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Title:
HYBRID CAN BUS SYSTEM
Document Type and Number:
WIPO Patent Application WO/2019/162891
Kind Code:
A1
Abstract:
A Controller Area Network (CAN) communication device, a communication system, and a method of communicating between a plurality of controller area network (CAN) communication devices connected over a CAN bus are provided. The CAN device includes a CAN controller having a plurality of independent CAN channels and a first transceiver coupled to a first one of the plurality of independent CAN channels. The first transceiver has a plurality of transceiver channels and includes circuitry. Further, the first transceiver is configured to repeat a first signal received via the first one of the plurality of independent CAN channels to transceiver channels. The device also includes a second transceiver coupled to a second one of the plurality of independent CAN channels. The CAN communication device also includes a third transceiver coupled to the first transceiver and a fourth transceiver coupled to the second transceiver.

Inventors:
SEKH MUSARRAF HOSSAIN (IN)
CHAWLA RAJAT (IN)
Application Number:
PCT/IB2019/051451
Publication Date:
August 29, 2019
Filing Date:
February 22, 2019
Export Citation:
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Assignee:
GREY ORANGE PTE LTD (SG)
International Classes:
H04L12/40
Foreign References:
EP3005624A22016-04-13
Other References:
TOM DE RYCK: "- Rev. 0 1 Publication Order Number: AND8351/D AND8351 Multiple CAN Bus Network", 1 October 2008 (2008-10-01), Denver USA, pages 1 - 6, XP055584290, Retrieved from the Internet [retrieved on 20190429]
AMI SEMICONDUCTOR: "AMIS-42770 Dual High Speed CAN Transceiver for Long Wire Networks", 1 June 2008 (2008-06-01), Denver USA, pages 1 - 19, XP055584257, Retrieved from the Internet [retrieved on 20190429]
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Claims:
CLAIMS

1. A Controller Area Network (CAN) communication device (200) comprising:

- a CAN controller (202) having a plurality of independent CAN channels (CAN 0, CAN 1);

- a first transceiver (206a) coupled to a first one of the plurality of independent CAN channels (CAN 0) of the CAN controller (202), the first transceiver (206a) having a first plurality of transceiver channels (Channels 1 and 2), the first transceiver (206a) being configured to transmit a first signal received via the first one of the plurality of independent CAN channels (CAN 0) to the first plurality of transceiver channels (Channel 1 and 2);

- a second transceiver (206c) coupled to a second one of the plurality of independent CAN channels (CAN 1) of the CAN controller (202), the second transceiver (206c) having a second plurality of transceiver channels (Channels 5 and 6), the second transceiver (206C) being configured to transmit a second signal received via the second one of the plurality of independent CAN channels (CAN 1) to the second plurality of transceiver channels (Channel 5 and 6);

- a third transceiver (206b) coupled to the first transceiver (206a); and - a fourth transceiver (206d) coupled to the second transceiver (206c); wherein the first transceiver (206a) is configured to transmit the first signal received via the first one of the plurality of independent CAN channels (CAN 0) to the third transceiver (206b), and the second transceiver (206c) is configured to transmit the second signal received via the second one of the plurality of independent CAN channels (CAN 1) to the fourth transceiver (206d).

2. The CAN communication device (200) of claim 1, wherein the first transceiver (206a) and the third transceiver (206b) are integrated within a single chip.

3. The CAN communication device (200) of any one of the preceding claims, wherein the device further comprises:

- a plurality of isolators (302, 304, 306 and 308) coupled to each line of the plurality of independent CAN channels (CAN 0 and 1) of the CAN controller (202); and

- a plurality of electromagnetic interference protection boxes (322, 324, 326, 328, 352, 354, 356, 358) coupled between an output of each of the first transceiver (206a), the second transceiver (206c), the third transceiver (206b), the fourth transceiver (206d), and the transceiver channels.

4. The CAN communication device (200) of any one of the preceding claims, wherein each of the plurality of independent CAN channels (CAN 0 and

CAN 1) operate at different baud rates.

5. The CAN communication device (200) of any one of the preceding claims, wherein the third transceiver (206b) has a third plurality of transceiver channels and the third transceiver (206b) is configured to transmit the first signal received via the first transceiver (206a) to the third plurality of transceiver channels (Channel 3 and Channel 4).

6. The device (200) of any one of the preceding claims, wherein the fourth transceiver (206d) has a fourth plurality of transceiver channels and the fourth transceiver (206d) is configured to transmit the second signal received via the second transceiver (206c) to the transceiver channels (Channel 7 and Channel

8).

7. The device (200) of any one of the preceding claims, wherein each of the transceivers (206a, 206b, 206c, 206d) has dual transceiver channels.

8. A communication system comprising:

- a Controller Area Network (CAN) bus; and

- a plurality of CAN communication devices (200a, 200b, 200c, 200d and 200e) connected over the CAN bus, wherein each of the plurality of CAN communication devices (200a, 200b, 200c, 200d and 200e) includes:

- a CAN controller (202) having a plurality of independent CAN channels (CAN 0, CAN 1);

- a first transceiver (206a) coupled to a first one of the plurality of independent CAN channels (CAN 0) of the CAN controller (202), the first transceiver (206a) having a first plurality of transceiver channels (Channels 1 and 2), the first transceiver (206a) being configured to transmit a first signal received via the first one of the plurality of independent CAN channels (CANO) to the first plurality of transceiver channels (Channel 1 and Channel 2);

- a second transceiver (206c) coupled to a second one of the plurality of independent CAN channels (CAN1), the second transceiver (206c) having a second plurality of transceiver channels (Channels 5 and 6), the second transceiver (206c) being configured to transmit a second signal received via the second one of the plurality of independent CAN channels (CAN 1) to the second plurality of transceiver channels (Channel 5 and Channel 6); - a third transceiver (206b) coupled to the first transceiver (206a); and

- a fourth transceiver (206d) coupled to the second transceiver (206c),

wherein the first transceiver (206a) is configured to transmit the first signal received via the first one of the plurality of independent CAN channels (CAN 0) to the third transceiver (206b) and the second transceiver (206c) is configured to transmit the second signal received via the second one of the plurality of independent CAN channels (CAN 1) to the fourth transceiver (206d).

9. The communication system of the claim 8, wherein the first transceiver (206a) and the third transceiver (206b) are integrated within a single chip.

10. The communication system of any one of the claims 8 to 9, wherein each of the plurality of independent CAN channels operate at different baud rates. 11. The communication system of any one of the claims 8 to 10, wherein the third transceiver (206b) has a third plurality of transceiver channels and the third transceiver (206b) is configured to transmit the first signal received via the first transceiver (206a) to the third plurality of transceiver channels (Channel 3 and Channel 4). 12. The communication system of any one of the claims 8 to 11, wherein the fourth transceiver (206d) has a fourth plurality of transceiver channels and the fourth transceiver (206d) is configured to transmit the second signal received via the second transceiver (206c) to the fourth plurality transceiver channels (Channel 7 and Channel 8).

13. The communication system of any one of the claims 8 to 12, wherein each of the transceivers (206a, 206b, 206c, 206d) has dual transceiver channels.

14. The communication system of any one of the claims 8 to 13, wherein each of the CAN communication devices further includes a plurality of isolators

(302, 304, 306 and 308) coupled to each line of the plurality of independent CAN channels (CAN 0 and 1) of the CAN controller (202) and a plurality of electromagnetic interference protection boxes (322, 324, 326, 328, 352, 354, 356, 358) coupled between an output of each of the first transceiver (206a), the second transceiver (206c), the third transceiver (206b), the fourth transceiver (206d), and the transceiver channels.

15. The communication system of any one of the claims 8 to 14, wherein the CAN controller (202) of each of the CAN communication devices has authority to reject or accept a signal received via the Controller Area Network (CAN) bus. 16. A method of communicating between a plurality of controller area network (CAN) communication devices connected over a CAN bus, wherein the method comprises:

- receiving an input signal by a CAN controller (202);

- transmitting the input signal via two or more independent CAN channels of the CAN controller (202) to a first transceiver (206a) and a second transceiver (206c);

- transmitting via the first transceiver (206a) and the second transceiver (206c) the input signal to a third transceiver (206c) and a fourth transceiver (206d), respectively, wherein the third transceiver (206c) is coupled to the first transceiver (206a), and the fourth transceiver (206d) is coupled to the second transceiver (206c); and - outputting the input signal from a plurality of transceiver channels (Channels 1, 2, 3, 4, 5, 6, 7, and 8) associated with each of the first, second, third and fourth transceivers (206a, 206b, 206c and 206d).

17. The method of claim 16, wherein the two or more independent CAN channels (CAN 0 and CAN 1) operate at different baud rates.

18. The method of claims 16, wherein each of the transceivers (206a, 206b, 206c, 206d) has dual transceiver channels.

19. The method of claim 16, wherein the CAN controller (202) of each of the CAN communication devices has authority to reject or accept the received input signal.

20. The method of claim 16, wherein the first transceiver (206a) and the third transceiver (206b) are integrated within a single chip.

Description:
HYBRID CAN BUS SYSTEM

TECHNICAL FIELD

The present disclosure generally relates to electronic circuit devices, and specifically to systems and devices for communication, and methods of communication.

BACKGROUND

CAN or Controller Area Network is a two wired half-duplex high-speed multi master serial bus for connecting Electronic Control Units [ECUs] which is also known as nodes/end devices. CAN is basically used for communication among different nodes in a low radius region, such as in an automobile. CAN provides the ability to work in different electrical environment and ensures noise free transmission. CAN eliminates the traffic congestion as messages are transmitted based on their priority and it allows the entire network to meet the timing constraints. CAN is designed for real-time requirements and ensure the short reaction times, timely error detection, quick error recovery and error repair. CAN has widespread application in industry because of the above- mentioned advantages.

However, CAN has certain disadvantages/limitations when it is implemented in long length industrial applications with high number of nodes. FIG. 1 (Prior Art) illustrates a schematic diagram of a conventional CAN system 100. The CAN system 100 includes CAN nodes 102a-102e in daisy-chain topology connected via a bus 104. Each of the CAN nodes 102a-102e includes a CAN controller and a transceiver. According to ISO-11898 standard the maximum length L of the conventional CAN 100 is limited by signaling rate requirements as summarized in the Table 1. The maximum bus length is determined by, or rather trade-off with the selected signaling rate.

Table 1: CAN bus maximum length

According to ISO-11898 standard the distance between a start node and an end node should not exceed 1000 m for a signaling rate (bus speed) of 50 Kbps. Thus, only when the network includes only two nodes the distance between the nodes are 1000 m for a bus speed of 50 Kbps. The standard also recommends that not more than 30 nodes should be incorporated in a network. In the conventional CAN 100, repeaters are used to extend the limit of the CAN above 1000m. Further, the nodes are connected to a controller area network (CAN) in a star topology or in a daisy chain topology by incorporating intermediate T-joints into the network allowing very short stub lengths. On the other hand, the star topology a requires a passive or active hub to facilitate communication. In both topologies, additional devices such as CAN signal repeaters are used to increase a length of the network which can add significant delay in the communication depending on the number of repeaters. Furthermore, every additional device (for example, such as repeaters, hubs, and the like) that is added to the network increases the likelihood of additional faults. A fault in such a device in the CAN may lead to failure in the complete network making the CAN less desirable for time/mission critical applications. In addition, failures make it compulsory to implement redundant networks thus increasing the overall implementation cost.

Further addition or deletion of nodes such as servo drivers, sensors, actuators, controller etc. can be a difficult task, as one has to check different parameters with respect to the whole CAN.

Implementing a long length CAN also poses additional challenges such as signal attenuation, cable routing, and limitations on the possible number of nodes in the network. These challenges make the CAN difficult to implement in long length industrial applications with high number of nodes

Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks associated with conventional Controller Area Network.

The foregoing "Background" description is for the purpose of generally presenting the context of the disclosure. Work of the inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention. SUMMARY

The present disclosure seeks to provide a Controller Area Network (CAN) communication device. The present disclosure also seeks to provide a communication system. Moreover, the present disclosure also seeks to provide a method of communicating between a plurality of controller area network (CAN) communication devices connected over a CAN bus. The present disclosure seeks to provide a solution to the existing problem of using CAN in long length industrial applications with high number of nodes and in a highly noisy industrial environment. An aim of the present disclosure is to provide a solution that overcomes at least partially the problems encountered in the prior art, and that facilitates usage of CAN in long length industrial applications with high number of nodes and in a highly noisy industrial environment without the use of repeaters.

In a first aspect, an embodiment of the present disclosure provides a Controller Area Network (CAN) communication device comprising:

- a CAN controller having a plurality of independent CAN channels;

- a first transceiver coupled to a first one of the plurality of independent CAN channels of the CAN controller, the first transceiver having a first plurality of transceiver channels, the first transceiver being configured to transmit a first signal received via the first one of the plurality of independent CAN channels to the first plurality of transceiver channels;

- a second transceiver coupled to a second one of the plurality of independent CAN channels of the CAN controller, the second transceiver having a second plurality of transceiver channels, the second transceiver being configured to transmit a second signal received via the second one of the plurality of independent CAN channels to the second plurality of transceiver channels;

- a third transceiver coupled to the first transceiver; and

- a fourth transceiver coupled to the second transceiver; wherein the first transceiver is configured to transmit the first signal received via the first one of the plurality of independent CAN channels to the third transceiver, and the second transceiver is configured to transmit the second signal received via the second one of the plurality of independent CAN channels to the fourth transceiver.

In second aspect, an embodiment of the present disclosure provides a communication system comprising:

- a Controller Area Network (CAN) bus; and

- a plurality of CAN communication devices connected over the CAN bus, wherein each of the plurality of CAN communication devices includes:

- a CAN controller having a plurality of independent CAN channels;

- a first transceiver coupled to a first one of the plurality of independent CAN channels of the CAN controller, the first transceiver having a first plurality of transceiver channels, the first transceiver being configured to transmit a first signal received via the first one of the plurality of independent CAN channels to the first plurality of transceiver channels;

- a second transceiver coupled to a second one of the plurality of independent CAN channels, the second transceiver having a second plurality of transceiver channels, the second transceiver being configured to transmit a second signal received via the second one of the plurality of independent CAN channels to the second plurality of transceiver channels;

- a third transceiver coupled to the first transceiver; and

- a fourth transceiver coupled to the second transceiver, wherein the first transceiver is configured to transmit the first signal received via the first one of the plurality of independent CAN channels to the third transceiver and the second transceiver is configured to transmit the second signal received via the second one of the plurality of independent CAN channels to the fourth transceiver. In third aspect, an embodiment of the present disclosure provides a method of communicating between a plurality of controller area network (CAN) communication devices connected over a CAN bus, wherein the method comprises:

- receiving an input signal by a CAN controller; - transmitting the input signal via two or more independent CAN channels of the CAN controller to a first transceiver and a second transceiver;

- transmitting via the first transceiver and the second transceiver the input signal to a third transceiver and a fourth transceiver, respectively, wherein the third transceiver is coupled to the first transceiver, and the fourth transceiver is coupled to the second transceiver; and

- outputting the input signal from a plurality of transceiver channels associated with each of the first, second, third and fourth transceivers.

Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments construed in conjunction with the appended claims that follow.

It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.

The foregoing paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the following claims. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those skilled in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers. A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: FIG. 1 is a schematic illustration of a conventional controller area network (CAN) arrangement, in accordance with an embodiment of the present disclosure;

FIG. 2 is a block diagram illustration of a basic architecture of a CAN communication device arrangement, in accordance with an embodiment of the present disclosure;

FIG. 3 is a block diagram illustration of additional details of the CAN communication device arrangement, in accordance with an embodiment of the present disclosure; FIG. 4 is a block diagram illustration of the CAN communication device arrangement employed in a standalone multiport repeater configuration, in accordance with an embodiment of the present disclosure;

FIG. 5 is a schematic diagram illustration of a plurality of CAN communication devices arrangement connected over a CAN bus, in accordance with an embodiment of the present disclosure;

FIG. 6A is a block diagram illustration of a hybrid CAN arrangement implemented using a plurality of CAN communication devices, in accordance with an embodiment of the present disclosure;

FIG. 6B is a block diagram illustration of a hybrid CAN arrangement implemented using a plurality of CAN communication devices and a server, in accordance with an embodiment of the present disclosure;

FIG. 6C is a schematic diagram illustration of tram system where hybrid CAN is implemented, in accordance with an embodiment of the present disclosure; FIG. 7 is a flow chart illustration of steps of a method for CAN communication between a plurality of CAN devices connected on a common bus, in accordance with an embodiment of the present disclosure; and

FIG. 8 is a flow chart illustration of steps of a method for CAN communication between a plurality of devices connected on a CAN bus, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practising the present disclosure are also possible.

In a first aspect, an embodiment of the present disclosure provides a Controller Area Network (CAN) communication device comprising: - a CAN controller having a plurality of independent CAN channels;

- a first transceiver coupled to a first one of the plurality of independent CAN channels of the CAN controller, the first transceiver having a first plurality of transceiver channels, the first transceiver being configured to transmit a first signal received via the first one of the plurality of independent CAN channels to the first plurality of transceiver channels;

- a second transceiver coupled to a second one of the plurality of independent CAN channels of the CAN controller, the second transceiver having a second plurality of transceiver channels, the second transceiver being configured to transmit a second signal received via the second one of the plurality of independent CAN channels to the second plurality of transceiver channels;

- a third transceiver coupled to the first transceiver; and

- a fourth transceiver coupled to the second transceiver; wherein the first transceiver is configured to transmit the first signal received via the first one of the plurality of independent CAN channels to the third transceiver, and the second transceiver is configured to transmit the second signal received via the second one of the plurality of independent CAN channels to the fourth transceiver.

In second aspect, an embodiment of the present disclosure provides a communication system comprising:

- a Controller Area Network (CAN) bus; and

- a plurality of CAN communication devices connected over the CAN bus, wherein each of the plurality of CAN communication devices includes:

- a CAN controller having a plurality of independent CAN channels;

- a first transceiver coupled to a first one of the plurality of independent CAN channels of the CAN controller, the first transceiver having a first plurality of transceiver channels, the first transceiver being configured to transmit a first signal received via the first one of the plurality of independent CAN channels to the first plurality of transceiver channels;

- a second transceiver coupled to a second one of the plurality of independent CAN channels, the second transceiver having a second plurality of transceiver channels, the second transceiver being configured to transmit a second signal received via the second one of the plurality of independent CAN channels to the second plurality of transceiver channels;

- a third transceiver coupled to the first transceiver; and

- a fourth transceiver coupled to the second transceiver, wherein the first transceiver is configured to transmit the first signal received via the first one of the plurality of independent CAN channels to the third transceiver and the second transceiver is configured to transmit the second signal received via the second one of the plurality of independent CAN channels to the fourth transceiver.

In third aspect, an embodiment of the present disclosure provides a method of communicating between a plurality of controller area network (CAN) communication devices connected over a CAN bus, wherein the method comprises:

- receiving an input signal by a CAN controller;

- transmitting the input signal via two or more independent CAN channels of the CAN controller to a first transceiver and a second transceiver;

- transmitting via the first transceiver and the second transceiver the input signal to a third transceiver and a fourth transceiver, respectively, wherein the third transceiver is coupled to the first transceiver, and the fourth transceiver is coupled to the second transceiver; and

- outputting the input signal from a plurality of transceiver channels associated with each of the first, second, third and fourth transceivers.

In overview, embodiments of the present disclosure are concerned with providing a Controller Area Network (CAN) communication device, a communication system and a method of communicating between a plurality of controller area network (CAN) communication devices connected over a CAN bus. The Controller Area Network (CAN) communication device enables the usage of CAN in long length industrial applications with high number of nodes and in a highly noisy industrial environment without the use of repeaters.

GLOSSARY

Brief definitions of terms used throughout the present disclosure are given below.

The term "CAN end device/CAN Node" generally refers to an end device which is connected to a CAN communication device. The CAN end device can be implemented as servo drivers, sensors, actuators, controllers, or the like.

The term "independent CAN channel" generally refers to a channel/link which connects a CAN controller with at least one transceiver.

The term "transceiver channel" generally refers to a channel/link which connects a transceiver of the CAN communication device with at least one of CAN end device. The term "CAN bus" generally refers to a channel/link which connects a plurality of CAN communication devices with each other, thereby providing the channel to the plurality of CAN end devices for real time communication. The term "server" generally refers to an application, program, process or device in a client/server relationship that responds to requests for information or services by another application, program, process or device (a client) on a communication network. The term "server" also encompasses software that makes the act of serving information or providing services possible. The terms " connected " or " coupled " and related terms are used in an operational sense and are not necessarily limited to a direct connection or coupling. Thus, for example, two devices may be coupled directly, or via one or more intermediary media or devices. As another example, devices may be coupled in such a way that information can be passed there between, while not sharing any physical connection with one another. Based upon the present disclosure provided herein, one of ordinary skill in the art will appreciate a variety of ways in which connection or coupling exists in accordance with the aforementioned definition.

The terms "first", "second", and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Furthermore, the terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

The terms "a" or "an", as used herein, are defined as one or more than one. The term "plurality", as used herein, is defined as two or more than two. The term "another", as used herein, is defined as at least a second or more. The terms "including" and/or "having", as used herein, are defined as comprising (i.e., open language). The term "coupled", as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically. The term "program" or "computer program" or similar terms, as used herein, is defined as a sequence of instructions designed for execution on a computer system. A "program", or "computer program", may include a subroutine, a program module, a script, a function, a procedure, an object method, an object implementation, an executable application, an applet, a servlet, a source code, an object code, a shared library / dynamic load library and/or other sequence of instructions designed for execution on a computer system.

Reference throughout this document to "one embodiment", "certain embodiments" , "an embodiment", "an implementation" , "an example" or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure, and may be included in more than one embodiment of the present disclosure. Importantly, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments without limitation.

The term "or" as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout several views, the following description relates to a controller area network (CAN) communication device and associated methodology. The CAN communication device described herein can be deployed in a large CAN and in a highly noisy industrial environment where a very high number of nodes need to be connected using a hybrid topology. FIG. 2 is a block diagram illustration of a basic architecture of a controller area network (CAN) communication device 200, in accordance with an embodiment of the present disclosure. The CAN communication device 200 includes a CAN controller 202 (for example a microcontroller) and a plurality of transceivers 206 (first transceiver 206a, second transceiver 206c, third transceiver 206b, and fourth transceiver 206d). Each of the plurality of the transceivers 206 is provided with logic unit 204 (204a, 204b, 204c, 204d). The logic unit 204provides a mechanism for coupling two or more transceivers together.

Each of the plurality of transceivers 206 includes circuitry that is configured to broadcast signals over a transceiver channel. The CAN controller 202 includes a plurality of independent CAN channels. The number of independent CAN channels (CAN 0 and CAN 1) coupled to the CAN controller 202 will be dependent on the technical specification of the CAN controller.

In one implementation, the CAN controller 202 is configured with two independent CAN channels (CANO and CAN1). Each of the independent CAN channel includes a transmit line and a receiver line (CAN 0 TX, CAN 0 RX, CAN 1 TX, and CAN 1 RX).

Each of the transceivers 206 includes dual transceiver channels. For example, first transceiver 206a includes channel 1 and channel 2, third transceiver 206b includes channel 3 and channel 4, and the like. Each of the channel includes two or three lines (CAN_FIIGFI, CAN_LOW, and optionally CAN_GND). For example, channel 1 of first transceiver 206a includes a CAN high voltage line (CAN HIGH 1) and a CAN low voltage line (CAN LOW 1).

Each of the independent CAN channel (CANO and CAN1) of the CAN controller 202 is coupled to at least one transceiver, which is logically connected to another transceiver. For example, the CAN controller 202 is coupled to the first transceiver 206a via a first independent CAN channel (i.e., CAN 0 TX and CAN 0 RX). In turn, the logic unit 204a for the first transceiver 206a is coupled to the logic unit 204b for the third transceiver 206b for providing an input signal to the third transceiver 206b. In an embodiment, the logic unit 204a and the logic unit 204b is coupled via a copper connection. The logic unit 204a is configured to repeat the signal received via the first independent CAN channel. Thereby, one independent CAN channel provides 4 independent transceiver channels (i.e., channel 1, channel 2, channel 3, and channel 4) which carries the same data with equal signal strength (each transceiver has a dual transceiver channel).

In one implementation, second transceiver 206c is coupled to the CAN controller 202 via a second independent CAN channel (CAN 1 TX and CAN 1 RX). Further, logic unit 204d for the fourth transceiver 206d is coupled to logic unit 204c which is configured to repeat the signal received via the second independent CAN channel from the CAN controller 202. Thus, the second independent CAN channel provides four transceiver channels (i.e., channel 5, channel 6, channel 7, and channel 8). Thus, the total number of transceiver channels are eight. The CAN communication device 200 also includes or supports other peripherals such as a power supply, an electromagnetic interference/electromagnetic compatibility (EMI/EMC) protection circuit, connectors, and an in-built selectable termination unit.

The CAN communication device 200 also supports multiple Ethernet ports (three Ethernet ports), multiple digital inputs/digital outputs (8 digital inputs/8 digital outputs), one or more Universal Encoder Interfaces, etc. The CAN communication device 200 helps in attaining a hybrid CAN for distributed embedded control enabling the combination of star and daisy chain networks as described further below. Every CAN communication device has the capability to retransmit the CAN differential signal eliminating the requirement of additional CAN repeaters. Further, the CAN communication device 200 can be configured to transmit the same signal to four additional transceiver channels, eliminating the need of using T joints in the network.

FIG. 3 is a block diagram illustration of additional details of the CAN communication device 200, in accordance with an embodiment of the present disclosure. In particular, FIG. 3 illustrates a detailed block diagram of the CAN communication device 200 and the data flow inside the CAN communication device 200.

The CAN controller 202 is implemented using a TM4C1294NCPDT microcontroller by Texas Instruments ® . The CAN communication device 200 includes at least one digital isolators (302, 304, 306 and 308) between the CAN controller 202 and the transceivers (310, 314, 316, 320, 340, 344, 346, 350) for providing isolation to each of the independent CAN channel. The digital isolator is implemented using ADuMllOO digital isolator by Analog Devices ® . A first digital isolator 302 is connected on CAN0_RX. A second digital isolator 304 is connected on CAN0_TX. A third digital isolator 306 is connected on CAN1_RX. A fourth digital isolator 308 is connected on CAN1_TX.

In one implementation, the transceivers are implemented using a dual CAN transceiver such as AMIS-42770 by ON Semiconductor ® . Each of the transceiver includes two independent CAN BUS/transceiver channels as described previously herein. For example, a first transceiver 310 and a second transceiver 316 receive a data signal via first logic unit 312. The first logic unit 312 is configured to transfer the data signal to second logic unit 318. The second logic unit 318 transfers the data signal to/from a third transceiver 314 and a fourth transceiver 320.

In one implementation, the first transceiver 310, the second transceiver 316, and the first logic unit 312 are associated with a single chip. The second logic unit 318 are associated with a second chip that includes the third and fourth transceivers 314 and 320. In one implementation, a first AMIS42770 is connected to a second AMIS42770 via their multisystem transmitter input and receiver output pins. Logic units 312, 318, 342, 348 maintain carrier-sense multiple access with collision detection (CSMA-CD) on the entire network.

The same arrangement is repeated on second independent CAN channel (CAN 1) of the CAN controller 202. The second independent CAN channel (CAN 1) is connected to third logic unit 342. The third logic unit 342 transfers the data signal to and from fifth and sixth transceivers 340 and 346. The third logic unit 342 is configured to repeat the data signal received via second independent

CAN channel (CAN 1) to fourth logic unit 348. The fourth logic unit 348 is coupled to seventh and eighth transceivers 344 and 350.

The transceiver channels output from the transceivers 310, 316, 314, 320, 340, 346, 344, 350 are fed to EMI/EMC protection blocks 322, 324, 326, 328, 352, 354, 356, 358 according to one embodiment. The EMI/EMC protection blocks include a combination of electrostatic discharge (ESD) diodes, gas discharge tubes and fuses. The EMI/EMC protection blocks protect the CAN communication device 200 in case of a surge or in case of an ESD, making the CAN communication device 200 suitable for robust industrial applications. The EMI/EMC protection blocks are further connected to split termination devices 330, 332, 334, 336, 360, 362, 364, 366 according to one embodiment. In one implementation, the signals are then fed to impedance matched M12 circular connectors (338, 368) for rugged field side applications, thus minimizing the risk of loose connections.

FIG. 4 is a block diagram illustration of the CAN communication device 200 employed in a standalone multiport repeater configuration 400, in accordance with an embodiment of the present disclosure. CAN end devices 402a, 402b, 402c, 402d, 402e, 402f, 402g and 402h (hereinafter referred to as 402a-402h, for sake of convenience only) are connected to each of the channels (channel 1 to 8) of the CAN communication device 200. The CAN end devices 402 can be any device such as servo drivers, sensors, actuators, controllers, or the like. For example, five servo drivers are controlled by a single CAN communication device 200. The CAN end devices 402 receive the signal with the same or similar strength. The CAN end devices 402a-402d have the same or a different baud rate than CAN end devices 402e-402h. Flowever, these two groups i.e. 402a-402d and 402e-402h can communicate with each other regardless of the baud rate.

FIG. 5 is a schematic illustration of multiple CAN communication devices 200a, 200b, 200c, 200d and 200e (hereinafter referred to as 200a-200e, for sake of convenience only), in accordance with an embodiment of the present disclosure. In one implementation, a plurality of CAN communication devices 200a-200e are connected to each other to form a chain topology. Each of the CAN communication devices 200 acts as a repeater. Thus, there is no need to utilize additional/separate repeaters. The number of the CAN communication devices 200 that can be connected to each other are only restricted by software and the application, and there is no restriction on the number of devices on the bus. Accordingly, the CAN communication device 200 is suitable for long length CAN applications.

It will be appreciated that, in conventional CAN, the bus length is limited to 1000 m for a bus speed of 50 Kbps. The distance between nodes (indicated by L in FIG. 5) can be between 40 m to 1000 m depending on the required bus speed (for example, node distance 1000 m for a bus speed of 50 Kbps). Further, in conventional CAN, the distance between a start node and an end node cannot exceed 1000 m for a bus speed of 50 Kbps in case where the network has two nodes. Flowever, the CAN communication device facilitates incorporation of the plurality of nodes, wherein the distance between a start node and an end node is much higher than the 1000 m.

The CAN communication device 200 facilitates the CAN end devices to be connected in a hybrid network topology. In addition, the CAN communication device 200 is easily modifiable based on end applications. FIG. 6A is a block diagram illustration of a hybrid CAN 600 implemented using a plurality of CAN communication devices, in accordance with an embodiment of the present disclosure. As shown in FIG. 6A, a plurality of CAN communication devices 200a, 200b, 200c, 200d and-200e are connected in a BUS topology. Additional CAN end devices 402 are connected in a star topology. CAN end devices 402 connected to each CAN communication device 200 can be any CAN end device. For example, CAN end devices 402 connected to CAN communication device 200a indicated by 602a may be different (or of a different type) from devices 402 connected to CAN end device 200b. In one implementation, the CAN communication device 200 have eight channels as described previously herein. Thus, six CAN end devices 402 are connected to each CAN communication device 200 in the network 600. Up to six devices are connected to a stub length of 1000 m at a bus speed of 50 Kbps. The stub length is indicated by L2 in FIG. 6. The node distance is indicated by LI in FIG. 6. In comparison, in conventional devices the stub length is limited to 0.3 m.

The combination of a plurality of CAN communication devices in a network eliminates the need of any additional devices such as repeater, hub, T joints, as all such features are built into the CAN communication device 200. The approach reduces multiple cables and also makes the communication channel more robust. The CAN communication device 200 can be used in industrial, warehouse, automotive and building automation applications for deploying a hybrid CAN BUS network, thereby providing real-time communication between different CAN end devices. The CAN communication device 200 can be connected to different third-party CAN end devices as per application requirements. Further, the devices are not limited by any protocol.

Each channel of the CAN communication device 200 is capable of driving 32 nodes at a maximum speed of 1 Mbps for a cable length 40 m. Further, a high number (for example 100 devices) may be connected to each other.

FIG. 6B is a block diagram illustration of a hybrid CAN is implemented using a plurality of CAN communication devices 200 and a sever SI, in accordance with an embodiment of the present disclosure. The plurality of CAN communication devices 200a, 200b, 200c....200n are connected in a BUS topology with each other over a CAN bus. The server SI provides a signal to each of the plurality of CAN communication devices 200a, 200b, 200c....200n. In an embodiment, the server SI can provide the signal to any one of the CAN communication devices 200, which is further communicated to the other CAN communication devices over the CAN bus. The CAN controller of each of the CAN communication devices has authority to accept or reject the received signal. The CAN controller receives the signal and analyze it to make sure that the signal is meant for the CAN end devices 402 associated with the respective CAN controller. The CAN controller also adjusts the baud rate of the signal in accordance with the baud rate of the connected CAN end devices. In an exemplary embodiment, the CAN end device 402a2 associated with a first CAN communication device 200a wanted to communicate with a CAN end device 402C4 of a third CAN communication device 200c. The CAN end device 402a2 will transmit a signal to a CAN controller of the first CAN communication device 200a via a respective transceiver and independent CAN channel. The CAN controller of the first CAN communication device 200a transmit the signal over the CAN bus, on which all other CAN communication devices 200a, 200b, 200c....200n are connected. The third CAN communication device 200c will pick up the signal from the CAN bus. A respective CAN controller of the third CAN communication device 200c adjusts the baud rate of the signal in accordance with the baud rate of the CAN end device 402C4 and transmits the adjusted signal to the transceiver associated with the CAN end device 402C4 via an independent CAN channel. The transceiver further transmits the adjusted signal to the CAN end device 402c4- In a similar way, the CAN end device 402C4 can send a response signal to the 402a2- FIG. 6C is a schematic diagram illustration of tram system 900 where hybrid CAN is implemented. The tram system 900 is essentially a combination of a plurality of cars/wagons 902, 904, 906, 908, 910, and 912 which are connected in sequence, to operate on a rail network. The tram system 900 can extend over hundreds of meters in length, and includes a plurality of electronic units/sub-units for providing different functionalities in each of the car/wagon. Each of the electronic units/sub-units requires a communication channel to connect with each other and operate in synchronous manner. The communication channel of the plurality of electronic units/sub-units are distributed over long lengths demands the time critical operation, redundancy, robust communication, ability to add multiple electronic units/sub-units on same channel, and availability and scalability of network. For example, an activity of controlling the doors 902D, 904D, 906D, 908D, 910D, and 912D of the tram requires the following functionalities: i) opening/closing of all the doors 902D, 904D, 906D, 908D, 910D, and 912D synchronously; ii) feedback on opening/closing of the doors 902D, 904D, 906D, 908D, 910D, and 912D; iii) response to passenger/object stuck at doors 902D, 904D, 906D, 908D, 910D, and 912D; iv) synced display/indication of status of door in real time; and v) ability to control any door independently. This single operation of controlling doors requires multiple sensors and actuators. The door opening operation is managed by motor driver which receives the command from a central processing system. The sensor which detect obstacle in the door path gives feedback to the central processing system and the central processing system has to take the correct decision in real time. Thus, the proposed invention provides a suitable solution for the above application. Each of the wagon/car is provided with the one or more CAN communication device(s). The doors along with the sensors, actuators and motor driver are connected to the CAN communication device present in each of the car/wagon, and the CAN communication devices present in every car/wagon are interconnected with each other and the central processing system, thus providing real-time communication between the central processing system and the multiple doors of the tram system. There is no limit (virtually) to the number of devices which can be connected to the CAN communication devices and therefore it will not restrict the length of overall tram, and redundancy can also be achieved for safety critical requirements inside tram. As independent communication channel still supports conventional CAN capabilities, multiple end devices can also be interfaced. Further there is no limit for the topologies (star, bus and the like) which have their own specific advantages.

FIG. 7 is a flow chart illustrating steps of a method 700 of communicating between a plurality of CAN communication devices connected over a CAN bus, in accordance with an embodiment of the present disclosure. At step 702, the CAN controller 202 receives an input signal, by a CAN controller (202). At step 704, the CAN controller 202 transmits the input signal via two or more independent CAN channels (for example CANO TX, CAN1 TX of FIG. 2) of the CAN controller (202) to a first transceiver (206a) and a second transceiver (206c). Then at step 706, the first transceiver (206a) and the second transceiver (206c) transmits the input signal to a third transceiver (206b) and a fourth transceiver (206d), respectively. The third transceiver (206c) is coupled to the first transceiver (206a), and the fourth transceiver (206d) is coupled to the second transceiver (206c). At step 708, the input signal is outputted from a plurality of transceiver channels (Channels 1, 2, 3, 4, 5, 6, 7, and 8) associated with each of the first, second, third and fourth transceivers (206a, 206b, 206c and 206d).

The depicted order and labeled steps are indicative of one embodiment of the presented method 700. Other steps and methods may be conceived that are equivalent in function, logic, or effect of one or more steps or portions thereof, of the illustrated method 700. Additionally, the format and symbols employed are provided to explain the logical steps of the method 700 and are understood not to limit the scope of the method 700. Further, although the method 700 is described with respect to transmitting a signal to the transceiver channels, it is understood that the method 700 applies to receiving data from the transceiver channels and transmitting data to the CAN controller 202.

FIG. 8 is a flow chart illustrating a method 800 of communicating between the plurality of CAN communication devices connected over the CAN bus according to an embodiment of the present disclosure. At step 802, the CAN end device 402 transmits a signal to the CAN controller 202 via the transceiver channels. At step 804, the logic units of two or more transceivers transmit the signal received by the two or more transceivers to the CAN controller 202 (for example via CANO RX, CAN1 RX of FIG. 2). The two or more transceivers receive the signal via the transceiver channels. At step 806, the logic units of two or more additional transceivers transmit the signal received by the two or more additional transceivers to the CAN controller 202. At step 808, the CAN controller 202 receives the signal.

The CAN communication device described herein is used in any distributed embedded control system.

Obviously, numerous modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. Thus, the foregoing discussion discloses and describes merely exemplary embodiments of the present invention. As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting of the scope of the invention, as well as other claims. The disclosure, including any readily discernible variants of the teachings herein, defines, in part, the scope of the foregoing claim terminology such that no inventive subject matter is dedicated to the public.

The above disclosure also encompasses the embodiments listed below. (1) A Controller Area Network (CAN) communication device comprising: a CAN controller (202) having a plurality of independent CAN channels (CAN 0, CAN 1); a first transceiver (206a) coupled to a first one of the plurality of independent CAN channels (CAN 0) of the CAN controller (202), the first transceiver (206a) having a first plurality of transceiver channels (Channels 1 and 2), the first transceiver (206a) being configured to transmit a first signal received via the first one of the plurality of independent CAN channels (CAN 0) to the first plurality of transceiver channels (Channel 1 and 2); a second transceiver (206c) coupled to a second one of the plurality of independent CAN channels (CAN 1) of the CAN controller (202), the second transceiver (206c) having a second plurality of transceiver channels (Channels 5 and 6), the second transceiver (206C) being configured to transmit a second signal received via the second one of the plurality of independent CAN channels (CAN 1) to the second plurality of transceiver channels (Channel 5 and 6); a third transceiver (206b) coupled to the first transceiver (206a); and a fourth transceiver (206d) coupled to the second transceiver (206c); in which the first transceiver (206a) is configured to transmit the first signal received via the first one of the plurality of independent CAN channels (CAN 0) to the third transceiver (206b), and the second transceiver (206c) is configured to transmit the second signal received via the second one of the plurality of independent CAN channels (CAN 1) to the fourth transceiver (206d). (2) The device (200) of feature (1), wherein the first transceiver (206a) and the third transceiver (206b) are integrated within a single chip.

(3) The device (200) of feature (1) or (2) further including a plurality of isolators (302, 304, 306 and 308) coupled to each line of the plurality of independent CAN channels (CAN 0 and 1) of the CAN controller (202); and - a plurality of electromagnetic interference protection boxes (322, 324, 326, 328, 352, 354, 356, 358) coupled between an output of each of the first transceiver (206a), the second transceiver (206c), the third transceiver (206b), the fourth transceiver (206d), and the transceiver channels. (4) The device (200) of feature (1) to (4), in which each of the plurality of independent CAN channels operate at different baud rates.

(5) The device (200) of feature (1) to (5), in which the third transceiver (206b) has a third plurality of transceiver channels and the third transceiver (206b) is configured to transmit the first signal received via the first transceiver (206a) to the third plurality of transceiver channels (Channel 3 and Channel 4).

(6) The device (200) of feature (1) to (6), in which the fourth transceiver (206d) has a fourth plurality of transceiver channels and the fourth transceiver (206d) is configured to transmit the second signal received via the second transceiver (206c) to the transceiver channels (Channel 7 and Channel 8). (7) The device (200) of feature (1) to (7), in which each of the transceivers

(206a, 206b, 206c, 206d) has dual transceiver channels.

(8) A communication system comprising: a Controller Area Network (CAN) bus; a plurality of CAN communication devices connected over the CAN bus, in which each of the plurality of CAN communication devices includes: a CAN controller (202) having a plurality of independent CAN channels (CAN 0, CAN 1); a first transceiver (206a) coupled to a first one of the plurality of independent CAN channels (CAN 0) of the CAN controller (202), the first transceiver (206a) having a first plurality of transceiver channels (Channels 1 and 2), the first transceiver (206a) being configured to transmit a first signal received via the first one of the plurality of independent CAN channels (CANO) to the first plurality of transceiver channels (Channel 1 and Channel 2), a second transceiver (206c) coupled to a second one of the plurality of independent CAN channels (CAN1), the second transceiver (206c) having a second plurality of transceiver channels (Channels 5 and 6), the second transceiver (206c) being configured to transmit a second signal received via the second one of the plurality of independent CAN channels (CAN 1) to the second plurality of transceiver channels (Channel 5 and Channel 6); a third transceiver (206b) coupled to the first transceiver (206a), and a fourth transceiver (206d) coupled to the second transceiver (206c), in which the first transceiver (206a) is configured to transmit the first signal received via the first one of the plurality of independent CAN channels (CAN 0) to the third transceiver (206b) and the second transceiver (206c) is configured to transmit the second signal received via the second one of the plurality of independent CAN channels (CAN 1) to the fourth transceiver (206d).

(9) The communication system of the feature (9), in which the first transceiver (206a) and the third transceiver (206b) are integrated within a single chip.

(10) The communication system of any of features (9) to (10), wherein each of the plurality of independent CAN channels operate at different baud rates. (11) The communication system of any one of the features (9) to (10), in which the third transceiver (206b) has a third plurality of transceiver channels and the third transceiver (206b) is configured to transmit the first signal received via the first transceiver (206a) to the third plurality of transceiver channels (Channel 3 and Channel 4).

(12) The communication system of any one of the features (9) to (11), in which the fourth transceiver (206d) has a fourth plurality of transceiver channels and the fourth transceiver (206d) is configured to transmit the second signal received via the second transceiver (206c) to the fourth plurality transceiver channels (Channel 7 and Channel 8).

(13) The communication system of any one of the features (9) to (13), in which each of the transceivers (206a, 206b, 206c, 206d) has dual transceiver channels.

(14) The communication system of any one of the features (9) to (14), in which each of the CAN communication devices further includes a plurality of isolators

(302, 304, 306 and 308) coupled to each line of the plurality of independent CAN channels (CAN 0 and 1) of the CAN controller (202) and a plurality of electromagnetic interference protection boxes (322, 324, 326, 328, 352, 354, 356, 358) coupled between an output of each of the first transceiver (206a), the second transceiver (206c), the third transceiver (206b), the fourth transceiver (206d), and the transceiver channels.

(15). The communication system of any one of the claims 8 to 14, wherein the CAN controller (202) of each of the CAN communication devices has authority to reject or accept a signal received via the Controller Area Network (CAN) bus. (16) A method of communicating between a plurality of controller area network (CAN) communication devices connected over a CAN bus. The method includes receiving an input signal by a CAN controller (202); transmitting the input signal via two or more independent CAN channels of the CAN controller to a first transceiver (206a) and a second transceiver (206c); transmitting via the first transceiver (206a) and the second transceiver (206c) the input signal to a third transceiver (206c) and a fourth transceiver (206d), respectively, wherein the third transceiver (206c) is coupled to the first transceiver (206a), and the fourth transceiver (206d) is coupled to the second transceiver (206c); and outputting the input signal from a plurality of transceiver channels (Channels 1, 2, 3, 4, 5, 6, 7, and 8) associated with each of the first, second, third and fourth transceivers (206a, 206b, 206c and 206d).

(17). The method of feature (17), in which the two or more independent CAN channels (CAN 0 and CAN 1) operate at different baud rates. (18). The method of claims 16, wherein each of the transceivers (206a, 206b,

206c, 206d) has dual transceiver channels.

(19). The method of claim 16, wherein the CAN controller (202) of each of the CAN communication devices has authority to reject or accept the received input signal. (20). The method of claim 16, wherein the first transceiver (206a) and the third transceiver (206b) are integrated within a single chip.