Event rule use case: display 'connected' assets (based on proximity) in the asset list

There might be a scenario where two assets may be close to each other for a long period of time, for example, a truck and a trailer both have their tracker. And as a user, you may want to see which truck is connected to which trailer.

How to set up:

1. Rendezvous plugin

2. Custom variable

Add a custom variable with the name of your choice (see Custom-Variables for how to add a custom variable). In this example, the variable is named AttachedTo.

Screenshot 2024-10-24 at 12.13.28.png

3. Event rule

Create a new event rule
- name it accordingly
- set which Groups it shall be applied to
- set when the rule shall be active

Under Expressions, add a Script Expression (make sure to have the privilege _EditScriptExpression activated, please follow this guide if it is not visible) and add the following code:

var st = context.state || { rvz_status: false, rvz_timestamp: null, rvz_name: null};
var searchtag = 'Trailers'; //Change to the name of the Group containing the device(s) you want to look for
var searchtagobj = session.directory.getTag(searchtag);
var searchtagid = searchtagobj.id;
var r = rendezvous.findAny(searchtagid,'Enter',10); //Within 10 meters
if(r != null) {
  st.rvz_name = r.name;
  st.rvz_status = true;
  st.rvz_timestamp = new Date();
  context.setVariable("UnitName", r.name);
  context.setState(st);
  return true;
}
else {
  var newdate = new Date();
  var timestamp = new Date(st.rvz_timestamp);
  var time_diff = newdate.getTime() - timestamp.getTime();
  if(st.rvz_status == true && time_diff > 300000) { //In milliseconds
    st.rvz_name = null;
    st.rvz_status = false;
    st.rvz_timestamp = null;
    context.setVariable("UnitName", "");
  }
  else {
  context.setVariable("UnitName", st.rvs_name);
  }
  context.setState(st);
  return false;
}

3. Under Notifications, configure as seen in the screenshot. Please type [UnitName] in the 'Source' field.

4. Save

4. Custom variable in the asset list

Add the custom variable 'AttachedTo' to the asset list. Please go to Manage-columns-add-variables-in-the-assets-panel for more information on how to do that.

5. Result

Now, when an asset is close to another asset and the criteria in the script match, you will have a result like this:

Note: You can test this rule by creating simulators and naming them Trucks and Trailers, and including the Trucks/Trailers (that you want to see under the 'AttachedTo' column) in the Group. Please remember to change the name of the Group in the code (where you have the comment //Change to the name of the Group containing the device(s) you want to look for) to the Group you created.