When an intrusion alarm goes off, the panel sends a signal to a monitoring centre, where an operator follows the instructions you agreed in advance: check what the signal shows, try to verify it, call the people on your list and, when the alarm looks real, request police or a guard. The quality of that response depends less on the technology than on the instructions, the call list and how the alarm is verified.
How the signal gets there
The alarm panel's communicator sends each event, such as an alarm, a trouble condition, an opening or closing, to receivers at the monitoring centre. Telephone lines used to be the standard path, but they are being removed from many buildings, and panels that depended on them may have lost their connection without anyone noticing.
Today, most commercial systems use two paths: IP over the building's internet connection as the primary path and a cellular network as the backup. The monitoring centre expects regular check-in messages on each path, so it knows quickly when one stops working.
What a monitoring centre does
A monitoring centre, sometimes called a central station or signal receiving centre, receives signals from many sites around the clock. Operators see each event with the site's instructions, zone list and call list. In Canada, many monitoring centres are listed by ULC, and some insurers require monitoring by a listed centre for higher-risk sites. Check what your insurer expects.
The kinds of signal a centre handles include:
- Alarms from intrusion zones, which follow the response instructions.
- Hold-up, panic and duress signals, which usually go straight to police with no call to the site, since calling could put staff at risk.
- Trouble signals such as low battery, power failure, tamper or a lost communication path, which go to the people responsible for maintenance.
- Openings and closings, which can be checked against a schedule so the centre notices if a site is not armed when it should be, or is opened at an unusual hour.
Verifying an alarm
Many police services in Canada have false alarm policies, which may include fees, suspension of response after repeated false alarms, or a lower priority for alarms that have not been verified. The details are set locally and change, so check with your police service. In any case, verification gives responders better information and reduces wasted trips.
Common verification methods are:
- Sequential zones: two or more detectors tripping in a pattern consistent with someone moving through the building.
- Video: operators view cameras linked to the zone that alarmed. Video monitoring raises privacy obligations; see video surveillance and privacy in Canada.
- Audio: listen-in or two-way audio at the site.
- Call verification: calling the site and keyholders to confirm whether anyone is there legitimately, with a password to cancel.
- Attendance: a guard or keyholder goes to the site and reports what they find.
Writing the response instructions
The monitoring centre does what your instructions say, so vague instructions produce vague responses. Good instructions cover:
- For each type of signal, what the operator should do and in what order.
- The call list: names, roles, phone numbers and passwords, with at least two people who can be reached at any hour.
- When to request police, when to send a guard, and when to wait for a keyholder.
- Opening and closing schedules, and what to do if the site is not armed on time.
- Who receives trouble signals, and how quickly they must be acted on.
- Site information for responders: access, hazards, key box location, dogs, where the panel is.
Keyholders should know what is expected of them. Going alone into a building where an intrusion may be in progress is not safe; instructions should say that keyholders wait for police or a guard, and meet them outside.
Supervising the paths
An alarm system that cannot reach the monitoring centre is worse than useless, because it gives false confidence. Supervision means the centre expects a regular check-in from each path and raises a trouble signal when one goes missing. With two paths, a failure on one is reported while alarms still travel over the other.
Test the paths yourself, too. Many panels and monitoring centres allow a test mode in which you trip a zone and confirm the centre received the right signal, from the right zone, on each path.
A typical scenario
Consider a light industrial building with an office at the front and a shop at the back. At 2 a.m. on a Sunday, the overhead door contact in the shop trips, followed less than a minute later by the shop motion detector.
- The signals arrive at the monitoring centre over the IP path. The operator sees two zones in sequence, which points to someone moving through the building rather than a door rattling in the wind.
- The site has cameras linked to the shop zones. The operator views them and sees a person near the workbenches. The alarm is now verified.
- Following the instructions, the operator requests police, tells them the alarm is verified by video, and passes on the site details: entrance, key box location and that the overhead door is the likely entry point.
- The operator calls the first keyholder, explains what is happening, and asks them to meet police at the front entrance rather than going in.
- Every step is logged with times, and the report goes to the property manager the next morning.
Compare this with a site where the overhead door alone trips every windy night, nobody answers the call list, and police have stopped treating the alarms as urgent. The equipment can be identical; the difference is design and instructions.
Common gaps
- Stale call lists. People leave, change phones or stop answering at night. Review the list on a schedule, and after any staff change.
- Trouble signals going nowhere. A lost path or low battery reported to someone who left years ago.
- Shared passwords. A single cancel password known to everyone, including former staff.
- Zone lists that do not match the building. Operators reading out "zone 14, north door" for a door that was moved in a renovation.
- No review. Monthly or quarterly reports from the centre that nobody reads, when they would show patterns of false alarms or late openings.
How ehZee can help
Our intrusion and security systems service includes designing the signal paths and writing the response plan with you, then testing that every zone reaches the monitoring centre correctly. For the system itself, see intrusion alarm systems explained; for staff safety alarms, see planning the response to a duress alarm.
Common questions
Is self-monitoring through an app enough?
For a small, low-risk site it may be. For a commercial building, consider who will see a notification at 3 a.m., whether they will act on it, and whether your insurer accepts it. Professional monitoring gives around-the-clock attention and a record of every event.
Should we hire guards to respond instead of relying on police?
Many sites use guard response for unverified alarms and keep police for verified intrusions. It depends on your risk, your location and local police policy.
How often should we test monitoring?
Your monitoring contract, insurer or the manufacturer may set an interval. Testing every zone during the annual inspection, plus checking that both paths report, is a common minimum, with automatic path supervision in between.