<xs:element name="command" minOccurs="1" maxOccurs="unbounded">
    <xs:complexType>
        <xs:sequence>
            <xs:element name="send" type="xs:string" minOccurs="1">
                <xs:annotation>
                    <xs:documentation>Message to send to camera. Format dependes on protocol setting.</xs:documentation>
                </xs:annotation>
            </xs:element>
            <xs:element name="receive" type="xs:string" minOccurs="0">
                <xs:annotation>
                    <xs:documentation>Acknowledgment expected back from camera, protocol should be same as used for send message. Next message is not sent until acknowledgement is received back from camera. Timeout is fixed at 100 msec.</xs:documentation>
                </xs:annotation>
            </xs:element>
        </xs:sequence>
        <xs:attribute name="comment" type="xs:string" use="optional" />
    </xs:complexType>
</xs:element>