Introduction

This page contains advanced settings that control when an alarm can be raised, including the queue suppression feature, where we can also enable a rule near a queue, along with a classification filter. The break count and break allowance are critical settings in deciding how quickly an alarm is raised and balancing the false alarm rate vs detection speed.

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Advanced Settings

Break Allowance (s): Alters the number of times that the rule can be broken before the defined Action is triggered. The default value of 0 will trigger an alarm at the first instance

Allowance Reset: This option is only available if not using the Allowance Curve. The reset time is the amount of time to wait once the rule is no longer being broken before resetting the break count. By default, this value is 0 (zero) which means the first time this rule is not broken, the break count is immediately not set. By providing a reset allowance, in seconds, it holds the current break allowance for a period of time which gives the opportunity to wait for a vehicle to break the rule again in which case the break count will continue without being reset. If the reset period expires without the rule being broken again then the break allowance is reset.

Use Allowance Curve: This option works in conjunction with the Break Allowance. When this option is enabled, the break count is permitted to go down as well as up. The break count will be incremented when a target is breaking the rule and then decremented when it is not. Additionally, you can set the Allowance Increment and Allowance Decrement values so that you can weight the rate at which a target increases and decreases its break count. The alarm will only be activated once the Break Allowance value is reached. This option is useful in situations where you expect targets to momentarily break rules but not to continue doing so and so prevent false alarms.

Allowance Increment: (Used only when Use Allowance Curve is enabled) Defines the amount by which the break count should be incremented every time a target breaks the rule.

Allowance Decrement: (Used only when Use Allowance Curve is enabled) Defines the amount by which the break count should be decremented every time a target ceases to break the rule. 

Relay: Defines the Id of the relay (external dry contact relays) that should be activated when the rule is broken. Choose ‘0’ to disable.

Trace Logging: Outputs more information about what causes the rule to break. Mainly used for carriageways with more convoluted rules.

Count Coasted Tracks: Select this to ensure coasted tracks count towards the Break Allowance.

Classification Filters

Filters tracks for this rule based on the selected classifications. You may select one, many or all. If the classification of the tracks match the selection then they will be considered by this rule. Tracks that don’t match will be ignored.

Classification: Select one or more classifications that you want use for this rule.

Classification Probability (%): Allows you to optionally define a confidence level which must be matched or exceeded for a given track (of the type selected within the Classification option discussed above) before it can be considered within the rule. The use of this option provides an opportunity to filter out poorly classified tracks. The probability value is created during the classification process and is displayed against each entry within the Tracks tab. When this option is set to zero, the requested Classification type will be accepted at any level of probability (as determined by the tracker), rendering this filter inactive.

Section Queue Alarm Suppression

The suppression mode to apply if the section containing the sighting is in queue:

Disabled: No suppression

Suppress All: No alarms will be created or maintained if the section is in queue. This is the default setting.

Suppress New: No new alarms will be raised but existing alarms will continue.

Alarm Suppression By Nearby Queue

The Alarm Suppression By Nearby Queue settings have the ability to suppress or invert the rule and associated alarms if there are queues nearby. This feature stops inaccurate tracks in one carriageway, which can be created from queues and very high traffic flow, from causing false alarms in another carriageway. The settings are used to decide how far away and in what carriageways the suppression or inversion logic should look for queues, and in which mode to apply them.

Mode:

Disabled: When mode is disabled the feature is disabled.

Suppress: If a queue is found within the specified distance and on the relevant carriageway then this rule will not trigger an alarm until the queue has cleared.

Invert: This rule will not trigger an alarm until a queue has been found within the specified distance and on the relevant carriageway.

Queue Source Filter: 

Other Carriageways: Look for queues on all carriageways expect the one this rule is associated with.

This Carriageway: Look for queues on the same carriageway as the one associated with the rule.

All Carriageways: Look for queues on all carriageways.

Queue Detection Distance (m): The distance from each section being checked in this rule to look for a queue. When this value is 0 (zero) the feature is disabled.

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