MQTT JSON Schema A Driver Guide - Create an MQTT Broker Item (Quick Start Tutorial)

Create an MQTT Broker Item

Add an MQTT Broker item to the database. You select the database item from the MQTT branch of the Create New menu. This branch comprises that of the 'parent' driver (the driver for which this MQTT JSON Schema A driver is an extension driver).

The Broker database item represents the broker to which Geo SCADA Expert is to connect, and from which it is to receive messages that contain the topics to which it has subscribed.

When you create the Broker item, you can leave most of the configuration fields at their default values. On the Broker tab of the configuration Form, the only fields that you need to change for this tutorial are:

In Service—Select this check box so that it displays a check mark.
Broker Host Address—Specify the IP address or host name of the broker to which Geo SCADA Expert is to connect.
Client Identifier—Use this field to enter a name or description to identify the connection to the broker. For example, you might want to specify the name of the remote MQTT client that publishes messages to the broker, containing the topics to which Geo SCADA Expert has subscribed.
Geo SCADA Expert supports multiple connections to a broker, for which the combined Broker Host Address, Port, and Client Identier settings have to be unique. (So, for example, you might have 2 Broker items that both have the same Broker Host Address and Port settings, but for which the Client Identifier property differs.)
User Name—You only need to populate this field if the broker has been configured to require a user name and password; in which case, enter the user name that enables Geo SCADA Expert to connect to the broker.
Password—You only need to populate this field if the broker has been configured to require a user name and password; in which case, enter the password that enables Geo SCADA Expert to connect to the broker.

The Port property identifies the port on which an MQTT broker listens. For this tutorial, leave the Port at its default setting of 1883.

If a secure session is required, the Port has to be set to 8883, and the properties in the Security section of the Broker tab enabled and populated appropriately.

WARNING

POTENTIAL SECURITY BREACH

We strongly recommend using network-connected Geo SCADA Expert drivers in a private network only (either physical or virtual). We recommend against using such drivers for communications over the public Internet. If the drivers are used over the public Internet, as a minimum those drivers should use valid SSL certificates to initiate secure connections and encrypt the data that is transmitted over the network.

Failure to follow these instructions can result in death, serious injury, or equipment damage. The breach in system security could expose sensitive data and the leave the database vulnerable to unauthorized and potentially malicious use.

NOTICE

unexpected impact on system performance

It is possible that excessive incoming data from a broker could adversely affect system performance. If performance is an issue, check:

The configuration of the downloaded or cloud-based broker that is represented by the Geo SCADA Expert MQTT Broker item
The configuration of the publishing devices that are connected to that broker.

Both mentions of configuration above refer to configuration outside of the Geo SCADA Expert database.

Failure to follow these instructions can impact adversely on system performance.

Save the configuration.

You can check that Geo SCADA Expert is able to connect successfully to the broker. To do this, view the Broker item's Status display (right-click on the Broker item in the Database Bar and select the 'View Status' option). On the Status display, scroll down to the 'Connection State' property, which should indicate that the connection is healthy.

Once you have configured the Broker item, you can proceed to Create a Device Item.

Further Information

For further information about configuring an MQTT Broker item, see Configure an MQTT Broker Item in the Geo SCADA Expert Guide to the MQTT Driver.