Data Access for the MQTT Publisher

Following options are available to define the data that should be published with the MQTT Publisher:

Data Point Groups

By default the data point group MQTTPub is used by the MQTT Publisher to define the data, which should be published.
Using the config entry [mqttpub] mqttPubGroup a different data point group can be specified.
The MQTT Publisher creates a dpConnect() to all the DPEs of this group and publishes them if a DPE is updated.
The value format (Transformation) for the published data (string or JSON format) can be configured in the MQTT Publisher Default/Last Will configuration panel.
To publish all values during connection establishment to the broker set the option AutoIGQ in the MQTT Publisher advanced configuration panel.
The topic used for publishing is derived from the DPE name or the alias, where all '.' and ':' are replaced by the MQTT hierarchy separator '/'.

The DPE System1:mqpub-0.alert.controlFuse is published under the topic System1/mqpub-0/alert/controlFuse

If there is at least one CNS Views contained in the DPE _MQTTPublisher.Config.CNSViews the publisher uses CNS Views instead of DP groups.

Restriction: You can only use either DP group or CNS Views for publisher configuration.
The MQTT Publisher creates a dpConnect() to each linked DPE oder DP if the corresponding CNS node is defined as readable via MQTT.
The topic is defined by the CNS ID path (See Common Name Service (CNS)). As for Data Point Groups all '.' and ':' are replaced by MQTT hierarchy separator '/'.
The value format (Transformation) for the published data (see Define Transformation) can be configured at each node.
Note: If no definition is done on the CNS node the default value from in the MQTT Publisher panel is used.
The access mode and the transformation are stored in the CNS user data (see cnsSetProperty, cnsGetProperty). The key for access mode is OA:MQTT and that for the transformation OA:MQTT:T.

Note: When a View ID is changed, the CNS View assignment must be updated.