per second. If you find it easier to think of force in terms of weight measurements, a Newton is about 0.224809 pounds or 0.101972 kg of force.

This pre-load issue relates to the jamming of electrically operated doors caused by pre-loads that are higher than the strike is rated to handle – a quality fire-rated lock might have a pre-load rating of around 200N and the entire locking solution will need to match this.

In addition, serious emergency escape locks will offer side-load immune release mechanisms. You might want this capability if your locks are going into egress points likely to carry large numbers of people in the event of emergency evacuation. Also it goes without saying that all emergency doors – and if possible all egress doors – should open outwards. Doors installed this way guarantee that a crush of people on the inside of a locked door can never block an inward opening emergency exit. Supporting this sort of installation, side-load immune locking mechanisms guarantee that no matter how much pressure panicked people put on the inside of an electrically locked door, the locking mechanism will still release in the event of a fire alarm and/or a fail-safe event.

Probably the most fundamental question security managers and installers will face relates to whether or not the door is fire rated or simply an internal access point. Fire rated doors need a heavy duty strike that has a fire rating and is specifically designed for high use applications.

Adding to the security manager’s dilemma will be the different types of door jamb – variations have differing needs and you’ll want to assess these requirements before making a decision. The three most common jamb types are timber, aluminium and steel. You’ll most commonly run into timber and aluminium door jambs in front and internal doors, with steel jambs used for fire proof doors. Complexity is also going to be introduced by relevant building codes – some codes insist that in drywall installations (either metal or timber jambs), only internal solenoid locks are used and teamed up with lanky faceplates which ensure minimum gouging of the wall itself.

Typically, hollow steel or aluminium jambs will accommodate pretty much any electric strike of suitable size. Things do get complicated with aluminium-framed glass doors. The glass is usually encased in the 3-odd centimetre wide jamb, surface of the jamb making installing the strike particularly hard.

Essentially, it means the installer is required to put in a strike that’s compact enough to fit the jamb width without cutting the glass. Sadly, the most compact and most secure strikes are not the same thing and in most cases finding some sort of balance between architecture and protection will test security policy. The same rules that apply for drywall installs should also be used as guidelines for concrete filled metal jambs – concrete is often used as a stabilizer in fire doors. Installs like this need a low profile strike with an internal solenoid. Another thing to take into account is the existing lockset. No question, the lockset type will have a determining effect on the strike chosen. Installers are usually expected to match whatever lock the interior designer or architect has chosen with the needs of an electric strike, and seldom will the needs of the two mechanisms be met.

“In a good installation, the lock will be a press-fit. Never overcut to allow for imperfections in your work. Any movement in the lock may impact on the tolerances of the lock and lower its security levels”

At the very least though, security managers should make sure installation teams get the benefit of working with an ANSI lock style that is catered for by strike manufacturers. Trying to wring some sort of security from architectural locks chosen on the basis of aesthetics will always compromise security. You’ll obtain a seal but only if no force is applied to the locked door.

The problem works in reverse, too. In the interests of coming up with the most competitive quote, a non-grade electric strike will be installed to keep a Grade 1 heavy duty lockset. These two will not be good friends. The problem is that the lockset is burdening the strike – especially if there’s any traffic using the egress point.

Any combination of heavy duty mortise lock incorporating a steel 3-piece anti friction latch and an auxiliary dead latch feature, with a light duty electric strike complete with a narrow style zinc cast faceplate, a zinc cast latch keeper and shallow cavity depth or height that’s designed for light application,s simply builds in malfunction.

All you installers forced to team up this sort of combination on glass doors that lack the room for a properly matched and graded electric strike should argue a case for electromagnetic locking solutions – at least on internal doors.

Handling installations

Before you set out to the site before access control installation, set up the locks properly at the work bench. First check to make sure the DC diode that crosses the positive and negative wires is already in place. If it’s not, the diode will be included in the packaging. Locate it and tape it to the lock. Next, check if the lock will fail safe or fail secure in the event of power failure.

If the lock needs to be set up manually, remove its cover and access the lock’s relay. The brass locking pins can be removed and their insertion pattern changed to fail safe. Decisions about fail safe and fail secure will be influenced by a site’s application and the customer’s requirements.

Good electric strikes are supplied with a template to assist with installation. Once at the site, place the template on the door then mark it out so you can make the necessary cuttings. Cut out both top and bottom marks on the jamb, as well as the markings on the opening edge of the door and once your initial cutting is completed, use the lock as a template.

In a good installation, the lock will be a press-fit. Never overcut to allow for imperfections in your work. Any movement in the lock may impact on the tolerances of the lock and lower its security levels.

The next step is to put in the cable. The method you’ll use will be dictated by the construction of door frames and walls. You’ll either come down through the wall and then through the frame (timber frame, timber door, gyprock wall) or you’ll conduit down the wall and come in through the frame from the side (concrete-filled, steel frame, steel door, cement wall).

Never use external conduit runs on the unsecured side of the door and try not to use them on the inside either. If you have to install cable this way, be sure to use steel conduit and if there’s camera support for the door, include the external cable run in the camera’s field of view if possible.

Major challenges will be fire doors. They have a fire-rated steel frame filled with cement to absorb heat and to resist buckling. Once your template is cut, use a cold chisel or similar tool to carve out a cable channel in the cement and then drill a hole through the jamb or the wall to carry cable from the lock to the controller.

Once the holes are drilled for wiring, take the cable back to an input on the door controller located in the closest electrical riser or wiring closet. Ensure your wiring is neat, firmly secured and tagged so it’s easy to identify. The cable will have a pair of power wires and additional wires reporting lock status including open, closed or alarm.

With the wiring in, you can look at the installation of the lock itself. Drill the top and bottom holes then tap them to suit the screws supplied. To give yourself a third hand, turn the lock back to front and screw it to its top positioning hole as you connect the exposed wiring. This practice will ensure you don’t use too much wire and it will get the lock closer to your face for the careful work needed.

Now twist the positive and negative wires together, placing the DC diode in position across them. The anode of the diode will go to the positive and the cathode to the negative wires respectively. You then solder the diode into place using the minimum amount of solder for a firm joint.

Once the solder has set, fold the joint down so it can be heat shrunk. If it’s not your practise to heat shrink soldered joints, it should be. Covering connections reduces the possibility of short circuits and costly maintenance call-outs.

Before you turn the lock back around by removing the third hand screw, make sure you label wires and once this is done, put the lock into the door, making sure wires don’t squeeze out the sides. Screw the lock into position, making sure the pivot lip is correctly aligned with the latch.

As you go through your commissioning procedure, check that door handles are correctly orientated and egress is possible from the secure side of the door by not the unsecured side. Now go to the reader and test the lock’s function using the appropriate credential or switch. The controller will power up the lock and the pivot lip will rotate, releasing the strike.

]]> http://www.antelsecuritysystems.com.au/choosing-right-electric-strike-for-access-control/feed/ 0 http://www.antelsecuritysystems.com.au/understanding-cctv-specifications/ http://www.antelsecuritysystems.com.au/understanding-cctv-specifications/#comments Sat, 28 Aug 2010 03:12:35 +0000 antel http://www.antelsecuritysystems.com.au/?p=335 “Understanding CCTV Series”. In this series, we cover some of the important CCTV components and explain some of the issues in simple user-friendly language.
We start the series with cameras. Cameras are the starting point of the video signal and is therefore are a critical component of a CCTV system. The word camera comes from the Latin ‘camara obscura’ and means ‘dark chamber’. Artists in the Middle Ages used a dark box to trace images. Since then the camera has come a long way. Today there are three types of cameras most commonly used:

• film cameras
• photographic cameras
• video cameras.

The construction and type of Charge Coupled Device (CCD) chip used in a camera is important. Some of the better quality cameras have superior chip design incorporating many innovative features such as On Chip Lens (OCL), Back Light Compensation (BLC), excess charge drainage technology etc. In this article we won’t look into these aspects, but will to understand some of the important camera specifications.

CAMERA SPECIFICATIONS

Any camera data sheet has a number of specifications shown, such as resolution, sensitivity, signal to noise ratio, camera voltage, chip type, and operating temperature. Some data sheets are detailed while others are quite sketchy and cover the bare minimum. To classify a camera, most people will first look at the resolution and sensitivity in the data sheet. These two specifications are the most important. In this article we will discuss these specifications in more detail. There is confusion surrounding these terms and I would like to demystify them.

RESOLUTION
Resolution is a picture’s quality of definition and clarity is defined in lines:

more lines = higher resolution = better picture quality.

Resolution depends on the number of pixels (picture elements) in the CCD chip. If a camera manufacturer can put a higher number of pixels in the same size CCD chip, that camera will have more resolution. In other words the resolution is directly proportional to the number of pixels in the CCD chip.

In some data sheets, two type of resolution, vertical and horizontal, are indicated.

Vertical Resolution

Vertical resolution = number of horizontal lines

Vertical Resolution is limited by the number of horizontal scanning lines. In PAL it is 625 lines and in NTSC it is 525 lines. Using the Kell or aspect ratio factor, the maximum vertical resolution is .7 of the number of horizontal scanning lines. Using this, the maximum vertical resolution is

for PAL 625 X .75 = 470 lines
for NTSC 525 X .7 = 393 lines

Vertical resolution is not critical as most camera manufacturers achieve this figure.

Horizontal Resolution = no. of vertical lines

Theoretically, horizontal resolution can be increased infinitely. However, it may not be technological possible to increase the number of pixles in a chip. As the number of pixels in the chip increase, the pixel size decreases which affects the sensitivity. There is a trade off between resolution and sensitivity. If only one resolution is shown in the data sheet, it is usually the horizontal resolution.

SENSITIVITY / MINIMUM SCENE ILLUMINATION

Sensitivity, measured in foot candles or lux, indicates the minimum light level required to get an acceptable video picture. There is a great deal of confusion in the CCTV industry over this specification. There are two definitions ‘sensitivity at faceplate’ and ‘minimum scene illumination’. Sensitivity at faceplate indicates the minimum light required at the CCD chip to get an acceptable video picture. This looks good on paper, but in reality does not give any indication of the light required at the scene.

Minimum scene illumination indicates the minimum light required at the scene to get an acceptable video picture. Though there is a correct way to show this specification, it depends on a number of variables. Usually the variables used in the data sheet are never the same as in the field and therefore do not give a correct indication of the actual light required. For example, a camera indicating the minimum scene illumination is 0.1 lux. Moonlight provides this light level, but when this camera is installed in moonlight, the picture quality is either poor or there is no picture. Why does this happen? It is because the field variables are not the same as those used in the data sheet.

How does it work? Usually light falls on the subject. A certain percentage is absorbed and the balance is reflected and this moves toward the lens in the camera. Depending upon the iris opening of the camera, a certain portion of the light falls on the CCD chip. This light then generates a charge, which is converted into a voltage. The following variables should be shown in the data sheet while indicating the minimum scene illumination.

• Reflectance
• F Stop
• Usable Video
• AGC
• Shutter speed

Reflectance

Light from a light source falls on the subject. Depending upon the surface reflectivity, a certain portion of this light is reflected back and moves towards the camera. Below are a few examples of surface reflectivity.

• snow = 90%
• grass = 40%
• brick = 25%
• black = 5%

Most camera manufacturers use an 89% or 75% (white surface) reflectance surface to define the minimum scene illumination. If the actual scene you are watching has the same reflectance as in the data sheet, then there is no problem, but in most cases this is not so. If you are watching a black car, only 5% of the light is reflected and therefore at least 15 times more light is required at the scene to give the same amount of reflected light. To compensate for the mismatch, use the modification factor shown below.

Modification factor F1 = Rd/Ra

Rd = reflectance used in the data sheet
Ra = reflectance of the actual scene

Lens Speed

The reflected light starts moving towards the camera. The first device it meets is the lens, which has a certain iris opening. While specifying the minimum scene illumination, the data sheet usually specifies an F Stop of F1.4 or F1.2. The F Stop gives an indication of the iris opening of the lens. The larger the F Stop value, the smaller the iris opening and vice versa. If the lens being used at the scene does not have the same iris opening, then the light required at the scene needs to be compensated for the mismatch in the iris opening.

Modification factor F2=- Fa² / Fd²

Fa = F stop of actual lens
Fd = F stop of lens used in data sheet

Usable Video
After passing through the lens, the light reaches the CCD chip and generates a charge that is proportional to the light falling on a pixel. This charge is read out and converted into a video signal. Usable video is the minimum video signal specified in the camera data sheet to generate an acceptable picture on the monitor. It is usually measured as a percentage of the full video.

Example: 30% usable video = 30% of 0.7 volts (full video or maximum video amplitude) = 0.2 volts. The question here is: Is this acceptable?

Unfortunately, there is no standard definition for usable video in the industry. Furthermore, most manufacturers do not indicate their definition in the data sheet when measuring the minimum scene illumination. It is recommended to be aware of the usable video percentage used by the manufacturer when specifying the minimum scene illumination in the data sheet. The minimum scene illumination should be modified if the usable video used in the data sheet is not acceptable.

Modification Factor F3 = Ua/Ud

Ua = actual video required at the site as % of full video
Ud = usable video % used by the manufacturer

AGC

AGC stands for Automatic Gain Control. As the light level decreases the AGC switches on and the video signal gets a boost. Unfortunately, the noise present also gets a boost. However when the light levels are high, the AGC switches off automatically, because the boost could overload the pixels and cause vertical streaking etc. The data sheet should indicate whether the AGC is On or Off while measuring minimum scene illumination. If the data sheet indicates AGC is “on” already, if in reality the AGC is “off”, then the minimum scene illumination on the data sheet should be modified.

Modification Factor F4 = Ad/Aa

Ad = AGC position in the data sheet
Aa = Actual AGC position

If AGC off = 1, then AGC on = db figure from the data sheet.

Shutter Speed
These days most cameras have an electronic shutter speed, which allows one to adjust the timing of the charge read of the CCD chip. The standard read out is 50 times (PAL) and 60 times (NTSC) per second. If the shutter speed is increased to say 1000 times per second, that means the light required at the scene should be 20 times higher (for PAL). Increasing the shutter speed allows the picture to be crisper, but requires more light. Use the following modification factor:

Modification Factor F5 = Sa/Sd

Sd = Default shutter speed (PAL – 1/50 sec NTSC – 1/60 sec)
Sa = Actual shutter speed being used

Adjusted Minimum Scene Illumination
The minimum scene illumination of the camera must be adjusted because of the mismatch between the actual conditions in the field and the variables used in the data sheet.

Ma = (F1*F2*F3*F4*F5) * Md

Ma = adjusted minimum scene illumination
Md = minimum scene illumination as per the camera data sheet

Comparison
Compare the actual light at the scene (L) with the adjusted minimum scene illumination (Ma). If the light available is more than the adjusted minimum scene illumination, then the current camera can be used. If the actual light at the scene is lower than the adjusted minimum scene illumination of the camera, then the camera setting may require adjustment or an alternative solution is necessary. The following steps will help resolve the issue.

Step 1
Check if camera variables can be changed

• If AGC is switched off, then switch AGC on
• Accept a lower usable video %
• Reduce shutter speed, if possible
• Use a lens with a lower F stop
• If no success go to step 2

Step 2

• Find a more sensitive camera
• Own grade from colour to B/W camera
• Add Infrared light if B/W camera is being used
• Add more lighting at the scene

Example

It maybe worth while to study an example so that all the above concepts can be understood correctly. Let us assume that the camera is focussed on green grass (20% reflectivity). The actual light level at the scene is 50 lux. The colour camera data sheet indicates the minimum scene illumination is 2.5 lux. The table below compares the variables as indicated in the data sheet and also the actual situation in the field.

Modified Minimum Scene Illumination = ( 4.45* 1.36 * 3.3 * 1 * 1 ) * 2.5 = 50 lux
This camera would work as the light level at the scene (50 lux) is higher than the modified minimum scene illumination of the camera (45 lux).

About the Author
Jayant Kapatker is an international authority on CCTV and is the brain behind STAM InSight, The Award Winning CCTV Program.

• In Australia someone is burgled approximately every 5 minutes*
• In Victoria, on average, 1 in 66 homes are burgled every year, equating to 1 burglary every 18 minutes
• According to Victoria Crime Statistics 2009, the number of aggravated burglaries has been risen by 10.2%
• In 2009, 68% of residential locations were the most likely place of unlawful entry with intent*
• More than 35% of Australians still leave doors and windows unlocked when they aren’t home
• The most common time for burglary is between 8am and noon when people are at work
• Thieves are more likely to return to the scene of the crime within three months of a break-in
• The riskiest suburbs was found in the inner city, northern and western suburbs

From statistics compiled by the ABS based on figures provided by State and Territory police organizations.

Make sure to:

• install a monitored security system
• prominently display window stickers
• secure deadlocks on external doors, windows, gates and sheds
• lock all manholes that are externally accessible
• ensure your authorized contact list is adequate and the phone numbers are correct – include neighbors, relatives, friends, business associates and/or a patrol service
• ensure your authorised contacts are educated on how to use your system, responsible, available
• engrave/mark valuable property with an identifiable number such as a driver’s license preceded by V for Victoria
• clear shrubs/trees that block the visibility of your premises from the street, thereby allowing would-be intruders privacy to enter
• install automatic external sensor lights and timing devices for internal/external lights and electrical appliances, such as radios and televisions, to simulate your living pattern.

As your holiday approaches:

• inform the monitoring center of your travel plans – leave a destination contact number
• let your neighbours/relatives know your holiday arrangements – ask them to observe your premises carefully during your absence
• ask a responsible person to park a car in your driveway occasionally
• have your mail, newspapers and other deliveries collected and stored, or redirected
• advise local police and the neighborhood watch area coordinator of your absence
• have the lawn mown and the garden watered regularly
• arrange for payment of essential utilities bills such as electricity and gas
• give keys to your authorized contacts, register keys with ART and/or have ART issue them to a patrol for internal responses.

Just before you go:

• test your security system for communication and have it assessed for premises cover and functionality
• check detectors for spiders, reapply surface spray to surrounding areas, and replace batteries
• disconnect electrical supply on radio-controlled or electronic garage doors/gates, and engage manual locks
• don’t leave keys concealed inside/outside the premises
• turn down the volume of your telephone the day you leave
• activate your timing devices for internal/external lights and electrical appliances to simulate your living pattern or activate them randomly
• ensure all valuables are not visible from outside your premises, particularly computers/laptops
• lock away items which assist intruders to break in – ladders/garden tools
• Secure cars left at home and leave keys with a responsible person
• do not publicise your unattended house to strangers – use a business address at such places as hotels, have a relative drive you to the airport

then enjoy your holiday . . . .