Migrating to Radio, Ethernet, or Fiber Panels from 100mA Loops

By Justin Sagalow

November 23, 2022

Last week, we took a look at why clients are moving away from telegraph fire alarm monitoring systems that utilize copper 100 milliamp (mA) loops. Towards the end of the article, we mentioned that many of the clients we work with that currently have coded telegraph-based fire alarm systems have shown intrigue in transitioning to fire protection networks that take advantage of new fire alarm reporting technology.

Today, we would like to focus on why clients are so interested in migrating to panels that report alerts via radio, Ethernet, or fiber communication when their copper 100mA Loops start to fail. We’d also like to take a closer look at the unique advantages and disadvantages of each method of communication. If you are looking to upgrade your coded telegraph-based alarm monitoring system, hopefully this article will provide you with some clarity regarding which method makes the most sense for you and your system.

If you decide that this is a prospect that makes sense for you, please do not hesitate to get in contact with a Digitize fire alarm monitoring expert for free by calling 1-800-523-7232. We will connect you with a member of our engineering team who will be happy to answer any of your questions and point you in the right direction, whatever it may be.

Mix and match your communication methods with Digitize panels

prism lx central display screen

This is an image of a Prism LX central display screen. For those who wish to monitor their fire monitoring system instead of hiring a third party service to do it, the Prism LX is one example of a readily available server on the market.

When their telegraph systems start to deteriorate, clients purchase our panels because of their ability to interface directly with the existing system and report to a Digitize System 3505 Prism LX™ head end unit. We design and manufacture a variety of equipment that can be used to send fire panel reports to our head end System 3505 Prism LX™ via radio, Ethernet and fiber connection.

Each of the aforementioned communication methods have their own features, limitations, advantages, and disadvantages. Many clients find that, depending on the unique features and limitations of their specific system, sometimes the best solution to their fire alarm monitoring problem is to mix and match the methods of communication between the panels and the head end unit. Our commitment to offering custom alarm monitoring solutions to clients relies on our ability to utilize a combination of various communication methods in one system.

The advantages and disadvantages of radio, Ethernet, and fiber communication

Radio, Ethernet and fiber cables all expand upon the communication abilities originally introduced by coded electronic telegraph alarm polling systems. Below, we’ll briefly review what distinguishes these methods of communication from each other.


Generally, many of the campuses and bases that we work with have internet access, even if they don’t choose to utilize it in their coded telegraph-based alarm monitoring system. When the copper cables in the telegraph system begin to fail and fire panel statuses are no longer being reported, we often recommend that they take advantage of their internet capability by replacing their telegraph polling system with Ethernet reporting.


The Digitize VersAlarm™ Panel is an IP Based monitoring system. The Digitize VersAlarm™ panel connects to a Digitize System 3505 Prism LX™, which must be equipped with an AlarmLanTM option.

Ethernet-enabled panels, such as the Digitize VersAlarm, receive alerts and updates from fire alarm control panels via contact closures. The VersAlarm sends all of this information to the Digitize System 3505 Prism LX™ head end unit via Ethernet connection. Like the copper cables along a telegraph loop, Ethernet cables are exposed to the elements and may eventually need maintenance or replacement. Fortunately, these wires are much easier to replace than their copper counterparts and only connect from the VersAlarms to the Prism. This IP-based alarm system allows information to be transmitted safely and instantly. To connect the Digitize VersAlarm™ panel to a Digitize System 3505 Prism LX™, the Prism must be equipped with an AlarmLanTM option.


The Standard (full) AlarmLanTM allows multiple System 3505 Prism LX™ units to share information via Ethernet thereby replaceing the network option and will accept signals from both System 3505 Prism LX™ head end units and field panels such as the VersAlarmTM, MeshSentry™ and iLNX™ subscriber units.


Radio in particular is a popular choice for clients looking to integrate newer polling methods into their telegraph-based system. The most obvious explanation of this is that radio polling allows clients to retain some of the simplicity and autonomy familiar to them from their 100mA loop system.

Unlike fiber and Ethernet, radio doesn’t require the laying of additional wiring, so the installation process is relatively unobstructive. It consists of little more than deploying radio-enabled communication panels along the existing 100mA loop and ensuring that they are able to transmit alerts to the Prism unit(s). However, to enable the Prism to receive radio transmissions, you would need to purchase a MARK-VI Radio Receiver. The receiver/radio tone decoder converts analog radio signals into digital signals for transmission to the Radio Box Interface card for processing by the System 3505 Prism Lx™.

prism lx central display screen

The Digitize Mark VI AM receiver is a crystal controlled receiver/tone decoder that converts the analog radio signal into a digital signal for transmission to the Radio Box Interface card for processing by the System 3505 Prism LX™.


Recently, we’ve also worked with many clients that have opted to use fiber-optic cables. If you’ve read about our work with the University of Pennsylvania, then you’ll already be familiar with the benefits of a fiber-optic alarm reporting system. UPenn actually opts to use a fiber-optic system in tandem with an Ethernet reporting system to ensure reliability and accuracy at all times.

Fiber cables are not only faster at transmitting data than copper cables, but also lighter and more resistant to moisture and extreme temperatures, making them easier to maintain and replace. They can also run longer distances without encountering the resistance limitations that plague telegraph loops. Many clients consider fiber cables the logical successor to the time-honored copper cables that make up old coded telegraph alarm systems.

The most noticeable disadvantage of fiber-optic cables is that they are just as exposed to the elements as their copper predecessors. Unlike Ethernet cables, which only need to connect to Digitize VersAlarms and Prisms, fiber-optic cables must cover the full distance of the copper cables that they are replacing in order to access all fire panels located along the loop.

Update your fire alarm monitoring system today

If your telegraph-based fire alarm system utilizes a 100mA loop and you are thinking of migrating to radio, Ethernet, or fiber panels, we recommend that you reach out to us immediately. Updating your fire alarm monitoring infrastructure is also a great opportunity to take care of any other improvements simultaneously.

When you call your Digitize engineer, you can also talk through any opportunities for improvement that you have in mind. We’ll also ask you a few questions to check for updated system design opportunities you may not have considered.

Digitize is ready to speak with you about your upgrade at 1-800-523-7232. If you prefer, you can also email us at info@digitize-inc.com

Justin Sagalow

Justin Sagalow

Justin Sagalow is quite uniquely qualified for his Marketing Writer Position at Digitize. Arriving at Digitize with experience in law, finance, and editorial positions, Justin's skillset allow him to effectively communicate how best Digitize can address each client's individual needs. From his...Read More