Create a Device Item
Add an MQTT JSON Schema A Device to the database. This type of database item is available from the JSON Schema A sub-branch within the MQTT branch of the Create New menu. The sub-branch corresponds to the message format that Geo SCADA Expert is to use to communicate with the broker.
The Device item represents the device that publishes the MQTT topics to which Geo SCADA Expert has subscribed.
When you create the Device item, you can leave most of the configuration fields at their default values. For this tutorial, the only fields that you need to change on the MQTT tab of the configuration Form are as follows:
- In Service—Select this check box so that it displays a check mark.
- Broker—Specify the MQTT Broker item that you created earlier in this tutorial.
- Topic Prefix—Specify the exact name of the topic for which the device publishes data. The topic is context-sensitive.
Each Topic Prefix that is associated with a given Broker database item has to be unique.
- Reported time offset from UTC—(Optional). If you want to, you can populate this field with a suitable value, to enable Geo SCADA Expert to adjust the timestamp that the publishing device sends in messages, to convert that timestamp into UTC.
This will cause Geo SCADA Expert to send a subscription request to the broker with which the database item is associated. (This will only happen if both the Broker and Device database items are In Service and have valid, saved, configuration, and Geo SCADA Expert is able to connect successfully to the broker.)
Once you have configured the Device item, you can proceed to Create an Analog Point.
Further Information
For further information about configuring an MQTT JSON Schema A Device item, see Configure an MQTT JSON Schema A Device Item.