METHOD FOR THE DATA EXCHANGE BETWEEN NETWORK DEVICES

Abstract: Two or more electronic devices are connected via a bus sys-tem (5) building a cluster or chain of devices (1, 3). A de-vice can be selected using a control device (1), wherein an user interface (6) for the selected device is generated based on description data which are stored in the selected device and are transferred to the control device. A single user interface is shown on a display of the control device which allows to operate at least two devices (1, 3) simulta-neously. The user interface of a first device is displayed as main user interface and the user interface of a second device is rendered within the main interface as reduced user interface (9) which includes only operation elements neces-sary for operation of the second device in combination with the first device.

Description: Method for the data exchange between network devices The invention relates to a method for the data exchange be- tween network devices, especially to the data exchange between two HAVi devices connected via IEEE1394 bus. Background For controlling several AV devices within a network of home entertainment products the so-called HAVi (Home Audio Video Interoperability) standard has been developed. This standard specifies the control of television sets, video recorders, set top boxes and other devices, especially for the control of the exchange of digital audio and video streams. The devices are connected via the IEEE 1394 bus (i.LINK ® or Fire- Wire ® ) , which has enough capacity to simultaneously carry multiple digital audio and video streams. Each device added to the HAVi network automatically installs its own application and interface software and is automatically registered by the system so that other devices know what it is ' capable of. So-called Application Programming In- terfaces of the most common AV functions have been standardized. Furthermore, functions on a device within the HAVi networking system may be controlled from another device within the system. HAVi defines two different ways of using User-Interfaces (UIs) . Both solutions are working in principle in the same way: one device within the network (target) provide UI- elements or a kind of a complete UI to a display device (controller) . The controller renders the UI-elements or exe- cutes the complete UI , respectively. The first mode is called Data Driven Interaction (DDI) , the second one UI by havlets . For a DDI-UI a part of a network is shown in figure 1. A display device 1 and a controlled device 3 are connected via an IEEE 1394 bus 5. The target device in the IEEE1394 network comprises a Device Control Module (DCM) 4, which can provide DDI-elements to the network for creating a UI . It is also able to control the device, natively, by commands. Because a DCM is registered within the HAVi network, a DDI controller 2 can "subscribe" to the DCM 4. This is the start of an interaction between the DDI controller 2 and the DCM 4 to transmit the DDI-elements to the controller, display them to the user and afterwards to translate the user's action on these DDI-elements to native commands in the DCM. Invention It is one object of the invention to disclose a method for the data exchange between network devices which allows to simplify the simultaneous operation of two or more devices. This object is achieved by the method disclosed in claim 1. The invention is based on the recognition of the following fact. The above described user interface is fine to control one device with its UI . However, the HAVi-standard shows a lack in setting up a service between two IEEE1394 devices, e.g. the copying of video-data from a camcorder to a VCR. This is because the user has to handle two UIs, on one he has to play the camcorder, on the other he has to set the VCR in record-mode . In principle, according to the inventive method at least two devices are simultaneously operated with a single user interface, wherein the user interface of a first device is displayed as main user interface and the user interfaces of a second device is rendered within the main interface as reduced user interface which includes only operation elements necessary for operation of the second device in combination with the first device. Advantageous additional embodiments of the inventive method are disclosed in the respective dependent claims. Drawing Embodiments of the invention are described with reference to figure 2, which shows an user interface according to the inventive method. Exemplary embodiments Fig. 2 shows an user interface according to the invention displayed by an display device. The user interface 6 com- prises several DDI-elements 7 which are provided by the DCM of the DDI -target. Also shown as an element 8 is a list of source or sink devices which is provided by the DDI- controller device. In this context a source device means a device which is able to deliver a data stream and a sink de- vice means a device able to receive a data stream. Also, a device can be a source and a sink device simultaneously, e.g. a VCR which can playback and record a data stream. Furthermore, a reduced user interface 9 is displayed which is provided by an other DCM. This reduced user interface 9 is generated as follows, wherein as an example the control device is a television set and the selected device is a camcorder. Initially, the user sitting in front of the television set selects the camcorder on the television screen, e.g. by clicking on an icon representing the camcorder. As a result the user is provided with the main panel for controlling the camcorder. Due to a registry scan of the controller, the user is able to provide possible sink and source devices within the network for the camcorder. So the controller is also able to render a/two choice lists of sink/source devices within the camcorder user interface. Two separate lists can be displayed, wherein the first list comprises sink devices and the second list comprises source devices. Also a combined list can be displayed which comprises sink devices and source devices. The sink/source devices can be listed in text form or can be displayed by corresponding icons. The list(s) can also comprise further details of the sink/source devices. So the kind of data streams processable by the devices can be displayed, e.g. source device for MPEG 2 audio and video signals. When selecting, for example, a digital VCR as a sink device from the list, the HAVi-stream-setup between the camcorder and the digital VCR will be done by the controller. In addition the sink device's DCM (VCR) will provide a reduced user interface, which is also rendered within the main (camcorder) user interface and comprises only the elements of the VCR which are necessary for operation as a sink device, e.g. "record", "play", "pause", "forward", "rewind". To help the controller rendering it's own elements within the DDI-targets UI , the DDI-target provide placeholder- elements for the sink/source choice lists and the reduced UI and rendering attributes for these elements. The interaction between the controller and the target starts in response to a subscribe command send from the controller to the target. The target memorizes the software element which sent this message and returns identification data (ID) . The controller uses this ID as an argument for a com- mand for obtaining the complete content of the DDI element for rendering on the display of the controller device. Contrary to the current HAVi specification the DDI-target must provide not only one RootPanellD for building the main UI , but it should provide 3 PanelIDs, one for each the MainRoot- Panel, the reduced SinkPanel and the reduced SourcePanel . These three PanellDs can be specified independently. Howerver, it is also possible to specify directly only the PanellD for the MainRootPanel and to specify further that the two following PanellDs correspond to the reduced Sink- Panel and reduced SourcePanel, respectively. In addition, certain functions of the sink and source devices can be combined, e.g. the camcorder UI's 'play' button and the sink UI's 'record' button can be replaced by one 'copy to' button. This not only enhances the clarity of the displayed user interface but also simplifies the simultaneous operation of the devices. For this handling it is mandatory that a 'play' button of a general UI must have the attribute 'start source' and a 'record' button of a general UI must have the attribute 'start sink' . Further on, the attributes 'start source' and 'start sink' must not assigned to more the one DDI-element of the whole UI , each. Respectively, a "stop source" and "stop sink" for the "stop" button or a "pause source" and "pause sink" for the "pause" button can be used for a general UI . The invention can be used for the simultaneous operation of two or more bus connected electronic devices, especially of two or more HAVi devices connected via IEEE1394 bus.

Claims: Claims 1. Method for the data exchange between network devices, which are connected via a bus system (5) building a clus- ter or chain of devices (1, 3) , wherein a device can be selected using a control device (1) and wherein an user interface (6) for the selected device is generated based on description data which are stored in the selected device and are transferred to the control device and wherein the user interface is shown on a display of the control device, characterised in that at least two devices (1, 3) are simultaneously operated with a single user interface (6) , wherein the user interface of a first device is displayed as main user interface and the user interface of a second device is rendered within the main interface as reduced user interface (9) which includes only operation elements necessary for operation of the second device in combination with the first device. 2. Method according to claim 1, wherein after selecting the first device at least one list (8) of possible sink or source devices within the network is displayed within the main user interface and wherein after selecting a second device from the list as a sink or source device, the re- duced interface (9) of the second device is rendered within the main interface . 3. Method according to claim 2, wherein two separate lists are displayed, the first list comprising sink devices and the second list comprising source devices. 4. Method according to claim 2, wherein a combined list is displayed, the combined list comprising sink devices and source devices . 5. Method according to any of claims 1 to 4, wherein an operation element of the first device and an operation element of the second device are integrated into a single common operation element. 6. Method according to claim 5, wherein an operation element of the first device for playback of a data stream is combined with an operation element of the second device for recording of the data stream. 7. Method according to claim 6, wherein the stream between the first and second device is set up by selecting a sink or a source from the main user interface and the whole recording process is initiated by pressing one "copy to" button. 8. Method according to any of claims 1 to 7, wherein a selected device provides elements for the generation of three different user interfaces, which are a main user interface, a reduced sink user interface and a reduced source user interface. 9. Method according to claim 8, wherein identification data for the panels of the user interfaces are provided by the selected device in response to a subscribe command. 10. Method according to claim 9, wherein a first identification data for the main user interface, a second identification data for the reduced sink user interface and a third identification data for the reduced source user interface are provided. 11. Method according to claim 9, wherein only a first identification data for the main user interface is provided by the selected device and wherein the reduced sink user interface and the reduced source user interface are specified by two dependent values, e.g. the two following values, of the first identifica ion data.

Inventors: BRUNE THOMAS, HUETTER INGO, BRUNE, THOMAS, HUETTER, INGO
Applicants: BRUNE THOMAS, HUETTER INGO, THOMSON LICENSING SA, BRUNE, THOMAS, HUETTER, INGO, THOMSON LICENSING S.A.
Application year: 2001
Main classification: H04L12
IPC codes: G06F3, H04B1, H04L12, H04N5, H04N7