Abstract: A message transmission between communication subscribers in an automation system is controlled, wherein publisher applications and/or subscriber applications are executed on each of the communication subscribers, wherein the automation system comprises a message broker configured to enter subscriptions for specified topics for designated subscriber applications into a topic tree. In reaction to a message on a specified topic of the topic tree being published by a publisher application of a first of the plurality of communication subscribers on the first communication subscriber offering one or a plurality of services, the message broker determines whether a subscriber application of a second of the plurality of communication subscribers has been entered for the specified topic.

Abstract: A connecting unit to transmit process data of an automation process of an automation system to an external data infrastructure, configured as a field device for arrangement on a field level of the automation system. The connecting unit comprises a field bus module, network module and interface module. The field bus module is configured to interchange the process data via the field bus with a signal unit connected to the automation process via a field connection. The network module is configured to interchange the process data with the external data infrastructure, use the data network to transmit input process data to the external data infrastructure, and retrieve output process data from the external data infrastructure. The interface module is configured to interchange the process data between the field bus module and the network module. The interface module prompts interchange of the process data autonomously.

Abstract: A message transmission between communication subscribers in an automation system is controlled, wherein publisher applications and/or subscriber applications are executed on each of the communication subscribers, wherein the automation system comprises a message broker configured to enter subscriptions for specified topics for designated subscriber applications into a topic tree. In reaction to a message on a specified topic of the topic tree being published by a publisher application of a first of the plurality of communication subscribers on the first communication subscriber offering one or a plurality of services, the message broker determines whether a subscriber application of a second of the plurality of communication subscribers has been entered for the specified topic.

Abstract: A connecting unit to transmit process data of an automation process of an automation system to an external data infrastructure, configured as a field device for arrangement on a field level of the automation system. The connecting unit comprises a field bus module, network module and interface module. The field bus module is configured to interchange the process data via the field bus with a signal unit connected to the automation process via a field connection. The network module is configured to interchange the process data with the external data infrastructure, use the data network to transmit input process data to the external data infrastructure, and retrieve output process data from the external data infrastructure. The interface module is configured to interchange the process data between the field bus module and the network module. The interface module prompts interchange of the process data autonomously.