Radio frequency (RF) coax interface for full data rate controller area network (CAN) protocol signaling with low latency

A method for implementing controller area network (CAN) communications between a plurality of CAN nodes using a single radio frequency (RF) coax cable is provided. In an aspect, a hardware interface (e.g., an electronic circuit) may be coupled to each of the plurality of CAN nodes. The hardware interface may receive a CAN signal from a first CAN node. The hardware interface may convert the CAN signal to a single RF signal and transmit the RF signal to a second CAN node over the single RF coax cable. Moreover, the hardware interface may transmit a CAN feedback signal received over the RF coax cable to the first CAN node. In an aspect, the hardware interface may include an amplitude modulation (AM) modulator, an AM detector, and a bandpass filter.

TECHNICAL FIELD

The present disclosure relates generally to controller area network (CAN) bus devices, and more specifically, to CAN bus devices having a single radio frequency (RF) coax interface for CAN protocol signaling.

BACKGROUND

A Controller Area Network (CAN) bus is an International Standardization Organization (ISO) serial communications bus protocol originally developed for the automotive industry to replace complex wiring harness with a two-wire bus. The specification calls for high immunity to electrical interference and the ability to self-diagnose and repair data errors. These features have led to CAN's popularity in a variety of markets including maritime, aeronautical, and terrestrial markets. In conventional CAN bus control systems, CAN signals are exchanged between a terminal and a transceiver using differential signaling over, for example, a twisted-pair cable. These CAN signals may be combined with several other control cables to be transmitted over numerous, commonly five, separate control cables. This configuration requires multiple cable runs, thereby creating latency, added cost, and installation complexity.

Therefore, there exists an unmet need in the art for an interface (e.g., an electronic circuit) to integrate the CAN bus communications protocol onto a single radio frequency (RF) coax cable to enable fully compliant CAN protocol signaling with low latency and superior form factor.

SUMMARY

In accordance with an aspect, the present disclosure may provide an electronic circuit for integrating CAN communications onto a RF coax cable. The electronic circuit may include an input port configured to receive a first CAN signal, a conversion circuit configured to convert the first CAN signal to a RF signal, and a first output port configured to transmit the RF signal.

In accordance with another aspect, the present disclosure may provide a method for implementing CAN communications between a plurality of CAN nodes using a RF coax cable. The method may include receiving a first CAN signal from a first CAN node. The method may further include converting the first CAN signal to a RF signal. In addition, the method may include transmitting the RF signal to a second CAN node over the RF coax cable.

In accordance with yet another aspect, the present disclosure may provide a computer-readable medium (e.g., a non-transitory medium) storing computer executable code for CAN communications. The computer-readable medium may include code for transmitting, at a first CAN node, a CAN signal to a second CAN node through a hardware interface, where the hardware interface is configured to convert the CAN signal to a RF signal for transmission over a RF coax cable to the second CAN node.

DETAILED DESCRIPTION

Several aspects of a CAN/RF conversion circuit for integrating the CAN-bus communications protocol onto a single RF coax cable will now be presented with reference to various methods, apparatuses, and media. These methods, apparatuses, and media will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall implementation.

Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium or media. Computer-readable media includes computer storage media. Storage media may be any available media that is able to be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), compact disk ROM (CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to carry or store desired program code in the form of instructions or data structures and that may be accessed by a computer. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), and floppy disk, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

Aspects of a CAN/RF conversion circuit presented herein may be compatible with transmitting and/or receiving CAN-bus signals between a terminal and an antenna over a single RF cable. In an aspect, the terminal may be a mobile user terminal such as, but not limited to, an earth terminal, a mobile satellite broadband terminal, or a land mobile terminal (LMT). Further, in an aspect, the terminal may be mounted to, for example, a vehicle, a maritime vessel, or an aircraft. In an aspect, the antenna may be a directional or beam antenna. For example, the antenna may be a phased array antenna configured to track a satellite such as, but not limited to, a low-earth orbit (LEO) satellite, a medium earth orbit (MEO) satellite, or a geostationary earth orbit (GEO) satellite. It should be understood that the CAN/RF conversion circuit of the present disclosure may be used with any of the terminals and antennas listed above without departing from the scope of the present disclosure.

FIG. 1illustrates an overall system diagram of an example communications system100for use in accordance with aspects of the present disclosure. The communications system100ofFIG. 1may include, for example, a terminal106, a single RF coax cable108, an antenna interface unit104, an antenna110, and a satellite102.

In an aspect, the terminal106may be communicatively coupled to the antenna interface unit104via, for example, the single RF coax cable108. In an aspect, the antenna interface unit104may be configured to electrically steer an antenna110towards a communications satellite (e.g., satellite102) in an orbital range of the terminal106. For example, in an aspect, the terminal106may include a satellite modem (e.g., satellite modem220inFIG. 2) for generating beam steering information and sending a control signal (e.g., a CAN-bus signal) including the beam steering information and other control information such as, but not limited to, health, status, and/or timing information, to the antenna interface unit104over the single RF coax cable108. The antenna110may acquire and continuously track the satellite102based on the control signal received from terminal106. In an aspect, an uplink satellite communications link120and/or a downlink satellite communications link122may be established and maintained between the terminal106and the satellite102based on the control signal. Moreover, in an aspect, the terminal106may transmit and/or receive data, timing reference, and/or power RF signals to antenna interface unit104over the single RF coax cable108.

It is to be appreciated that the single RF coax cable108may include a length such as, but not limited to, 100 feet. For example, in some aspects, the single RF coax cable108may have either a longer or shorter length than 100 feet. It is to be appreciated that, according to aspects of the present disclosure, an RF signal may be transmitted over the RF coax cable108up to a speed of one megabit per second (1 Mbps).

Moreover, it is to be appreciated that the example communications system ofFIG. 1is intended for illustrative purposes and is not intended to limit the scope of the present disclosure. For example, the present disclosure may also be extended to other communications systems such as, but not limited to, an in-vehicle network.

FIG. 2illustrates a diagram including an example of a terminal106(e.g., the terminal106inFIG. 1). According to the present aspects, the terminal106may include one or more modems220, a CAN/RF conversion unit230, and a discrete diplexer240. The CAN/RF conversion unit230may be a hardware interface (e.g., an electronic circuit) communicatively coupled to the modem220and the discrete diplexer240.

In an aspect, the modem220may be, for example, a satellite modem, which may process digital data and facilitate communications with a satellite102(FIG. 1). For example, in an aspect, the modem220may be used to transmit and/or receive RF signals including one or more of a data signal250or a timing reference signal252to satellite102(FIG. 1). The data signal250may be transmitted and/or received over a main communication channel of satellite102(e.g., a 1616-1626.5 MHz band). The timing reference signal252may be transmitted and/or received over a secondary communication channel of satellite102(e.g., a band of frequencies produced by a sum of frequencies 14.4 MHz and 19.2 MHz). It is to be appreciated that the modem220may also be a modem compatible with other wired and/or wireless communications networks and that the modem220may be used to transmit and/or receive other types of RF signals between devices using different frequency channels as well.

Moreover, in aspect, the modem220may operate in combination with a CAN control unit224for enabling transmission and/or reception of CAN-bus signals. The CAN control unit224may include hardware, firmware, and/or software code executable by a processor222(e.g., a microprocessor) for transmitting and/or receiving CAN-bus signals210,212, the code comprising instructions and being stored in a memory226(e.g., non-transitory computer-readable medium). The CAN control unit224may be coupled to the memory226via a bus216.

In an aspect, the CAN/RF conversion unit230(see, e.g., details inFIG. 4) may comprise circuitry for converting a CAN-bus signal to a single RF signal. For example, in an aspect, the CAN/RF conversion unit230may convert a CAN-bus signal212received from modem220to an RF signal214. The CAN/RF conversion unit230may transmit the RF signal214to the discrete diplexer240. Moreover, in an aspect, the CAN/RF conversion unit230may convert an RF signal214to a CAN-bus signal210. For example, in an aspect, the CAN/RF conversion unit230may convert an RF signal214received from the discrete diplexer240to a CAN-bus signal210.

In an aspect, the discrete diplexer240may comprise suitable circuitry, logic, and/or code for merging one or more signals of different frequency into a single RF signal. For example, in an aspect, the discrete diplexer240may merge one or more of the data signal250, the timing reference signal252, or a power signal254received from modem220with an RF signal214received from CAN/RF conversion unit230to generate a single RF signal for transmission over a single RF coax cable108(FIG. 1). In another aspect, the discrete diplexer240may extract one or more signals of different frequencies from a single RF signal. For example, in an aspect, the discrete diplexer240may extract an RF signal214and one or more of a data signal250, timing reference signal252, or power signal254from a single RF signal received over the single RF coax cable108.

FIG. 3illustrates a diagram including an example of an antenna interface unit104(e.g., the antenna interface unit104inFIG. 1). According to the present aspects, the antenna interface unit104may include an RF front end320, a CAN/RF conversion unit330, and a discrete diplexer340. The CAN/RF conversion unit330may be an electronic circuit communicatively coupled to the RF front end320and the discrete diplexer340.

In an aspect, the RF front end320may be connected to one or more antennas110(FIG. 1) for receiving and/or transmitting communications, for example, over uplink satellite communications link120(FIG. 1) and/or a downlink satellite communications link122(FIG. 1). In an aspect, antenna110(FIG. 1) may be a phased array antenna including a plurality of antenna elements. For example, in an aspect, the RF front end320may comprise a power divider and a corresponding phase shifter and/or amplifier for each antenna element of the plurality of antenna elements (not shown).

Moreover, in aspect, the RF front end320may comprise a CAN control unit324for enabling transmission and/or reception of CAN-bus signals. The CAN control unit324may include hardware, firmware, and/or software code executable by a processor322(e.g., a microprocessor) for transmitting and/or receiving CAN-bus signals310,312, the code comprising instructions and being stored in a memory326(e.g., non-transitory computer-readable medium). The CAN control unit324may be coupled to the memory326via a bus316.

In an aspect, the CAN/RF conversion unit330(see, e.g., details inFIG. 4) may comprise circuitry for converting a CAN-bus signal310to an RF signal314. For example, in an aspect, the CAN/RF conversion unit330may convert a CAN-bus signal310received from RF front end320to an RF signal314. Moreover, in an aspect, the CAN/RF conversion circuit330may convert an RF signal314to a CAN-bus signal312. For example, in an aspect, the CAN/RF conversion unit330may convert an RF signal314received from discrete diplexer340to a CAN-bus signal312. The CAN-bus signal312may include control information such as, but not limited to, beam-steering information for setting a phase of each of the phase shifters of RF front end320.

In an aspect, the discrete diplexer340may comprise suitable circuitry, logic, and/or code for extracting one or more signals of different frequencies from a single RF signal. For example, in an aspect, the discrete diplexer340may extract one or more of a data signal352, timing reference signal354, or power signal356and a RF signal314from a single RF signal received over the single RF coax cable108. In another aspect, the discrete diplexer340may merge one or more signals of different frequency into a single RF signal. For example, in an aspect, the discrete diplexer340may merge a data signal352or timing reference signal354received from RF front end320with an RF signal314received from CAN/RF conversion unit330to generate a single RF signal for transmission over the single RF coax cable108.

FIG. 4illustrates a diagram including an example of a CAN/RF conversion unit400. In an aspect, the CAN/RF conversion unit400may comprise an amplitude modulation (AM) modulator410, a bandpass filter440, and an AM detector420, each coupled to one another.

In an aspect, the CAN/RF conversion unit400may correspond to the CAN/RF conversion unit230of terminal106inFIG. 2. In this aspect, the CAN/RF converter400may receive a CAN-bus signal430from the modem220(FIG. 2), transmit a CAN-bus feedback signal432to the modem220(FIG. 2), and transmit an RF signal436to the discrete diplexer240(FIG. 2). Here, the CAN-bus signal430may correspond to CAN-bus signal212ofFIG. 2, the CAN-bus feedback signal432may correspond to CAN-bus signal210ofFIG. 2, and the RF modulated signal436may correspond to RF signal214ofFIG. 2.

In an aspect, the AM modulator410may comprise suitable circuitry (e.g., one or more transistors) for converting a CAN-bus signal430to an RF signal434. For example, in an aspect, the AM modulator410may modulate a CAN-bus signal430received from modem220(FIG. 2) to a radio frequency such as, but not limited to, 316 megahertz (MHz) to generate an RF signal434.

In an aspect, the bandpass filter440may comprise suitable circuitry for filtering an RF signal434. For example, in an aspect, the bandpass filter440may be a surface acoustic wave (SAW) filter with a center frequency such as, but not limited to, 316 MHz. In an aspect, the bandpass filter440may filter an RF modulated signal434received from AM modulator410to generate a filtered RF signal436. The filtered RF signal436may then be transmitted over a single RF coax cable108(FIG. 2). For example, in an aspect, the filtered RF signal436may be transmitted to a discrete diplexer240, where the filtered RF signal436may be combined with other RF signals (e.g., data signal(s)250, timing reference signal(s)252, and/or power signal(s)254) to generate a single RF signal. The discrete diplexer240may then transmit the single RF signal over the single RF coax cable108(FIG. 1) to an antenna interface unit104(FIG. 1).

In an aspect, the AM detector420may comprise suitable circuitry for detecting a presence of an RF modulated signal434and converting the RF modulated signal434to a CAN-bus signal432. For example, in an aspect, the AM detector420may detect a presence of an RF modulated signal434that includes a CAN-bus feedback signal.

It is to be appreciated that a CAN-bus controller, for example, CAN control unit224of the modem220(FIG. 2), may, in accordance with the CAN-bus protocol, allocate a priority to each CAN-bus signal430transmitted over a CAN-bus and continuously monitor the transmission of each bit of the CAN-bus signal430over the CAN-bus. For example, the CAN control unit224(FIG. 2) may set an identifier field of a CAN-bus signal430to a specific priority number prior to transmission. The lower the value of the priority number, the higher the priority of the CAN-bus signal. The CAN control unit224(FIG. 2) may then repeatedly transmit a CAN-bus signal430over the CAN-bus until the CAN control unit224determines that another CAN-bus controller, for example, CAN control unit324of the RF front end320(FIG. 3), wants to transmit a CAN-bus signal with a higher priority. For example, if another CAN-bus controller with a higher priority begins to transmit on the CAN-bus simultaneously, then the CAN-bus controller with the higher priority may overwrite the identifier field of the CAN-bus signal430. Otherwise, the identifier field of the CAN-bus signal430may not be overwritten by another modem.

In an aspect, the AM detector420may detect the presence of an RF modulated signal434that includes a CAN-bus signal with a modified or a non-modified identifier field. The AM detector420may then convert the RF modulated signal434to a CAN-bus signal432and transmit the CAN-bus signal432to modem220(FIG. 2). It is to be appreciated that, according to the present aspects, the CAN-bus signal432may be transmitted to the modem220(FIG. 2) within 200 ns of the modem220transmitting the CAN-bus signal430.

In another aspect, the CAN/RF converter400may correspond to the CAN/RF conversion unit330of antenna interface unit104(FIG. 3). In this aspect, the CAN/RF converter400may receive a CAN-bus signal430from an RF front end320of antenna interface unit104(FIG. 3), transmit an CAN-bus feedback signal432to the RF front end320(FIG. 3), and transmit an RF signal434to the discrete diplexer340(FIG. 3). Here, the CAN-bus signal430may correspond to CAN-bus signal310ofFIG. 3, the CAN-bus feedback signal432may correspond to CAN-bus signal312, and the RF signal436may correspond to RF signal314ofFIG. 3.

As described above, the CAN/RF converter400may include an AM modulator410for modulating the received CAN-bus signal430to an RF signal434, a bandpass filter440for filtering the RF modulated signal434to produce a filtered RF signal436for transmission over a single RF coax cable108(FIG. 3), and an AM detector420for converting a detected RF modulated signal434to a CAN-bus signal432for transmission to an RF front end320.

In yet another example, aspects presented herein may be implemented using software or a combination of both hardware and software.

FIG. 5is an example system diagram of various hardware components and other features, for use in accordance with aspects presented herein. The aspects may be implemented using hardware, software, or a combination thereof and may be implemented in one or more computer systems or other processing systems. In one example, the aspects may include one or more computer systems capable of carrying out the functionality described herein, e.g., in connection withFIG. 2,FIG. 3, andFIG. 4. An example of such a computer system (e.g., terminal106and/or satellite102) is shown inFIG. 1.

InFIG. 5, computer system500includes one or more processors, such as processor504. For example, the processor505may be configured for signal processing at a ground terminal (e.g., terminal106ofFIG. 1) and/or a satellite (e.g., satellite102inFIG. 1). The processor505may be connected to a communication infrastructure506(e.g., a communications bus, cross-over bar, or network). The communication infrastructure506may correspond to bus216(FIG. 2). Various software aspects are described in terms of this example computer system. After reading this description, it will become apparent to a person skilled in the relevant art(s) how to implement the aspects presented herein using other computer systems and/or architectures.

Computer system500may include a display interface502that forwards graphics, text, and other data from the communication infrastructure506(or from a frame buffer not shown) for display on a display unit530. In an aspect, the display unit530may be located in the ground terminal106illustrated inFIG. 1and configured to display data and/or control information obtained from the satellite102illustrated inFIG. 1. Computer system500may also include a main memory508, e.g., RAM, and may also include a secondary memory510. The main memory508may correspond to, for example, memory226(FIG. 2). The secondary memory510may include, for example, a hard disk drive512and/or a removable storage drive514, representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive514may read from and/or write to a removable storage unit518in a well-known manner. Removable storage unit518, represents a floppy disk, magnetic tape, optical disk, etc., which may be read by and written to removable storage drive514. As will be appreciated, the removable storage unit518may include a computer usable storage medium having stored therein computer software and/or data.

In alternative aspects, secondary memory510may include other similar devices for allowing computer programs or other instructions to be loaded into computer system500. Such devices may include, for example, a removable storage unit522and an interface520. Examples of such may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an erasable programmable read only memory (EPROM), or programmable read only memory (PROM)) and associated socket, and other removable storage units522and interfaces520, which allow software and data to be transferred from the removable storage unit522to computer system500.

Computer system500may also include a communications interface524. Communications interface524may allow software and data to be transferred between computer system500and external devices. Examples of communications interface524may include a modem, network interface (such as an Ethernet card), a communications port, a Personal Computer Memory Card International Association (PCMCIA) slot and card, etc. For example, the communications interface524may correspond to modem220(FIG. 2). Software and data transferred via communications interface524may be in the form of signals528, which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface524. These signals528may be provided to communications interface524via one or more communications paths (e.g., channel)526. The path526may carry signals528and may be implemented using wire or cable, fiber optics, a telephone line, a cellular link, wireless communications link, a RF link and/or other communications channels. In the present disclosure, the terms “computer program medium” and “computer usable medium” may be used to refer generally to media such as a removable storage drive514, a hard disk installed in hard disk drive512, and signals528. These computer program products provide software to the computer system500. Aspects presented herein may include such computer program products.

Computer programs (also referred to as computer control logic) may be stored in main memory508and/or secondary memory510. Computer programs may also be received via communications interface524. Such computer programs, when executed, may enable the computer system500to perform the features presented herein, as discussed herein. In particular, the computer programs, when executed, may enable the processor505to perform the features described supra with respect toFIG. 1,FIG. 2,FIG. 3, andFIG. 4, as well as to perform the features described infra with respect toFIGS. 6A and 6B. Accordingly, such computer programs represent controllers of the computer system500.

In aspects implemented using software, the software may be stored in a computer program product and loaded into computer system500using removable storage drive514, hard drive512, or communications interface520. The control logic (software), when executed by the processor505, may cause the processor505to perform the functions as described supra with respect toFIG. 1,FIG. 2,FIG. 3, andFIG. 5, and as described infra with respect toFIGS. 6A and 6B. In another example, aspects may be implemented primarily in hardware using, for example, hardware components, such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s).

FIGS. 6A and 6Bare a flowchart600of a method for implementing CAN communications between a plurality of CAN nodes using a RF coax cable in accordance with certain aspects of the present disclosure. The method may be performed by a CAN/RF converter (e.g., the CAN/RF conversion unit230,322, CAN/RF converter400, the computer system500). InFIGS. 6A and 6B, operations indicated with dashed lines may represent optional operations for various aspects of the disclosure.

As seen inFIG. 6A, at602, the CAN/RF converter may receive a first CAN signal from a first CAN node. In an aspect, the first CAN node may be or include a modem or an antenna interface unit of an antenna, for example. In another aspect, the modem may be or include a satellite modem. In a further aspect, the antenna may be or include a phased array antenna configured to track a satellite. For example, referring toFIGS. 1, 2, and 4, the CAN/RF converter400may receive a CAN-bus signal430from the modem220(FIG. 2). In one aspect, the modem220may be, for example, a satellite modem, which may process digital data and facilitate communications with a satellite102(FIG. 1). In another aspect, antenna110(FIG. 1) may be a phased array antenna, including a plurality of antenna elements.

At604, the CAN/RF converter may convert the first CAN signal to a RF signal. For example, referring toFIG. 4, the AM modulator410may comprise suitable circuitry (e.g., one or more transistors) for converting a CAN-bus signal430to an RF signal434.

At606, the CAN/RF converter may convert the first CAN signal to the RF signal by modulating the first CAN signal to produce a RF modulated signal. For example, referring toFIG. 4, the AM modulator410may modulate a CAN-bus signal430received from modem220(FIG. 2) to a radio frequency such as, but not limited to, 316 megahertz (MHz) to generate an RF signal434.

At608, the CAN/RF converter may convert the first CAN signal to the RF signal by filtering the RF modulated signal to produce the RF signal. For example, referring toFIG. 4, the bandpass filter440may comprise suitable circuitry for filtering an RF signal434. For example, in an aspect, the bandpass filter440may be or include a surface acoustic wave (SAW) filter with a center frequency such as, but not limited to, 316 MHz. In an aspect, the bandpass filter440may filter an RF modulated signal434received from AM modulator410to generate a filtered RF signal436.

At610, the CAN/RF converter may transmit the RF signal to a second CAN node over the RF coax cable. For example, referring toFIG. 4, the filtered RF signal436may then be transmitted over a single RF coax cable108(FIG. 2).

At612, the CAN/RF converter may transmit the RF signal to a second CAN node over the RF coax cable by combining the RF signal with one or more different RF signals. For example, referring toFIGS. 2 and 4, the filtered RF signal436may be combined with other RF signals (e.g., data signal(s)250, timing reference signal(s)252, and/or power signal(s)254) to generate a single RF signal.

At614, the CAN/RF converter may transmit the RF signal to a second CAN node over the RF coax cable by transmitting the combined RF signals to the second CAN node over the RF coax cable. For example, referring toFIGS. 2 and 4, the filtered RF signal436may be transmitted to a discrete diplexer240, where the filtered RF signal436may be combined with other RF signals (e.g., data signal(s)250, timing reference signal(s)252, and/or power signal(s)254) to generate a single RF signal. The discrete diplexer240may then transmit the single RF signal over the single RF coax cable108(FIG. 1) to an antenna interface unit104(FIG. 1).

As seen inFIG. 6B, at616, the CAN/RF converter may detect a presence of the RF modulated signal. For example, referring toFIG. 4, the AM detector420may detect the presence of an RF modulated signal434that includes a CAN-bus signal with a modified or a non-modified identifier field.

At618, the CAN/RF converter may convert the RF modulated signal to a second CAN signal. In an aspect, the second CAN signal may be a CAN feedback signal. For example, referring toFIG. 4, the AM detector420may then convert the RF modulated signal434to a CAN-bus feedback signal432.

At620, the CAN/RF converter may transmit the second CAN signal to the first CAN node. For example, referring toFIG. 4, the AM detector420may transmit the CAN-bus feedback signal432to modem220(FIG. 2).

While the aspects described herein have been described in conjunction with the example aspects outlined above, various alternatives, modifications, variations, improvements, and/or substantial equivalents, whether known or that are or may be presently unforeseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the example aspects, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure. Therefore, the disclosure is intended to embrace all known or later-developed alternatives, modifications, variations, improvements, and/or substantial equivalents.

It is understood that the specific order or hierarchy of the processes/flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy in the processes/flowcharts may be rearranged. Further, some features/steps may be combined or omitted. The accompanying method claims present elements of the various features/steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

Further, the word “example” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “example” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. Nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.