MQTT Server Settings

Check this box to tell the application to try to connect to the MQTT server (aka host or broker.) If this setting isn't checked the application will essentially be disabled, because it needs a connection to an MQTT server before it can publish any data.

If the Server Name Type is URL, you will need to enter the IPV4 address of a DNS server here, so that the URL can be resolved.

Choose the Server Name Type. Options are URL or IPV4 Address.

The MQTT application can be configured to connect to up to 4 different servers. Only one server can be connected at one time, however.

 

 When the application is first started, it will always try to connect to the server in Server Name 0. If connection to that server fails, it will try to connect to the next server, but only if the Use Server option is enabled. It no other User Server option is enabled, or none of the other servers can be connected to, then the application will start again with Server Name 0.

 

If the Server Name Type is URL, enter a URL here. If the Server Name Type is IPV4 address, enter an IPV4 address, like 192.168.0.1, for example. All Server Names must match the formatting of the selected Server Name Type.

 

Status Parameters indicate whether the application has a connection to any server, and which server is actually connected.

Configure the port. This setting should match the port that the MQTT server is listening on.

Check this option to force the application to use a TLS (encrypted) connection to the server. TLS versions 1.0 to 1.2 are supported. Older versions of SSL are not supported. STARTTLS is not supported.

 

Note that the MQTT application executable comes in two versions: with and without TLS support. Only select this option if you are using the executable that supports TLS.

 

TLS is a licensed feature. Your license will need to support the TLS feature on the MQTT application.

 

The MQTT protocol requires that each client has a unique ID. Enter a client ID here that is unique to your MQTT server. When the Publish Format is Sparkplug B this value is the "edge_node_id" field.

Choose the format to publish data in. The choices are are Tags, JSON or Cirrus Logic Sparkplug B. When the Publish Format is Sparkplug B this value is the "group_id" field.  See the Operational Details section on what data looks like for each option.

The Topic Prefix is prepended to all tags as they are published. This setting allows you to choose a unique prefix for all data from this RTU.   See the Operational Details section and Examples section for details on how this field is used.

Check this setting if your MQTT server requires authentication.

Enter a user name here if the Authentication setting is checked.

Enter a password here if the Authentication setting is checked.

Select this option if the High Level and Low Level values for each monitored value should be should be pushed to the EngHigh and EngLow tags during an NBIRTH event. This option is only used when the Publish Format is Sparkplug B.

Select this option if the Units value for each monitored value should be should be pushed to the EngUnit tag during an NBIRTH event. This option is only used when the Publish Format is Sparkplug B.

Select this option if you want the application to subscribe to changes. This option has no effect if the Publish Format is not Sparkplug B.

 

When this option is selected, the application will subscribe to all topics (monitored values on the RTU), using a wildcard. When this option is not selected, the subscribe message will not be sent and no writes from the host will be possible.

 

Note that each monitored value also has an individual Subscribe Enable. This allows updates to be enabled or disabled for any individual value. However, this global enable must be set before updates to any individual tag are possible.

 

Updating a monitored value will only be possible if the monitored value has its Subscribe Enable option selected, if monitoring is enabled on the value and if Publish on Change is enabled on the value. When only some of these options are enabled, the update will be rejected.

Select this option if the application should send an MQTT disconnection message when disconnecting. Sending an MQTT disconnect message will likely suppress publishing a Last Will and Testament (LW&T) on behalf of the node by the broker. If the LW&T should be published when the application disconnects, do not choose the Clean Disconnect option.