5. QoS Provider

Each Vortex DDS block has a QoS that can be set using the Block Parameters.

The following section explains how the QoS is set for a DDS entity using the QoS Provider.

5.1. QoS Provider File

Quality of Service for DDS entities is set using XML files based on the XML schema file DDS_QoSProfile.xsd. These XML files contain one or more QoS profiles for DDS entities. An example with a default QoS profile for all entity types can be found at DDS_DefaultQoS.xml.

Note: Sample QoS Profile XML files can be found in the examples directories.

5.2. QoS Profile

A QoS profile consists of a name. The file contains QoS elements for one or more DDS entities. A skeleton file without any QoS values is displayed below to show the structure of the file.

<dds xmlns="http://www.omg.org/dds/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="file:DDS_QoSProfile.xsd">
    <qos_profile name="DDS QoS Profile Name">
        <datareader_qos></datareader_qos>
        <datawriter_qos></datawriter_qos>
        <domainparticipant_qos></domainparticipant_qos>
        <subscriber_qos></subscriber_qos>
        <publisher_qos></publisher_qos>
        <topic_qos></topic_qos>
    </qos_profile>
</dds>

Example: Specify Publisher Partition

The example below specifies the publisher’s partitions as A and B.

<publisher_qos>
    <partition>
        <name>
            <element>A</element>
            <element>B</element>
        </name>
    </partition>
</publisher_qos>

You can also set the partition from the QoS tab of Publisher and Subscriber blocks. Please see Publisher Block: Override Partition and Subscriber Block: Override Partition sections for more information.

5.3. Setting QoS Profile in Simulink

QoS profiles are set using the Simulink block’s parameters dialog under the QoS tab. If the QoS File parameter is set to None the default QoS settings will be used. The Reset button sets the parameters to the default values.

A QoS Provider file can be selected by browsing to the XML file. Once the file is chosen the file name is displayed and the user is presented with a drop down list of all QoS Providers in the file.

Note: Seeing the QoS Profile in the drop down list only guarantees the QoS Profile exists in the file. It does not mean the qos tag exists for the entity. The user is responsible for verifying the entity qos tag exists in the file.

Simulink block annotations are visible by default to display the QoS File Name and the QoS Profile settings.

5.4. Known Limitations

See QoS Provider Known Limitations for a list of limitations on QoS Provider support.