Target Group and Requirements

Target Group

Belonging to the target group of the WinCC OA BACnet Application are users who model the different devices of a building automation project as a collection of objects and want to visualize them in WinCC OA .


The requirements for the use of the WinCC OA BACnet Application are:

  • An installed WinCC OA

  • Installed WinCC OA add-ons - "Standard Object Library" and "BACnet"

  • Embedded Standard Object Library and BACnet Object Library in an existing WinCC OA project - see Embedding and Configuring the Object Library

  • The WinCC OA server is embedded into the BACnet network (online Engineering) or an EDE file is available (offline Engineering)

  • The "BACnet_DeviceOnline.ctl" control script has been started in a Control Manager (<C:\Siemens\Automation\WinCC_OA\3.18\ _installation_path>\BACnet_<version>\scripts)

  • The used BACnet driver must be started with the manager parameter "-num 1".

Restriction: The BACnet Application only supports the usage of History DB.


A redundant system is supported by the WinCC OA BACnet Application. This requires that:

  • The requirements for the WinCC OA BACnet driver have been met (see WinCC OA Online Help Drivers -> BACnet -> Redundancy).

  • The "BACnet_DeviceOnline.ctl" control script has been started in a Control Manager (<C:\Siemens\Automation\WinCC_OA\3.18\ _installation_path>\BACnet_<version>\scripts) in both projects. This script generates a common state from the connection states of both BACnet drivers in a redundant system. That means that it connects the internal datapoint elements _BacnetDevice.<DeviceName>.Online and _BACnetDevice.<DeviceName>_2.Online to one system state.

Distributed Systems

In simplest case a distributed system consists of two projects on different computers. The distributed WinCC OA systems are connected via an own manager. This is the Dist manager (WCCOAdist). The Dist manager builds the logical connection to several Dist managers of other WinCC OA systems. There is one Dist manager per system and it is responsible for the connection to all other systems (for further information on distributed systems see WinCC OA Online Help chapter Special functions -> Distributed systems -> Distributed systems, basics).

Once the e.g. both Dist managers of the projects of a distributed system have been started, the two BACnet systems are shown in the tree view of the Engineering Explorer and of the Device Explorer. The information regarding the available devices, objects and properties of the specific system are shown at the corresponding node in the tree view of the Engineering and the Device Explorer.

On the first system it is possible to browse for devices of the second system. If a device was found, this can also be created on the distributed WinCC OA system. The same applies to BACnet objects and the deletion of devices/objects of a distributed system.


The creation of new BACnet devices on the distributed system using the BACnet Explorer is only possible for the "root" user. The other user do not have the permission, even if they belong to the "root" group. If a device could not be created, an error message is displayed only in the log file of the target system, but not on the local system.

For the other functions of the context menu, which are also supported for distributed systems, see Context menu of the tree root.