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Active vs. Passive Fire Alarm and Security Monitoring

One question we are asked frequently is how do we receive the alarms in our monitoring station? At FMC, we are equipped to be able to monitor your fire system in any number of ways, to remain as flexible as possible for any potential scenario your site may present.  There are two categories of monitoring (as defined by CAN/ULC-S561, the recognized standard for fire alarm monitoring in the Fire Code and Building Code) to consider when thinking about the monitoring of your site:  Active and Passive forms of monitoring.  We will deal with each below to help you better understand:


Active Alarm Monitoring

“Active” alarm monitoring consists of communication channels to our Signals Receiving Centre (SRC) which are actively supervised by the SRC.  This supervision is completed once every 180 seconds, with a handshake between the monitoring transmitter in your building and the monitoring receiver in FMC’s SRC.  This means that if a communication breakdown happens between your building and our SRC, we will know about it within 180 seconds.  ULC-S561 requires FMC to notify you if the communication channel has not been restored within 5 minutes, however if the communication channel is down, the system will have to be placed on “manual watch” (meaning that if an alarm on site sounds it must be manually phoned into 9-1-1).  Systems that utilize “active” monitoring include:

  • DVACS;
  • Cellular and;
  • IP (provided that all pieces along the IP pathway have 24-hour battery back-up).

Systems that utilize active monitoring are very stable and provide little downtime to service.  Prior to implementing any active communication pathway, FMC rigorously tests the service to ensure its reliability.

Passive Alarm Monitoring

Where active alarm monitoring concentrates on the SRC actively making sure the communication pathway is open, “passive” alarm monitoring relies on your facility checking in to our SRC once daily at a pre-determined time and acknowledging their presence on the network.

Forms of “Passive” monitoring can include:

  • Digital Dialer (phone line);
  • Cellular and;
  • IP.

If this sounds less secure than “active”, then you are correct.  Systems that properly test and then have the communication pathway disrupted (phone line cuts, for example) would not be known about until they miss their next scheduled reporting period.  Testing times can be daily, weekly or sometimes monthly.

This is why for fire alarm monitoring scenarios, or security alarm scenarios which may require (or desire) higher-level security, dual-path monitoring is required.  CAN/ULC-S561 states that where passive forms of communications are used, two non-redundant forms of communication are present.  In this scenario, each pathway monitors each other, so that if one goes down the other advises the monitoring station and confirms its activity.  For example, where a digital dialer and cellular communicator are used, if the phone line to the system is cut, the cellular communicator would activate, send a signal to the monitoring station advising that its phone line has gone missing.  Any signals from that panel could still be received via the cellular link, and vice versa if the cellular channel went offline.


Passive forms of communication are less secure by their nature than active forms, but dual-path communications have become more popular.  Secondary forms of communication can easily be added to existing monitoring systems, through the addition of communication modules (and potentially some additional monthly monitoring fees), so please call FMC to discuss this further.  We’d be pleased to help you and determine how to better communicate with your building.

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  • "Fire Monitoring of Canada impressed us with their efficient, professional manner – an approach that not only inspired confidence, but resolved existing service issues with another alarm service provider." - Administrative Coordinator
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