Configure MQTT device items

Device items provide alternative names for specifying MQTT items. To add device items to your group, select the new group object and select the Device Items tab.

Note: The MQTT topic name and item name are case-sensitive.

The Device Items configuration view is used to add, clear all, rename, delete, import, and export device items.

The Device Items configuration view has the following two columns:

• Name: This column defines the alias names to actual data source items.

• Item Reference: The actual data source item names defined in this column.

  Note: When you create or add a new device item, a unique name needs to be entered for it.

Create or add device items

1. Right-click anywhere in the Device Items configuration view, and select the Add command from the shortcut menu.

   • A device item is created, and it is numerically named by default.
     For example, Item_0, Item_1, and so on.

2. To change the default name, double-click it and enter the new name.

   • Enter a unique name for the new device item.

Add item references

Item references for each of the device items that have been created can be added as follows:

3. In the Item Reference column, double-click on the area in the same horizontal line as the selected device item.

4. In the frame that appears, type in the actual data source item name or copy the tag reference from the Currently Selected Tag Reference field under the MQTT Browser window and paste it. For more information see Browse tag items.

   Note: To copy the tag references in bulk, use exporting and importing tag references options. For more information see Export and import tag references.

5. Select anywhere in the configuration view or press the Enter key to apply the change.

Rename a device item from the list

6. Right-click on the device item to be renamed, and select the Rename command from the shortcut menu.

7. Enter the new device item name.

8. Select anywhere in the configuration view or press the Enter key to apply the change.

To delete a device item from the list

• Right-click on the device item to be deleted, and select the Delete command from the shortcut menu.

  The device item and its corresponding data source item name are deleted from the configuration view.

Note: When you select another part of the MQTT tree hierarchy, you are prompted to save the modifications to the configuration set.

Clear all device items

• Right-click anywhere in the Device Items configuration view, and select the Clear All command from the shortcut menu.

  All the device items listed in the configuration view, including their corresponding data source item names, are deleted.

Export device items

When you want to archive a list of device items, use the Export feature in the Device Items configuration view.

9. Right-click anywhere in the Device Items configuration view, and select the Export command from the shortcut menu.

10. Select the folder into which the list is to be saved.

11. Name the list to be exported.

12. Select the Save button.

    The entire list is saved as a .csv file.

Import device items

The Import feature in the Device Items configuration view is used to import an archived list of device items into the configuration view.

13. Right-click anywhere in the Device Items configuration view, and select the Import command from the shortcut menu.

14. Select the archived list (.csv file) to be imported, and select Open.

    The entire list is imported into the Device Items configuration view.

Note: Duplicate items with the same Item References are ignored during import. Duplicate items with different Item References cause a dialog box to be displayed, in which you must make a selection.

Resolve Item Names from Clients

MQTT Communication Driver resolves item names from its clients at runtime in the following order:

System items (those prefixed with $SYS$) > Device items (those defined in the Device Items configuration view) > All other items (validated directly from the PLC device)