6.5 Configuration of a Fieldbus Master

Device-specific bus parameters are needed to configure the Frame Application’s fieldbus master or communication scheduler. To retrieve these parameters an interaction between DTMs and a master configuration tool is required. To provide a standard access to this bus-specific data, it is stored as a public data accessible by the predefined XML tag

<busMasterConfigurationPart>

<busMasterConfigurationPart> is a binary stream which contains the device specific bus information according to the Fieldbus-Protocol-Specification.

Each DTM must at least fill in the device specific parameters and all parameters which can be changed by its application.

All other entries may be filled up with substitute values like zeros. The substituted values of the <busMasterConfigurationPart> structure will be set by the environment’s master configuration tool according to the requirements of the complete bus.

Independent of the values filled in, it is very important that the structure generated by the DTM adheres to the definitions of the fieldbus-specification.

After all network participants have written their instance data, the master configuration tool can commission the fieldbus. For that purpose it collects the <busMasterConfigurationPart> of each network participant and calculates the bus parameters of the corresponding master device.

The master configuration tool can be part of the DTM of the master device or like in the following example part of the Frame Application. If a DTM for a master device exists, the master configuration will be downloaded by IDtmOnlineParameter::DownloadRequest().