Vedard Alarm Security Export Sales Company
Vedard Alarm Security Export Sales Company

Common wired security alarm system working principle

Date: 2023/08/08
Security system is mainly divided into three blocks: monitoring, alarm and access control. In the security group, we shared a lot of things about video surveillance, so today we will talk about alarm system. Our common security alarm system is mainly divided into wired and wireless. Most of the home alarm is wireless, because it is easy to install, no cable constraints, and does not destroy the overall environmental style of the home, so it is deeply liked by home users. Smart home security products are mainly based on wireless alarm and monitoring.
But in the business environment, or systems engineering, the disadvantage of wireless appears. Therefore, wired burglar alarms are trusted by most engineers because of their stability and affordable price, but for personnel who are generally not professionals, it seems that it is a little difficult to connect wired detectors and burglar alarm hosts.
We know that the main components of an anti-theft alarm system are composed of three parts: alarm motherboard, front-end detector and alarm transmission device (network alarm communication and on-site sound and light alarm).
The front-end detector includes passive infrared, infrared plus microwave double detection, infrared through-beam, infrared guardrail, manual alarm, fire house detection, glass breakage, etc., which are suitable for different environments according to different functions.
The front-end detector is the sensor of the alarm system, and the detection of the external alarm situation by the alarm system is completed through the front-end detector. As far as the connection and signal transmission between the front-end detector and the alarm host are concerned, in the final analysis, it is a switching signal transmission and reception process. The so-called switching signal is the process of opening and shorting an electrical circuit.
Taking the conventional alarm system generally adopts normally closed working mode as an example, when the system is powered on normally, if the detector is powered off or triggered by the alarm, the relay in the detector sends out an action, the contact changes from the closed state to the disconnected state, when the alarm host detects this change in the corresponding defense zone port, it will take corresponding reactions according to the current state settings (including ignorance, alarm, signal output, etc.).
In fact, the working principle of alarm host and alarm detector is very simple, but why many people in practice cannot be properly configured and used, in fact, some key basic knowledge is not well understood. Today, let’s talk to you about the wired defense zone and the connection between the wired detector and the alarm system.
The basics can’t be less: what is end-of-wire resistance.
End-of-line resistance (or end-of-line resistance) English EOL Resistor: End-of-line resistance (EOL, End of Line) circuit, the circuit is characterized by the loop terminal access resistance, the short circuit to the ground will trigger the circuit contact action, such as when the system is armed, the loop is broken or short circuit will trigger an alarm. The scientific name is end-of-line resistance, the specific specifications of end-of-line resistance different brands and models of alarm hosts have their own specifications, the resistance of each manufacturer is different, commonly used are 1KΩ, 2.2KΩ, 4.7KΩ, 5.6KΩ, 6.8KΩ, installed on various detectors, that is, the end of the line.

With normally closed circuit, the EOL is connected in series to the circuit, with normally open circuit, the EOL is connected in parallel to the circuit, when alarming, the host will detect the change of resistance value, in other words, as long as the resistance output to the host is not the nominal resistance value (such as 4.7KΩ), the alarm will be alarmed. The task is to prevent vandalism, and you will also call the police if you cut the line or short circuit.
To put it very clearly, there are two ways of end-of-line resistance: one in series and one in parallel.
Normally closed loop (NC): normal short circuit, open circuit alarm. The disadvantage of this circuit formation is that if someone shorts the line, the probe loses its effect. The alarm host cannot identify the human short circuit.
Normally open loop (NO): short circuit alarm, open circuit normal. The disadvantage of this circuit formation is that if someone breaks the line (cuts the signal line), the probe loses its effect. The alarm host cannot identify the section that is human.
Line tail resistance EOL: normal short circuit, open circuit alarm. The advantage of this circuit formation is: if someone breaks the loop line (short circuit back circuit), the alarm host can alarm. Short circuit alarm, open circuit fault, resistance value (such as 4.7KΩ) is normal. The advantage of this circuit form is: different reactions to short circuits and open circuits, especially suitable for smoke detectors and emergency buttons, if it is a mouse bite or tears off due to helping something, the alarm host thinks that the circuit is faulty.
Therefore, in practical applications, without passing the detection of end-of-line resistance, but simply connecting normally closed and normally open circuits, there are great alarm safety risks.
Meaning of alarm host AUX, Z-, Z+:
Unlike wireless detectors, which use battery power, wired detectors are usually powered by DC voltage, and the AUX of the alarm host provides power to the wired detector at the detector power output. Usually the voltage value output of the alarm host AUX is DC12V, DC14V.
Z- represents the negative pole of the wired defense zone, generally Z-ground (GND), Z+ represents the positive pole of the wired defense zone, usually with a certain voltage.

Common connections for alarm detectors:
The lead port of the front-end detector generally has six: power supply + (generally marked as +), power supply – (generally marked as -), alarm signal normally closed output (generally marked as NC or ALARM), alarm signal common end (generally marked as C or ALARM) and two disassembly signal output ports (generally marked as T or TAMPER), we can achieve different anti-dismantling functions and alarm effects through different line wiring and resistance mating.
1. No tamper-proof wiring
Do not enable the detector anti-dismantling function, the alarm system can not sense whether the detector is damaged, this way of wiring in the alarm host does not set a separate anti-dismantling zone or anti-dismantling setting, the detector’s signal cable only needs four cores. Its wiring method is the simplest and most reliable, but it is less secure. In this wiring method, the alarm host can only sense whether the detector is triggered by the alarm situation, but cannot detect other things such as the box cover is opened and the line is damaged (when the line is short-circuited, the alarm system still thinks that the detector is working normally, and when the line is cut or the detector loses power, the alarm system believes that the alarm situation has occurred).
2. Separate anti-dismantling zone wiring
The detector tampering port signal is specially connected to the alarm host dedicated to the anti-dismantling area, the wiring of this method is reliable and simple, and the anti-dismantling zone is separately programmed by the alarm host to achieve the equipment and line dismantling. Because additional lines are required to transmit tamper-proof signals, the cable selection of the detector must be more than six cores. In this wiring method, when the detector box cover is opened, the line is cut or the detector loses power, regardless of whether the alarm system is in the arming state, the anti-dismantling zone corresponding to the alarm host will be triggered to issue an alarm that the equipment is disassembled, but this method will not trigger the alarm when the detector tamper-proof interface or the line is short-circuited, which has certain limitations.
3. Single-wire end-of-line resistance wiring
This wiring method has the basic equipment tamper-proof identification, and there is no need to set up a separate anti-dismantling zone in the alarm host, and the signal cable of the detector only needs four cores, and only the corresponding defense zone of the detector needs to be set as a single-line terminal defense zone. In this wiring method, the alarm host judges what kind of alarm situation occurs by the different resistance values output to different states of the detector signal line.
4. Resistance at the end of two wires
This wiring method has the strongest equipment tamper-proof identification, and there is no need to set up a separate anti-dismantling zone in the alarm host, and the signal cable of the detector only needs four cores, and only the corresponding defense zone of the detector needs to be set as a two-wire terminal resistance zone. In this wiring method, the alarm host judges what kind of alarm situation occurs by the different resistance values output to different states of the detector signal line.

Common connection methods of wired infrared through-beam detector:
More News
The difference between loop control and direct control in automatic fire alarm system
The importance of intelligent security system management software
Key points for the installation of various detectors
Enhance security of public places security
Linear infrared beam smoke detector
Wireless fire alarm linkage system
Residual current electrical fire detector
Simple and effective perimeter security equipment
Wire multiple detectors to one wired zone
Smart home and safe home
Outdoor perimeter security solutions
How to install professional alarm system
Fire fighting gas extinguish
Combustible gas alarm
Combustible gas detection
Carbon monoxide detection system
Fire alarm system input module
Fire alarm manual call point and hydrant button
Fire alarm Bus loop short circuit isolator module
Division of fire alarm areas
Fire alarm system fire graphic display device
Fire alarm system fire control panel types
Addressable fire alarm bus loop
addressable fire alarm system loop
Linkage fire alarm system parts
Fire alarm linkage smoke exhausting
Independent electric fire detection system
division of fire alarm area
Selection and requirements of fire alarm control system
Wiring and principle of wired detector
Precautions for RS485 wiring
Why is electrical fire monitoring system needed
Program Beam sensor before installing
Guidance to shop solar wireless security system
Driveway Alarm System
How to test and install solar beam system
Perimeter security should be included in home security system
Perimeter security solution
Install Infrared Beams Detector
Can solar beam be used at gas station or oil depots
Improvement of active infrared detector
Types and features of outdoor security equipment
Security Solution for community safety
Plant area perimeter security solution
Questions of solar beam systems
Automatic fire alarm system and linkage
combustible gas detection is a subsystem
Prevention of fire and carbon monoxide poisoning
Don’t forget home security on Christmas and New Year
Precautions for use of fire alarm facilities after flood
LoRa intelligent wireless fire alarm system
Technical code for fire alarm system in wireless networking
What are the components of the automatic fire alarm system
Replace smoke alarms in time to avoid fire disasters
Gas fire extinguishing controller
Photoelectric beam smoke detector
Wireless fire alarm system
A life-saving smoke alarm in a fire
The three elements of Security Precaution
Alarm System Linkage
Do not use water for these types fire extinguishing
Loss free new anti theft alarm device
Combustible gas toxic gas monitoring system
The different security needs of shops with different size
Security alarm in intelligent parking lot
Linkage of burglar alarm and video surveillance system
Security service management platform
CO carbon monoxide detector
How to set up fire security system
Bus code fire control detector and module
Smoke detector types and application
Smoke detectors types and wiring
How to DIY home security
Fire alarm system types
Lower explosive limit of combustible gas
Home Security Fire Alarm and fire fighting
Connect solenoid valve with gas detector
How to design a 1000 channel large-scale monitoring system
Burglar alarm failure and troubleshooting
How does the access control system link up with fire alarm and surveillance
Debugging of automatic fire alarm system
Home security solution
Why choose TCP/IP RJ45 network alarm control panel?
Integration of security system
Fire alarm system troubleshooting
Security industry development stages
Setting and Debugging of automatic fire alarm system
Analysis and solution of false alarm problem
China Top ten brands of burglar alarm system manufacturers
Why is electrical fire monitoring system needed
Training for installing fire alarm system
How to build up security service center
How to minimize latency of monitoring systems
Surveillance alarm troubleshooting
What type smoke alarm is better
Difference of sound light alarm and explosion proof alarm
Smart fire alarm system
How to choose active infrared beams
China Security Exhibition 2019 Oct. 28th to 31st
Shopping mall and market interconnection security solution
Intelligent optical fiber perimeter security system
Garden solar alarm lamp
China Chemical plant explosion and Security Consideration
Fire and Explosion in Chemical Plant causes and prevention
Chemical plants fire escape methods and points for attention
Fire Alarm and automatic panel operation training
China Chemical plant explosion and Security Consideration
What to do with Fire alarm and How to recover alarm devices
How to install PIR and Door Contact for home security
7 causes for false alarm of fire detectors
PIR Passive Infrared Detector installing notice
Automatic fire alarm system terms of manual and automatic control
Is Burglar Alarm System useless?
6 home security solution for different budget and security levels
Electric Fire and Electric Socket
Security Service Network Alarm System upgrade
Explosion proof Fire Alarm Gas Detector Sounder Beacon
Solar Wireless PIR Detectors Features
Fire Alarm System Troubles Resolve Solutions
Fire Alarm Systems Maintenance and trouble shooting
How to avoid CO carbon monoxide poisoning
What is beam system and how does it work
Customers frequently asked questions about Solar Beam systems
How to clean Smoke Detector
Test Method and Notes for the Solar Powered Wireless Beams
Do not use water for these types fire extinguishing
How to disable Smoke Alarm temporarily?
Professional Security System installation standards
Home Security anti-theft knowledge and technology
How to escape from bus fire
How to use fire extinguishers
Flammable gas alarm installation and inspection
Addressable Fire Alarm System illustration
Building Fire Security System
Christmas Home Security Protection cautions
Wireless Fire Alarm System for commercial security
2017 China Security Fair News
Installing outdoor security cameras
Is Smart Home equal to App controlled Home
2017 China Public Security Exposition & Security Forum
Notice for wiring FC-7448 bus-line alarm system
How to install and debug FC-7448 Commercial Security Alarm System
2017 China Public Security Exposition
Combination of fingerprint lock and home security system
Cold Storage needs fire alarm system
Fire Security for garage, motor repair shop, parking area
FAS design notice
Photoelectric Beam Detection System Solution
How is sensor important for smart home
How to set up driveway alarm systems
Install intruder detector
Upgrade of PSTN network alarm service center
CMS server requirement and operation
meian tech wireless motion detector
Intrusion detector technology and development
intelligent security
Wireless fire alarm system
General Operation of Fire Alarm Control System
Addressable FACP MN300 Instruction
Alarm System Troubleshooting–Part 1 CMS
Alarm System Troubleshooting–Part 2 Alarm Control Panel
Alarm System Troubleshooting–Part 3 Detector
New technology security alarm server EAVS
Fire alarm system design
bus system security alarm technology
Fire Detectors types and selection
Exterior Security Protection
Home Incidents Prevention
Dangerous gas leakage Alarm Device Installation
Hotel Security Solution
Burglar Alarm System Installation Notes
Intelligent Community Security FAQ
Fire Indication on Alarm Control Panel
Fire Defighting System
Fire prevention and escape
Base Station Integrated Security Solution
Community Security Solution
October 25-28, 2016 China Security Exhibition
China Security Alarms Technology
Theft & Burglar Alarms for Home Security
Install Infrared Beams Detector
China Security Alarms Technology
Security System and Smart Home
Home Fire Prevention in Summer
Set up IP camera for home surveillance
Home Security Systems company Karassn cooperation
Pet immune Motion Detectors and the technology
How would you like to manage home security
Program Alarm Systems Solar Beam Detectors
Smoke Alarm types and connection
Question of Focus Security Alarm Systems
Security Alarm Systems Technical Supports
Security Service & DIY home security
Fire Alert Security Alarm Solution Signal Systems
Security Exhibition 2015 in Shenzhen China from 29th Oct.
Advanced Technology Burglar Alarm Systems
Install wireless door magnetic alarm sensor for rolling door
Fire guard read fire alarm manuals and test fire alarm systems before fire happening
Correct wiring Smoke Alarms for Fire Alarm systems
Carbon Monoxide danger
Questions for Solar-powered wireless infrared grating
Smoke Alarm Questions
Alarm system industry trend and alarm system installer job
Conventional Fire Alarm Security Solution
Perimeter Security Solution with Solar Beams
Reliable Wireless Alarm Systems
Smart Home & Secure Home
Flammable gas alarm installation and inspection
Program Alarm System and understand the terms
2014 Security China International Exhibition
Test Method and Notes for the Solar Powered Wireless Beams
Energy saving theft deterrent
Wireless Fire Alarm Solution For Hotel
Additional wireless detectors to existing alarm system
Home Alarm Security Service Development and the importance
Cheap or Quality China Alarms System
DIY alarms or Professional installed alarms
We help buyer buying China Alarm Security Systems
Alarm System Store for DIY without any consultant's advice
Cooperate with Alarm Systems Installers and Security Service
Digital Network Video Server alarm panel
Quick guide to program FC-7448 building security alarm panel
How to choose Motion Sensors from technology views
Advanced technique of intruder detectors
Integration of Security System
Wireless compare with Wired Alarm System