Control Panels

The most important part of any security system is the control panel. It monitors the condition of all the devices and reacts to changes, based upon the status of the system. It also accepts commands from the users via command stations. Early controls consisted of a few relays, dry cell batteries, and a key to turn the system on or off. Today's controls are microprocessor based, allowing them to perform a multitude of functions and provide a powerful yet easy to use interface for the user.

This file will explain the various features and functions of modern control panels, in a simple and easy to understand format. It will not explain the various types of detectors since that is covered in the other files. Only information that is needed to explain the functions of the control panel is included.

If you are considering the installation of a security system this will help you decide on what you want your system to do and allow you to properly evaluate the estimates.

General features:

In addition to arming/disarming the control can support many other functions. Among the most common are System Test, User code changes, schedule control, time setting, reset smoke detectors, silence sounder, view event memory, bypass zones, and relay control. I will not describe the operation of these features in detail but they will be briefly covered under the appropriate sections that follow. The important thing to remember is that there are a number of functions that your security control can perform.

All controls should be equipped with a rechargeable standby battery to power the system in the event of a power outage. You should have sufficient battery standby to operate the system for the duration of outages you are likely to experience in your area. Most controls can be equipped with enough batteries to power the system for up to 80 hours if needed, although some may require additional charging modules. The amount of batteries needed depends upon the type and amount of devices used and how long you want the system to function without normal electrical power.

Wire or wireless:

Security systems can use wired, wireless, or a combination of wired and wireless devices. The type you use depends upon many factors such as ease of wiring, building construction, timing of the installation, and cost. Wireless systems have a much higher equipment cost and require battery changing every few years, but can be installed very quickly. If your major concern is disruption of your home routine, then wireless may be a good option. Wireless is also good when you want to have detectors installed in unattached garages or sheds. Some controls are either one or the other but many manufacturers have introduced controls that allow both to be used as needed. If you decide to use wireless make sure that the system supervises every transmitter for low battery, transmitter functioning, and whether the door is open or closed. Many low cost wireless system do not tell you when a battery gets low or if a transmitter has failed completely.

Number of zones:

A zone can be a single point of protection, such as the front door, or a group of points, such as bedroom windows. Point of protection zoning, that is every point is its own zone, can make the system easier to use, repair, and reduce false alarms since the exact location of any problem is immediately identified. Many control panels can monitor over 100 points of protection, more than enough for most installations. How many zones you require depends upon the number of devices you will have and room for future potential additions. Make sure that your control can be expanded to meet your future needs or you may be faced with replacing the control when you want to add devices. Zones can either be supervised or non-supervised. Supervised zones use an end of line resistor (EOL) to maintain a given voltage, if the zone is opened or shorted this voltage will change and activate the control. Unsupervised zones may be normally open or normally closed, normal being the non-alarm state. Zones that are normally open, non-supervised will not alert you to a broken wire in the system. A normally closed, non-supervised system would, but it would not notify you if the wires were accidentally shorted. For the best security, zones should be supervised with an EOL resistor electronically located at the end of the wire run.

Types of zones:

Zones fall into 5 major categories fire, hold-up, medical, burglary, and supervisory. Each type of device has a specific alarm and trouble procedure, for example a fire device will always cause the sounders to activate and notify the monitoring location, but many control panels allow you to program a custom response to any type of detector.

1) Fire zones can be smoke detectors, heat detectors, or manual stations (devices that you activate if you detect a fire). Fire zones are always active, ready to alert you in the event of a fire. A useful feature for smoke detectors is verification. This is a feature where if a smoke detector trips the control will not immediately sound the alarm, but will reset the smoke detector and wait a predetermined period of time for a second trip. Only if the smoke detector trips again during this period the alarm will sound. This feature helps reduce false alarms cause by insects or dust entering the detector.

2) Hold-up zones can be audible or silent (Note: Silent hold-up requires remote monitoring). You may choose either or both. Audible hold-up can be used to "scare' away prowlers but care must always be exercised when activating hold-up devices since there is no way of predicting the action a prowler may take when he hears the sounders or the police arrive. Even if your system is monitored, you can even have an audible hold-up that does not send a signal to the monitoring location.

3) Medical alert devices work basically the same as hold-up devices and have the same options. The only difference is the action that the monitoring company takes when it receives the signals.

4) Burglary devices fall into 3 categories, 24 hour (always active), perimeter (doors and windows), and interior (motion detectors).

5) Supervisory devices can be water or gas detectors, low temperature and the like. Normally these devices are active 24 hours a day and when tripped they do not cause the sounders to sound. They will annunciate at the command centre and send a signal to the monitoring location. I have connected my outside speakers, storage shed, and pool alarm as supervisory zones.

Arming levels:

Time was a security system was either on or off. Today's control allow many levels of arming. The basic ones are AWAY, HOME DELAY, and HOME INSTANT. AWAY arms all perimeter and interior devices and provides an exit/entry delay. It is used when everyone is leaving the home. HOME DELAY arms only perimeter devices and provides exit/entry delay. It is used if some are leaving and some are still home. HOME INSTANT arms only perimeter devices without any exit/entry delay. It is used when everyone is at home.

Arming devices or Command stations:

These are the devices that you would use to arm/disarm and control your system. They may be Alphanumeric, that is they display information in text format, LED, which use light emitting diodes to indicate system status, key switch, requires a key to turn the system on or off, or wireless. Which type you use depends upon several factors such as control type, personal taste, and of course budget. The alphanumeric are generally the most expensive of the wired devices with key switches being the least expensive. Many controls can support only a limited number of command stations, so make sure that the control you choose has the ability to supervise the number of command stations you need.

The alphanumeric command stations may be capable of displaying true custom text, such as Jacks door, or may use a library of pre-programmed descriptions like North door. The display may be LCD, liquid crystal display, or fluorescent. The LCD's tend to be less expensive while the fluorescent are generally brighter and easier to read. While these devices are the most expensive arming device, I believe that they are worth the money, since they are the only part of the system that you will use every day and it makes sense to have a unit that makes operating the system very simple. They can prompt you for the required data, such as Enter Code when the system is activated and provide a clear visual indication of the system status. It is very uncommon for a security systems to be key operated, since a simple key can not perform all of the functions that the control can support. They do have applications, the most important of which is the interfacing with a home automation system. The automation controller can provide an output that can be used to arm/disarm the security system. While this is not a true key switch, it appears that way to the control.

Wireless arming devices may be 1 way, that is they are only capable of sending a signal, or 2 way. The 2 way devices are more expensive but they do confirm that your command was received and carried out. These devices are necessary when you want to arm/disarm the system from your car or when it would not be possible to run wire to a location that needs a command station. Most systems limit the functions of wireless command stations so it is important that you have at least 1 wired station as part of your system.

Outputs:

All controls have some output to activate a sounder but many can also be equipped with relays that can be controlled from a command station, by some type of system activity, or by a pre-programmed time schedule. These relays can allow you to perform many functions such as sprinkler control or as a means of interfacing with a home automation system. The number of available relays depends upon the control used, but some manufacturers have the ability to connect over 100 outputs to the system.

User codes and Authority levels:

Most controls provide multiple user codes. This allows the user to assign each operator of the system their own code, making it easy to remember. The authority levels allow you to control what features/functions each user can perform. You may want your code to control every feature but the codes you give to your children may only arm/disarm the system. Having the ability to add or delete codes can be very useful when you have weekend guests or employ a baby-sitter. You can assign them a simple code and then delete it after they no longer need it, keeping your code secure and your security intact. If your control has a viewable memory log you can review it and determine exactly who performed a function and at what time, an easy way to tell if the curfew was violated or if the system was armed when your spouse went shopping.

Multiple areas:

It may be desirable to divide your security system into a few areas, such as Main, Interior, Safe, and Gun Cabinet. A multiple area system allows one control to be segregated into a number of areas that can be armed/disarmed individually. This allows you to keep the system active for your safe while the rest of the security system is off. If your control has authority levels you can also assign the areas to the individual codes. This feature allows your children to arm/disarm the main system but will not allow them to turn off your gun cabinet or safe. This feature is also useful if you have married children or parents living in a separate part of the house. You could assign all of the protection in their part of the home to one area and allow them access to only that area.

Zone bypassing and forced arming:

Sometimes you may want to disconnect, bypass, some of your protection. If you are having a window replaced, you may have to bypass the protection on that zone until your security company can reinstall the device. Force arming is the arming of a system with one or more zones in trouble. It is similar to bypassing with one exception. If the troubled zone returns to normal after the system is force armed it can become active. This is helpful if the zone was a motion detector that was not reset when you were arming the system but does reset a minute later. A variation of bypassing is called swinger shunt. This is a control panel function that will automatically bypass a zone if it trips more than a pre-programmed number of times. For example if a severe storm should cause a motion detector to continually trip, the control will bypass it after 3 or 4 alarms to prevent additional signals. Once a zone is bypassed in this manner it may remain bypassed until the system is disarmed or some controls will reactivate it, if it remains stable for a period of time, typically 1 hour. This allows the system to maintain the maximum level of protection at all times.

Communication techniques:

If your system is monitored it must be connected to the monitoring office by some means of communication. The most common used today is called digital communication, using your existing telephone line. When the control needs to send a signal it "seizes" the line, disconnecting your telephones, and calls the monitoring office. These systems do not require any special telephone lines but have the disadvantage that if your telephone line is out the control cannot communicate. Your control can be programmed to send a simple test message to the monitoring office every 24 hours to check the integrity of the line. If this signal is not received then the monitoring office knows that something is wrong. It may not detect a burglar cutting the line but it is better than nothing. You can also connect a telephone line monitor to your telephone line to activate your system if the line fails, providing a local indication of the problem.

If additional security is desired you may be able to add cellular telephone, long range radio, derived channel, or one of the special lines that are available from the telephone company in your area. Cellular uses the wireless cellular network to provide a path for your control panel to call the monitoring office. Long range radio provides a wireless path between your home and the monitoring office. Derived channel is a service offered by some telephone companies that uses your existing telephone line and adds a special tone to the line to detect someone cutting the wires. Unlike cellular or radio this system will not send the alarm to the monitoring office, after the wires are cut, it only tells them that they were cut. In certain areas the telephone company will lease a dedicated line that connects your home to the monitoring office. This approach is the most expensive and has limited applications in home security.