CN113612674B

CN113612674B - Time division multiplexing communication method for EPA system, EPA device and medium

Info

Publication number: CN113612674B
Application number: CN202111158421.3A
Authority: CN
Inventors: 李红波; 邓文敏; 陈建飞; 王迎; 王海帆
Original assignee: Zhejiang Guoli Xin'an Technology Co ltd
Current assignee: Zhejiang Guoli Xin'an Technology Co ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2022-01-04
Anticipated expiration: 2041-09-30
Also published as: CN113612674A

Abstract

The invention provides a time division multiplexing communication method for an EPA system, an EPA device and a computer readable storage medium. The EPA system includes a plurality of EPA devices. The method comprises the following steps: at each EPA device, receiving configuration information for the EPA system; determining whether the EPA device is a sibling device that shares a same periodic time slice with at least one other EPA device of the plurality of EPA devices based on the configuration information; in response to determining that the EPA device is a sibling device, determining whether a next communication cycle of the communication cycle is a transmission cycle of the EPA device based on the configuration information and a cycle time slice occupancy indication received at one communication cycle; and in response to determining that a next communication cycle of the communication cycles is a transmission cycle of the EPA device, transmitting a cycle message during a cycle time period of the next communication cycle.

Description

Time division multiplexing communication method for EPA system, EPA device and medium

Technical Field

The present invention relates generally to the field of communications, and more particularly, to a time division multiplexing communication method for an EPA system, an EPA apparatus, and a computer-readable storage medium.

Background

The industrial Ethernet (EPA) bus is the first fieldbus standard with completely proprietary intellectual property rights in china, and is also an international standard for industrial Automation, and has been widely used in the field of industrial Automation control. The EPA bus uses the physical layer of the Ethernet as a transmission basis and realizes high-speed, strong real-time and reliable transmission through the EPA protocol. As the EPA bus becomes more complex, its application scenarios become more diverse, and the different EPA networks used are increasing.

In an EPA system containing multiple EPA devices, a deterministic scheduling scheme is employed to allocate the time each EPA device occupies the EPA bus. Deterministic scheduling refers to assigning a fixed transmission time slice to each EPA device for transmitting periodic messages during the periodic time period of each communication cycle.

However, in some cases, some EPA devices in an EPA system may not need to send periodic messages every communication cycle, and reserving transmission slots for these EPA devices every communication cycle would be wasteful of resources. On the other hand, as the EPA system increases, the number of EPA devices included in the EPA system increases, and such a deterministic scheduling scheme will inevitably make the communication cycle side long, thereby causing a decrease in transmission efficiency.

Disclosure of Invention

In view of at least one of the above problems, the present invention provides a time-division multiplexing communication method for an EPA system, in which the bandwidth utilization of the system is improved by setting two or more EPA devices (e.g., EPA devices with low real-time requirements) in the EPA system as sibling devices and making these sibling devices share the same cycle time slice in a time-division multiplexing manner, and the response time of key information is improved by even further shortening the communication cycle length.

According to one aspect of the present invention, a time division multiplexing communication method for an EPA system is provided. The EPA system includes a plurality of EPA devices. The method comprises the following steps: at each EPA device, receiving configuration information for the EPA system; determining whether the EPA device is a sibling device that shares a same periodic time slice with at least one other EPA device of the plurality of EPA devices based on the configuration information; in response to determining that the EPA device is a sibling device, determining whether a next communication cycle of the communication cycle is a transmission cycle of the EPA device based on the configuration information and a cycle time slice occupancy indication received at one communication cycle; and in response to determining that a next communication cycle of the communication cycles is a transmission cycle of the EPA device, transmitting a cycle message during a cycle time period of the next communication cycle.

In some embodiments, the periodic time slice occupancy indication comprises a heartbeat message received from a master clock device of the EPA system, and wherein determining whether a next communication cycle of the communication cycles is a transmission cycle of the EPA device comprises: and determining whether the next communication period of the communication period is the sending period of the EPA equipment or not based on the heartbeat message and the configuration information.

In some embodiments, the heartbeat message includes a heartbeat cycle code and the configuration information includes a time division multiplexing rule of a plurality of sibling devices for a same cycle time slice.

In some embodiments, the time-division multiplexing rule includes a multiplexing occupancy or an occupancy order of the periodic time slices by each of the plurality of sibling devices.

In some embodiments, the periodic time slice occupancy indication comprises a periodic message received from the at least one other EPA device, and wherein determining whether a next communication period of the communication period is a transmission period of the EPA device comprises: determining whether a next communication cycle of the communication cycle is a transmission cycle of the EPA device by determining whether the cycle message contains a declaration by the other EPA device of a cycle time period of the next communication cycle.

In some embodiments, the configuration information includes sibling device priority information indicating a sibling device preferentially transmitted among a plurality of sibling devices occupying a same cycle time slice.

In some embodiments, the sibling device priority information indicates the sibling device with the smallest IP address.

In some embodiments, the method further comprises: in response to determining that a next communication cycle of the communication cycles is not a transmission cycle of the EPA device, to remain silent during a cycle period of the next communication cycle.

According to another aspect of the present invention, there is provided an EPA apparatus comprising: a processor and a memory, the memory storing instructions executable by the processor, the processor being configured to, upon execution of the instructions, cause the EPA device to perform any of the methods described above.

According to yet another aspect of the invention, there is provided a computer readable storage medium having stored thereon computer program code which, when executed by a processor, performs any of the methods described above.

Drawings

The invention will be better understood and other objects, details, features and advantages thereof will become more apparent from the following description of specific embodiments of the invention given with reference to the accompanying drawings.

Fig. 1 shows a schematic diagram of an exemplary EPA system 100 according to an embodiment of the present invention.

Fig. 2 shows a transmission timing diagram of respective EPA devices of the EPA system 100 according to the prior art.

Fig. 3 illustrates a flow diagram of a time division multiplexed communication method 300 for EPA system 100 according to some embodiments of the present invention.

Fig. 4 illustrates a transmission timing diagram for various EPA devices of EPA system 100 according to some embodiments of the present invention.

Fig. 5 shows a block diagram of an EPA device 500 suitable for implementing embodiments of the invention.

Detailed Description

Preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In the following description, for the purposes of illustrating various inventive embodiments, certain specific details are set forth in order to provide a thorough understanding of the various inventive embodiments. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of the specific details. In other instances, well-known devices, structures and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Throughout the specification and claims, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be understood as an open, inclusive meaning, i.e., as being interpreted to mean "including, but not limited to," unless the context requires otherwise.

Reference throughout this specification to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in some embodiments" 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.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between various objects for clarity of description only and do not limit the size, other order and the like of the objects described therein unless otherwise specified.

Fig. 1 shows a schematic diagram of an exemplary EPA system 100 according to an embodiment of the present invention. As shown in fig. 1, EPA system 100 includes a plurality of

EPA devices

10, 20, 30, 40 and 50 (5 EPA devices are schematically shown in fig. 1), where EPA

devices

10 and 20 are connected by link 12,

EPA devices

20 and 30 are connected by link 22,

EPA devices

30 and 40 are connected by link 32,

EPA devices

40 and 50 are connected by link 42, EPA

devices

50 and 10 are connected by link 52, EPA

devices

10 and 40 are connected by link 62, and EPA

devices

10 and 30 are connected by link 72. Note that the EPA system 100 is illustrated in fig. 1 as a hybrid topology, but those skilled in the art will appreciate that the EPA system 100 is not limited to the hybrid topology shown in fig. 1, but may have other types of topologies, such as a star configuration, a ring configuration, and the like.

Fig. 2 shows a transmission timing diagram of respective EPA devices of the EPA system 100 according to the prior art. As shown in fig. 2, each EPA device performs periodic communication using the same communication period T, also referred to as a macrocycle, which is a basic scheduling unit, continuous in time. The macrocycle is again divided into a periodic time period Tp and a non-periodic time period Tn.

The period time period Tp of each communication cycle T is used for each EPA device to send periodic messages, such as the periodic messages P10, P20, P30, P40, and P50 shown in FIG. 2. Wherein, in a given communication mode, each EPA device in the EPA system 100 may be assigned a fixed transmission time slice (also referred to as a cycle time slice) during the cycle time period Tp to transmit its cycle message, the start time point and length of the cycle time slice being unique for each EPA device without overlapping and conflicting with other EPA devices. Thus, the timing diagram shown in fig. 2 is a deterministic scheduling scheme. The period time period Tp is mainly used to transmit a specified type of big data or a specific type of message data, which is a main data transmission time.

The aperiodic time period Tn of the communication cycle T is a time period common to all EPA devices, and each EPA device may carry an aperiodic declaration field in a cycle message sent in the cycle time period Tp according to actual needs to declare a transmission time slice (also referred to as an aperiodic time slice) of the aperiodic time period Tn. Each EPA device calculates its own transmission start time based on the aperiodic declarations of the other EPA devices and makes its own aperiodic declaration such that the aperiodic time slices declared by the respective EPA devices do not overlap each other. Such calculation and declaration is made every cycle time period Tp to determine the time allocation of the non-cycle time period Tn of the current communication cycle T. In the non-periodic time period Tn, each EPA device may be configured to send various control messages or a few key messages with different lengths, which may also be referred to as non-periodic messages, as shown in fig. 2 by diagonal boxes.

As shown in fig. 2, the EPA system 100 allocates a periodic transmission time slice to each EPA device in each communication period T, and the time slice is occupied regardless of whether the EPA device has periodic data to transmit, thereby ensuring real-time and reliability. However, in practical applications, the real-time requirements for sending data by different EPA devices may be different, even very different. For example, assuming that the duration of one communication period T is 50us, information for controlling the wheel speed from an important control device (for example, EPA device 20 shown in fig. 1 and 2) requires high real-time performance and high reliability. It is therefore necessary to ensure that its cycle time slot per communication cycle T is not occupied, so that the information on the rotational speed of the wheel is reported to the control device every 50 us. However, the information feedback of the EPA devices (such as the EPA

devices

40 and 50 shown in fig. 1 and 2) such as a rainfall sensor, a temperature sensor, and a brightness sensor does not need as high real-time performance, and the information can be reported in tens of milliseconds or even in seconds, and it is obvious that they still occupy a fixed cycle time slice every communication cycle T and cause resource waste.

In view of this, the present invention contemplates that it may be determined whether there are at least two EPA devices in the EPA system 100 that may share the same periodic timeslice, and in the presence of such EPA devices, a time division multiplexing communication scheme is designed to enable these EPA devices to time-multiplex the same periodic timeslice.

Fig. 3 illustrates a flow diagram of a time division multiplexed communication method 300 for EPA system 100 according to some embodiments of the present invention. The method 300 may be implemented, for example, at various EPA devices in the EPA system 100 shown in fig. 1. Fig. 4 illustrates a transmission timing diagram for various EPA devices of EPA system 100 according to some embodiments of the present invention.

The EPA system 100 may be configured prior to the beginning of the method 300 or as part of the method 300. In configuring the configuration, each EPA device may be assigned cycle time slice information for the EPA device to send periodic messages during the cycle time period Tp of each communication cycle T. For example, each EPA device may be assigned a transmission start time offset and end time offset/duration for its unique periodic time slice. Further, unlike conventional techniques, at configuration time, it may also be determined whether there are at least two EPA devices in the EPA system 100 that may share the same cycle time slice, and the same cycle time slice is specified for such EPA devices when they are present (such EPA devices are also referred to as sibling devices). Specifically, whether at least two EPA devices can share the same periodic time slice may be determined based on the real-time requirement of the data that each EPA device needs to report periodically. For example, as described above, for a communication cycle with a duration of 50us, if at least two EPA devices in the EPA system 100 need to report information only once in tens of milliseconds or even in seconds, it is considered that these EPA devices can share the same cycle time slice.

In addition, prior to the beginning of method 300 or as part of method 300, contention and synchronization may also be performed between the various EPA devices in EPA system 100 to determine the master clock device from among the EPA devices. In the following, it is assumed that the EPA device 10 becomes the master clock device of the EPA system 100 by contention, also referred to as master clock device 10. In some embodiments of the present invention, the master clock device 10 may send a periodic heartbeat message in the aperiodic time period Tn of each communication cycle T to indicate to the sibling devices whether they should occupy their allocated cycle time slice in the next communication cycle T.

As shown in fig. 3, each EPA device receives configuration information for EPA system 100 at step 310. As mentioned above, the configuration information may include cycle time slice information for each EPA device to send a cycle message. In addition, the configuration information should also indicate to each EPA device its sibling information, i.e. whether it shares the same periodic time slice with other EPA devices and which periodic time slice with which other EPA devices. The sibling information may be indicated explicitly or implicitly. The explicit method includes, for example, the configuration information including the sibling device group information, in which a plurality of sibling devices sharing the same cycle time slice and the cycle time slice occupied by the sibling devices are specified. Note that in one EPA system 100, there may be a plurality of sibling device groups, and EPA devices included in these sibling device groups do not overlap with each other. For example, as shown in fig. 1 and 2, in the case where

EPA devices

20, 30, 40, and 50 are all devices with low real-time requirements, the EPA devices may be divided into one or more sibling device groups depending on the difference in real-time requirements of the EPA devices. For example, if

EPA devices

20, 30, 40 and 50 are all devices that need to upload control information every few seconds, they may be divided into a homogeneous group of devices sharing the same periodic time slice. If

EPA devices

20, 30, 40 and 50 are all devices that need to upload control information once every 100us, they may be divided into two sibling device groups, each sharing one cycle time slice. The implicit approach may not include any additional information in the configuration information. In this case, each EPA device may determine whether it is a sibling device with at least one other EPA device by configuring the periodic time slice specified for each EPA device in the configuration information.

At step 320, each EPA device may determine whether the EPA device is a sibling device sharing the same periodic time slice with at least one other EPA device based on the configuration information received at step 310.

As described above, in the case where the configuration information explicitly includes the sibling device group information, each EPA device may determine whether it belongs to a sibling device group based on the sibling device group information, and if it belongs to a sibling device group, it may also determine the cycle time slice corresponding to the sibling device group. For example, if the sibling device group information included in the configuration information includes two sibling device groups,

EPA devices

20 and 30 belong to a first sibling device group assigned a first periodic time slice, and

EPA devices

40 and 50 belong to a second sibling device group assigned a second periodic time slice. In this case, EPA device 20 may determine that it belongs to the first sibling device group with EPA device 30 based on the configuration information, whose cycle time slice is the first cycle time slice.

In the case where the configuration information implicitly indicates sibling information, the EPA device may determine whether it is a sibling device with at least one other EPA device by the periodic time slice specified for each EPA device in the configuration information. For example, if the EPA device 40 determines that its assigned periodic time slice is the same as the EPA device 50, the EPA device 40 may determine that it is a sibling device with the EPA device 50.

Hereinafter, as shown in fig. 4, with EPA device 10 in EPA system 100 as the master clock device,

EPA devices

20, 30 need not share a periodic time slice with other EPA devices (i.e., not a co-owned device), while EPA device 40 needs to share the same periodic time slice with EPA device 50 (i.e., both are co-owned devices), for example.

If it is determined in step 320 that the EPA device is a sibling device, in step 330, the EPA device may determine whether the next communication cycle T +1 of the communication cycle T is the transmission cycle of the EPA device based on the configuration information received in step 310 and the cycle slot occupancy indication received in the current communication cycle T.

In some embodiments, the periodic time slice occupancy indication comprises a periodic heartbeat message 410 received from master clock device 10 of EPA system 100, as shown in fig. 4. The periodic heartbeat message 410 may include a cyclic heartbeat code and may use any known or newly defined messaging encapsulation format. In this case, the EPA device may determine whether the next communication cycle T +1 of communication cycle T is the sending cycle of the EPA device based on the heartbeat message 410 and the configuration information received in step 310.

The heartbeat message 410 may be sent during a non-periodic time period Tn of the communication cycle T. As mentioned earlier, the occupation of the aperiodic time period Tn by the respective EPA device is achieved by making an aperiodic declaration in its periodic message. Thus, in the presence of a co-owned device in EPA system 100, master clock device 10 may include an aperiodic declaration in the period time period Tp of each communication cycle T (which may be part of periodic message P10 of master clock device 10, as indicated by reference numeral 420 in fig. 4), sending periodic heartbeat message 410 in an aperiodic time slice that declares the aperiodic time period Tn of that communication cycle T.

For this reason, the configuration information may include a time division multiplexing rule of a plurality of sibling devices for a same cycle time slice, for example, in a case that a periodic heartbeat message includes a cyclic heartbeat code, the configuration information may include a multiplexing occupation ratio or an occupation sequence of each sibling device for the cycle time slice. Therefore, the EPA device as a peer device may determine whether the next communication cycle T +1 of the communication cycle T is the sending cycle of the EPA device based on the heartbeat message 410 and the time division multiplexing rule in the configuration information. For example, assuming that the

EPA devices

40 and 50 are the same device, the cyclic heartbeat code is a cyclic heartbeat code that cycles from 0 to 255, and the multiplexing percentage of the

EPA devices

40 and 50 to the periodic time slice is 50% each, or the occupation sequence is that the EPA device 40 sends the EPA device 50 first, it can be determined that the EPA device 40 can send its period message P40 in the periodic time slice when the cyclic heartbeat code is 0, 2, 4 … … 254, and the EPA device 50 can send its period message P50 in the periodic time slice when the cyclic heartbeat code is 1, 3, 5 … … 255.

In this case, if the cyclic heartbeat code in the heartbeat message received at communication period T is 31, at step 330, EPA device 40 may determine that the next communication period T +1 is not its transmission period, and EPA device 50 may determine that the next communication period T +1 is its transmission period.

In other embodiments, the periodic time slice occupancy indication comprises a periodic message received from at least one other EPA device (i.e., other sibling devices of the EPA device). In this case, the EPA device may determine whether the next communication cycle T +1 of the communication cycle T is a transmission cycle of the EPA device by determining whether the cycle message contains a declaration of the other EPA device for the cycle period of the next communication cycle T +1 at step 330. If the period message contains the declaration of the period time period of the next communication period T +1 by the other EPA device, it may be determined that the next communication period T +1 of the communication period T has been declared and occupied by the sibling device of the EPA device, and thus the next communication period T +1 is not the transmission period of the EPA device. If the period message does not contain the declaration of the other EPA device to the period time period of the next communication period T +1, it may be determined that the next communication period T +1 of the communication period T is not declared and occupied by the sibling device of the EPA device, and thus the next communication period T +1 may be used as the transmission period of the EPA device. That is, in such an embodiment, the occupancy of the same cycle time slice by each sibling device is determined by the autonomous coordination of the sibling devices. For example, the EPA device 50 may determine whether the next communication cycle T +1 of the communication cycle T is the transmission cycle of the EPA device 50 by determining whether the cycle message P40 received from the EPA device 40 as its affiliated device contains a declaration by the EPA device 40 of the cycle period of the next communication cycle T + 1. If the period message P40 contains an assertion of the period time of the next communication period T +1 by the EPA device 40, it may be determined that the next communication period T +1 of the communication period T has been asserted and occupied by a sibling device of the EPA device 50, and therefore the next communication period T +1 is not a transmission period of the EPA device 50. If the period message P40 does not contain an assertion of the period time of the next communication period T +1 by the EPA device 40, it may be determined that the next communication period T +1 of the communication period T is not asserted and occupied by a sibling device of the EPA device 50, and thus the next communication period T +1 may be used as a transmission period of the EPA device 50.

For this purpose, the configuration information may include the priority information of the sibling devices. The sibling device priority information indicates a sibling device preferentially transmitted among a plurality of sibling devices occupying the same cycle time slice. For example, the sibling device priority information may indicate that the sibling device with the smallest IP address transmits preferentially. In this way, each sibling device may be enabled to determine the first sibling device occupying the shared cycle time slice at initialization.

If it is determined at step 330 that the next communication cycle T +1 is the transmission cycle of the EPA device, the EPA device may transmit the cycle message during the cycle period of the next communication cycle T +1 at step 340. For example, if at step 330 the EPA device 50 determines that the next communication cycle T +1 is its transmission cycle, at step 340 the EPA device 50 may transmit its cycle message P50 during the cycle time period of the next communication cycle T + 1. That is, the EPA device 50 may occupy the cycle time slice allocated to the EPA device 40 and the EPA device 50 at the next communication cycle T + 1.

On the other hand, if it is determined at step 330 that the next communication period T +1 is not the transmission period of the EPA device, the method 300 may further include step 350, where the EPA device may remain silent during the period of the next communication period T + 1. For example, if at step 330 the EPA device 40 determines that the next communication period T +1 is not its transmission period, at step 350 the EPA device 40 may remain silent during the period of the next communication period T + 1.

On the other hand, if it is determined in step 320 that the EPA device is not a different device, i.e., does not need to share the same periodic time slice with other EPA devices, the method 300 may further include step 360 in which the EPA device transmits a periodic message during the periodic time period of the next communication period T + 1. That is, the EPA device may send its own periodic messages at the periodic timeslices indicated by the configuration information for the EPA device. For example, for

EPA devices

20 and 30 that they are not the same device as determined in step 320, the transmission of periodic messages P20 and P30 may be performed normally every communication cycle.

By using the scheme, a plurality of EPA devices (e.g., a plurality of EPA devices with low real-time requirements) that can share the same cycle time slice are set as the same-family devices in the system configuration stage, and the master clock device sends the periodic heartbeat packet in each communication cycle or the same-family devices coordinate autonomously based on the priority rule, so that the plurality of same-family devices can multiplex the same cycle time slice in a time-sharing manner, thereby improving the bandwidth utilization rate. In addition, by the scheme, the duration of the communication period can be reduced, so that the response time of key information (such as periodic data of EPA equipment with high real-time requirement) is prolonged.

Fig. 5 shows a block diagram of an EPA device 500 suitable for implementing embodiments of the invention. EPA device 500 may be used to implement any of a number of EPA devices as shown in fig. 1.

As shown in fig. 5, EPA device 500 may comprise a processor 510. Processor 510 controls the operation and functions of EPA device 500. For example, in some embodiments, processor 510 may perform various operations by way of instructions 530 stored in memory 520 coupled thereto. The memory 520 may be of any suitable type suitable to the local technical environment and may be implemented using any suitable data storage technology, including but not limited to semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems. Although only one memory 520 is shown in fig. 5, those skilled in the art will appreciate that EPA device 500 may include many more physically distinct memories 520.

The processor 510 may be of any suitable type suitable to the local technical environment, and may include, but is not limited to, one or more of general purpose computers, special purpose computers, microprocessors, Digital Signal Processors (DSPs) and processor-based multi-core processor architectures. EPA device 500 may also include multiple processors 510. The processor 510 is coupled to a transceiver 540, which transceiver 540 may facilitate the reception and transmission of information by way of one or more antennas 550 and/or other components. All of the features described above with reference to fig. 1 to 4 apply to the EPA device 500 and will not be described in detail here.

The present invention may be embodied as methods, apparatus, systems, and/or computer program products. The computer program product may include a computer-readable storage medium having computer-readable program instructions embodied therein for carrying out aspects of the present invention.

In one or more exemplary designs, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. For example, if implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium.

The units of the apparatus disclosed herein may be implemented using discrete hardware components, or may be integrally implemented on a single hardware component, such as a processor. For example, the various illustrative logical blocks, modules, and circuits described in connection with the invention may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both.

The previous description of the invention is provided to enable any person skilled in the art to make or use the invention. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the present invention is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A time division multiplexing communication method for an EPA system, the EPA system comprising a plurality of EPA devices, the method comprising:

receiving configuration information of the EPA system at each EPA device, wherein the configuration information comprises time division multiplexing rules of a plurality of affiliated devices to a same cycle time slice;

determining whether the EPA device is a sibling device that shares a same periodic time slice with at least one other EPA device of the plurality of EPA devices based on the configuration information;

in response to determining that the EPA device is a sibling device, determining whether a next communication cycle of the communication cycle is a transmission cycle of the EPA device based on the configuration information and a cycle time slice occupancy indication received at one communication cycle; and

in response to determining that a next communication cycle of the communication cycles is a transmit cycle of the EPA device, transmit a cycle message during a cycle time period of the next communication cycle.

2. The method of claim 1, wherein the periodic time slice occupancy indication comprises a heartbeat message received from a master clock device of the EPA system, and wherein determining whether a next communication cycle of the communication cycles is a transmission cycle of the EPA device comprises:

and determining whether the next communication period of the communication period is the sending period of the EPA equipment or not based on the heartbeat message and the configuration information.

3. The method of claim 2, wherein the heartbeat message includes a heartbeat cycle code.

4. The method of claim 3, wherein the time-division multiplexing rule comprises a multiplexing occupancy or an occupancy order of the periodic time slices by each of the plurality of sibling devices.

5. The method of claim 1, wherein the periodic time slice occupancy indication comprises a periodic message received from the at least one other EPA device, and wherein determining whether a next communication period of the communication period is a transmission period of the EPA device comprises:

determining whether a next communication cycle of the communication cycle is a transmission cycle of the EPA device by determining whether the cycle message contains a declaration by the other EPA device of a cycle time period of the next communication cycle.

6. The method of claim 5, wherein the configuration information comprises sibling device priority information indicating a sibling device preferentially transmitting among a plurality of sibling devices occupying a same cycle time slice.

7. The method of claim 6, wherein the sibling device priority information indicates the sibling device with the smallest IP address.

8. The method of claim 1, further comprising:

in response to determining that a next communication cycle of the communication cycles is not a transmission cycle of the EPA device, to remain silent during a cycle period of the next communication cycle.

9. An EPA device comprising:

a processor and a memory, the memory storing instructions executable by the processor, the processor configured to, upon execution of the instructions, cause the EPA device to perform the method of any of claims 1-8.

10. A computer readable storage medium having stored thereon computer program code which, when executed by a processor, performs the method of any of claims 1 to 8.