Alarm Areas

Owned by Isabelle Avery (Unlicensed)
Last updated: Jul 18, 2022 by Charlotte Dakin-Norris
4 min read

Introduction

An Alarm Area or Alarm Zone is linked to a rule; usually one that triggers an alarm, and essentially limits the rule to be applied within the boundaries of the area. Alarm areas can be used alongside other checks to ensure alarms are only trigger as required. For example a target speed might need to be above a specified threshold as well as being within a designated alarm zone.

In addition an alarm area can be used as an Alarm Exclusion Zone. This means it has the reverse affect in that it prevents any alarms for a specific rule being generated in the designated area.

Using Alarm Areas to suppress alarms has a major advantage over suppressing target detection with Detection Exclusion Areas because you can be very precise with where you place them and they do not interfere with target tracking.

Because of the different Rule functions in ClearWay™ and AdvanceGuard®, the Alarm Area is configured differently for each product.

Contents

ClearWay™

In ClearWay™, an Alarm Area is used to limit a rule to a specific area. The rule doesn't need an alarm area because by default all ClearWay™ rules will use the carriageway and sections as boundaries for the alarms. However if you need to reduce the alarm zone to an area smaller than the carriageway or smaller than a section then the you can use one or more alarm areas.

Note that when using alarm areas with carriageway rules you will restrict all alarms to just these areas. In addition, these areas can only be placed on the carriageway because this is the only location where vehicles will be detected.

To place a rule within an Alarm Area:

  1. Create an Alarm Area in the Create a New Area wizard, by selecting Alarm from the drop-down list of Area types, then selecting Finish.

  2. Select your Carriageway, then select Rules from the Actions ☰ drop-down. The Rules window will open.

  3. Create a New Rule or select an existing Rule.

  4. In the Rule configuration options, select the Area tab.

     

  5. A list of available Alarm Areas will be tabled. To assign a rule, select Edit and then select the Enable box beside the desired Alarm Area. Select Save to confirm.

The secondary purpose of an Alarm Area is to allow alarms, or other actions triggered by rule breaks, to be carried out in lanes or sections of the carriageway where they are being suppressed. By default, all alarms are suppressed for sections which are in queue. Therefore, Ignore Queues can be selected (per lane) to enable alarms during queuing in the selected lanes. However, if you wish to Ignore Queues in only specific sections, not an entire lane, then Alarm Areas can be placed over the desired sections.

AdvanceGuard®

In AdvanceGuard®, a Security Rule can include an Area Check. The areas used for an Area Check should be Alarm Areas, as an Area Check is essentially equivalent to limiting the rule to an area. See AdvanceGuard® for more information.

Alarm Areas can also be used to suppress alarms in particular areas. An Alarm Exclusion Area can be created through a Track Query:

  1. Perform a Track Query, in the Playback tab, and select Show on the track results in the Query Results Panel.

     

  2. Identify potential areas of repeated debris or unclassified tracks, then select and Locate a specific track. Selected tracks will highlight individual sightings on the PPI when selected.

     

  3. Select Create Exclusion to insert an Alarm Exclusion Area around the track's Area Covered. The area below is outlined in orange.

     

  4. The new Alarm Exclusion Area will appear in the Configuration Tree under the Areas folder, and can be enabled or disabled by toggling Armed/Disarmed in the Area Details Panel.

 

Safety is everything.