Hello Stefan,
the databus is only reachable internally from the Industrial Edge Device.
There is another app called external databus, which can be used for fullfilling your use case. You can configure that the external databus synchronizes the topics with the databus, if required.
Please see the manual of the external databus: https://support.industry.siemens.com/cs/us/en/view/109818807
To share the description from the manual:
The External Databus allows you to connect remote clients to the IED over MQTT. The data pushed to External Databus is pushed to Databus on the configured topics and is available to be consumed by other apps within the IED if it is configured to operate this way.
The External Databus consists of the following two components:
Databus Configurator in Industrial Edge Management:
Databus Configurator in IEM includes user interface for configuring Databus and External Databus called Databus Configurator and External Databus Configurator respectively. Hence, Databus Configurator has to be installed on IEM to be able to configure External Databus of the corresponding IED.
External Databus:
The External Databus is a distributed application that runs on the individual Industrial Edge Device.