You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 2 Next »

The number of connected clients is available as an Ignition tag in the MQTT Distributor tag provider. The tag path for this tag is [MQTT Distributor]Distributor Info/Connected Clients.

Every client that connects to the broker, for example for MQTT Engine or MQTT.fx is considered a connection and is included in this client count.

MQTT Engine Clients

MQTT Engine has two potential client connections.

One will publish the v3.0.0 Sparkplug™ B STATE message which will be initiated by default.

A second optional client is available to publish the legacy Sparkplug™ B STATE message and is disabled by default.

MQTT Transmission Clients

MQTT Transmission each unique combination of a Group and Edge Node ID is one MQTT client.

For example, the following Sparkplug Edge Nodes will result in 3 MQTT clients:

Group1/EdgeNode1
Group1/EdgeNode2
Group2/EdgeNode1

The MQTT Transmission Transmitters and Tag Trees document describes how Transmitters and Tag Trees can be arranged, which in turn will define how many MQTT clients get created from a single Transmission instance.

In addition, MQTT Transmission supports an optional RPC Client which is used when publishing from Ignition Python scripts. This is enabled by default and can be disabled under the Transmission Server Settings > Advanced section if not being used.



Additional Resources





  • No labels

New to MQTT? Start Here!