If you live or work in New Britain, Connecticut, you've probably swiped a badge at least once today and wondered why the reader chirps twice when you think you did everything right. Anti-passback rules and badge accounting might sound like cold security jargon, but they shape how people flow through offices, campuses, hospitals, and even parking garages here. And, oh, do they spark debate.
At its simplest, anti-passback (APB) is a rule that says you can't use your card to enter a secured zone unless the system believes you're currently “outside,” and you can't exit unless it believes you're “inside.” It's a digital version of a doorman keeping a clipboard of who went in and who came out. The idea is to stop “passback,” where someone hands their badge to a friend to sneak them in. Badge accounting goes hand-in-hand: it's the tally of who's in a space at any given moment (and who isn't), often used for safety counts, compliance, and a bit of HR housekeeping. In New Britain, Connecticut, Anti-passback rules and badge accounting aren't just theoretical; they're part of daily life in facilities that care about safety, fairness, and rules.
Walk around downtown near municipal buildings, or step onto a corporate campus (New Britain's got some big names), and you'll see why this matters. There's sensitive equipment, confidential data, and folks who need to know that spaces aren't overcrowded or open to just anybody. APB and accounting make it harder for tailgaters and badge-sharing, and they give first responders data when, say, a fire alarm empties a building. The system says, we think 327 people are still inside; here's where their last reads were. That's not nothing.
But the tech isn't perfect. Readers can fail, doors prop open, and access panels drift out of sync. There's many reasons the database might think you exited when you didn't, or vice versa (someone piggybacked, a door contact was flaky, your badge was read twice in a jittery second). Then you try to re-enter after a coffee break and the panel goes red. You tap harder like that'll help, and a small line forms behind you. If this happens at a shift change outside a garage near a busy artery, what a mess!
Locals tell stories that sound mundane but matter. At a hospital campus, a clinician rushing between buildings can't afford to be “locked out” because the APB state never updated on a skywalk reader. At a university facility, a student group returns after a late practice; one person forgot to badge out earlier, so the system won't let them back in now. And in a factory where time is literally money, an APB glitch at the main turnstile can chew up minutes that nobody gets back. It's not that the idea is bad-it's that the execution needs to be tuned to the way people actually move.
That's where policy comes in. Smart administrators in New Britain adapt APB, rather than worship it. They use soft APB (which warns but doesn't hard-lock) during the first weeks of a rollout, and then ramp up to hard APB once people understand the rhythm. They put “forgive” buttons in the guard console and train attendants to resolve a stuck credential fast (like 15 seconds fast). They define clean zones: if there's a public lobby that folks cross frequently, they don't put hard APB on that boundary. And they don't pretend that a single rule fits a hospital, a city office, and a baseball stadium the same way.
Badge accounting also walks a fine line. Counting occupants supports life safety and compliance, but it shouldn't become a shadow timesheet. In Connecticut, employers are already careful about timekeeping and privacy, and many workers expect reasonable transparency. If a New Britain site uses badge data for payroll or investigations, it mustn't be a surprise. Clear notices, union consultation where it applies, and a narrow use policy (no fishing expeditions) go a long way. People accept controls when they understand the why and the limits. They reject them when they feel watched for no good reason.
The tech stack matters too. Modern systems tie door contacts, motion sensors, and camera analytics into APB logic. If a door is forced or propped, the system can “heal” the APB state or at least flag a mismatch. Mobile credentials reduce passback because it's harder to hand someone your phone than a plastic card (and geofencing helps validate presence). Offline readers in stairwells sync state when they reconnect (but really, try not to strand people there). And the best deployments add graceful exits: turnstiles where you can badge-out even if you forgot, and clearly marked portals with separate readers for each direction (one reader for both in and out is just asking for chaos).
There's also a very New Britain way of looking at it: practical, cost-conscious, and community-minded. Security isn't a trophy; it's a tool. You won't win points by bragging that no one can get in or out-unless that also means first responders, contractors, and late-shift staff can move smoothly when they need to. So facilities teams here try not to pile on rules they can't support. If there's no overnight guard, maybe don't enable strict hard APB on every exterior door at 2 a.m. If the parking garage sees heavy traffic after a game night, consider time-based relaxations so residents aren't stuck idling and honking (not good for anyone). And if a building serves the public, a visible help point with a live voice beats a laminated sign that nobody reads.
Some practical tips I've heard around town (and they're common sense, really):
And one more thing-interoperability isn't optional. If the city upgrades fire panels or changes elevator controls, the APB and accounting logic should be reviewed. People will move differently, and the system mustn't pretend otherwise. Oh, and keep an eye on your integrations (camera pop-ups, visitor systems, mobile wallets). When one piece hiccups, the APB state can drift in subtle ways you won't notice until the Monday rush.
In the end, anti-passback and badge accounting in New Britain aren't about catching bad actors as much as they're about fairness and safety. They say, we share spaces, we respect limits, and we're trying to keep things running. Done well, they fade into the background. Done poorly, they trip us up at the door. And, well, nobody here really has time for that.
Redirect to:
In physical security and information security, access control (AC) is the action of deciding whether a subject should be granted or denied access to an object (for example, a place or a resource). The act of accessing may mean consuming, entering, or using. It is often used interchangeably with authorization, although the authorization may be granted well in advance of the access control decision.[1]
Access control on digital platforms is also termed admission control. The protection of external databases is essential to preserve digital security.[2]
Access control is considered to be a significant aspect of privacy that should be further studied. Access control policy (also access policy) is part of an organization’s security policy. In order to verify the access control policy, organizations use an access control model.[3] General security policies require designing or selecting appropriate security controls to satisfy an organization's risk appetite - access policies similarly require the organization to design or select access controls.
Broken access control is often listed as the number one risk in web applications.[4] On the basis of the "principle of least privilege", consumers should only be authorized to access whatever they need to do their jobs, and nothing more.[5]
Geographical access control may be enforced by personnel (e.g. border guard, bouncer, ticket checker), or with a device such as a turnstile. There may be fences to avoid circumventing this access control. An alternative of access control in the strict sense (physically controlling access itself) is a system of checking authorized presence, see e.g. Ticket controller (transportation). A variant is exit control, e.g. of a shop (checkout) or a country.[6]
The term access control refers to the practice of restricting entrance to a property, a building, or a room to authorized persons. Physical access control can be achieved by a human (a guard, bouncer, or receptionist), through mechanical means such as locks and keys, or through technological means such as access control systems like the mantrap. Within these environments, physical key management may also be employed as a means of further managing and monitoring access to mechanically keyed areas or access to certain small assets.[6]
Physical access control is a matter of who, where, and when. An access control system determines who is allowed to enter or exit, where they are allowed to exit or enter, and when they are allowed to enter or exit. Historically, this was partially accomplished through keys and locks. When a door is locked, only someone with a key can enter through the door, depending on how the lock is configured. Mechanical locks and keys do not allow restriction of the key holder to specific times or dates. Mechanical locks and keys do not provide records of the key used on any specific door, and the keys can be easily copied or transferred to an unauthorized person. When a mechanical key is lost or the key holder is no longer authorized to use the protected area, the locks must be re-keyed.[7]
Electronic access control (EAC) uses computers to solve the limitations of mechanical locks and keys. It is particularly difficult to guarantee identification (a critical component of authentication) with mechanical locks and keys. A wide range of credentials can be used to replace mechanical keys, allowing for complete authentication, authorization, and accounting. The electronic access control system grants access based on the credential presented. When access is granted, the resource is unlocked for a predetermined time and the transaction is recorded. When access is refused, the resource remains locked and the attempted access is recorded. The system will also monitor the resource and alarm if the resource is forcefully unlocked or held open too long after being unlocked.[6]
When a credential is presented to a reader, the reader sends the credential's information, usually a number, to a control panel, a highly reliable processor. The control panel compares the credential's number to an access control list, grants or denies the presented request, and sends a transaction log to a database. When access is denied based on the access control list, the door remains locked. If there is a match between the credential and the access control list, the control panel operates a relay that in turn unlocks the resource. The control panel also ignores an opening signal to prevent an alarm. Often the reader provides feedback, such as a flashing red LED for an access denied and a flashing green LED for an access granted.[8]
The above description illustrates a single factor transaction. Credentials can be passed around, thus subverting the access control list. For example, Alice has access rights to the server room, but Bob does not. Alice either gives Bob her credential, or Bob takes it; he now has access to the server room. To prevent this, two-factor authentication can be used. In a two factor transaction, the presented credential and a second factor are needed for access to be granted; another factor can be a PIN, a second credential, operator intervention, or a biometric input.[8]
There are three types (factors) of authenticating information:[9]
Passwords are a common means of verifying a user's identity before access is given to information systems. In addition, a fourth factor of authentication is now recognized: someone you know, whereby another person who knows you can provide a human element of authentication in situations where systems have been set up to allow for such scenarios. For example, a user may have their password, but have forgotten their smart card. In such a scenario, if the user is known to designated cohorts, the cohorts may provide their smart card and password, in combination with the extant factor of the user in question, and thus provide two factors for the user with the missing credential, giving three factors overall to allow access.[citation needed]
A credential is a physical/tangible object, a piece of knowledge, or a facet of a person's physical being that enables an individual access to a given physical facility or computer-based information system. Typically, credentials can be something a person knows (such as a number or PIN), something they have (such as an access badge), something they are (such as a biometric feature), something they do (measurable behavioural patterns), or some combination of these items. This is known as multi-factor authentication. The typical credential is an access card or key-fob, and newer software can also turn users' smartphones into access devices.[10]
There are many card technologies including magnetic stripe, bar code, Wiegand, 125 kHz proximity, 26-bit card-swipe, contact smart cards, and contactless smart cards. Also available are key-fobs, which are more compact than ID cards, and attach to a key ring. Biometric technologies include fingerprint, facial recognition, iris recognition, retinal scan, voice, and hand geometry. The built-in biometric technologies found on newer smartphones can also be used as credentials in conjunction with access software running on mobile devices.[11] In addition to older more traditional card access technologies, newer technologies such as near-field communication (NFC), Bluetooth low energy or Ultra-wideband (UWB) can also communicate user credentials to readers for system or building access.[12][13][14]
Components of an access control system include:
Access control decisions are made by comparing the credentials to an access control list. This look-up can be done by a host or server, by an access control panel, or by a reader. The development of access control systems has observed a steady push of the look-up out from a central host to the edge of the system, or the reader. The predominant topology circa 2009 is hub and spoke with a control panel as the hub, and the readers as the spokes. The look-up and control functions are by the control panel. The spokes communicate through a serial connection; usually RS-485. Some manufactures are pushing the decision making to the edge by placing a controller at the door. The controllers are IP enabled, and connect to a host and database using standard networks[16]
Access control readers may be classified by the functions they are able to perform:[17]
Some readers may have additional features such as an LCD and function buttons for data collection purposes (i.e. clock-in/clock-out events for attendance reports), camera/speaker/microphone for intercom, and smart card read/write support.
1. Serial controllers. Controllers are connected to a host PC via a serial RS-485 communication line (or via 20mA current loop in some older systems). External RS-232/485 converters or internal RS-485 cards have to be installed, as standard PCs do not have RS-485 communication ports.[citation needed]
Advantages:[citation needed]
Disadvantages:[citation needed]
2. Serial main and sub-controllers. All door hardware is connected to sub-controllers (a.k.a. door controllers or door interfaces). Sub-controllers usually do not make access decisions, and instead forward all requests to the main controllers. Main controllers usually support from 16 to 32 sub-controllers.
3. Serial main controllers & intelligent readers. All door hardware is connected directly to intelligent or semi-intelligent readers. Readers usually do not make access decisions, and forward all requests to the main controller. Only if the connection to the main controller is unavailable, will the readers use their internal database to make access decisions and record events. Semi-intelligent reader that have no database and cannot function without the main controller should be used only in areas that do not require high security. Main controllers usually support from 16 to 64 readers. All advantages and disadvantages are the same as the ones listed in the second paragraph.
4. Serial controllers with terminal servers. In spite of the rapid development and increasing use of computer networks, access control manufacturers remained conservative, and did not rush to introduce network-enabled products. When pressed for solutions with network connectivity, many chose the option requiring less efforts: addition of a terminal server, a device that converts serial data for transmission via LAN or WAN.
All the RS-485-related advantages and disadvantages also apply.
5. Network-enabled main controllers. The topology is nearly the same as described in the second and third paragraphs. The same advantages and disadvantages apply, but the on-board network interface offers a couple of valuable improvements. Transmission of configuration and user data to the main controllers is faster, and may be done in parallel. This makes the system more responsive, and does not interrupt normal operations. No special hardware is required in order to achieve redundant host PC setup: in the case that the primary host PC fails, the secondary host PC may start polling network controllers. The disadvantages introduced by terminal servers (listed in the fourth paragraph) are also eliminated.
6. IP controllers. Controllers are connected to a host PC via Ethernet LAN or WAN.
7. IP readers. Readers are connected to a host PC via Ethernet LAN or WAN.
The advantages and disadvantages of IP controllers apply to the IP readers as well.
The most common security risk of intrusion through an access control system is by simply following a legitimate user through a door, and this is referred to as tailgating. Often the legitimate user will hold the door for the intruder. This risk can be minimized through security awareness training of the user population or more active means such as turnstiles. In very high-security applications this risk is minimized by using a sally port, sometimes called a security vestibule or mantrap, where operator intervention is required presumably to assure valid identification.[18]
The second most common risk is from levering a door open. This is relatively difficult on properly secured doors with strikes or high holding force magnetic locks. Fully implemented access control systems include forced door monitoring alarms. These vary in effectiveness, usually failing from high false positive alarms, poor database configuration, or lack of active intrusion monitoring. Most newer access control systems incorporate some type of door prop alarm to inform system administrators of a door left open longer than a specified length of time.[19][20][21]
The third most common security risk is natural disasters. In order to mitigate risk from natural disasters, the structure of the building, down to the quality of the network and computer equipment vital. From an organizational perspective, the leadership will need to adopt and implement an All Hazards Plan, or Incident Response Plan. The highlights of any incident plan determined by the National Incident Management System must include Pre-incident planning, during incident actions, disaster recovery, and after-action review.[22]
Similar to levering is crashing through cheap partition walls. In shared tenant spaces, the divisional wall is a vulnerability. A vulnerability along the same lines is the breaking of sidelights.[citation needed]
Spoofing locking hardware is fairly simple and more elegant than levering. A strong magnet can operate the solenoid controlling bolts in electric locking hardware. Motor locks, more prevalent in Europe than in the US, are also susceptible to this attack using a doughnut-shaped magnet. It is also possible to manipulate the power to the lock either by removing or adding current, although most Access Control systems incorporate battery back-up systems and the locks are almost always located on the secure side of the door. [citation needed]
Access cards themselves have proven vulnerable to sophisticated attacks. Enterprising hackers have built portable readers that capture the card number from a user's proximity card. The hacker simply walks by the user, reads the card, and then presents the number to a reader securing the door. This is possible because card numbers are sent in the clear, no encryption being used. To counter this, dual authentication methods, such as a card plus a PIN should always be used.
Many access control credentials unique serial numbers are programmed in sequential order during manufacturing. Known as a sequential attack, if an intruder has a credential once used in the system they can simply increment or decrement the serial number until they find a credential that is currently authorized in the system. Ordering credentials with random unique serial numbers is recommended to counter this threat.[23]
Finally, most electric locking hardware still has mechanical keys as a fail-over. Mechanical key locks are vulnerable to bumping.[24]
In computer security, general access control includes authentication, authorization, and audit. A more narrow definition of access control would cover only access approval, whereby the system makes a decision to grant or reject an access request from an already authenticated subject, based on what the subject is authorized to access. Authentication and access control are often combined into a single operation, so that access is approved based on successful authentication, or based on an anonymous access token. Authentication methods and tokens include passwords, biometric analysis, physical keys, electronic keys and devices, hidden paths, social barriers, and monitoring by humans and automated systems.
In any access-control model, the entities that can perform actions on the system are called subjects, and the entities representing resources to which access may need to be controlled are called objects (see also Access Control Matrix). Subjects and objects should both be considered as software entities, rather than as human users: any human users can only have an effect on the system via the software entities that they control.[citation needed]
Although some systems equate subjects with user IDs, so that all processes started by a user by default have the same authority, this level of control is not fine-grained enough to satisfy the principle of least privilege, and arguably is responsible for the prevalence of malware in such systems (see computer insecurity).[citation needed]
In some models, for example the object-capability model, any software entity can potentially act as both subject and object.[citation needed]
As of 2014[update], access-control models tend to fall into one of two classes: those based on capabilities and those based on access control lists (ACLs).
Both capability-based and ACL-based models have mechanisms to allow access rights to be granted to all members of a group of subjects (often the group is itself modeled as a subject).[citation needed]
Access control systems provide the essential services of authorization, identification and authentication (I&A), access approval, and accountability where:[25]
Access to accounts can be enforced through many types of controls.[26]
In telecommunications, the term access control is defined in U.S. Federal Standard 1037C[34] with the following meanings:
This definition depends on several other technical terms from Federal Standard 1037C.
Special public member methods – accessors (aka getters) and mutator methods (often called setters) are used to control changes to class variables in order to prevent unauthorized access and data corruption.
In public policy, access control to restrict access to systems ("authorization") or to track or monitor behavior within systems ("accountability") is an implementation feature of using trusted systems for security or social control.
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A fire alarm system is a building system designed to detect, alert occupants, and alert emergency forces of the presence of fire, smoke, carbon monoxide, or other fire-related emergencies. Fire alarm systems are required in most commercial buildings. They may include smoke detectors, heat detectors, and manual fire alarm activation devices (pull stations). All components of a fire alarm system are connected to a fire alarm control panel. Fire alarm control panels are usually found in an electrical or panel room. Fire alarm systems generally use visual and audio signalization to warn the occupants of the building. Some fire alarm systems may also disable elevators, which are unsafe to use during a fire under most circumstances.[1]
Fire alarm systems are designed after fire protection requirements in a location are established, which is usually done by referencing the minimum levels of security mandated by the appropriate model building code, insurance agencies, and other authorities. A fire alarm designer will detail specific components, arrangements, and interfaces necessary to accomplish these requirements. Equipment specifically manufactured for these purposes is selected, and standardized installation methods are anticipated during the design. There are several commonly referenced standards for fire protection requirements, including:
There are national codes in each European country for planning, design, installation, commissioning, use, and maintenance of fire detection systems with additional requirements that are mentioned on TS 54 -14:
Across Oceania, the following standards outline the requirements, test methods, and performance criteria for fire detection control and indicating equipment utilised in building fire detection and fire alarm systems:
Fire alarm systems are composed of several distinct parts:
Initiating devices used to activate a fire alarm system are either manually or automatically actuated devices. Manually actuated devices, also known as fire alarm boxes, manual pull stations, or simply pull stations, break glass stations, and (in Europe) call points, are installed to be readily located (usually near the exits of a floor or building), identified, and operated. They are usually actuated using physical interaction, such as pulling a lever or breaking glass.
Automatically actuated devices can take many forms, and are intended to respond to any number of detectable physical changes associated with fire: convected thermal energy for a heat detector, products of combustion for a smoke detector, radiant energy for a flame detector, combustion gases for a fire gas detector, and operation of sprinklers for a water-flow detector. Automatic initiating devices may use cameras and computer algorithms to analyze and respond to the visible effects of fire and movement in applications inappropriate for or hostile to other detection methods.[13][14]
Alarms can take many forms, but are most often either motorized bells or wall-mountable sounders or horns. They can also be speaker strobes that sound an alarm, followed by a voice evacuation message for clearer instructions on what to do. Fire alarm sounders can be set to certain frequencies and different tones, either low, medium, or high, depending on the country and manufacturer of the device. Most fire alarm systems in Europe sound like a siren with alternating frequencies. Fire alarm electronic devices are known as horns in the United States and Canada and can be continuous or set to different codes. Fire alarm warning devices can also be set to different volume levels.
Notification appliances utilize audible, visible, tactile, textual or even olfactory stimuli (odorizers)[15][16] to alert the occupants of the need to evacuate or take action in the event of a fire or other emergency. Evacuation signals may consist of simple appliances that transmit uncoded information, coded appliances that transmit a predetermined pattern, and/or appliances that transmit audible and visible information such as live or prerecorded instructions and illuminated message displays. Some notification appliances are a combination of fire alarm and general emergency notification appliances, allowing both types of emergency notifications from a single device. In addition to pre-recorded and predetermined messages and instructions, some systems also support the live broadcasting and recording of voice announcements to all or certain parts of the property or facility, including customized instructions for the situation for each area, such as by emergency or facility management personnel. Outdoor appliances (such as large-scale speaker/horn/strobe poles to effectively reach outdoor occupants over potentially larger distances or areas), lighting control, and dynamic exit signage may also be used in certain circumstances.
Some fire alarm systems utilize emergency voice alarm communication systems (EVAC)[17] to provide prerecorded and manual voice messages. Voice alarm systems are typically used in high-rise buildings, arenas, and other large "defend-in-place" occupancies such as hospitals and detention facilities where total evacuation is difficult to achieve.[citation needed] Voice-based systems allow response personnel to conduct orderly evacuation and notify building occupants of changing event circumstances.[citation needed]
Audible textual appliances can be employed as part of a fire alarm system that includes EVAC capabilities. High-reliability speakers notify the occupants of the need for action concerning a fire or other emergency. These speakers are employed in large facilities where general undirected evacuation is impracticable or undesirable. The signals from the speakers are used to direct the occupant's response. The fire alarm system automatically actuates speakers in a fire event. Following a pre-alert tone, selected groups of speakers may transmit one or more prerecorded messages directing the occupants to safety. These messages may be repeated in one or more languages. The system may be controlled from one or more locations within the building, known as "fire warden stations", or from a single location designated as the building's "fire command center". From these control locations, trained personnel activating and speaking into a dedicated microphone can suppress the replay of automated messages to initiate or relay real-time voice instructions.[18]
In highrise buildings, different evacuation messages may be played on each floor, depending on the location of the fire. The floor the fire is on along with ones above it may be told to evacuate while floors much lower may be asked to stand by.[citation needed]
In the United States, fire alarm evacuation signals generally consist of a standardized audible tone, with visual notification in all public and common-use areas. Emergency signals are intended to be distinct and understandable to avoid confusion with other signals.
As per NFPA 72, 18.4.2 (2010 Edition), Temporal Code 3 is the standard audible notification in a modern system. It consists of a repeated three-pulse cycle (0.5 s on, 0.5 s off, 0.5 s on, 0.5 s off, 0.5 s on, 1.5 s off). Voice evacuation is the second most common audible notification in modern systems. Legacy systems, typically found in older schools and buildings, have used continuous tones alongside other audible notifications.
In the United Kingdom, fire alarm evacuation signals generally consist of a two-tone siren with visual notifications in all public and common-use areas. Some fire alarm devices can emit an alert signal, which is generally used in schools for lesson changes, the start of morning break, the end of morning break, the start of lunch break, the end of lunch break, and when the school day is over.
New codes and standards introduced around 2010, especially the new UL Standard 2572, the US Department of Defense's UFC 4-021-01 Design and O&M Mass Notification Systems, and NFPA 72 2010 edition Chapter 24, have led fire alarm system manufacturers to expand their systems voice evacuation capabilities to support new requirements for mass notification. These expanded capabilities include support for multiple types of emergency messaging (i.e., inclement weather emergency, security alerts, amber alerts). The major requirement of a mass notification system is to provide prioritized messaging according to the local facilities' emergency response plan, and the fire alarm system must support the promotion and demotion of notifications based on this emergency response plan. In the United States, emergency communication systems also have requirements for visible notification in coordination with any audible notification activities to meet the needs of the Americans with Disabilities Act.
Mass notification system categories include the following:
Mass notification systems often extend the notification appliances of a standard fire alarm system to include PC-based workstations, computers, mobile devices, text-based or display monitor-based digital signage, and a variety of remote notification options including email, text message, RCS/other messaging protocols, phone calls, social media, RSS feed, or IVR-based telephone text-to-speech messaging. In some cases and locations, such as airports, localized cellular communication devices may also send wireless emergency alerts to cell phones in the area, and radio override may override other radio signals to play the emergency message and instructions to radios in range of the signal.
Residential fire alarm systems are commonplace. Typically, residential fire alarm systems are installed along with security alarm systems. In the United States, the NFPA requires residential fire alarm system in buildings where more than 12 smoke detectors are needed.[19] Residential systems generally have fewer parts compared to commercial systems.
Various equipment may be connected to a fire alarm system to facilitate evacuation or to control a fire, directly or indirectly:
In the United Kingdom, fire alarm systems in non-domestic premises are generally designed and installed in accordance with the guidance given in BS 5839 Part 1. There are many types of fire alarm systems, each suited to different building types and applications. A fire alarm system can vary dramatically in price and complexity, from a single panel with a detector and sounder in a small commercial property to an addressable fire alarm system in a multi-occupancy building.
BS 5839 Part 1 categorizes fire alarm systems as:[21]
Categories for automatic systems are further subdivided into L1 to L5 and P1 to P2.
An important consideration when designing fire alarms is that of individual "zones". The following recommendations are found in BS 5839 Part 1:
The NFPA recommends placing a list for reference near the fire alarm control panel showing the devices contained in each zone.