Add & Remove Devices from Group Dynamically

Automatically add or remove a device from an entity group based on incoming telemetry, using the Rule Engine. The group is created on the fly when the first matching device is added.

Example: Place devices that report temperature > 30 into a High temperature group and remove them when temperature drops back to ≤ 30.

• A device publishing temperature telemetry — see Devices
• Familiarity with Rule Engine and Entity Groups

1. Go to Data processing ⇾ Rule chains and click + Add rule chain ⇾ Create new rule chain.
   • Name it Add Device to Group
   • Click Add and open it.
2. Add a script filter node:
   • Name it Has temperature

   • Set the script to:

     return msg.containsKey('temperature') && msg.temperature != null;

   • Click Add.

   This expression returns true if msg contains the temperature field and its value is not null; otherwise, it returns false.

3. Add a second script filter node:
   • Name it High temperature

   • Set the script to:

     return msg.temperature > 30;

   • Click Add.

   This expression returns true if the temperature value is greater than 30; otherwise, returns false.

4. Add an add to group action node:
   • Name it Add to High Temperature group

   • Specify group name pattern:

     High Temperature (${deviceType})

   • Enable Create new group if not exists
   • Click Add.
5. Add a remove from group action node:
   • Name it Remove from High Temperature group

   • Specify group name pattern:

     High Temperature (${deviceType})

   • Click Add.
6. Connect the nodes:
   • Has temperature ⇾ True ⇾ High temperature
   • High temperature ⇾ True ⇾ Add to High temperature group
   • High temperature ⇾ False ⇾ Remove from High Temperature group
7. Save the rule chain.

Alternatively, you can skip the manual setup and import the ready-made configuration: add_device_to_group_rule_chain.json

1. Open the Root Rule Chain.
2. Add a Rule Chain node:
   • Name it Add Device to Group
   • Select Add Device to Group rule chain as the target.
3. Connect the existing telemetry path (e.g. the Save Timeseries node output, or a Message Type Switch Post telemetry branch) to this rule chain node.
4. Apply changes.

When a device publishes telemetry:

Condition	Outcome
temperature > 30	Device added to High temperature {deviceType} group (created automatically if needed)
temperature ≤ 30	Device removed from that group

Open the Devices & assets ⇾ Devices page and verify that the device is not assigned to any group (the Groups column is empty).

• When a device publishes telemetry temperature > 30 ⇾ the device is automatically added to the High Temperature (thermostat) group.
• When a device publishes telemetry temperature ≤ 30 ⇾ the device is automatically removed from the High Temperature group.