CN116582384A

CN116582384A - 485 bus-based communication method and intelligent home system

Info

Publication number: CN116582384A
Application number: CN202310431003.XA
Authority: CN
Inventors: 冯凯; 董美雪; 王明
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2023-04-19
Filing date: 2023-04-19
Publication date: 2023-08-11

Abstract

The invention discloses a 485 bus-based communication method and an intelligent home system, relates to the technical field of communication, and aims to solve the problem of lower 485 bus communication efficiency when a random delay mode is adopted to solve the problem of 485 bus conflict in the traditional 485 bus multi-master communication process. The method comprises the following steps: when receiving the data error indication sent by the slave devices, the plurality of master devices determine the delay time for delaying the data sending according to the device addresses of the master devices, and the rest master devices except the at least two master devices enter a waiting sending state. And the first master device with the shortest delay in the at least two master devices resends the data to the slave device when the first delay time of the first master device is reached, and if the plurality of master devices all receive the correct data indication, the master devices except the first master device in the at least two master devices resend the data.

Description

485 bus-based communication method and intelligent home system

Technical Field

The invention relates to the technical field of communication, in particular to a 485 bus-based communication method and an intelligent home system.

Background

In the 485 bus multi-master communication process, when a plurality of master devices send data to slave devices at the same time, the 485 bus can be caused to collide, so that the slave devices can not accurately analyze the data information sent by the master devices. At present, the problem of 485 bus conflict is mainly solved by adopting a random delay processing mode for main equipment with conflict. However, when the collision probability of the 485 bus is high, multiple random delay processes are required to be performed on the master device with the collision, so that the communication efficiency of the 485 bus is low.

Disclosure of Invention

The embodiment of the application provides a 485 bus-based communication method and an intelligent home system, which solve the problem of lower 485 bus communication efficiency when the problem of 485 bus conflict is solved by adopting a random delay mode in the traditional 485 bus multi-master communication process.

In order to achieve the above object, the following technical solution is adopted in the embodiments of the present application.

In a first aspect, the present application provides a 485 bus based communication method, the method being applied to an intelligent home system, the intelligent home system including a plurality of master devices, slave devices and a 485 bus, the plurality of master devices and slave devices being coupled to the 485 bus, the method comprising: at least two of the plurality of masters simultaneously transmit data to the slaves. When receiving the data error indication sent by the slave devices, the plurality of master devices determine the delay time for delaying the data sending according to the device addresses of the master devices, and the rest master devices except the at least two master devices enter a waiting sending state. And the first master device with the shortest delay in the at least two master devices resends the data to the slave device when the first delay time of the first master device is reached, and if the plurality of master devices all receive the correct data indication, the master devices except the first master device in the at least two master devices resend the data. And when the plurality of master devices receive the data correct indication and the 485 bus idle time reaches a preset time period, the rest master devices start to send data to the slave devices.

Thus, in the present application, when at least two master devices among a plurality of master devices simultaneously transmit data to a slave device, a bus collision is caused. The slave device cannot correctly analyze the data sent by the at least two master devices, and sends a data error indication to the at least two master devices. When a plurality of main devices receive the data error indication, at least two main devices respectively determine respective delay time according to the device address of the main device. And the first master device with the shortest delay in the at least two master devices sends data to the slave devices again when the first delay time of the first master device is reached. When the plurality of master devices each receive the data correct indication, the master devices except the first master device in the at least two master devices send the data again. When the bus is in conflict, the master device which is in conflict preferentially transmits data to the slave device according to the length of the delay time. I.e. when one of the conflicting master devices sends data again to the slave device, the remaining conflicting master devices are in a waiting state. In this way, the multiple master devices that collide can sequentially transmit data according to the delay time in a staggered manner. Compared with the problem of lower communication efficiency caused by the fact that multiple times of random delay processing is needed in the prior art, the master device for preferentially processing the conflict, disclosed by the application, has the advantages that after the multiple conflict master devices complete communication, other master devices initiate communication after waiting for a bus to be idle, the problem that a certain master device cannot complete communication due to the conflict can be avoided, and the communication efficiency of a 485 bus is improved.

In some embodiments, each of the plurality of masters corresponds to a delay time equal to a value of a device address of each master itself.

In some embodiments, before at least two of the plurality of masters simultaneously transmit data to the slaves, the method further includes: for any one of the at least two master devices, when any one of the at least two master devices determines that data from the slave device is not received within a preset time period, any one of the master devices sends a first communication request to the slave device, and the first communication request is used for any one of the master devices to request to send data to the slave device. The slave device sends a first communication response to any master device, wherein the first communication response is used for indicating any master device to allow communication with the slave device.

In some embodiments, before the slave device sends the first communication response to any master device, the method further comprises: if any one of the master devices does not receive the first communication response within a first preset time interval after the first communication request is sent, the any one of the master devices sends the first communication request to the slave device again. If the number of times that any master device repeatedly sends the first communication request to the slave device reaches the first preset number of times and the first communication response is not received, after the second preset time interval, any master device continuously sends the first communication request to the slave device. If the number of times that any master device repeatedly sends the first communication request to the slave device reaches the second preset number of times and the first communication response is not received, any master device determines that the communication is abnormal.

In some embodiments, the sending the data again by a master device other than the first master device of the at least two master devices includes: for a second master device except the first master device in at least two devices, when the second master device does not receive data from the slave device within a preset time period, the second master device sends a second communication request to the slave device, wherein the second communication request is used for the second master device to request to send data to the slave device. And the slave device checks the data received by the slave device, wherein the data received by the slave device comprises the data sent by the second master device, and if the check of the slave device fails, the slave device sends data error indication to a plurality of master devices. And the second master device determines a second delay time for delaying the transmission of the data according to the device address of the second master device, and retransmits the data to the slave device when the second delay time arrives.

In a second aspect, the present application provides a smart home system comprising a plurality of master devices, slave devices, and a 485 bus, the plurality of master devices and slave devices being coupled to the 485 bus. At least two of the plurality of masters are configured to simultaneously transmit data to the slaves. And the at least two master devices are further configured to determine delay time for delaying the transmission of data according to the device addresses of the master devices respectively when receiving the data error indication transmitted by the slave devices. The other master devices except at least two master devices among the plurality of master devices are configured to enter a waiting-to-send state. A first master device of the at least two master devices having the shortest delay is configured to resend data to the slave device when its own first delay time has arrived. The master devices of the at least two master devices, except the first master device, are configured to send data again to the slave device if a data correct indication is received. And the rest of the master equipment is configured to start to send data to the slave equipment when the correct indication of the data is received and the 485 bus idle time reaches a preset time period.

In some embodiments, any one of the at least two master devices is configured to determine that the data from the slave device is not received within a preset period of time, send a first communication request to the slave device, the first communication application being for any one of the master devices to request to send data to the slave device. The slave device is configured to send a first communication response to any master device, wherein the first communication response is used for indicating any master device to allow communication with the slave device.

In some embodiments, any of the host devices is further configured to: if the first communication response is not received within a first preset time interval after the first communication request is sent, the first communication request is sent to the slave device again. If the number of times that any master device repeatedly sends the first communication request to the slave device reaches the first preset number of times and does not receive the first communication response, continuing to send the first communication request to the slave device after the second preset time interval. If the number of times that any master device repeatedly sends the first communication request to the slave device reaches the second preset number of times and the first communication response is not received, determining that the communication is abnormal.

In some embodiments, for a second master device of the at least two devices, other than the first master device, configured to send a second communication request to the slave device when data from the slave device is not received within a preset period of time, the second communication request being for the second master device to request to send data to the slave device. And the slave equipment is configured to verify the data received by the slave equipment, wherein the data received by the slave equipment comprises the data sent by the second master equipment, and if the slave equipment fails to verify, the data error indication is sent to the plurality of master equipment. And the second master device is configured to determine a second delay time for delaying the transmission of the data according to the device address of the device itself, and to retransmit the data to the slave device when the second delay time arrives.

The advantages of the second aspect may be seen in the description of the first aspect, and are not repeated here.

Drawings

Fig. 1 is a 485 bus communication schematic diagram of an intelligent home system provided by the application;

FIG. 2 is a schematic diagram of a household water turbine control system;

fig. 3 is a schematic flow chart of a 485 bus communication method provided by the application;

FIG. 4 is a schematic diagram of a bus idle detection mechanism according to the present application;

Fig. 5 is a schematic diagram of a master device 10 according to the present application initiating a communication application to a slave device 11;

fig. 6 is a schematic diagram of two master devices transmitting data simultaneously with the slave device 11 according to the present application;

fig. 7 is a communication schematic diagram of a host device 10 reinitiating a communication application according to the present application;

fig. 8 is a schematic flow chart of checking a data frame by the slave device 11 according to the present application;

FIG. 9 is a schematic diagram of a data resolution error according to the present application;

fig. 10 is a schematic flow chart of a 485 bus communication method of the household water turbine control system 200 provided by the application.

Detailed Description

Embodiments of the present application will be described in detail below with reference to the accompanying drawings.

In the description of the present application, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present application, it should be noted that, unless explicitly stated and limited otherwise, the term "coupled" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art. In addition, when describing a pipeline or channel, the terms "connected" and "connected" as used herein have the meaning of conducting. The specific meaning is to be understood in conjunction with the context.

In embodiments of the application, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g." in an embodiment should not be taken as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

485 bus multi-master communication means that multiple master devices can each transmit data to a slave device. When a slave device transmits data through the 485 bus, a plurality of master devices coupled to the 485 bus receive the data transmitted by the slave device.

In the traditional 485 bus multi-master communication process, the problem of 485 bus conflict is solved by adopting a random delay processing mode for main equipment with conflict. The random delay processing mainly determines the idle waiting time of the master device through the random attribute information of the master device. The random attribute information here includes at least one of a hardware parameter of the host device in the current environment and any random number of 0 to 255. For example, the hardware parameters of the host device in the current environment may be understood as the current ambient temperature of the host device, for example, 20 degrees. For any one of the plurality of masters, the master may send data to the slave only if the idle time of the 485 bus is equal to the idle latency of the master. The idle latency of the master device is understood to be the time required for the master device to wait from no data transfer on the bus to the master device being able to send data to the slave device. The idle time of the 485 bus is equal to the idle waiting time of the main device, which is understood as that no data is transmitted on the 485 bus in the idle waiting time of the main device.

If a certain master device needs to send data to a slave device, but the master device detects that data transmission exists on the 485 bus within the idle waiting time, the master device needs to wait for the completion of the data transmission on the 485 bus, and then determines the idle waiting time of the master device again according to the random attribute information of the master device. And the master needs to send data to the slave when the idle time of the 485 bus is equal to the idle latency that the master re-determines and there is no data transmission on the 485 bus. For example, assuming that the idle waiting time determined by the master device with address 60 according to its own random attribute information is 25ms, and the idle waiting time determined by the master device with address 62 according to its own random attribute information is 30ms, when the idle time of the 485 bus reaches 30ms, if the master device with address 60 starts to transmit data to the slave device, the master device with address 62 also needs to transmit data to the slave device. When the master device with the address 62 detects that data transmission exists on the 485 bus when the own idle waiting time reaches 30ms, the master device with the address 62 needs to wait until the data of the master device with the address 60 is completely transmitted, and then determines a new idle waiting time according to own random attribute information, for example, the new idle waiting time can be 32ms. When the 485 bus idle time reaches 32ms, the master device with address 62 can start sending data to the slave device.

However, when the idle latency of the master device with address 62 is equal to 32ms, there may still be data on the 485 bus to be transmitted, and the master device with address 62 needs to determine a new idle latency again according to its random attribute information. When the collision probability of the 485 bus is high, the master device with the address of 62 needs to determine the idle waiting time for multiple times, so that the communication efficiency of the 485 bus is low.

In view of the above, the application provides a 485 bus-based communication method and an intelligent home system, which are used for preferentially processing a master device with conflict when the 485 bus is in conflict. When the conflicting master and slave complete data transmission, the other master can send data to the slave. According to the application, the idle waiting time of the main equipment with conflict does not need to be determined for many times, and the communication efficiency of the 485 bus is improved.

As shown in fig. 1, a 485 bus communication schematic diagram of an intelligent home system provided by the application is shown. The smart home system comprises a plurality of master devices 10, slave devices 11 and 485 buses. Wherein a plurality of master devices 10 and slave devices 11 are coupled on a 485 bus. The number of the plurality of masters 10 may be n, that is, the plurality of masters 10 includes the master 1, the master 2, and the master n shown in fig. 1, where n is an integer of 2 or more. The number of slave devices 11 is only 1. Each of the master device 10 and the slave device 11 is provided with a different device address.

The smart home system herein may be, for example, a home water machine control system. The plurality of master devices 10 may be, for example, end thermostats. The slave device 11 may be, for example, a water temperature controller. The embodiment of the application can also be applied to other intelligent home systems except the household water machine control system, in other intelligent home systems, the plurality of master devices and slave devices can also be other types of devices, and the device types of the plurality of master devices and slave devices are not limited.

In the present application, the master device 10 may send data information to the slave device 11 through the 485 bus, and the slave device 11 may operate on the received data information sent by the master device 10. Where the master device 10 transmits data information to the slave device 11 through the 485 bus, the baud rate may be 9600 in the home-type water machine control system.

Taking the master device 10 as a terminal temperature controller, the slave device 11 is taken as a water temperature controller as an example. The user sets a temperature information on the terminal temperature controller, the terminal temperature controller sends the set temperature information to the water temperature controller, and the water temperature controller calculates the received set temperature information to obtain a temperature regulation control instruction.

Fig. 2 is a schematic diagram of a residential water machine control system 200. The home-type water machine control system 200 includes a plurality of air reels 21, a plurality of end temperature controllers 22, a plurality of floor heating valves 23, a water temperature controller 24, and an outdoor unit 25. In fig. 2, n is the number of the plurality of air reels 21, the plurality of end temperature controllers 22, and the plurality of floor heating valves 23, and n is an integer of 2 or more, for example, 31.

Wherein, terminal temperature controller 22 is used for controlling branch dish 21 and ground heating valve 23. For example, the user may set the temperature of the air pan 21 through the end temperature controller 22.

The water temperature controller 24 is used to control the outdoor unit 25. For example, the water temperature controller 24 may control the outdoor unit 25 to adjust the operation state of the compressor so that the air pan 21 reaches a temperature set by a user.

Illustratively, the user sets the temperature at 25 degrees on the end thermostat 22, the end thermostat 22 sends the set temperature information to the water temperature controller 24, and the water temperature controller 24 calculates the received set temperature information to obtain the temperature adjustment control command. And transmits the calculated temperature adjustment control command to the outdoor unit 25. The outdoor unit 25 adjusts the operation state of the compressor in the outdoor unit according to the temperature adjustment control command so that the temperature of the air pan 21 reaches 25 degrees.

Fig. 3 is a schematic flow chart of a 485 bus communication method provided by the application.

301. At least two master devices 10 of the plurality of master devices 10 simultaneously transmit data to the slave device 11.

Data herein may be understood as frames of data. Taking the master device 10 as a terminal temperature controller, the slave device 11 is taken as a water temperature controller as an example. The format of the data frame may be as shown in table 1.

TABLE 1

Illustratively, two or more master devices 10 transmit data to slave device 11 simultaneously. For example, the master device 10 having the device address 1 and the master device 10 having the device address 3 simultaneously transmit data to the slave device 11.

302. When the plurality of master devices 10 receive the data error indication transmitted from the slave device 11, at least two master devices 10 determine delay times for delaying transmission of data according to device addresses of the respective master devices, and the remaining master devices 10 except for the at least two master devices 10 among the plurality of master devices 10 enter a waiting transmission state.

In some embodiments, each master device 10 herein corresponds to a delay time equal to the value of the device address of each master device itself. For example, the delay time of the master device 10 with the device address 1 is 1ms. The data frames indicated by the data errors herein may be as shown in table 2.

TABLE 2

Illustratively, the 485 bus conflicts when the master device 10 with device address 1 and the master device 10 with device address 3 simultaneously transmit data frames to the slave device 11. The slave device 11 checks the received data frames transmitted from the master device 10 with address 1 and the master device 10 with address 3, and an error in resolving the data frames received from the slave device 11 from the master device 10 with address 1 and the master device 10 with address 3 occurs. At this time, the slave device 11 may send a data error indication to each master device 10 through the 485 bus, including the master device 10 with device address 1 and the master device 10 with device address 3 also receive the data frame of the data error indication sent by the slave device 11. When the master device 10 with the device address 1 and the master device 10 with the device address 3 receive the data frame indicated by the data error, the 485 bus is determined to collide, and the master device 10 with the device address 1 and the master device 10 with the device address 3 need to determine the delay time to try to send data again according to the delay time.

The master device 10 with the device address of 1 determines the delay time to be 1ms according to the address of the device, and the master device 10 with the device address of 3 determines the delay time to be 3ms according to the address of the device. When the other master devices 10 that do not transmit data receive the data frame indicated by the data error, it is also determined that 485 bus collision occurs at this time, and the other master devices 10 need to enter a state waiting for transmission, that is, the other master devices 10 do not transmit data.

303. The first master device 10 having the shortest delay among the at least two master devices 10 resends data to the slave device 11 when the own first delay time arrives, and if the plurality of master devices 10 each receive the data correct indication, the master devices 10 other than the first master device 10 among the at least two master devices 10 resend data.

It should be understood that, among the master devices 10 that collide, the first master device 10 having the shortest delay time will transmit data again first.

Illustratively, when the number of the conflicting master devices 10 is 2, the first delay time of the master device 10 with the device address 1 is 1ms, the second delay time of the master device 10 with the device address 3 is 3ms, and since the first delay time 1ms of the master device 10 with the device address 1 is shorter than the second delay time 3ms of the master device 10 with the device address 3, the first master device 10 may be understood as the master device 10 with the device address 1.

At this time, the master device 10 having the device address 1 first transmits a data frame to the slave device 11 again after a delay of 1 ms. The slave device 11 receives only the data frame transmitted by the master device 10 with the device address 1 at the same time, the slave device 11 analyzes the data frame correctly, and the slave device 11 transmits the data frame correctly indicated by the data to the plurality of master devices 10. If a plurality of master devices 10 each receive a data frame that the data correctly indicates, the master device 10 having the device address 3 may immediately transmit the data frame in the format shown in table 1 again to the slave device 11.

The data frames where the data is correctly indicated may be as shown in table 3.

TABLE 3 Table 3

304. When the plurality of master devices 10 each receive the data correct indication and it is determined that the 485 bus idle time reaches the preset time period, the remaining master devices 10 start to transmit data to the slave device 11.

The plurality of master devices 10 are in the reception state all the time while in the waiting transmission state, and the 485 bus can be considered to be in the idle state when the plurality of master devices 10 do not receive data within a preset period of time.

Since data is transferred between the master device 10 and the slave device 11, the baud rate of the 485 bus is 9600. And wherein the longest frame of data in the data frame is 10 bytes, i.e. the time for data transmission by the master device 10 and the slave device 11 is about 10ms at maximum. The preset time period here may be, for example, 20ms. That is, when each master 10 of the plurality of masters 10 continuously receives no data within 20ms, each master 10 may consider the 485 bus to be in an idle state at this time.

For example, when the data transmission of the master device 10 with the device address 3 is completed, after the slave device 11 transmits a data frame correctly indicated by the data to the master device 10 with the device address 3, if the plurality of master devices 10 each receive the data frame correctly indicated by the data and continuously do not receive other data frames within 20ms at this time, the remaining master devices 10 except the master device 10 with the device address 1 and the master device 10 with the device address 3 may transmit data to the slave device 11.

Thus, in the present application, when at least two master devices 10 among the plurality of master devices 10 simultaneously transmit data to the slave device 11, a bus collision is caused. The slave device 11 cannot correctly parse the data transmitted from the at least two master devices 10 and transmit a data error indication to the at least two master devices 10. When the plurality of master devices 10 receive the data error indication, at least two master devices 10 determine respective delay times according to the device addresses of the own devices, respectively. The first master device 10 having the shortest delay among the at least two master devices 10 transmits data again to the slave device 11 when its own first delay time arrives. When the plurality of master devices 10 each receive the data correct indication, the master device 10 other than the first master device 10 of the at least two master devices 10 transmits the data again. That is, when a bus collision occurs, the master device 10 having the collision preferentially transmits data to the slave device 11 in accordance with the length of the delay time. I.e. when one of the conflicting master devices 10 sends data again to the slave device 11, the remaining conflicting master devices 10 are in a waiting state. This makes it possible to sequentially transmit data with a delay time by the plurality of master devices 10 that have made collisions. Compared with the problem of lower communication efficiency caused by the need of carrying out multiple random delay processing in the prior art, the master device 10 for processing conflict preferentially provided by the application has the advantages that after the plurality of conflict master devices 10 complete communication, other master devices 10 initiate communication after waiting for a bus to be idle, the problem that a certain master device 10 cannot complete communication due to conflict can be avoided, and the communication efficiency of a 485 bus is improved.

In step 304 of the method of fig. 3, how to determine 485 bus idle time reaches a preset time period may be as shown in fig. 4.

Fig. 4 is a schematic diagram of a bus idle detection mechanism according to the present application. Where a data acknowledgement may be understood as a data correct indication.

The master device 10 transmitting data may be understood as a master device 10 of a plurality of master devices 10 transmitting data to the slave device 11, for example, a master device 10 having a device address of 1. The master device 10 that is ready to transmit data may be understood as a master device 10 that transmits data to the slave device 11 other than the master device 10 that is transmitting data among the plurality of master devices 10, and may be, for example, the master device 10 whose device address is 3.

Illustratively, when the master device 10 with device address 1 on the 485 bus is transmitting data to the slave device 11, the master device 10 with device address 3 may not transmit data to the slave device 11 at this time. When the master device 10 with the device address 1 receives a correct indication of the data transmitted from the slave device 11, that is, the master device 10 with the device address 1 completes data transmission to the slave device 11, the master device 10 with the device address 3 can transmit data to the slave device 11. When the master device 10 with the device address 3 does not receive the correct data indication after waiting for 20ms, that is, the 485 bus is in an idle state, the master device 10 with the device address 3 transmits data to the slave device 11. When the master device 10 with the device address 3 receives the data correct instruction sent by the slave device 11, the master device 10 with the device address 3 completes data transmission to the slave device 11.

The following procedure may also be included in some embodiments prior to step 301 described above.

For any master device 10 of the at least two master devices 10, when any master device 10 determines that data from the slave device 11 is not received within a preset period of time, any master device 10 transmits a first communication request to the slave device 11, the first communication request being for any master device 10 to request transmission of data to the slave device 11. The slave device 11 transmits a first communication response to any of the master devices 10, the first communication response indicating that any of the master devices 10 is permitted to communicate with the slave device 11.

That is, when the bus is in an idle state, before any master device 10 transmits data to the slave device 11, a communication application needs to be transmitted to the slave device 11, and after the slave device 11 allows communication, any master device 10 can transmit data to the slave device 11.

Fig. 5 is a schematic diagram of a master device 10 according to the present application initiating a communication application to a slave device 11.

As can be seen from fig. 5, when the master device 10 transmits data to the slave device 11, the master device 10 first transmits a communication request to the slave device 11, and after receiving the communication request from the slave device 11, transmits a communication permission to the master device 10. When the master device 10 receives the communication permission, data is transmitted to the slave device 11, and after the slave device 11 receives the data, the data is parsed and the result of the data confirmation is transmitted to the master device 10.

The first communication request may be understood as a data frame of a communication application transmitted from the master device 10 to the slave device 11, as shown in table 4.

TABLE 4 Table 4

The first communication response may be understood as the transmission of a communication-allowed data frame from the slave device 11 to the master device 10, as shown in table 5.

TABLE 5

Illustratively, the master device 10 with device address 1 and the master device 10 with device address 3 continue after no data frames sent by the slave device 11 are received within 20 ms. The master device 10 with the device address 1 and the master device 10 with the device address 3 transmit the data frame of the communication application to the slave device 11. After receiving the data frame of the communication application, the slave device 11 transmits a data frame of the first communication response to the master device 10 with the device address 1 and the master device 10 with the device address 3. The master device 10 with the device address 1 and the master device 10 with the device address 3 may transmit the data frame to the slave device 11 after receiving the data frame of the first communication response transmitted from the slave device 11.

In step 301 of the method of fig. 3, at least two master devices 10 of the plurality of master devices 10 simultaneously transmit data to the slave devices, for example, two master devices 10 simultaneously transmit data with the slave device 11, as shown in fig. 6.

Fig. 6 is a schematic diagram of two master devices 10 transmitting data simultaneously with a slave device 11 according to the present application.

As can be seen from fig. 6, when the master device 10 with the device address 1 and the master device 10 with the device address 3 simultaneously transmit data to the slave device 11, first, the master device 10 with the device address 1 and the master device 10 with the device address 3 transmit a communication application to the slave device 11. After receiving the communication application from the device 11, the communication permission is transmitted to the master device 10 having the device address 1 and the master device 10 having the device address 3. After receiving the communication permission, the master device 10 having the device address 1 and the master device 10 having the device address 3 simultaneously transmit data to the slave device 11. At this time, the bus collision occurs, and the slave device 11 cannot accurately analyze data transmitted from the master device 10 having the device address 1 and the master device 10 having the device address 3. The slave device 11 transmits a data error to the master device 10 having the device address 1 and the master device 10 having the device address 3. After receiving the data error, the master device 10 with the device address 1 and the master device 10 with the device address 3 re-initiate the communication application to the slave device 11 after the delay, wherein the first delay is shorter in the master device 10 with the device address 1 and the master device 10 with the device address 3. That is, the master device 10 having the device address 1 resends the communication application to the slave device 11. When the master device 10 of the device address 1 receives the data acknowledgement transmitted from the slave device 11, the master device 10 of the device address 3 immediately transmits a communication application to the slave device 11.

On the basis of fig. 5, in some embodiments, the sending of the communication application from the master device 10 to the slave device 11 may further include the following procedure.

If any master device 10 does not receive the first communication response within a first preset time interval after sending the first communication request, any master device 10 sends the first communication request to the slave device 11 again. If the number of times that any master device 10 repeatedly sends the first communication request to the slave device 11 reaches the first preset number of times and the first communication response is not received, after the second preset time interval, any master device 10 continues to send the first communication request to the slave device 11. If the number of times that any master device 10 repeatedly sends the first communication request to the slave device 11 reaches the second preset number of times and the first communication response is not received, any master device 10 determines that the communication is abnormal.

The first preset time interval here may be, for example, 5ms. That is, the master device 10 cannot exceed 5ms from the transmission of the data frame of the communication application to the slave device 11 to the reception of the data frame allowed by the communication transmitted from the slave device 11. The first preset number of times here may be, for example, 3 times. The second preset number of times here may be 6 times, for example. The second preset time interval here = device address of master device 10/2+10. For example, the second preset time interval of the master device 10 having the device address 1 is 10.5ms.

That is, when the master device 10 does not receive the communication reply from the slave device 11, it will re-initiate the communication request to the slave device 11.

As shown in fig. 7, a communication schematic diagram of a host device 10 according to the present application for reinitiating a communication application is provided.

As can be seen from fig. 7, for example, the master device 10 with the device address 1 transmits a data frame of a communication application to the slave device 11. If the master device 10 with the device address 1 does not receive the communication-allowed data frame within 5ms after transmitting the communication-applied data frame to the slave device 11, the master device 10 with the device address 1 transmits the communication-applied data frame to the slave device 11 for the second time. If the master device 10 having the device address 1 continuously transmits the data frame of the first communication response to the slave device 11 3 times, no data frame of communication permission is received. The master device 10 with device address 1 sends a data frame of the communication application to the slave device 11 a second time after 10.5 ms. If the master device 10 with the device address 1 continuously sends the data frame of the 6 communication applications to the slave device 11, and still does not receive the data frame allowed by communication, it indicates that the master device 10 with the device address 1 has abnormal communication.

The above-described retransmission of data by a master device other than the first master device among at least two master devices 10 in the step 303 in the method flow of fig. 3 may further include the following flow.

In some embodiments, for a second master device 10 of the at least two devices other than the first master device 10, the second master device 10 immediately sends a second communication request to the slave device 11, the second communication request being for the second master device 10 to request data to be sent to the slave device 11. The slave device 11 checks the data received by the slave device 11, the data received by the slave device 11 includes the data transmitted by the second master device 10, and if the slave device 11 fails to check, the slave device 11 transmits a data error indication to the plurality of master devices 10. The second master device 10 determines a second delay time to delay transmission of data according to the device address of the device itself, and transmits the data again to the slave device 11 when the second delay time arrives.

The second communication request is understood to mean a data frame from which the master device 10 again initiates a communication application to the slave device 11.

The second master device may be understood as master device 10 with a device address of 3. The second delay time is 3ms.

Illustratively, when the master device 10 with the device address 1 completes data transmission to the slave device 11, the master device 10 with the device address 3 immediately transmits a data frame of a communication application to the slave device after receiving a data frame indicated by the data right. After receiving the data frame of the communication application transmitted by the master device 10 with the device address 3, the slave device 11 transmits a communication permission data frame to the master device 10 with the device address 3. After receiving the communication-allowed data frame, the master device 10 having the device address 3 transmits the data frame to the slave device 11. The slave device 11 receives the data frame transmitted by the master device 10 with the device address 3 and checks the received data frame. If the slave device 11 fails to check the received data frame, a data frame with a data error indication is sent to the master device 10 with a device address of 3. When the master device 10 with the device address 3 receives the data frame indicated by the data error transmitted from the slave device 11, the master device 10 with the device address 3 delays for 3ms and then transmits the data frame to the slave device 11 again.

In the above embodiment, the process of verifying the data received from the device 11 by the device 11 is shown in fig. 8.

Fig. 8 is a schematic flow chart of checking a data frame by the slave device 11 according to the present application.

801. The slave device 11 receives the data frame transmitted by the master device 10.

802. The slave device 11 determines whether the data frame header is correct.

The slave device 11 parses the received data frame, compares the parsed data frame header with the received data frame header, determines that the data frame header is correct if it is consistent, and then performs step 803. If the parsed header of the data frame does not match the header of the received data frame, step 808 is performed.

803. The slave device 11 determines whether the data length is correct.

The slave device 11 parses the received data frame, compares the parsed data length with the received data length, determines that the data length is correct if it is consistent, and then performs step 804. If the parsed data length does not match the received data length, then step 808 is performed.

804. The slave device 11 determines whether the initiating device type is correct.

The slave device 11 parses the received data frame, compares the parsed type of the initiator device with the received type of the initiator device, determines that the type of the initiator device is correct if it is consistent, and then performs step 805. If the parsed originating device type does not match the received originating device type, step 808 is performed.

805. The slave device 11 determines whether the receiving device type is correct.

The slave device 11 parses the received data frame, compares the parsed type of the receiving device with the type of the receiving device received, determines that the type of the receiving device is correct if it is identical, and then performs step 806. If the parsed receiving device type is inconsistent with the received receiving device type, step 808 is performed.

806. The slave device 11 determines whether the CRC check code is correct.

The slave device 11 parses the received data frame and compares the parsed CRC check code with the received CRC check code, and if they are identical, determines that the CRC check code is correct, and then performs step 807. If the parsed CRC check code is inconsistent with the received CRC check code, step 808 is performed.

807. The slave device 11 transmits a data frame indicating that the data is correct to the master device 10.

808. The slave device 11 transmits a data frame of a data error indication to the master device 10.

In the above steps 802-806, if the slave device 11 parses the error in the received data frame, the following procedure may be included.

Fig. 9 is a schematic diagram of a data parsing error according to the present application.

As can be seen from fig. 9, when the master device 10 transmits data to the slave device 11, the master device 10 first transmits a communication request to the slave device 11, and after receiving the communication request from the slave device 11, transmits a communication permission to the master device 10. When the master device 10 receives the communication permission, data is transmitted to the slave device 11, and the slave device 11 parses the data after receiving the data. When the master device 10 receives the data analysis error, it will send data to the slave device 11 again, and when the master device 10 receives the data analysis is correct, the communication ends.

The 485 bus communication method of the application is described below by taking a household water machine control system 200 as an example. Fig. 10 is a schematic flow chart of a 485 bus communication method of the household water turbine control system 200 according to the present application.

1001. When 485 bus is in idle state, terminal temperature controller 1 and terminal temperature controller 2 send the data frame of communication application to the temperature controller simultaneously.

Illustratively, the 485 bus is in an idle state when the end thermostat 1 and the end thermostat 2 do not receive the data sent by the water temperature controller for 20ms in succession to parse the correct data frame. The end temperature controller 1 and the end temperature controller 2 simultaneously send data frames with the request frame header code of 'A1' to the water temperature controller. The data frames with the request frame header code of "A1" sent to the water temperature controller by the end temperature controller 1 and the end temperature controller 2 are different.

1002. The water temperature controller allows the end thermostat 1 and the end thermostat 2 to send data frames to the water temperature controller.

Illustratively, the water temperature controller transmits a data frame with an allowable frame header code of "A2" to the end temperature controller 1 and the end temperature controller 2. I.e. the water temperature controller allows the end thermostat 1 and the end thermostat 2 to send data to the water temperature controller.

1003. The end temperature controller 1 and the end temperature controller 2 send data frames to the water temperature controller at the same time.

Illustratively, the end thermostat 1 and the end thermostat 2 simultaneously transmit a data frame with a data frame header of "51" to the water temperature controller. The data frames with the data frame header code of 51 are different from the end temperature controller 1 and the end temperature controller 2 for sending the data frames to the water temperature controller.

1004. The water temperature controller sends data frames with data analysis errors to the n end temperature controllers.

Illustratively, since the end temperature controller 1 and the end temperature controller 2 simultaneously transmit data frames to the water temperature controller, 485 bus collision is caused, and the water temperature controller parses errors of the received data frames. The n end temperature controllers are always in a receiving state, and the water temperature controller sends data frames with data frame header codes of 52 to the n end temperature controllers.

1005. The end temperature controller 1 and the end temperature controller 2 receive data frames with data analysis errors.

Illustratively, the end temperature controller 1 and the end temperature controller 2 receive a data frame with a data error of a data frame header of "52".

1006. The end temperature controller 1 and the end temperature controller 2 confirm the delay time according to the self equipment address and send data to the water temperature controller according to the length of the delay time.

For example, assume that the device address of the end thermostat 1 is 1 and the device address of the end thermostat 2 is 2. The delay time of the end temperature controller 1 is 1ms, and the delay time of the end temperature controller 2 is 2ms. The delay time of the tail end temperature controller 1 is smaller than that of the tail end temperature controller 2, and the tail end temperature controller 1 firstly sends a data frame with the header code of 51 to the water temperature controller again. When the end temperature controller 1 receives the data frame with the correct data frame header of 52, the end temperature controller 2 again sends the water temperature controller a data frame with the data frame header of 51.

1007. The n end temperature controllers all receive the data frame which is sent by the water temperature controller and is accurate in data analysis.

Illustratively, when the end temperature controller 2 receives a data frame with a data frame header of "52" for which the data is correct. The other end temperature controllers all receive the data frame with the correct data of which the data frame header code is 52. I.e., each of the n end temperature controllers receives a data frame with a data frame header of "52" and the data frame header is correct, step 1008 is performed.

1008. The other end temperature controllers other than the end temperature controller 1 and the end temperature controller 2 may transmit data frames to the water temperature controller.

For example, when the other end temperature controllers except the end temperature controller 1 and the end temperature controller 2 continuously receive the data sent by the water temperature controller for 20ms and analyze the correct data frame, the data frame with the request frame header code of "A1" is sent to the water temperature controller. If the other end temperature controllers except the end temperature controller 1 and the end temperature controller 2 receive the data frame with the allowable frame header code of 'A2' sent by the water temperature controller, the other end temperature controllers except the end temperature controller 1 and the end temperature controller 2 can send the data frame to the water temperature controller again.

Based on the description of the 485 bus communication method, the application also provides an intelligent home system. The smart home system includes a plurality of master devices, slave devices, and a 485 bus, the plurality of master devices and slave devices being coupled to the 485 bus. Wherein at least two of the plurality of masters are configured to simultaneously transmit data to the slaves. And the at least two master devices are further configured to determine delay time for delaying the transmission of data according to the device addresses of the master devices respectively when receiving the data error indication transmitted by the slave devices. The other master devices except at least two master devices among the plurality of master devices are configured to enter a waiting-to-send state. A first master device of the at least two master devices having the shortest delay is configured to resend data to the slave device when its own first delay time has arrived. The other master devices are configured to start sending data to the slave device when the data correct indication is received and the 485 bus idle time reaches a preset time period.

In some embodiments, if the first communication response is not received within a first preset time interval after the first communication request is sent, the first communication request is sent to the slave device again. If the number of times that any master device repeatedly sends the first communication request to the slave device reaches the first preset number of times and does not receive the first communication response, continuing to send the first communication request to the slave device after the second preset time interval. If the number of times that any master device repeatedly sends the first communication request to the slave device reaches the second preset number of times and the first communication response is not received, determining that the communication is abnormal.

The smart home system may be, for example, the home water machine control system 200, and the home water machine control system 200 is described above and will not be described herein.

Although the application is described herein in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Although the application has been described in connection with specific features and embodiments thereof, it will be apparent that various modifications and combinations can be made without departing from the spirit and scope of the application. Accordingly, the specification and drawings are merely exemplary illustrations of the present application as defined in the appended claims and are considered to cover any and all modifications, variations, combinations, or equivalents that fall within the scope of the application. It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A 485 bus based communication method, characterized in that the method is applied to an intelligent home system, the intelligent home system comprising a plurality of master devices, slave devices and a 485 bus, the plurality of master devices and the slave devices being coupled on the 485 bus, the method comprising:

At least two master devices in the plurality of master devices simultaneously transmit data to the slave device;

when the plurality of master devices receive the data error indication sent by the slave devices, the at least two master devices respectively determine delay time for delaying sending data according to device addresses of the at least two master devices, and other master devices except the at least two master devices in the plurality of master devices enter a waiting sending state;

the first master device with the shortest delay in the at least two master devices sends data again to the slave device when the first delay time of the first master device is reached, and if the plurality of master devices all receive the correct data indication, the master devices except the first master device in the at least two master devices send data again;

and when the plurality of master devices all receive the data correct indication and the 485 bus idle time reaches a preset time period, the rest master devices start to send data to the slave devices.

2. The method of claim 1, wherein each master of the plurality of masters corresponds to a delay time equal to a value of a device address of the each master itself.

3. The method of claim 1 or 2, wherein before at least two of the plurality of masters simultaneously transmit data to the slave device, the method further comprises:

for any one of the at least two master devices, when the any one master device determines that data from the slave device is not received within the preset time period, the any one master device sends a first communication request to the slave device, wherein the first communication request is used for the any one master device to request to send data to the slave device;

the slave device sends a first communication response to any master device, wherein the first communication response is used for indicating that any master device allows communication with the slave device.

4. A method according to claim 3, wherein prior to the slave device transmitting the first communication response to the any master device, the method further comprises:

if the first communication response is not received by any master device within a first preset time interval after the first communication request is sent, the first communication request is sent to the slave device again by any master device;

If the number of times that the any master device repeatedly sends the first communication request to the slave device reaches a first preset number of times and the first communication response is not received, after a second preset time interval, the any master device continuously sends the first communication request to the slave device;

and if the number of times that any master equipment repeatedly sends the first communication request to the slave equipment reaches a second preset number of times and the first communication response is not received, determining that the communication is abnormal by any master equipment.

5. The method of claim 1, wherein retransmitting data from a master device of the at least two master devices other than the first master device comprises:

for a second master device of the at least two devices, except the first master device, the second master device immediately sends a second communication request to the slave device, wherein the second communication request is used for the second master device to request to send data to the slave device;

the slave device checks the data received by the slave device, wherein the data received by the slave device comprises the data sent by the second master device, and if the slave device fails to check, the slave device sends data error indications to the plurality of master devices;

And the second master device determines a second delay time for delaying the transmission of data according to the device address of the second master device, and retransmits the data to the slave device when the second delay time arrives.

6. An intelligent home system, comprising a plurality of master devices, slave devices and a 485 bus, wherein the plurality of master devices and the slave devices are coupled on the 485 bus;

at least two master devices of the plurality of master devices configured to simultaneously transmit data to the slave devices;

the at least two master devices are further configured to determine delay time for delaying transmission of data according to device addresses of the master devices when receiving data error indications transmitted by the slave devices;

the other master devices except the at least two master devices in the plurality of master devices are configured to enter a waiting-to-send state;

a first master device with the shortest delay in the at least two master devices is configured to send data to the slave device again when the first delay time of the first master device reaches;

the master devices except the first master device in the at least two master devices are configured to send data to the slave device again if a data correct indication is received;

And the rest master equipment is configured to start to send data to the slave equipment when receiving the data correct indication and determining that the 485 bus idle time reaches a preset time period.

7. The smart home system of claim 6, wherein each master device of the plurality of master devices has a corresponding delay time equal to a value of a device address of the each master device itself.

8. The smart home system as claimed in claim 6 or 7, wherein,

any one of the at least two master devices is configured to determine that a first communication request is sent to the slave device when data from the slave device is not received within the preset time period, wherein the first communication request is used for the any one of the master devices to request to send data to the slave device;

the slave device is configured to send a first communication response to any master device, wherein the first communication response is used for indicating that any master device allows communication with the slave device.

9. The smart home system of claim 8, wherein any master device is further configured to:

if the first communication response is not received within a first preset time interval after the first communication request is sent, the first communication request is sent to the slave equipment again;

If the number of times that any master device repeatedly sends the first communication request to the slave device reaches a first preset number of times and the first communication response is not received, continuing to send the first communication request to the slave device after a second preset time interval;

and if the number of times that any master equipment repeatedly sends the first communication request to the slave equipment reaches a second preset number of times and the first communication response is not received, determining that the communication is abnormal.

10. The smart home system as claimed in claim 6, wherein,

for a second master device of the at least two devices, except the first master device, configured to send a second communication request to the slave device when data from the slave device is not received within the preset time period, wherein the second communication request is used for the second master device to request to send data to the slave device;

the slave device is configured to verify the data received by the slave device, the data received by the slave device comprises the data sent by the second master device, and if the slave device fails to verify, a data error indication is sent to the plurality of master devices;

The second master device is configured to determine a second delay time for delaying transmission of data according to a device address of the second master device, and to retransmit the data to the slave device when the second delay time arrives.