Understanding Rule 'Behavior'
When a rule condition is breached and an action is generated, the rule is in breach status. This means that if the next Event also breaches the condition no action will occur.
An event which unbreaches the condition must be sent to set the rule back in its triggering status so that when another Event that breaches a condition is sent, the action will be generated.
Example
A rule has a condition to be triggered when Temperature > 25, the following readings are sent:
2, 7, 16, 4, 23, 27, 26, 32, 26, 42, 18, 26, 28, 23, 27
Only the readings in bold will trigger an action!