Understanding Zone Monitor Modules in Fire Alarm Systems

Fire alarm systems are imperative to effectively ensure the safety and security of a wide range of infrastructures. These systems owe their efficiency and effectiveness to several crucial components, and one such essential component is the Zone Monitor Module, which is used alongside conventional heat detectors. This article examines the purpose, importance, and functioning of Zone Monitor Modules in Fire Alarm Systems. If you’re a facilities manager or an engineer – or perhaps are simply keen on learning about the contemporary tools making fire safety possible – this post will equip you with professional perspectives on how these modules enable effective fire management through detection and response. Keep reading as we elaborate on how these modules work, their applications, and why they are cornerstone assets of fire safety protocols.

What is a Zone Monitor Module?

A Zone Monitor Module is essential for integrating traditional fire detection devices into the addressable fire alarm system. It examines a particular area to see if devices such as smoke detectors or manual call points have signaled anything. The module communicates with the control panel during a fire or when a fault occurs with the device aimed at to alert the fire panel, enabling users to respond swiftly. The zone of these modules smooths the connection of existing technologies with new addressable systems, maximizing the effectiveness and extent of fire detection.

How does a monitor module work?

A monitor module manages and reports the conditions of devices connected to the fire alarm control panel. It operates in the manner of periodically scanning for conditions, for example, whether a smoke detector has been engaged or a manual call point has been activated, that are deemed to be outside of the normal conditions. A module executes such an action by informing the control panel upon detection for a responsive action to be taken. Furthermore, it can identify malfunctions due to wiring and other factors. This means the system is functional in the event of a malfunction, enabling a seamless operation. Due to this capability, the monitor module is critical in efficiently operating the fire detection and alarm systems.

What role does a zone monitor play in a fire alarm system?

Zone controllers are perhaps conventional fire alarm systems’ most significant and crucial element. Zone controllers allow for the segregation of the area in which several detecting equipment need to be coordinated and controlled.   In this context, it is primarily used to monitor the state of the devices within the assignment area, manually activated devices and smoke and heat detectors. Also, it indicates the fire alarm control panel when a fire, fault, or normal condition occurs.

Zone monitors are at present also provided with self-diagnosing capabilities, which in turn improves reliability on these devices. For example, it is able to report open and short circuits and even the failure of the device, hence reducing downtime by being able to zero in on the problem. Other models can also deal with multiple zones and thus can be more dynamic. Typically, diesel generators are connected with 20 or 30 zone monitors. This is considered an optimum number to cater to the efficiency and area needed to be covered.

Zone controllers also enhance the security of proceedings by ensuring that regulations, policies, and procedures are not violated. This is achieved by allowing the rapid targeting of malfunctions and reoccurrence of certain events, speeding up the response to such occurrences so as to mitigate the amount of damage caused and ensure the safety of those during the event.

Why is a zone monitor module important for safety?

A zone monitor module performs an important function in various systems, providing safety features. For instance, as a part of monitoring and supervisory fire alarm and detection systems, it is able to employ continuous zone monitoring and supervising of specific zones, ensuring that threats of such elements as open circuits, short circuits, or devices breaking down are averted. By containing the faults and finding them within a certain location, the module minimizes the chances of false alarms and allows the system in other areas to remain operational.

The modules must assure their utility and effectiveness by inter alia being capable of meeting internationally recognized benchmark requirements, such as NFPA 72 and EN 54-13, which require adequate monitoring and fault tolerance in life safety systems. In practice, a fault in the fire alarm system can be detected almost in milliseconds, which hastens up the response during a fire. Industry reports indicate that quicker detection and response enabled by these modules can provide up to 35% savings in potential losses from damages than systems not equipped with advanced monitoring.

These modules further increase the scalability and flexibility of the system. In the case of, for example, of hospitals or industrial plants, zone monitors may control the interconnections of a great number of detection devices without loss of communication. They are also connected with advanced diagnostics and provide tightly integrated log data for predictive maintenance, avoiding system failures during uptime events. Giving assurance of accurate fault diagnosis with continuous reliability of aid operation, zone monitor modules are necessary in the prevention of loss of equipment and life.

How Does a Zone Monitor Module Integrate with a Fire Alarm System?

How do zone monitor modules connect to the fire alarm control panel?

Fire alarm control panels are interconnected with zone monitor modules through wiring that is designed and built to ensure robust and reliable control signals. It is most common for these modules to be connected to either Class A circuits or Class B circuits, depending on the design and topology of the system. Class A circuits allow for communication paths through other redundant circuits, which increases reliability against cable faults, whereas Class B circuits allow for communications using a single path, hence offering a higher economy.

Each zone of a building is assigned a module that is programmed exclusively for that zone. When detectors and manual call points in the zone detect a zone to be in an anomaly like smoke or excessive heat or are manually activated, the module returns a digital signal to the control panel. Some of the more advanced Fire Alarm Systems include loop protocols with, for example, Addressable Device Protocol (ADP) or Signalling Line Circuits (SLC), which make it possible to identify the device that has been activated more quickly to assist in emergency response situations.

In today’s generation, both non-addressable and addressable fire alarm systems have been integrated into one system. Data transmission integrity is handled well with built-in fail-safes, which include end-of-line resistors that check the continuity of the circuit wires. Technical papers reviewed for professional purposes, such as those for the NFPA 72, require that cable module wiring be suitable to deal with harsh environmental conditions, including fire-resistant or low-smoke zero-halogen cables.

Zone monitor modules facilitate communication between the various detection zones and the fire alarm control panel, which is central to system performance in commercial, residential, and industrial applications. In combination with appropriate site zoning and placement of the modules, life safety systems, including fire alarms, can be improved in their efficiency.

What is the relationship between detectors and monitor modules?

Detectors and monitor modules rely on one another for fire detection and fire alarm activation. I believe detectors act as smoke or heat sensors to determine a fire’s presence. In contrast, monitor modules connect to the fire alarm signal control panel to ensure the signals received are transmitted correctly. This cooperation enables the system to detect and address threats to security promptly.

How does a zone monitor module interface with other devices?

Zone monitor modules communicate between the fire alarm panel and the traditional detection devices within a specified zone. As previously mentioned, it interfaces with the control panel and oversees whether the circuits receive and relay alarms, are permanently closed, or have been managed. This allows for a routine diagnosis of conditions or emergencies within the system while ensuring seamless communication with connected devices using the control module to interact with them.

What are the Differences Between Conventional and Addressable Zone Monitor Modules?

What makes conventional zone monitor modules unique?

Zone monitor modules, more particularly the conventional zone monitor modules, are able to provide increased ability and cost-effective circuit monitoring in fire alarm systems when compared to the addressable systems. The addressable demolition, unlike its addressable counterpart, employs the practice of sectioning the protected lines into different zones, each being the responsibility of its own designated circuit so as to enable a detection zone of the fire alarm, not a device. This enhances the design and maintenance process as smaller systems do not require for the device to be monitored.

One of the foremost advantages of using the conventional zone monitor modules is the ability to apply a plethora of standard detection devices which include smoke and heat detectors. These devices are activated and BUILT to rely on changes within the current or voltage levels of the set voltage to learn information of the environment around them and can detect changes enabled by a control device. Other than the above-mentioned factors, traditional systems are quite popular due to their ease of installation, simplicity, and fantastic durability. A research analysis based on the fire alarm system history suggests that these types of modules are mostly used in small buildings where there is no accurate accuracy needed at the device level.

In addition to this, the modules enable advanced supervision of the integrated circuits, facilitating the identification of faults caused by open wires, short circuits, or defective devices in real-time. Due to the evolution of technology, modern conventional systems have increased in sensitivity and compatibility, thereby ensuring that these modules remain relevant in situations that require cheap fire alarm systems.

How does an addressable system differ from a conventional one?

Depending on design characteristics, purpose, or functionality, there are some characteristic features that split the addressable fire alarm systems from conventional systems, as these two types of systems greatly differ from one another. A conventional fire protection system works by dividing premises into zones that have their own detectors and call points wired into separate circuits. In a conventional system, once the alarm is triggered, the control panel is only able to display the zone that was activated and not the exact device, thus leaving further investigation to be done manually – which can result in important responses being hampered for a certain period of time, especially in bigger buildings.

Conversely, these addressable systems give unique identifiers or ‘addresses’ to every switchable device, with sensors pointing to smoke detectors, heat sensors, and manual call points. Because of this feature, the control panel can display the exact device that was engaged, which leads to a dramatic decrease in response times for hazards and enhances the location accuracy for hazards. For example, addressable fire alarm systems can differentiate between a smoke detector on the 2nd floor of a building and that within a specific business suite.

In terms of technology, addressable systems use advanced communication protocols, enabling two-way dialogue between the devices and the central panel. This makes real-time monitoring and diagnostics possible, including battery diagnostics, maintenance, and fault status checks. Addressable systems are also more robust with regard to wiring faults; in such systems, the communication remains intact with one wire cut because of the use of loop configurations.

Further available data confirms that these addressable systems have better scaling, which makes them suitable for large or more involved institutions like hospitals, airports, and commercial offices. The overheads of installing addressable systems are quite high when compared to conventional systems, however their greater efficiency, lower maintenance burden and higher reliability puts them above traditional systems for long term use. Addressable fire alarm systems have clear air superiority over their conventional counterparts due to the evolving fire safety technology in the contemporary world.

What are the advantages of using addressable fire alarm systems?

Addressable systems correlate with a multitude of advantages in comparison to conventional approaches. Such as:

• Accuracy in Reporting: After activating the device, the device can provide details of where it was activated. This information helps in dealing with the emergency situation more efficiently.
• Increased Trustworthiness: As was previously mentioned, these systems provide advanced monitoring capabilities; addressable systems have all the features to eliminate false alarms.
• Reduced Maintenance Cost: It is easier to restore the devices due to their ability to locate their faults when needed.
• Scalability is reinforced, which permits the over-building of more relay modules to be optimized for operation.: Addressable systems can be fitted for buildings of different natures and scopes, ensuring a large operational reach.
• Interfacing with Other Systems: This facilitates project operational performance improvement through seamless integration with other safety and building management systems.

How to Install and Maintain a Zone Monitor Module?

Steps to Properly Install a Zone Monitor Module

1. Check System Requirements: Verify that the zone monitor module is functional with the fire alarm control panel and complies with the required specifications.
2. Place the Module Appropriately: Find the appropriate installation site, which is often adjacent to the devices it will monitor, allowing for easy maintenance.
3. Shut Down the System: Disconnect any power to eliminate electrical hazards during the installation.
4. Wire Connections: Connect the module to the system using the manufacturer’s diagram. This usually consists of device inputs and panel outputs.
5. Fasten Module: Use the supplied hardware to fasten the module in place and secure it from the outside elements.
6. Confirm Connections: Use a continuity test or an equivalent procedure to check that all connections have been made correctly.
7. Restore System Power: After installing the module, restore power and check for any faults.
8. Modules’ functional test: The purpose is to check if the module operates well while monitoring and communicating with the connected devices, and the results should be documented.

Module Installation Documentation: Maintain the documents in regards to systems records in relation of the installation, its location and wiring configuration of the module. .

How often should monitor modules be checked for faults?

The required monitoring modules must be routinely added to the list, and comprehensive inspections are mandatory so as to ensure the effective functionality of the system and the identification of issues as early as possible. The industry’s recommendations provide that such modules are included on the list of equipment that undergoes sorting not less than once a year as part of planned maintenance. Several codes also indicate the same principle, such as NFPA 72 (National Fire Alarm and Signaling Code), which cites that fire alarm systems, inclusive of some components such as the monitor modules, should be inspected and tested on an annual basis.

The rate of checking may also vary from what is stated in some conditions, for instance, in cases of extreme temperatures, high humidity climates, and a lot of dust and debris, as these might wear the material out faster than usual. These conditions would warrant more check-ups. In the case of high-risk facilities such as data centers or hospitals, it would be appropriate to consider the duration of Downtime risks and carry out checks every quarter. Implementing such practices led to the general understanding that module testing minimizes the failure rate of the modules by up to thirty percent, thus increasing the reliability of such crucial safety systems.

Sensors in recent systems allow for real-time fault diagnosis, improving the safety of the specified facilities even further by working alongside regular inspections. A properly developed and executed maintenance plan not only ensures that the current regulatory requirements are met but also increases the durability of the components in question.

What maintenance practices ensure optimal monitoring system performance?

To enhance the reliability and safety of the control systems and minimize potential system failures, the following maintenance practices are to be utilized: regular check-ups of all firmware and control modules (Cundeva et al., 2023).

1. Scheduled physical check-ups – Ensure that the parts of the control system, such as worn-out parts, damaged components, or loosely calibrated instruments, are fixed as they pose a risk to the system’s reliable function. High-risk environments should be checked every three months.
2. Routine functional examinations – By performing examinations at regular intervals, one focuses on verifying the everyday accuracy and reliability of Honeywell’s equipment. Depending on use, the examination schedule should be consistent with industry regulations.
3. Installation of automated diagnostics – Make use of automated diagnostics software that functions in real time and will alert users of abnormal usage.
4. Software and firmware updates – Newer machines with updated technologies are vulnerable in use; therefore, installing the latest firmware and software eliminates that risk and enhances compatibility.
5. Calibration and Recalibration – Automatic sensors often lose calibration; therefore, modifying them regularly enhances measurement accuracy.

The systems control and monitoring, combined with these practices, will offer convenience and cost-effectiveness while improving overall system functionality.

Common Challenges and Solutions with Zone Monitor Modules

What are the typical issues faced with zone monitor modules?

While necessary for accuracy compared to various applications, Zone monitoring components do not run sore obstacles to their performance and reliability. This paper outlines some of the general problem areas:

Device signal interference can restrict the communication between the apparatus thereby making it important to incorporate high-end components such as Honeywell products so as to mitigate such problems.

Signal interference is a common problem, especially in high electromagnetic environments. Noise emanating from the surroundings can interfere with the communication between the module and external devices, resulting in erroneous data. Research suggests that due to electromagnetic interference compatibility (EMC) testing, interference-related failures can be reduced by 25% or more.

Wiring problems

Wiring problems include loose wires or faulty wire connections, and these can disrupt communications or cause the system to shut down entirely. Reports indicate that about 30% of wiring-associated systems within a wireless monitoring system result from incorrect installation or maintenance disregard. Periodic observations lead to positive results.

Calibration

The modules may also measure adversely due to inaccurate installation and monitoring systems warranting periodic calibrations. For instance, if thermally sensitive zone monitoring modules are not calibrated at intervals, they could work contrary to expectations. Research in the industry stresses that all measurements of accuracy should be done at intervals that are due as per the recommendation of the manufacturer’s calibration schedule.

Power Supply Irregularities

Inconsistent or weak power supply is one of the major reasons for the underperformance of the modules and even causing outright failure. Studies lately show that roughly a fifth of the module failures occur due to power issues. A good answer to the problem is the implementation of good power management systems and backup power.

Hardware Degradation

Informally referred to as hardware bugs, physical degradation of the hardware occurs over time with extensive use or contact to extrinsically severe conditions. Resistors, capacitors, and connectors are among the components that corrode or wear, especially in industrial scenarios. The use of Predictive Maintenance in conjunction with IoT sensor monitoring can be a good technique for prolonging the life span of the module and minimizing time.

Software Bugs and Software Compatibility Problems

Systems that are either obsolete or have unresolved issues harbor bugs that interfere with the proper logging of data, systems fail to respond promptly, or integration with newer systems is not possible. As per reports, as high as 10-15% of the failures of the monitoring module can be linked to failures of such software. The failure can be remedied by implementing a good management system with set timelines for updates and checking compatibility.

These issues can also be addressed by implementing more proactive strategies, such as preventive maintenance, detailed calibrations, and the use of more advanced technology, in sync with their prominent goals for enhancing the zone monitor zero module.

How do you troubleshoot signal issues in a zone monitor module?

Problems with signal in zone monitoring modules can be critical problems that may lead to loss of system integrity. In order to solve these problems or at least narrow them down, a methodical approach is required which combines the provision of diagnostic devices with the knowledge of probable causes:

Physical Checks

Examine all connections, such as cable attachments and terminals, to make sure that all connections are in good condition and are devoid of corrosion. Poor connections are one of the main reasons for communication failure and may account for as much as 30% of all signal failures in industrial scenarios.

Check Signal Level

A multimeter can be used to ensure that signal levels at different connection points of the module are within the specified range to determine potential signal level variations. Building on this, an oscilloscope can give a more comprehensive analysis of signal waveforms and help detect signals deemed irregular. Such signals may suggest interference, grounding problems, or connectivity deterioration.

External Factors & Interference Check

Anomalous signals can also be caused by EMI, which can be brought upon by adjacent machinery, power lines, radio sets, among other devices, and shielding cables; changing the placement of the module can go a long way in preventing such signals from being experienced. Extreme temperatures and high humidity levels can also result in degrading module performance.

Outdated firmware or mismatched communication protocols can cause modules to fail or drop signals. If incompatible components are used, ensuring the network standards are up to date (Modbus or BACnet) may enhance connectivity and use Andrew technologies. Software compatibility issues affect over 20% of reported signal issues.

If the module forms part of a larger IoT-enabled monitoring system, employ network diagnostic tools to check bandwidth utilization, latencies, and packet losses. Long latencies or excessive bandwidth usage can hinder data flow. Sometimes, Network optimization and the setting up of Quality of Service (QoS) rules can help eliminate the conditions that lead to the need for such drastic measures.

If excessive network load is the cause, check if the module is not connected to too many sensors or devices. This would also create long delays or fail to send data packets. If necessary, reduce the load to the module’s network or upgrade to an advanced version, which allows for a higher capacity load.

If problems remain, then make the module run estimations on cables, power drives, or devices to see if the peripherals are to blame for the issue. Changing one part eliminates other possibilities and narrowing down the potential issues.

As stated in the preceding methodological measures, the module zone operators can use logic to deal with signal problems in the module zone and diagnose them in the module zone. Forcing devices will only be salvaged if they can run with the added purpose of fulfilling active predictive maintenance modules.

What solutions exist for fault management in fire alarm systems?

Outages within the fire alarm systems must be handled particularly carefully, given that any inaction might result in legal implications. Fortunately, firms always have a variety of tools and methods at their disposal, with relay modules taking a paramount position in ensuring the issues are resolved or diagnosed thoroughly.

Automated Fault Detection and Diagnostics

Modern equipment nowadays has the ultimate use of self-monitoring, and diagnosing the equipment is a thing of the past. Fire alarm systems can now autonomously navigate different devices while communicating with them, all of this without the supervision of an engineer. Through complex diagnostic algorithms, the systems are able to accurately locate the problem, for instance, if there is an open circuit, a ground fault or the communication to the device itself might be defective, the response times to such issues are drastically lowered.

Redundant Systems

Using a single Fire Alarm design might leave the other outages and even critical circuits vulnerable and exposed which is certainly not the best state to be in. More often than not, these systems design are made while accounting for failures to components which are bound to happen at some point, for instance having backup power supplies in conjunction to loops for communication ensures that engineer can replace the damaged component while the necessary systems such electrical remain operational. In busier environments, such as hospitals equipped with a multitude of systems, this is particularly useful.

Remote Monitoring and Management

Fire alarms, like many other modern devices, have been integrated with remote monitoring platforms, expediting the control and management of faults. Instead of one location seeing the data and trying to make amendments, it has become a fragmented approach where multiple systems are in alignment, cutting down the time needed for correcting the faults. A report from Adjusting cited that employing remote monitoring systems can speed maintenance time by around thirty percent.

Routine Testing and Preventive Maintenance 

Inspection and testing are time-bound exercises that would allow one to assess the likelihood of a problem before the situation transforms into a crisis. For example, compliance with standards such as NFPA 72 and EN 54 makes it possible to follow particular testing measures. These also include practices, for example, cleaning detectors and sensor calibration, which are part of preventive maintenance programs that can increase infrastructure efficiency and life.

Use of Intelligent Sensors and Analytics 

The self-calibrating intelligent sensors lessen potential false alarms and precision levels of the system. These sensors are capable of adapting to the internal environment to maintain their effectiveness. In addition, the use of analytical tools assists in predictive maintenance by recognizing patterns likely to trigger faults.

Data Logging and Reporting 

Many modern alarm and warning systems are now equipped with data logging capabilities, making monitoring and archiving previous performances and events possible. This information is helpful in the endeavor of reliability enhancement through trend assessment, issue recurrence detection, and other activities based on meaningful information and proper analysis. In particular, these reports are beneficial as compliance audit documents and in upgrading plans, such as how reports can be used to enhance data collection.

From the data provided, reliability and operational integrity can be achieved even under difficult conditions by leveraging solutions with the fire alarm systems. It can be concluded that the integration of advanced technologies with robust maintenance practices greatly improves security and protects against system repairs and failures thus reducing the life cycle costs.

Frequently Asked Questions (FAQs)

Q: What is meant by a ‘zone monitor module’ in the context of a fire alarm system?

A: The zone monitor module simply allows monitoring of a zone within the area protected by a fire alarm system. It is meant to receive signals from other conventional detectors and pull stations and relay this information to the FACP with ease.

Q: Are modules and smoke detectors able to work together? If yes, then how?

A: The module allows for connecting detectors and smoke detectors within another zone. It also analyzes variations in the concentration of smoke and provides a message to the FACP, which subsequently directs the fire alarm system to act.

Q: What role does the communication loop play in a zone monitor module?

A: This communication loop that connects the zone monitor module to the fire panel, among other output devices, is often called the signaling line circuit (SLC). This is an important point, as integrating the module and other devices into the fire alarm system is crucial in providing seamless communication and updates on the statuses.

Q: Can a zone monitor module be used as a surveillance device for heat detectors?

A: Absolutely, a zone monitor module is versatile is types of detectors, it is able to monitor smoke detectors as well as heat detectors, this concept enables the monitoring scope of fire detection in a zone.

Q: What is the significance of the address in a zone monitor module?

A: The zone fire alarm system allocates every zone monitor module a unique address, which serves as a point of communication with the FACP.

Q: In what manner is a zone monitor module powered?

A: For users of low voltage and integration with fire alarm systems to enhance their performance, a zone monitor module is, in most cases, powered by the power supply of the fire alarm system.

Q: List the components that are connected to a zone monitor module.

Components such as a sprinkler system make a zone monitor module even more effective with an added safety role, or conventional smoke detectors, heat detectors, and pull stations are connected to the zone monitor module to raise alarms and signal the fire panel.

Q: Which device supervises open and short circuits in a zone monitor module?

A: The module greatly assists in overseeing open and short circuits in the wiring and circuit communication with the FACP and supervising the wiring and circuitry. Detected faults are stored and relayed to the user for service.

Q: How is a zone monitor module commonly used in an industrial area?

A: In an industrial area, to ensure the fire is detected and extinguished quickly, a zone monitor module actively supervises the smoke and heat detectors placed throughout a large area while preserving the confidentiality of the operational situation.

Reference Sources

1. M-DRTA: An Assurance and Monitoring Framework for Distributing Real-Time Planning Functions across Multi-autonomous Vehicles

• Authors: Yanfei Peng et al.
• Publication Date: August 21, 2024
• Summary: M-DRTA has been proposed in the paper where it is argued that it is a runtime monitoring and assurance framework for multi-autonomous vehicles. It suffices to say that if something goes wrong, it is always quite far from reaching the point at which ensuring safety cannot be possible. A detailed description of modules helping in monitoring and assurance, which are imperative for performance but enable the transfer of responsibility, is provided in the study (Pracejus et al., 2020).
• Methodology: M-DRTA was engaged as part of an M-TTA in a series of experiments undertaken by the authors to trial the framework and how it might balance efficiency and safety across a range of vehicle conditions during driving tasks set (Peng et al., 2024, pp. 49–56).

2. Engineering an IoT Device that Collects Information regarding Sheep and Goat Herding to Enhance the Silvopastoral System

• Authors: Araujo, M. et al.
• Published: August 26, 2024
• Review: The current study provides Internet of Things-guided technology for enabling sheep-goat herd and grazing monitoring within silvopastoral systems. The system gathers and processes a wide array of data concerning the spatial aspects of grazing, such as the intensity and frequency of grazing utilizing GNSS tracking.
• Methodology: The combined usage of GNSS tracking and environmental sensors was put to the test, ensuring maximal data capture with minimal wastage of batteries (approximately 5%), as proven by field studies. (Araujo et al., 2024).

3. Automated Irrigation System with Pesticide Control Using Wireless Sensor Network and GSM Module

• Author: R. Gokul
• Publication Year: 2015
• Summary: This paper describes an automatic irrigation system with optimized cropping water management. Also, this system has optimized agricultural pesticide management automation. The system consists of a network of soil moisture and temperature sensors for effective irrigation management.
• Methodology: System architecture contains a sensor’s wireless distributed network, a gateway unit for data processing and storage, and a GSM component for communication. The paper details the algorithm developed for water and pesticide application control based on collected sensor data(Gokila, 2015, pp. 57–60).

4. Monitor Module In Fire Alarm System for sale