Sensors use variables, and you can set a variable per role. You can override sensor variable values for any system assigned to the selected role.
To trigger a sensor under different conditions for specific systems, add variable overrides to the roles that those systems use. The new value must differ from the current value of the variable. Reverting the variable removes it from the override list.
Add a New Variable
To add a new variable:
Go to Configure > System Configuration > Roles.
Click the lock icon in the upper-right corner to unlock Configure for editing.
Select the role.
From the Additional Settings list, select Variables.
Click Add Variable.

In the Add Variables dialog box, select the variables to add to the role and enter a new value for each.

Click Add.
Click Save Changes in the upper-right corner.

Change Sensor Variables
To change a variable override in a role, open the Variables settings of the role as in Add a New Variable above, enter the new value for the variable, and click Save Changes. To remove an override, revert the variable.
Systems that use the role apply the change the next time they read their configuration. To apply it right away, run Read Configuration on those systems. See Operations: Command Dashboard.
If a variable override doesn't seem to apply, check how the variable expects its values. For an example, see Nonstandard Shared Folder Sensor Issue.