Enable/Disable Rule

Owned by Isabelle Avery (Unlicensed)
Last updated: Oct 24, 2023 by Charlotte Dakin-Norris
3 min read

Introduction

This rule represents a pattern that can be used to enable or disable entities or to control actions in response to track behaviour. Note that the timer input is required to ensure the actions do not flip-flop when different tracks are processed by rule. For example a track inside the area will meet the requirements of the area check and therefore the actions will be triggered, however the next track checked could be outside the area in which case the area check will fail and the actions will be reversed. To avoid the actions being continuously triggered and then reversed the timer is used to keep the area rule output true for the specified time period. This means as long as a track is in the area the timer period will be reset and the rule will remain broken until the track has left the area and the timer has expired.

This example demonstrates the ability to enable or disable another rule based on whether a track is detected in the specified area.

Contents

Configuration

Nodes

Inputs

Track Sighting Input

Time Input

Time Frame: This defines the length of time the rule will be disabled for. In this example, after 8 seconds, the rule will become active again.

Check

Area Check

Actions

Rule State

Enabled: Select to enable a disabled rule. Leave unchecked to disable an enabled rule. 

Rule: Select the rule to enable/disable.

Action: Input. 

PPI Example

In this example Disable Rule, an Area Check disables another rule. The area is the Orchard Area, in blue, and the rule is the . Here, track 0-1 enters the Orchard Area and therefore disables the Gate Rule; a rule which controls access to the Field Area (in purple). Track 0-2 approaches the Field Area.

Because the Gate Rule is disabled, track 0-2 does not trigger an alarm by breaking a rule in the Field Area. 

However, the Gate Rule was only disabled for 8 seconds. Therefore, after 8 seconds, the Gate Rule is enabled and track 0-2 now breaks the rule and triggers an alarm in the Field Area. 

Video

The following video demonstrates how to create an Enable / Disable Rule. This rule disables the Gate Rule for 8 seconds when a track enters the Orchard Area. After 8 seconds has elapsed the Gate Rule is enabled and the track that breaks the rule triggers the alarm:

Safety is everything.