Apparatus and method for enhancing reliability of digital audio bus

Abstract

The invention relates to an apparatus and method for enhancing reliability of a digital audio bus. The invention discloses a digital audio bus reliability apparatus and method. In some embodiments, a digital audio system includes a plurality of audio devices connected by a first digital audio chain in a clockwise direction and a second digital audio chain in a counterclockwise direction. The first digital audio chain and the second digital audio chain run concurrently, and the controller selects which audio chain to operate at a given time to implement the audio connection. For example, a controller may initially select a first digital audio chain to provide an audio connection, but in response to detecting a node failure in the first digital audio chain, transition the selection from the first digital audio chain to a second digital audio chain. Thus, the system tolerates node failures while maintaining system connectivity.

Description

Technical Field

[0001] The disclosed technology relates generally to electronic devices and, more particularly, to digital audio buses. Background Art

[0002] The A to B bus (A2B) can be used to connect multiple audio devices together. For example, each audio device can be associated with an audio node, and A2B can connect the audio nodes in series to form a daisy chain. By using A2B in this manner, a significant reduction in wiring length can be achieved. Therefore, the overall design cost is reduced because fewer cables are required. In addition, the complexity of design, installation and / or maintenance can be reduced. Summary of the invention

[0003] Aspects of the present disclosure relate to a digital audio bus, such as an A to B bus (A2B), implemented with redundancy to improve network reliability. Providing such redundancy addresses the inherent limitations of the A2B daisy chain topology, such as susceptibility to single node failures.

[0004] In one aspect, a digital audio system includes: a plurality of audio nodes, each audio node being associated with a corresponding audio device, a first digital audio chain connecting the plurality of audio nodes; and a second digital audio chain connecting the plurality of audio nodes. The first digital audio chain and the second digital audio chain operate simultaneously, and at least one of the plurality of audio nodes includes a controller configured to select one of the first digital audio chain or the second digital audio chain for audio connection.

[0005] In another aspect, a method for providing digital audio connection includes: connecting a plurality of audio nodes using a first digital audio chain, the plurality of audio nodes each being associated with a respective audio device. The method also includes connecting the plurality of audio nodes using a second digital audio chain, operating the first digital audio chain and the second digital audio chain simultaneously, and selecting one of the first digital audio chain or the second digital audio chain for audio connection using a controller of at least one of the plurality of audio nodes.

[0006] In another aspect, a digital audio system includes a plurality of audio sub-nodes and a master audio node, wherein the master audio node includes a plurality of audio sub-node selectors respectively connected to corresponding ones of the plurality of audio sub-nodes. The master audio node also includes a master transceiver configured to communicate with the plurality of audio sub-nodes in the chain through the plurality of audio sub-node selectors.

[0007] In another aspect, a method for providing digital audio connectivity includes connecting a master audio node and a plurality of audio subnodes using a plurality of audio subnode selectors of a master audio node, each of the plurality of audio subnode selectors being connected to a corresponding one of the plurality of audio subnodes. The method also includes communicating with the plurality of audio subnodes in a chain using a master transceiver of the master node through the plurality of audio subnode selectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1A is a schematic diagram of a digital audio system including a digital audio bus according to one embodiment.

[0009] Figure 1B is a schematic diagram of a digital audio system including a digital audio bus according to another embodiment.

[0010] Figure 2 is a schematic diagram of a digital audio system including a digital audio bus according to another embodiment.

[0011] Figure 3A is a schematic diagram of a digital audio system including a digital audio bus according to another embodiment.

[0012] Figure 3B is a schematic diagram of a power sharing circuit for a digital audio bus according to one embodiment.

[0013] Figure 4A is a schematic diagram of one embodiment of an audio node.

[0014] Figure 4B yes Figure 4A One embodiment of a state diagram of a transceiver of an audio node.

[0015] Figure 5A is a schematic diagram of a digital audio system including a digital audio bus according to another embodiment.

[0016] Figure 5B yes Figure 5A Schematic diagram of the digital audio system after a node goes offline.

[0017] Figure 5C yes Figure 5A Schematic diagram of the digital audio system after it has been reconfigured to bypass dropped nodes. DETAILED DESCRIPTION

[0018] The following detailed description of the embodiments presents various descriptions of specific embodiments of the present invention. However, the present invention can be embodied in many different ways. In this specification, reference is made to the accompanying drawings. It should be understood that the elements shown in the accompanying drawings are not necessarily drawn to scale. In addition, it should be understood that some embodiments may include more elements and / or a subset of the elements shown in the drawings than shown in the drawings. In addition, some embodiments may combine any suitable combination of features from two or more drawings.

[0019] The A to B bus (A2B) can be used to connect multiple audio devices together in a daisy chain. However, the daisy chain topology of A2B is susceptible to reliability issues. For example, the loss of one audio node in the daisy chain (e.g., due to node failure and / or cable disconnection) may disrupt multiple audio nodes downstream. In addition, in these cases, the scope of partial recovery and / or automatic recovery is very limited.

[0020] This reliability issue makes daisy-chained A2B unsuitable for high-reliability audio applications, including but not limited to live performances, stage audio connections, building alarms and security, emergency announcements, and / or mission-critical conferencing. As A2B expands beyond automotive, plug-and-play with tolerance to single-node failures is needed, especially for professional audio systems.

[0021] Aspects of the present disclosure relate to a digital audio bus, such as an A to B bus (A2B), implemented with redundancy to improve network reliability. Providing such redundancy addresses the inherent limitations of the A2B daisy chain topology, such as susceptibility to single node failures.

[0022] In one aspect, a digital audio system includes a plurality of audio devices connected via a first digital audio chain in a clockwise direction and a second digital audio chain in a counterclockwise direction. The first digital audio chain and the second digital audio chain operate simultaneously, and a controller selects which audio chain to operate at a given time to achieve an audio connection. For example, the controller may initially select the first digital audio chain to provide an audio connection, but in response to detecting a node failure in the first digital audio chain, switch the selection from the first digital audio chain to the second digital audio chain. Thus, the system tolerates node failures while maintaining system connections.

[0023] This configuration includes two half rings (a clockwise half ring and a counterclockwise half ring) that can communicate over a common cable to reduce cable and connector costs. In one example, a first digital audio chain communicates over a first twisted pair of a cable (e.g., a Cat5 cable) and a second digital audio chain communicates over a second twisted pair of the cable.

[0024] In another aspect, a pseudo hub is used to implement a digital audio system. This configuration can utilize a star topology while maintaining the physical requirements of a daisy chain. The number of connectors can be reduced by merging the A and B ports. In addition, the master node can intelligently decide to exclude or include audio subnodes in the network using the corresponding audio subnode selectors.

[0025] Embodiments of the present disclosure may be implemented in a variety of electronic devices and applications, such as those related to professional audio, musical instrument connectivity, and next generation automobiles. Examples of electronic devices may include, but are not limited to, consumer electronics, audio devices, automotive devices, and the like.

[0026] Figure 1A 2 is a schematic diagram of a digital audio system 20 including a digital audio bus according to an embodiment. The digital audio system 20 includes a main audio node 1, a first audio sub-node 11, a second audio sub-node 12, a third audio sub-node 13 and a fourth audio sub-node 14.

[0027] In the illustrated embodiment, each of the master audio node 1 and the audio sub-nodes 11-14 is associated with an audio device, such as a musical instrument, a speaker, a microphone, an audio amplifier, an audio mixer, or other devices that comply with a digital audio standard (e.g., comply with the A2B standard). Although an example with four audio sub-nodes is shown, the master audio node 1 can be connected to more or fewer audio sub-nodes (e.g., x sub-nodes, where x is a positive integer).

[0028] In order to provide audio connections between nodes (and thus between corresponding audio devices), a first daisy chain and a second daisy chain have been included to connect each node. For example, a first or primary daisy chain 17a-17d includes a first portion or chain 17a between a primary audio node 1 and a first audio subnode 11, a second chain 17b between the first audio subnode 11 and a second audio subnode 12, a third chain 17c between the second audio subnode 12 and a third audio subnode 13, and a fourth chain 17d between the third audio subnode 13 and a fourth audio subnode 14. In addition, a second or secondary daisy chain 18a-18d includes a first chain 18a between the primary audio node 1 and the first audio subnode 11, a second chain 18b between the first audio subnode 11 and the second audio subnode 12, a third chain 18c between the second audio subnode 12 and the third audio subnode 13, and a fourth chain 18d between the third audio subnode 13 and the fourth audio subnode 14.

[0029] For A2B implementations, each daisy-chain section can be implemented as a twisted pair cable, acting as a bidirectional data bus, supporting multi-channel audio with low jitter and low latency.

[0030] Each audio node may include a controller, such as a microcontroller unit (MCU) and / or a digital signal processor (DSP), that monitors signaling conditions on the primary daisy chain 17a-17d and the secondary daisy chain 18a-18d. In addition, when a fault in the primary daisy chain 17a-17d is detected, the controller may switch from transmitting audio data through the primary daisy chain 17a-17d to transmitting audio data through the secondary daisy chain 18a-18d. In addition, the controller may switch the selection of the daisy chain while also ensuring a smooth transition of the audio clock.

[0031] In the illustrated embodiment, the primary daisy chain 17a-17d and the secondary daisy chain 18a-18d can each have the same configuration, so when switching from one daisy chain to another, no rediscovery (e.g., audio nodes) is required. In addition, each node can draw power from either the primary daisy chain 17a-17d or the secondary daisy chain 18a-18d. Therefore, if one network loses power, the load can be switched to being powered by the second network.

[0032] Figure 1A The digital audio system 20 is fault tolerant to faulty cables or cable disconnections, but it is not fault tolerant when the entire audio device associated with a node loses power from the network (eg, due to a complete device failure).

[0033] In some implementations, each link of each daisy chain is associated with a separate cable (e.g., a cable including twisted pairs) that plugs into a corresponding connector of the audio node at each end. In such an implementation, the depicted digital audio system 20 may include 4 cables for each daisy chain, 2 connectors for the master audio node 1, and 4 connectors for each audio sub-node. In addition, each node may include two transceivers, one for communicating through each daisy chain.

[0034] However, other implementations are possible, such as a configuration that provides two daisy-chain connections between adjacent audio nodes over a single cable.For example, certain cables, such as Cat5 cables, carry multiple twisted pairs.

[0035] Figure 1B 2 is a schematic diagram of a digital audio system 30 including a digital audio bus according to another embodiment. The digital audio system 30 includes a main audio node 21, a first audio sub-node 31, a second audio sub-node 32, a third audio sub-node 33 and a fourth audio sub-node 34.

[0036] In order to provide audio connections between nodes, a first daisy chain and a second daisy chain for connecting audio nodes have been included. For example, the main daisy chain 37a-37d includes a first chain 37a between the main audio node 21 and the first audio sub-node 31, a second chain 37b between the first audio sub-node 31 and the second audio sub-node 32, a third chain 37c between the second audio sub-node 32 and the third audio sub-node 33, and a fourth chain 37d between the third audio sub-node 33 and the fourth audio sub-node 34. In addition, the secondary daisy chain 38a-38b includes a first chain 38a between the second audio sub-node 32 and the third audio sub-node 33, and a second chain 38b between the third audio sub-node 33 and the fourth audio sub-node 34.

[0037] Apart from Figure 1B In addition to the digital audio system 30 adopting a branch from one daisy chain to two daisy chains at the second audio sub-node 32, Figure 1B The digital audio system 30 is similar to Figure 1A The digital sound system 20. This configuration may be suitable for applications where it can be assumed that the main audio node and one or more audio sub-nodes are robust and therefore will not be affected by the node being offline or disconnected.

[0038] In the example shown, the primary daisy chain includes four chains, and the secondary daisy chain includes two chains. However, the primary daisy chain and / or the secondary chain can be associated with more or fewer chains (e.g., the primary daisy chain has n child nodes, and the secondary daisy chain has m child nodes, where m and n are positive integers, n>m).

[0039] Figure 2 is a schematic diagram of a digital audio system 50 including a digital audio bus according to another embodiment. The digital audio bus 50 includes a main audio node 41, which includes a controller (corresponding to MCU 42 in this example), a memory 43 storing address extensions, and a connector 44. The digital audio bus 50 includes a first audio sub-node 45a / 45b / 45c / 45d, a second audio sub-node 46a / 46b / 46c, and various daisy chains for connecting the audio sub-nodes.

[0040] For example, the first daisy chain 51a-51b includes a first chain 51a between the main audio node 41 and the first audio subnode 45a and a second chain 51b between the first audio subnode 45a and the second audio subnode 46a. In addition, the second daisy chain 52a-52b includes a first chain 52a between the main audio node 41 and the first audio subnode 45b and a second chain 52b between the first audio subnode 45b and the second audio subnode 46b. In addition, the third daisy chain 53a-53b includes a first chain 53a between the main audio node 41 and the first audio subnode 45c and a second chain 53b between the first audio subnode 45c and the second audio subnode 46c. In addition, the chain 54a connects the main audio node 41 and the audio subnode 45d.

[0041] Thus, various daisy chains extend from the master audio node 41 in a star configuration. The daisy chains may be of any length. Thus, certain daisy chains are depicted as including two audio sub-nodes, but more or fewer audio sub-nodes may be included in each chain.

[0042] The depicted configuration can be relatively robust while providing fault tolerance for the master node 41. In addition, each audio sub-node can operate using two or fewer connectors, thereby achieving simplicity. In addition, the audio sub-nodes can operate in situations where soft switching is required.

[0043] However, the downstream audio sub-nodes in each daisy chain may still fail, and the master node 41 is bulky due to high wiring costs and / or a large number of connectors. Therefore, the master node 41 may be suitable for some audio equipment, such as professional audio mixers, but may not be suitable for smaller peripheral devices.

[0044] Figure 3A 1 is a schematic diagram of a digital audio system 150 including a digital audio bus according to another embodiment. The digital audio system 150 includes a main audio node 101, a first audio sub-node 111, a second audio sub-node 112, and a third audio sub-node 113. The main audio node 101 includes an MCU 141, the first audio sub-node 111 includes an MCU 142, the second audio sub-node 112 includes an MCU 143, and the third audio sub-node 113 includes an MCU 144.

[0045] In the illustrated embodiment, each of the main audio node 101 and the audio sub-nodes 111-113 is associated with an audio device, such as a musical instrument, a speaker, a microphone, an audio amplifier, an audio mixer, or other devices that conform to a digital audio standard (e.g., conform to A2B in some embodiments). Although an example with three audio sub-nodes is shown, more or fewer audio sub-nodes may be included.

[0046] In addition, although certain components of an audio node are depicted, an audio node may include other components. For example, an audio node may include any combination of the components described herein. Figure 3A These features are omitted.

[0047] In order to provide audio connections between nodes (and thus between corresponding audio devices), a first digital audio chain (daisy chain) and a second digital audio chain have been included to connect each node. For example, the first digital audio chain 121a-121c includes a first portion or chain 121a between the main audio node 101 and the first audio sub-node 111, a second chain 121b between the first audio sub-node 111 and the second audio sub-node 112, and a third chain 121c between the second audio sub-node 112 and the third audio sub-node 113. In addition, the second digital audio chain 122a-122c includes a first chain 122a between the main audio node 101 and the third audio sub-node 113, a second chain 122b between the third audio sub-node 113 and the second audio sub-node 112, and a third chain 122c between the second audio sub-node 112 and the first audio sub-node 111.

[0048] In some implementations, each portion of the digital audio chain between a pair of nodes is implemented over a common cable. For example, chain 121c of the first digital audio chain and chain 122b of the second digital audio chain can be carried on a common cable 125, which includes a first twisted pair 127 for chain 121c and a second twisted pair 128 for chain 122b. An example of a suitable cable having multiple twisted pairs is a Cat5 cable.

[0049] Each audio node may include a controller (e.g., an MCU in this example) that monitors signaling conditions on the first digital audio chain 121a-121c and the second digital audio chain 122a-122c. In addition, when a fault in the first daisy chain 121a-121c is detected, the controller may switch from transmitting audio data through the first digital audio chain 121a-1221c to transmitting audio data through the second digital audio chain 122a-122c.

[0050] In the illustrated embodiment, the first digital audio chain 121a-121c connects the audio nodes in a clockwise direction, while the second digital audio chain 122a-122c connects the video nodes in a counterclockwise direction. The first digital audio chain 121a-121c and the second digital audio chain 122a-122c run simultaneously, and the controller of each node (MCU in this example) selects which audio chain to operate at a given time to achieve the audio connection.

[0051] For example, the controller may initially select the first digital audio chain 121a-121c to provide the audio connection, but in response to detecting a node failure in the first digital audio chain 121a-121c, switch the selection from the first digital audio chain 121a-121c to the second digital audio chain 122a-122c. Thus, the system tolerates node failures while maintaining system connectivity.

[0052] In some implementations, each of the depicted nodes is part of two networks (e.g., two A2B networks), one associated with the first digital audio chain 121a-121c and the other associated with the second digital audio chain 122a-122c. In addition, each node can access audio data from both directions. In addition, the audio nodes of the first digital audio chain 121a-121c are found in a clockwise direction, while the audio nodes of the second digital audio chain 122a-122c are found in a counterclockwise direction (thus in the opposite direction of the first digital audio chain 121a-121c).

[0053] This configuration includes two half rings (a clockwise half ring and a counterclockwise half ring) that can communicate through a common cable (e.g., common cable 125) between adjacent nodes to reduce cable and connector costs.

[0054] In some implementations, the digital audio system 150 is an A2B system.In addition, the master audio node 101 includes separate B ports for the first digital audio chain 121a-121c and the second digital audio chain 122a-122c, and can maintain a common stream configuration for each chain.

[0055] Figure 3B 2 is a schematic diagram of a power sharing circuit 210 for a digital audio bus according to an embodiment. The power sharing circuit 210 includes a first rectifier 201, a second rectifier 202 and a capacitor 203.

[0056] Figure 3B The power sharing circuit 210 depicts an example of a circuit that can be used as part of an audio sub-node to receive power from two different digital audio links. In addition, when one of the digital audio links is powered off, the operation of the audio sub-node can continue without interruption.

[0057] For example, the first rectifier 201 includes an anode connected to a first power supply (Power 1) from a first digital audio chain and a cathode connected to a capacitor 203. In addition, the second rectifier 202 includes an anode connected to a second power supply (Power 2) from a second digital audio chain and a cathode connected to the capacitor 203. The capacitor 203 serves as a charge storage node for a shared power supply that can be used to power one or more components of the audio sub-node.

[0058] When the first power source (power source 1) or the second power source (power source 2) is active, the shared power source can be used to power the components of the audio sub-node. Therefore, a power sharing circuit is included in one or more audio sub-nodes of the audio network, such as Figure 3B The power sharing circuit 210 can improve the reliability of the network.

[0059] Figure 4A 3 is a schematic diagram of an embodiment of an audio node 260. The audio node 260 includes a first transceiver 251 (TRX1) for communicating through a first digital audio chain (daisy chain), a second transceiver 252 (TRX2) for communicating through a second digital audio chain, and a controller 250 (MCU in this example) for selectively enabling communication through the first digital audio chain or the second digital audio chain. The audio node 260 can be implemented in the digital audio system of the present invention, for example, in one or more audio nodes of FIG. 3. Figure 4B yes Figure 4A One embodiment of a state diagram 270 of a transceiver of an audio node 260.

[0060] refer to Figure 4A and 4B , a transceiver (e.g., TRX1 or TRX2) may be operated in a node ready state 261 when an associated digital audio chain is operational. For example, an operational digital audio chain may be associated with active power, a locked phase locked loop (PLL) of an audio clock, and / or other characteristics associated with a running and otherwise operating digital video chain.

[0061] However, when the PLL is unlocked, the transceiver may transition to the Hold state 262 when the Hold signal is valid, or to the Reset state 264 when the Hold signal is invalid. Under certain logic conditions of the Reset signal (RST) and the Power-on Reset signal (Porst), the transceiver may transition from the Hold state 262 to the Power-on Reset state 263 (when the hold is complete) or to the Reset state 264. When the PLL regains lock, the transceiver may transition from the Power-on Reset state 263 back to the Node Ready state 261. Various other state transitions to and from the Reset state 264 and the Power-on Reset state 263 are depicted based on various logic conditions of RST and Porst.

[0062] like Figure 4A As shown, the controller 250 detects the sustain state of TRX1 (sustain 1) and the sustain state of TRX2. Therefore, the controller 250 can be ready to switch to a transceiver with a stable clock as needed.

[0063] By implementing the audio nodes in this manner, a smooth transition from one digital audio chain to another digital video chain is provided.

[0064] Figure 5A is a schematic diagram of a digital audio system 520 including a digital audio bus according to another embodiment.

[0065] The digital audio system 520 includes a main audio node 500, a first audio sub-node 501, a second audio sub-node 502, and a third audio sub-node 503. Although an example with three audio sub-nodes is shown, the digital audio system 520 may include more or fewer audio sub-nodes as required by a given application.

[0066] The master audio node 500, the first audio sub-node 501, the second audio sub-node 502, and the third audio sub-node 503 are connected to utilize a star topology while maintaining the physical requirements of an A2B daisy chain. In addition, the master audio node 500 intelligently decides to include or exclude specific sub-nodes in the network. The digital audio system 520 is also referred to herein as a pseudo hub 520.

[0067] In the illustrated embodiment, the number of connectors is reduced by merging the A port and the B port of the A2B. Thus, in this embodiment, both the A port and the B port are merged into a single connector, and the same cable carries both upstream and downstream data.

[0068] like Figure 5A As shown, the master audio node 500 includes various components, including a controller 510 (corresponding to an MCU in this example), a master transceiver 511, a soft switch 512, a first demultiplexer / repeater (DEMUX / repeater) 513, a second DEMUX / repeater 514, and a third DEMUX / repeater 515.

[0069] Continue to refer Figure 5A , the first demultiplexer / repeater 513 communicates with the first audio sub-node 501 through the A port or the B port (A+B port). In addition, the first demultiplexer / repeater 513 communicates with the second demultiplexer / repeater 514. In addition, the second demultiplexer / repeater 514 communicates with the second audio sub-node 502 through the A+B port. In addition, the third demultiplexer / repeater 515 communicates with the third audio sub-node 503 through the A+B port. The demultiplexers / repeaters 513-515 serve as audio node selectors.

[0070] The master audio node 500 and the audio sub-nodes 501-503 can communicate with each other using the depicted components. For example, the master transceiver 521 of the master audio node 500 is shown as transmitting audio data to the first demultiplexer / repeater 513 via the B port, which can provide the audio data to the first audio sub-node 501. In addition, the first audio sub-node 501 can communicate with the second audio sub-node 502 via the first demultiplexer / repeater 513 and the second demultiplexer / repeater 514. In addition, the second audio sub-node 502 can communicate with the third audio sub-node 503 via the second demultiplexer / repeater 514 and the third demultiplexer / repeater 515.

[0071] Therefore, the physical requirements of the A2B daisy chain can be met. However, as will be referred to below Figure 5B and 5C As further discussed, the master audio node 500 intelligently decides to include or exclude specific child nodes in the network, thereby utilizing a star topology.

[0072] One or more of the illustrated components of the master audio node 500 may be implemented and / or controlled by a controller 503. For example, the controller 503 may include data processing hardware and memory hardware storing instructions (also referred to as computer programs, software, software applications, or code) that, when executed by the data processing hardware, cause the data processing hardware to perform various operations to implement the desired functionality. In some implementations, the audio subnode selector is implemented by the controller 503.

[0073] Figure 5B After the node goes offline Figure 5A Schematic diagram of a digital audio system 520. In this example, the second audio sub-node 502 has been offline. Without reconfiguration, the first demultiplexer / repeater 513 can no longer transmit audio data to the first sub-node 502 through the second demultiplexer / repeater 515 and the A port of the second audio sub-node 502. In addition, the second audio sub-node 502 can no longer transmit data from the B port to the third demultiplexer / repeater 515 through the second demultiplexer / repeater 514.

[0074] Without reconfiguration, the removal of the second audio sub-node 502 from the network will break the daisy chain and prevent the communication of audio data that would otherwise run through the second audio sub-node 502.

[0075] Figure 5C yes Figure 5A Schematic diagram of digital audio system 520 after being reconfigured to bypass a dropped node.

[0076] The MCU 510 of the master audio node 500 has reconfigured the second demultiplexer / repeater 514 to route data directly between the first demultiplexer / repeater 513 and the third demultiplexer / repeater 515. Therefore, even though the second audio sub-node 502 remains physically connected to the master audio node 500 via a cable, the second audio sub-node 502 has effectively been dropped from the network and the daisy chain.

[0077] Therefore, once the master audio node 500 detects that a node is offline, a bypass mode is activated to close the connection and bypass the offline node. During this bypass period, the remaining audio sub-nodes can be rediscovered and the audio can be rerouted. In addition, in some implementations, the internal connections can be rearranged so that the offline node becomes the downstream of the last active audio sub-node.

[0078] Figures 5A-5C The digital audio system 520 is fault tolerant to situations where a cable fails or is disconnected, as well as situations where an audio device is removed from the network or fails.

[0079] in conclusion

[0080] The above description may refer to elements or features as being "connected" or "coupled" together. As used herein, unless otherwise expressly stated, "connected" means that one element / feature is directly or indirectly connected to another element or feature, and is not necessarily mechanically connected. Similarly, unless otherwise expressly stated, "coupled" means that one element / feature is directly or indirectly coupled to another element or feature, and is not necessarily mechanically coupled. Therefore, although the various schematic diagrams shown in the figures depict example arrangements of elements and components, in actual embodiments there may be additional intervening elements, devices, features, or components (assuming that the functionality of the depicted circuits is not adversely affected).

[0081] Although certain embodiments have been described, these embodiments are presented only as examples and are not intended to limit the scope of the present disclosure. In fact, the novel devices, methods, and systems described herein may be embodied in various other forms; in addition, various omissions, substitutions, and changes may be made to the forms of the methods and systems described herein without departing from the spirit of the present disclosure. For example, although the disclosed embodiments are presented in a given arrangement, alternative embodiments may perform similar functions using different components and / or circuit topologies, and may delete, move, add, subdivide, combine, and / or modify some elements. Each of these elements may be implemented in a variety of different ways. Any suitable combination of the elements and actions of the various embodiments described above may be combined to provide further embodiments. Therefore, the scope of the present invention is limited only by reference to the appended claims.

[0082] Although the claims set forth herein are filed with the USPTO in a single-dependency format, it should be understood that any claim may depend on any prior claim of the same type unless this is clearly technically infeasible.

Claims

1. A digital audio system, comprising: A plurality of audio nodes, each audio node being associated with a corresponding audio device; a first digital audio chain connecting the plurality of audio nodes; and a second digital audio chain connecting the plurality of audio nodes, the first digital audio chain and the second digital audio chain running simultaneously, Wherein at least one of the plurality of audio nodes comprises a controller configured to select one of the first digital audio chain or the second digital audio chain for an audio connection.

2. The digital audio system of claim 1, wherein the first digital audio chain and the second digital audio chain are both A2B daisy chains.

3. The digital audio system of claim 1, wherein the first digital audio chain runs in a clockwise direction and the second digital audio chain runs in a counterclockwise direction.

4. The digital audio system of claim 3, wherein the first digital audio chain is found in a clockwise direction and the second digital audio chain is found in a counter-clockwise direction.

5. The digital audio system of claim 1 , wherein the plurality of audio nodes comprises a main audio node and two or more audio sub-nodes, wherein the first digital audio chain extends from the main node through the two or more sub-nodes, and wherein the second digital audio chain extends from the main node through the two or more sub-nodes.

6. The digital audio system of claim 5, wherein each of the two or more audio sub-nodes comprises a corresponding controller for selecting one of the first digital audio chain or the second digital audio chain for audio connection.

7. The digital audio system of claim 1 , wherein the controller initially selects the first digital audio chain to provide an audio connection and switches from the first digital audio chain to the second digital audio chain in response to detecting a node failure in the first digital audio chain.

8. The digital audio system of claim 1 , wherein at least one of the plurality of audio nodes receives power from a combined power supply, the combined power supply being combined from a first power supply of the first digital audio chain and a second power supply of the second digital audio chain.

9. The digital audio system of claim 8, further comprising a first rectifier located between the first power supply of the first digital audio chain and the combined power supply, and a second rectifier located between the second power supply of the second digital audio chain and the combined power supply.

10. The digital audio system of claim 1, wherein the first digital audio chain and the second digital audio chain are carried over a common cable.

11. The digital audio system of claim 10, wherein the common cable comprises a first twisted pair of wires for the first digital audio chain and a second twisted pair of wires for the second digital audio chain.

12. A method for providing a digital audio connection, the method comprising: Connecting a plurality of audio nodes using a first digital audio chain, the plurality of audio nodes being each associated with a corresponding audio device; connecting the plurality of audio nodes using a second digital audio chain; Running the first digital audio chain and the second digital audio chain simultaneously; and A controller of at least one of the plurality of audio nodes is used to select one of the first digital audio chain or the second digital audio chain for an audio connection.

13. The method of claim 12, wherein the first digital audio chain and the second digital audio chain are both A2B daisy chains.

14. The method of claim 12, wherein the first digital audio chain runs in a clockwise direction and the second digital audio chain runs in a counterclockwise direction.

15. The method of claim 14, wherein the first digital audio chain is found in a clockwise direction and the second digital audio chain is found in a counter-clockwise direction.

16. The method of claim 12, wherein the plurality of audio nodes comprises a main audio node and two or more audio sub-nodes, wherein the first digital audio chain extends from the main node through the two or more sub-nodes, and wherein the second digital audio chain extends from the main node through the two or more sub-nodes.

17. The method of claim 16, further comprising selecting one of the first digital audio chain or the second digital audio chain for an audio connection using a corresponding controller of each of the two or more audio sub-nodes.

18. The method of claim 12, further comprising using the controller to initially select the first digital audio chain to provide an audio connection and then switching from the first digital audio chain to the second digital audio chain in response to detecting a node failure in the first digital audio chain.

19. The method of claim 12, further comprising powering at least one of the plurality of audio nodes using a combined power supply, the combined power supply being combined from a first power supply of the first digital audio chain and a second power supply of the second digital audio chain.

20. The method of claim 19, further comprising a first rectifier between the first power supply of the first digital audio chain and the combined power supply, and a second rectifier between the second digital audio chain and the combined power supply.

21. A digital audio system comprising: Multiple audio subnodes; and A main audio node, comprising a plurality of audio sub-node selectors, each selector being connected to a corresponding one of the plurality of audio sub-nodes; as well as The master transceiver is configured to communicate with a plurality of sub-nodes in the chain through the plurality of sub-node selectors.

22. The digital audio system of claim 21, wherein the master audio node is configured to bypass an audio sub-node of the plurality of audio sub-nodes in response to detecting a disconnection of the audio sub-node.

23. The digital audio system of claim 22, wherein the master audio node is configured to bypass the audio subnode using a corresponding audio subnode selector of the plurality of audio subnode selectors.

24. The digital audio system of claim 21, wherein the chain is an A2B daisy chain.

25. The digital audio system of claim 21, wherein the master audio node and each of the audio sub-nodes are associated with a corresponding audio device.

26. A digital audio system according to claim 21, wherein the multiple audio sub-nodes include a first audio sub-node and a second audio sub-node, and the multiple sub-node selectors include a first audio sub-node selector and a second audio sub-node selector, wherein the main transceiver is configured to transmit audio data to the first audio sub-node through the first audio sub-node selector, and wherein the first audio sub-node transmits the audio data to the second audio sub-node through the first audio sub-node selector and the second audio sub-node selector.

27. The digital audio system of claim 21, wherein the plurality of audio subnodes further include a third audio subnode, and the plurality of audio subnode selectors further include a third audio subnode selector, wherein the second audio subnode transmits the audio data to the third audio subnode via the second audio subnode selector and the third audio subnode selector.

28. The digital audio system of claim 27, wherein in response to the second audio sub-node being disconnected, the master audio node reconfigures the second audio sub-node selector.

29. A digital audio system according to claim 28, wherein the main audio node reconfigures the second audio subnode selector to bypass the second audio subnode, so that the first audio subnode transmits the audio data to the third audio subnode through the first audio subnode selector, the second audio subnode selector and the third audio subnode selector.

30. The digital audio system of claim 21, wherein the plurality of audio sub-node selectors are implemented by a controller of the master audio node.

31. A method of providing a digital audio connection, the method comprising: connecting the main audio node and the plurality of audio subnodes using a plurality of audio subnode selectors of the main audio node, each of the plurality of audio subnode selectors being connected to a corresponding one of the plurality of audio subnodes; as well as A master transceiver of the master node is used to communicate with the plurality of audio sub-nodes in the chain through the plurality of audio sub-node selectors.

32. The method of claim 31 further comprising, in response to detecting a disconnection of the audio sub-node, using the master audio node to bypass an audio sub-node of the plurality of audio sub-nodes.

33. The method of claim 32, further comprising bypassing the audio subnode using a corresponding audio subnode selector from the plurality of audio subnode selectors.

34. The method of claim 31 , wherein the chain is an A2B daisy chain.

35. The method of claim 31, wherein each of the master audio node and the audio sub-nodes is associated with a corresponding audio device.

36. The method of claim 31, wherein the plurality of audio subnodes include a first audio subnode and a second audio subnode, and the plurality of audio subnode selectors include a first audio subnode selector and a second audio subnode selector, the method further comprising transmitting audio data from the main transceiver to the first audio subnode through the first audio subnode selector, and transmitting the audio data from the first audio subnode to the second audio subnode through the first audio subnode selector and the second audio subnode selector.

37. The method according to claim 31, wherein the plurality of audio subnodes further include a third audio subnode, and the plurality of audio subnode selectors further include a third audio subnode selector, the method further comprising transmitting the audio data from the second audio subnode to the third audio subnode via the second audio subnode selector and the third audio subnode selector.

38. The method of claim 37, wherein in response to the second audio sub-node being disconnected, the master audio node reconfigures the second audio sub-node selector.

39. The method of claim 38, wherein the main audio node reconfigures the second audio subnode selector to bypass the second audio subnode, so that the first audio subnode transmits the audio data to the third audio subnode through the first audio subnode selector, the second audio subnode selector and the third audio subnode selector.

40. The method of claim 31, wherein the plurality of audio sub-node selectors are implemented by a controller of the master audio node.

Images