Event delay

Avoid getting to many speeding events

We have seen that many users setup event rules to trigger an alarm or email when a driver exceeds a specific speed limit, e.g. 100 kph.

One of the problems is that if the driver keeps a speed of about 100 kph, and alters lets say between 90 and 110, you will get a lot of emails/alerts.

To filter out most of the unnecessary events you can add an End Expression. In Step 4. of the Event Wizard, click on advanced and add an expression which says e.g. Speed Less than 80 

The exact steps:

Select Admin -> Event Rules from menu
Click "Add new Event Rule" (or edit an existing one)

Step 1. Enter a name e.g. "Speeding 100kph". Click Next.
Step 2. Select which Tags the rule is active for. Click Next
Step 3. Set schedule for when rule is active. Click Next

Step 4.

Select "Analog Expression" in drop down.
Select "Speed" "Greater" and then enter 100
Click on "Show advanced options"
Select "Analog Expression" in drop down.
Select "Speed" "Less" and then enter 80
Click Next

Step 5. Setup the Notifiers you want. Click Next and Save.

Now you have a rule that triggers at 100, and will not trigger again until the speed has gone below 80 once. The technical term for this is "hysteresis".

Handle false unrealistic speed values from tracker

If you have many false triggers of the Event Rule because the tracker sometimes send up false unrealistic speeds, you can try some of the following things.

Add a max speed for Event Rule

1. Add an additional "Analog Expression" in Step 4.
2. Set Speed "Less" than e.g. 150 kph, if the vehicle never can go that fast.
3. Select "Match all".
4. Save rule.

Now the Event Rule will not trigger on false unrealistic speed values sent from the tracker.

Delay start for event rule.

1. Select "Delayed event" in step 4.
2. Select a value in minutes for how long time the speed value should exceed the speed limit before the event rule is triggered.
3. Click Save.

If you for example have one update per minute, a value of 1 minute will require 3 updates before the rule triggers.