Redundant contactless communication

Methods, systems, and apparatus for EM communications. One of the apparatus includes a first device comprising: a first contactless connector and a second contactless connector, and a first controller configured to test the first contactless connector and the second contactless connector to determine a primary connector and a redundant connector, wherein the primary connector is configured to establish a communication link with a connector of another device.

BACKGROUND

This specification relates to electromagnetic communications.

Advances in semiconductor manufacturing and circuit design technologies have enabled the development and production of integrated circuits (ICs) with increasingly higher operational frequencies. In turn, electronic products and systems incorporating high frequency integrated circuits are able to provide greater functionality than previous generations of products. The additional functionality has typically included the processing of increasingly larger amounts of data at increasingly higher speeds.

Contactless connectors can be used to transfer data between devices. In contrast to conventional cabled connectors, contactless connectors can be used to provide point-to-point data communication between two devices without requiring a mechanical coupling to enable data transfer.

SUMMARY

In general, one innovative aspect of the subject matter described in this specification can be embodied in systems that include a first device comprising: a first contactless connector and a second contactless connector, and a first controller configured to test the first contactless connector and the second contactless connector to determine a primary connector and a redundant connector; and a second device comprising: a third contactless connector and a fourth contactless connector, and a second controller configured to test the third contactless connector and the fourth contactless connector to determine a primary connector and a redundant connector, wherein each of the first contactless connector and the second contactless connector is configured to selectably establish a communication link with either the third contactless connector or the fourth contactless connector. Other aspects of this embodiment include corresponding methods and apparatus.

The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. In particular, one embodiment includes all the following features in combination. The first and second contactless connectors of the first device each include a transceiver having an antenna oriented such that the first and second contactless connector are communicatively coupled to each other.

The third and fourth contactless connectors of the second device each include a transceiver having an antenna oriented such that the third and fourth contactless connector are communicatively coupled to each other. The first device is positioned in proximity to the second device such that the first contactless connector is aligned with the third contactless connector, a communication link is selectively formed between any one of the first and second contactless connector and any one of the third and fourth contactless connector. The first device further comprises one or more additional contactless connectors configured as a redundant connectors. The second device further comprises one or more additional contactless connectors configured as a redundant connectors. The first controller includes a state machine configured to test the operation of the first contactless connector and the second contactless connector, wherein a primary connector and a redundant connector is established based on the testing.

In general, one innovative aspect of the subject matter described in this specification can be embodied in methods that include the actions of performing a loopback test on a first contactless connector and a second contactless connector of a first device, wherein performing the loopback test comprises: configuring the first contactless connector as a transmitter and the second contactless connector as a receiver, sending a signal pattern from the first contactless connector to the second contactless connector, determining whether the received pattern matches the sent signal pattern, in response to determining that the received pattern matches, configuring the first contactless connector as a receiver and the second contactless connector as a transmitter, sending a signal pattern from the second contactless connector to the first contactless connector, determining whether the received pattern matches the sent signal pattern, in response to determining that the received pattern matches, setting the first contactless connector as a primary connector and the second contactless connector as a redundant connector; and establishing a communication link between the first device and a second device using the primary connector. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods. For a system of one or more computers to be configured to perform particular operations or actions means that the system has installed on it software, firmware, hardware, or a combination of them that in operation cause the system to perform the operations or actions. For one or more computer programs to be configured to perform particular operations or actions means that the one or more programs include instructions that, when executed by data processing apparatus, cause the apparatus to perform the operations or actions.

The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. In particular, one embodiment includes all the following features in combination. Establishing the communication link between the first device and the second device includes configuring half-duplex communication. The half duplex communication includes switching the transceiver of the primary connector between transmitter and receiver modes. In response to determining that the received pattern does not match, determining a loopback error response. The loopback error response establishes a primary connector for communication with the second device by alternating transmission by the first contactless connector and the second contactless connector and establishing the primary connector based on confirmation messages received from the second device. The method further includes determining an error condition in the first contactless connector; and responsive to the error, activating the second contactless connector and using the second contactless connector to provide the communication link between the first device and the second device.

In general, one innovative aspect of the subject matter described in this specification can be embodied in systems that include a first device comprising: a first pair of connectors including a first contactless connector and a second contactless connector, a second pair of connectors including a third contactless connector and a fourth contactless connector, and a first controller configured to test the first pair of contactless connectors and the second pair of contactless connectors to determine a respective primary connector an redundant connector for each pair; and a second device comprising: a third pair of connectors including a fifth contactless connector and a sixth contactless connector, a fourth pair of connectors including a seventh contactless connector and an eighth contactless connector, and a first controller configured to test the first pair of contactless connectors and the second pair of contactless connectors to determine a respective primary connector an redundant connector for each pair wherein each of the first pair of connectors is configured to selectably establish a communication link with a respective connector of the third pair of connectors and each of the second pair of connectors is configured to selectably establish a communication link with a respective connector of the fourth pair of connectors.

In general, one innovative aspect of the subject matter described in this specification can be embodied in methods that include the actions of performing a loopback test on a first pair of contactless connectors and a second pair of contactless connectors, wherein performing the loopback test for each pair of contactless connectors comprises: configuring a first contactless connector of the pair as a transmitter and a second contactless connector of the pair as a receiver, sending a signal pattern from the first contactless connector to the second contactless connector, determining whether the received pattern matches the sent signal pattern, in response to determining that the received pattern matches, configuring the first contactless connector as a receiver and the second contactless connector as a transmitter, sending a signal pattern from the second contactless connector to the first contactless connector, determining whether the received pattern matches the sent signal pattern, in response to determining that the received pattern matches, setting the first contactless connector as a primary connector for the pair and the second contactless connector as a redundant connector for the pair; and establishing respective communication links between the first device and a second device for each pair of contactless connectors using the primary connector for each pair. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

In general, one innovative aspect of the subject matter described in this specification can be embodied in systems that include a first device comprising: a first contactless connector and a second contactless connector, and a first controller configured to test the first contactless connector and the second contactless connector to determine a primary connector and a redundant connector, wherein the primary connector is configured to establish a communication link with a connector of another device.

The subject matter described in this specification can be implemented in particular embodiments so as to realize one or more of the following advantages. Contactless connectors can be used to provide data communication between two devices positioned within a specified proximity to each other. Since no mechanical connection is required, redundant data paths can be established by positioning multiple transceivers in one or more electromagnetic (EM) field regions, e.g., an EM field bubble. The best transmitter and receiver pairs can be selected for data communication dynamically from among the redundant transceivers. Additionally, the other transceivers can be maintained in standby mode capable of taking over communication if needed. The contactless connector redundancy can be used to provide high reliability when operating in harsh environments. Furthermore, the contactless connectors can be sealed making them suitable for exposure to harsh environments without impacting performance.

DETAILED DESCRIPTION

Overview

This specification describes contactless connectors that allow for redundant data communication EM paths between devices. The ability to provide redundant contactless communication can be important in many different settings. For example, the connectors can be located in difficult to access, environmentally harsh, or time-consuming locations where redundancy reduces the costs associated with a failed connection. In some implementations, the connectors can be used to couple an underwater device, e.g., a remotely operated vehicle, to a surface device, (e.g., through a data cable). Mechanical underwater connectors can lead to galvanic corrosion or can require elaborate sealed connector designs to prevent water exposer to the electrical connection pins. By contrast, a contactless connector can be sealed and establish a communication link by placing contactless connection areas in close proximity, they can be used to establish dynamic connections underwater.

The contactless connector can include one or more communication modules having one or more integrated circuit packages. Each integrated circuit package can have a transceiver. The contactless connector for each device can include two or more transceivers, which allow for redundant communication. This specification describes structures and processes for providing redundant data communication between devices having contactless connectors.

Contactless Communication Modules

Contactless communication may be used to provide signal communications between components on a device or may provide communication between devices. In one example, tightly-coupled transmitter/receiver pairs may be deployed with a transmitter disposed at a terminal portion of a first conduction path and a receiver disposed at a terminal portion of a second conduction path. The transmitter and receiver may be transceivers operating in respective transmitter and receiver modes. The transmitter and receiver may be disposed in close proximity to each other depending on the strength of the transmitted energy, and the first conduction path and the second conduction path may not be contiguous with respect to each other. In some examples, the transmitter and receiver may be disposed on separate circuit carriers positioned with transducers (e.g., one or more antennas) of the transmitter/receiver pair in close proximity.

A transmitter, receiver, or transceiver may be configured as an integrated circuit (IC) package, in which one or more transducers may be positioned adjacent to a die and held in place by a dielectric or insulating encapsulation or bond material. A transducer may also be held in place by a lead frame substrate. Note that IC packages are examples of contactless communication units that are also variously referred to as communication units, communication devices, comm-link chips, comm-link chip assemblies, comm-link chip packages, and/or comm-link packages, which may be configured in various ways. For example, IC packages, communication units, communication devices, comm-link chips, comm-link chip assemblies, comm-link chip packages, and/or comm-link packages may each include one or more ICs, chips, or dies and have circuit functionality appropriate for particular applications.

FIG. 1shows an example IC package100. The IC package100includes a die102and a transducer104providing conversion between electrical and EM signals. The IC package100may include additional structures, for example, conductive connectors, such as bond wires, electrically connecting the transducer to bond pads connected to a transmitter and/or receiver circuit included in die102. The IC package100further includes an encapsulating material106formed around at least a portion of the die102and/or the transducer104. In the example IC package100, the encapsulating material104completely covers the die100and the transducer104.

The die102includes any suitable structure configured as a circuit on a suitable die substrate. In some implementations, the die can alternatively be referred to as a chip or an integrated circuit. The die substrate may be composed of any suitable semiconductor material, for example, silicon. The die102may be mounted with electrical conductors, such as a lead frame, not shown inFIG. 1, electrically coupling the die102to one or more external circuits. The IC package100can further include a transformer to provide impedance matching between a circuit on the die102and the transducer104.

The transducer104may be in the form of a folded dipole or loop antenna and is configured to transmit and/or receive electromagnetic signals. In some implementations, the transducer104is configured to operate at radio frequencies including radio frequencies in the extremely high frequency (EHF) band of the electromagnetic spectrum, e.g., frequencies from 30 to 300 gigahertz. As shown in IC package100, the transducer104is separate from the die102, but is coupled to the die102by suitable conductors, not shown. The dimensions of the transducer are determined such that they are suitable for operation in the specified frequency band of the electromagnetic spectrum, e.g., the EHF band.

The encapsulating material106can be used to assist in holding the various components of IC package100in fixed relative positions. The encapsulating material106may be formed from a suitable material configured to provide electrical insulation and physical protection for the components of IC package100. Additionally, the encapsulating material106can be selected from a material that does not impede, or that optimizes passage of, signals to or from the transducer104. For example, the encapsulating material106can be composed of glass, plastic, or ceramic. The encapsulating material106may also be formed in any suitable shape. For example, the encapsulating material106may be in the form of a rectangular block, encapsulating all components of the IC package100except for any unconnected ends of conductors connecting the die102to external circuits.

FIG. 2shows a side view representation of an example communication device200including an IC package202mounted to a PCB204. The IC package202includes a die206, a ground plane208, a transducer210, and one or more bond wires212connecting the die206to the transducer210. The die206and transducer210are mounted on a package substrate214and encapsulated in an encapsulating material. The ground plane208is within the package substrate214and is a suitable structure configured to provide an electrical ground for the transducer210. The ground plane208can extend the entire length of the package substrate214or just a portion, in particular, a portion underneath the transducer210. The PCB204includes a top dielectric layer216having a surface218. The IC package202is mounted to the surface218with mounting bumps220attached to a metallization pattern (not shown).

The PCB204also optionally includes a layer222spaced from dielectric layer216made of conductive material forming a ground plane within the PCB204. The PCB ground plane may be any suitable structure configured to provide an electrical ground to circuits and components on the PCB204.

FIG. 3is a side view of an example communication module300including a signal guiding structure. As shown inFIG. 3, the communication module300includes a PCB302, an IC package304, and a signal guiding structure306providing a signal pathway. The communication module300, can include a transmitter or receiver for transmitting or receiving signals, e.g., radio frequency signals.

In particular, the IC package304can correspond to the IC packages described above with respect toFIGS. 1 and 2. The IC package304is mounted on the PCB302. For example, the IC package304can be mounted to the PCB as described with respect toFIG. 2.

The communication module300can be configured to transmit or receive data using radio frequency communication. For example, if the communication module300includes a transmitter, the communication module300can transmit data, which can then be received by a receiver, e.g., of another communication module.

The signal guiding structure306is configured to aid in directing radio frequency (RF) signals as well as to reduce interference from spurious signals. The signal guiding structure306can surround a perimeter of the IC package and extend in the direction of signal transmission and/or reception by a specified amount to provide a channel for emitted or received RF signals. For example, the signal guiding structure306can have a height310suitable for a particular device including the communication module300and that allows the signal guiding structure306to be positioned in proximity to a corresponding signal guiding structure of another communication module when used to communicate with another device. The height of the signal guiding structure306relative to the PCB302can be configured such that when the communication module300is positioned the signal guiding structure306is proximal to an external device housing. The signal guiding structure can be composed of a suitable material that is configured to reduce extraneous signals without disrupting passage of communications along the channel formed by the signal guiding structure306.

FIG. 3illustrates one IC package304mounted to the PCB302. However, in other implementations, more than one IC package can be mounted to the same PCB302. For example, a linear array of two or more IC packages, each having a corresponding signal guiding structure, are mounted to a single PCB.

The communication module300can be part of a communication system of a device, e.g., a computer, mobile phone, tablet, kiosk, or other device/system. The communication system can be configured to provide contactless communication using one or more IC packages. For example, the communication system can include two IC packages, one configured as a transmitter and the other configured as a receiver. The communication system can be in communication with a storage device. Thus, for example, the communication system can transfer data between the data storage unit and an external device using contactless communication provided by the IC packages.

The communication module300can establish communication with one or more other communication modules when placed in close proximity. For example, two devices can be positioned in proximity to each other such that the respective communication modules for transmitting and receiving data are aligned and in range of each other. In particular, for EHF frequencies, the transmitter and receiver of the two devices may need to be within specified distances. The distances can vary, for example, depending on the particular frequencies used, the materials between the transmitter and receiver, and the strength of the transmission.

In particular, the devices may be configured such that the communication module300of a first device can establish communication with more than one transceiver associated with a second device or one or more other transceivers that are part of the first device. For example, the communication module300may be able to establish communication with any transceiver within a shared EM field, e.g., an EHF field, that encompasses the transceivers, as described in detail below.

Redundant Contactless Communication

FIG. 4is a block diagram400illustrating an example of a shared communication field between contactless connectors. In particular,FIG. 4illustrates a representation of a shared EM field for providing redundant contactless communication between a first device402and a second device404. The first device402includes a first transceiver406and a second transceiver408. The second device404includes a third transceiver410and a fourth transceiver412. The first transceiver406and the second transceiver408are oriented in a way that both can communicate, e.g., transmit and receive data, from the third transceiver410or the fourth transceiver412. Additionally, the first transceiver406can communicate with the second transceiver408and the third transceiver410can communicate with the fourth transceiver412.

An EM shared field is conceptually illustrated by dotted circle414, which encompasses respective antenna locations represented by the black dots. The shared field represents a region of overlapping EHF antennas from each of the transceivers such that communication can be established between any of the transceivers. Consequently, the first transceiver406and the second transceiver408are in a redundant data path configuration in the first device402such that if either fails, the other one can resume the connection. The third transceiver410and the fourth transceiver412are in a similar redundant path configuration. As long as one of the first and second transceivers406,408can connect to one of the third and fourth transceivers410,412, the contactless connection link can remain active.

FIG. 5is a block diagram500illustrating an example of half-duplex redundant connectors. In particular,FIG. 5shows an arrangement between a first device502and a second device504that provides redundant half-duplex communication. Half duplex communication uses a single transceiver of each device to both transmit and receive data. Thus, half duplex communication requires the respective transceivers of each device to switch between transmitting and receiving modes.

The first device502includes a first contactless connector506and a second contactless connector508, each having a transceiver. Each contactless connector506,508is coupled to a first controller510by respective control and data lines. Other implementations can include additional contactless connectors that provided further redundancy.

The second device504includes a third contactless connector512and a fourth contactless connector514, each having a transceiver. Each contactless connector512,514is coupled to a second controller516by respective control and data lines. Other implementations can include additional contactless connectors that provided further redundancy.

When the first device502and the second device504are positioned such that the respective contactless connectors are aligned, e.g., first contactless connector506is aligned with the third contactless communicator512, each contactless connector can connect to the other three contactless connectors. Thus, the first contactless connector506can connect to the second contactless connector508of the first device502, e.g., for testing purposes, as well as the third contactless connector512and fourth contactless connector514of the second device504.

In some implementations, an initial pairing of connectors is preset. For example, the first contactless connector506and the third contactless connector512may be set to pair while the other contactless connectors are powered down. However, when needed, the first contactless connector506can also pair with the fourth contactless connector514. Thus, the fourth contactless connector514is an example of a redundant connector that can be activated when needed, for example, in response to an error or failure of the third contactless connector512.

Each controller can manage data flow to and from respective contactless connectors. Additionally, each controller can perform a loopback test using the overlapping EM field at startup or in response to particular link errors being detected. For example, each controller can include a state machine for performing the loopback testing. The loopback test can be performed to determine a quality of the redundant links in order to determine a connection path between the first device502and the second device504. The loopback testing can be performed locally or remotely.

FIG. 6is a flow diagram600illustrating a loopback test and link setup for a half-duplex configuration.FIG. 6will be described with respect to the first device502and second device504ofFIG. 5. A controller, e.g., first controller510, of the first device, e.g., first device502configures a first connector, e.g., first contactless connector506, as a transmitter and a second connector, e.g., second contactless connector508, as a receiver (602).

The controller provides a particular unique signal pattern to the first connector for transmission to the second connector (604). The controller determines whether the signal pattern received by the second connector matches the signal pattern transmitted by the first connector (606). In some implementations, the signal pattern includes field information on an identifier of the integrated circuit packages of the connector, for example, indicating which integrated circuit package is a transmitter or a receiver and the RF parameters of both connectors. The receiver receives a packet containing the information and performs a checksum or parity test that confirms that the connection is valid.

In response to a determination that the signal pattern does not match, no branch, a loopback error occurs and a loopback error response is determined (620). The loopback error response can include modifying an attempted communication link establishment as will be described in greater detail below.

In response to a determination that the signal pattern matches, yes branch, the controller configures the first connector as a receiver and the second connector as a transmitter (608). The controller provides a unique signal pattern to the second connector for transmission to the first connector (610). The controller determines whether the signal pattern received by the first connector matches the signal pattern transmitted by the second connector (612).

In response to a determination that the signal pattern does not match, no branch, a loopback error occurs and a loopback error response is determined (620). The loopback error response can include modifying an attempted communication link establishment as will be described in greater detail below.

In response to a determination that the signal pattern matches, yes branch, the controller sets the first connector as the primary connector that acts alternatively as a transmitter or receiver when communicating with the second device (614). The controller powers down the second connector, which can be activated if needed, e.g., in response to a failure of the first connector.

The loopback test, e.g., steps602to614, is similarly carried out by the second device for a third and fourth connector. The second device can perform the loopback test in parallel with the first device, sequentially with the first device, or partially in parallel with the first device. In some implementations, the second device can set the third connector as the primary connector that acts alternatively as a transmitter or receiver when communicating with the first device. The fourth connector can be set a backup connection for use in case the third connector has an error or failure.

Once the loopback test is complete, the controller of the first device establishes a communication link between the first and second devices based on the loopback test results (616). If the loopback test is completed without error, the controller of the first device configures the first connector as a transmitter for a specified time period T1. Following time period T1, the controller switches the first connector to a receiver to listen for a confirmation response from the second device. Similarly, if the loopback test is completed for the second device without error, the controller of the second device configures the third connector as a receiver. In response to receiving a transmission from the first device, the controller switches the third connector to a transmitter and transmits a confirmation message. The third connector can transmit data or switch back to a receiver for a specified time T2to listen for a transmission from the first connector. Any suitable half-duplex protocol can be used to govern communication between the particular pair of contactless connectors. For example, the half-duplex protocol can govern signals to indicate when the particular transceivers should switch between transmitter and receiver modes as well as determining when data has been correctly received or needs to be resent, e.g., using acknowledgment packets.

In response to a loopback error in the first device, instead of establishing the first connector as the primary transmitter and receiver, the controller alternates the transmitter between the first and second connectors for a fixed time, e.g., ½ T1, and then switches to a receiver to listen for a confirmation from the second device. The first or second connector can then be selected as the primary connector based on the confirmation reception. During transmission by each transmitter, the payload packet can have identifiers such as an identifier field of the particular transmitter.

Similarly, in response to a loopback error in the second device, instead of establishing the third connector as the primary transmitter and receiver, both the third and fourth connectors can initially be set as receivers. Based on whether a confirmation message is received, the third or fourth connector can then be established as the primary connector of the second device while powering down the other.

After setting up the communication link between the first and second devices, both controllers can have selected respective primary connections and powered down one or more redundant connections. Communications can then proceed between the first and second devices according to the specified half-duplex protocol. Additionally, while the communication link is established, the loopback testing status can be queried by a respective device over the communication link.

After the communication link has been established, an error condition or failure can occur in one of the respective primary connections. In some implementations, an error can be identified based on analysis of received packets. For example, a particular payload packet can include corrupt information, which can be validated by the controller with respect to a known good payload packet. In response to determining an error, the controller can generate an error flag.

In response to detecting the error condition or failure, a powered down redundant connection can be activated. This redundant connection can seamlessly take the place of the primary connection without establishing a new communication link since the redundant connection is within the shared EM field and is coupled to the same data controller as the primary connection.

FIG. 7is a block diagram700illustrating an example of full-duplex redundant connectors. In particular,FIG. 5shows an arrangement between a first device702and a second device704that provides redundant full duplex communication. Full duplex communication uses a dedicated transmitter and receiver in each device for communication without having to switch a transceiver back and forth between a transmitter and receiver. Thus, two or more communication links are established between the two devices. Full duplex communication can provide high speed data communication between devices.

The first device702includes a pair of transmitter connectors and a pair of receiver connectors. In particular, a first contactless connector706and a second contactless connector708operate as receivers. A third contactless connector710and a fourth contactless connector712operate as transmitters. Each contactless connector706,708,710, and712is coupled to a first controller714by respective control and data lines.

The second device704includes a pair of transmitter connectors and a pair of receiver connectors. In particular, a fifth contactless connector716and a sixth contactless connector718operate as receivers. A seventh contactless connector720and an eighth contactless connector722operate as transmitters. Each contactless connector716,718,720, and722is coupled to a first controller724by respective control and data lines.

When the first device702and the second device704are positioned such that the respective contactless connectors are aligned, pairs of redundant connectors can connect. In particular, each of the first contactless connector706and the second contactless connector708can connect to either of the fifth contactless connector716and the sixth contactless connector718. Similarly, each of the third contactless connector710and the fourth contactless connector712can connect to either of the seventh contactless connector720and the eighth contactless connector722. Furthermore, the contactless connectors of each pair can connect to each other. For example, the first contactless connector706can connect to the second contactless connector708.

In some implementations, an initial pairing of connectors between the first and second devices702and704is preset. For example, the first contactless connector706and the fifth contactless connector716can be set as a transmitter receiver pair as well as the third contactless connector710and the seventh contactless connector720. However, when needed, the redundant contactless connectors can be activated to provide the pairing. For example, a failure of the third contactless connector710operating as a transmitter can cause the fourth contactless connector712to activate and take over the connection with the seventh contactless connector720operating as a receiver for the second device.

Each controller can manage data flow to and from respective contactless connectors. Additionally, each controller can perform a loopback test using the overlapping EM field at startup or in response to particular link errors being detected. For example, each controller can include a state machine for performing the loopback testing. The loopback test can be performed to determine a quality of the redundant links in order to determine a connection path between the first device702and the second device704. The loopback testing can be performed locally or remotely.

FIG. 8is a flow diagram800illustrating a loopback test and link setup for a full duplex configuration.FIG. 8will be described with respect to the first device702and second device704ofFIG. 7.

A controller, e.g., first controller714, of the first device, e.g., first device702configures a first connector, e.g., first contactless connector706, as a transmitter and a second connector, e.g., second contactless connector708, as a receiver (802). In particular, the first connector and the second connector form a first pair of connectors of the first device. In operation, one connecter of the pair is active as the primary connector of the first pair and the second connecter of the first pair is a redundant powered down connector. The controller provides a particular unique signal pattern to the first connector for transmission to the second connector (804). The controller determines whether the signal pattern received by the second connector matches the signal pattern transmitted by the first connector (806).

In response to a determination that the signal pattern does not match, no branch, a loopback error occurs and a loopback error response is determined (820). The loopback error response can include modifying a communication link establishment process as will be described in greater detail below.

In response to a determination that the signal pattern matches, yes branch, the controller configures the first connector as a receiver and the second connector as a transmitter (808). The controller provides a unique signal pattern to the second connector for transmission to the first connector (810). The controller determines whether the signal pattern received by the first connector matches the signal pattern transmitted by the second connector (812).

In response to a determination that the signal pattern does not match, no branch, a loopback error occurs and a loopback error response is determined (820). The loopback error response can include modifying a communication link establishment process as will be described in greater detail below.

In response to a determination that the signal pattern matches, yes branch, the controller sets the first connector as the primary connector for the first pair (814). In some implementations, the first connector is designated as a receiver for the first device. The controller powers down the second connector, which can be activated as the receiver for the first device if needed, e.g., in response to a failure of the first connector.

The loopback test, e.g., steps802to814, is similarly carried out for a second pair of connectors of the first device (816). The controller can perform the loopback test for the second pair of connectors in parallel with the first pair of connectors, sequentially with the first pair, or partially in parallel with the first pair.

In particular, the third connector and a fourth connector form the second pair of connectors of the first device. In operation, one connecter of the second pair is active as the primary connector of the second pair and the second connecter of the second pair is a redundant powered down connector. In response to a successful loopback test, the controller sets the third connector as the primary connector of the second pair. In some implementations, the third connector is designated as a transmitter for the first device. The controller powers down the fourth connector, which can be activated as the transmitter for the first device if needed, e.g., in response to a failure of the third connector.

Once the loopback test is complete, the controller of the first device establishes a link between the first and second devices based on the loopback test results (818). With reference toFIG. 7, if the loopback test is completed without error, the controller of the first device configures the first connector706as a receiver for the first device and the third connector710as the transmitter for the first device. The controller of the second device, in response to corresponding error free loopback tests, configures the fifth connector716as the transmitter for the second device and the seventh connector720as the receiver for the second device. Any suitable full duplex protocol can be used to govern communication between the particular pair of contactless connectors.

In response to a loopback error in the first device for the first pair of connectors, both are activated as receivers and the first connector or the second connector is set as the primary receiver based on data reception.

In response to a loopback error in the first device for the second pair of connectors, transmissions of control packets are alternated between the third connector and the fourth connector of the second pair. Either the third or the fourth connector can be selected based on data reception of the control packet. Each connector transmits a unique control packet that is identified in the return message so that the controller can determine which transmitter of the third connector and fourth connector is operating. The second device can perform similar operations to establish a communication link in response to a loopback error.

After setting up the communication link between the first and second devices, both controllers will have selected the primary transmitter and receiver connectors and powered down the redundant connection. Communications can then proceed between the first and second devices according to the specified full duplex protocol. Additionally, while the communication link is established, the loopback testing status can be queried by a respective device over the communication link.

FIG. 9is a block diagram900illustrating an example of redundant connectors with more than two connectors. Such a system could exist, for example, for systems transporting video data. Diagram900shows Device A and Device B. Each device has six potential connectors.

In one example, successive loopback tests can be performed to determine connectors. In particular, three connectors can be examined at a time. Take Device A connectors2,4, and6and Device B connectors1,3, and5. A respective device controller can perform a loopback test between Device A connectors2and4and Device B connectors1and3. If the loopback test is completed successfully, lane2-1becomes a communication lane. Connectors4and3perform a similar loopback test on connectors6and5. If the loopback test is successful, lane6-5can become a communication lane. Connectors4and3become the drop in replacement connectors if the loopback fails.

If the number of connectors increases then a mechanism needs to be in place if more than two connectors would fail the loopback to keep the system link active between the devices. By having symmetry and control for every three successive connectors, primary and secondary rings can be formed.