Monitor Modules in Fire Alarm Systems - What do they do?

By Andrew Erickson

March 19, 2023

Monitor modules are essential components of an addressable fire alarm system. They allow non-addressable devices, like sprinkler flow switches or loops of standard heat detectors, to be monitored and connected with the main fire alarm control panel (F A C P). We've previously looked at the basic technology of monitor modules, so today we'll look more broadly at their overall use case and how they can preserve your budget dollars.

Monitor modules are crucial parts of a comprehensive fire alarm system. The added layer of security they offer ensures that all risks are detected and responded to quickly, giving you the peace of mind that you and your building occupants will be protected in the event of an emergency.

How does an "addressable" device like a monitor module differ from a "non-addressable" device?

There was a time when all fire alarm initiating devices (ex. smoke detectors and pull handles) were non-addressable. You didn't know which device was indicating an alarm within a particular zone. You only knew that one or more devices in that zone had gone off.

Addressability is a newer innovation in fire alarm control panels. It allows each device to effectively "send a message" digitally along shared lines, giving much tighter granularity to building managers and first responders.

An addressable device is capable of communicating with the main fire alarm control panel (a modern one that expects to use digital addressed communication), while a non-addressable device is not.

It's for this reason that we need a monitor module at all. The monitor module acts as an intermediary, converting the analog signal from the non-addressable device into an addressable signal that can be understood by the main fire alarm control panel.

This is actually very much like the work we do at Digitize. Many of our devices are responsible for translating an older type of signal from legacy equipment to something modern that your central collector can use.

This "mediation" function means that you preserve your existing infrastructure investment for as long as possible.

Can't I just remove all of my non-addressable initiating devices and install new addressable initiating devices?

Although mediation devices like monitor modules can seem like an annoyance, they are very important tools for working within your limited budget dollars.

Sure, it's technically possible and actually "cleaner" to just rip out everything and buy new gear every time a new technology comes along. What you lose with that method, however, is any concept of cost control. It would be nice to have an organization with budgets like that, but few of us do. Even if you do, that money is better spent elsewhere.

Mediation devices like monitor modules allow you to keep getting value out of your existing equipment investment. You don't have to perform a "forklist swapout" and spend a bunch of money all at once. You just spend a small fraction of that amount on monitor modules today.

Then, organically over a period of years or decades, you can replace failing legacy devices with new modern ones as needed. With basic initiating devices, there's not much contained within that can fail. That's why you can push replacement off into the future almost indefinitely without any real problems.

What kind of signals can a monitor module receive?

The most common kind of signal monitored by a monitor module is a temperature, humidity, or gas leak alarm. This is sent to the FACP, which then sends out an alert if it detects something out of range.

On detecting any potential risk, such as a drop in temperature, an increase in humidity, or a gas leak alarm triggering, a monitor module will convert the analog signal into an addressable signal that’s easy for the FACP to read and understand. This allows it to send out signals and alerts of a potential fire emergency. In this way, the system can alert building managers and first responders to any potential hazardous situation quickly and accurately.

Who manufactures fire alarm monitor modules? What about installers?

Several companies manufacture monitor modules and other fire alarm system components. You can find addressable monitor modules, as well as conventional non-addressable ones, from a variety of suppliers.

A quick web search turns up manufacturers, distributors, and installers like:

  • Honeywell
  • GEYA Electrical
  • ADI Global Distribution
  • RYBB Fire Alarm
  • Ravel Fire
  • BAYT
  • National Time & Signal
  • TC Life Safety
  • and many more...

A major deciding factor for you when choosing a manufacturer is going to be the compatibility with your existing fire panels (or those you are also purchasing as part of this project).

Beyond that, choosing a distributor or installer is often about their reputation and any existing business relationships your company may have.

The price to install fire alarm monitoring is not small, but it's overall less important than the quality of service you actually receive for your money.

Look for UL/ETL listing and any other required certifications

When choosing the right monitor module for your needs, you should always consider the certifications it holds, its compatibility with your existing FACP hardware and software, and the overall performance and reliability of the device.

When you're working on fire alarms, you need to think both about compliance with relevant regulations and the actual technical compatibility that will enable you to be compliant.

Work with a company who has experience with monitor modules

When it comes to heavily regulated systems like fire alarms, experience is king. You want to work with companies who have done this before. Every previous project is a chance to earn battle scars while getting burned by little-known sections of the fire code.

A highly experienced design or install company will bring that experience to the table when working with you. In my work at Digitize, I've heard plenty of horror stories from our clients about what can happen when you don't respect the value of industry experience. Hopefully, you have enough budget left after your first mistake to finish your project. Ideally, you won't make that mistake in the first place.

Digitize can help you with your project

At Digitize, we're a manufacturer of fire alarm monitoring systems. That industry experiences means that we can point you in the right direction as you research fire alarm monitor modules that are purpose-built for addressable systems. You may or may not also need our central monitoring equipment, but we're happy to help you no matter what.

Digitize engineers can help you determine what is best for your needs, so get in touch with us today if you need any help selecting or installing your fire alarm system components.

Call Digitize at 1-800-523-7232 or email us at

Andrew Erickson

Andrew Erickson

Andrew Erickson is an Application Engineer at DPS Telecom, a manufacturer of semi-custom remote alarm monitoring systems based in Fresno, California. Andrew brings more than 17 years of experience building site monitoring solutions, developing intuitive user interfaces and documentation, and...Read More