WO2018113432A1

WO2018113432A1 - Broadcast realisation method, apparatus and device

Info

Publication number: WO2018113432A1
Application number: PCT/CN2017/109754
Authority: WO
Inventors: 苏本胜
Original assignee: 华为技术有限公司
Priority date: 2016-12-24
Filing date: 2017-11-07
Publication date: 2018-06-28
Also published as: CN108243017A; CN108243017B

Abstract

Disclosed are a broadcast realisation method, wherein a slave device receives a broadcast frame sent by a master device, the broadcast frame comprising response slave machine information for instructing a plurality of slave devices in an RS-485 bus network to respond in order; and when determining that a response is required according to the response slave machine information, a first slave device calculates a response starting moment according to the response slave machine information, and responds when the response starting moment is reached. By means of the broadcast realisation method, a plurality of slave devices in an RS-485 bus network respond to a broadcast frame in order, and response collision between the slave devices can be avoided, thus improving the communication efficiency of the RS-485 bus network.

Description

Broadcast implementation method, device and device

Technical field

The present invention relates to the field of communications, and in particular, to a broadcast implementation method, apparatus, and device.

Background technique

The Recommended Standard (RS)-485 specifies the electrical characteristics of the driver (driver/generator/transmitter) and receiver (receiver) in a serial communication system. RS-485 is jointly released by the Telecommunications Industry Association and Electronic Industries Alliance (TIA/EIA) and is therefore also known as EIA-485 or TIA-485.

RS-485 only specifies the electrical characteristics of the driver and receiver. No communication protocol is specified or recommended. That is, RS-485 only specifies the physical layer. The Modbus protocol is a communication protocol for the master/slave architecture. In the Modbus-based network, one node is the master node, and other nodes that use the Modbus protocol to participate in communication are slave nodes. Each slave has a unique address. The bus type network based on RS-485 deployment (hereinafter referred to as RS-485 bus network) adopts master-slave communication mode, so Modbus devices often communicate through the RS-485 physical layer. According to the Modbus protocol, addresses 0x01 to 0xF7 are slave addresses, and 0x00 is a broadcast address.

When the master device in the RS-485 bus network needs to communicate with multiple slave devices, the traditional method may be to separately send a unicast frame to the multiple slave devices, or send a broadcast frame to the entire network. However, the method of transmitting a unicast frame multiple times consumes a large amount of resources of the master device and takes a long time. In the manner of sending broadcast frames, all slave devices will respond to the broadcast frame after receiving the broadcast frame. There is a response conflict between the slave devices. It is necessary to continuously try to answer and backoff conflicts, wasting the processing resources of the slave device and causing the RS-485 bus to be long. Occupied.

Summary of the invention

Embodiments of the present invention provide a broadcast implementation method and apparatus, where a master device transmits a broadcast frame including a response slave information, and instructs multiple devices on the RS-485 bus network to respond in order to avoid a response broadcast between multiple devices. Time conflicts improve the efficiency of broadcast communication, thereby improving the performance of the RS-485 bus network.

In a first aspect, a broadcast implementation method is provided for use in an RS-485 bus network. The method includes:

Receiving, by the first slave device, a broadcast frame sent by the master device, where the broadcast frame includes response slave information, where the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond in order;

When it is determined that the broadcast frame needs to be answered according to the response slave information, the first slave device acquires a response start time according to the response slave information, and responds when the response start time is reached.

When the slave device determines that the response needs to be answered according to the response slave information in the broadcast frame, determines the response sequence and calculates the response start time, and then responds when the response start time is reached, thereby avoiding the broadcast response conflict between the slave devices, and improving the slave device. Resource utilization and communication success rate.

In a first possible implementation of the first aspect, the first slave device acquires a response start time according to the responding slave information, and includes:

Obtaining, by the first slave device, the response sequence N of the first slave device according to the response slave information, where the response sequence is that the first slave device answers the broadcast frame in the multiple slave devices order;

The first slave device calculates a response start time of the first slave device according to a single point timeout duration and a response order of the first slave device. When the single-point timeout is long, the response order of the first slave device is N, N≥1, and the response start time Tsn of the first slave device is T0+(N-1)*D, where T0 is The moment when the first slave device receives the broadcast frame.

In conjunction with the first aspect or the first possible implementation of the first aspect, in a second possible implementation of the first aspect,

When the response order N of the first slave device is 1, that is, the first slave device is the first slave device to be replied, the response start time of the first slave device is Tsn=T0, that is, The first slave device starts to respond immediately after receiving the broadcast frame.

When the response order of the first slave device is N≥2, the first slave device listens to the RS-485 bus before reaching the response start time Tsn of the first slave device; according to the response order The response start time Tek of the second slave device updates the response start time Tsn of the first slave device, and the updated Tsn is Tek+(NK-1)*D, where K is the response order of the second slave device. N>K≥1. The first slave device may obtain the response order K of the second slave device according to the address of the second slave device and the broadcast frame.

The first slave device can adjust the response start time of the slave device in the response sequence, and adjust the response start time in real time according to the response end time of the previous slave device in the response sequence, thereby avoiding the backoff conflict according to the fixed single point timeout duration. The resulting delay increases the efficiency of the broadcast response.

In combination with the first aspect and any of the foregoing possible implementations, in a third possible implementation of the first aspect, the response slave information is a type-length-value (TLV) format. ;

The response slave information of type 0 indicates that all slave devices in the RS-485 bus network need to respond in order. Correspondingly, each slave device can determine its own response order according to the difference between its own address and the start address;

The response slave information of type 1 indicates that multiple slave devices in the value field from the start address to the end address range need to respond in order. Correspondingly, each slave device can determine its own response order according to the difference between its own address and the starting address;

The response slave information of type 2 indicates that the slave devices corresponding to the respective addresses in the value field need to respond in order. Correspondingly, each slave device that needs to respond can use its own address in the value field as its own response order;

The response slave information of type 3 indicates that the response indication bit in the value field indicates that the slave devices that need to answer are responsive in order. Correspondingly, the slave device that needs to respond can use its own response indication bit in the sequence of all response indication bits with a value of 1 as its own response sequence.

In conjunction with the first aspect and any of the foregoing possible implementations, in a fourth possible implementation of the first aspect, the first slave device determines, according to the response slave information, that the broadcast frame does not need to be acknowledged The information in the broadcast frame can be recorded and then discarded.

A second aspect provides a broadcast implementation method for use in an RS-485 bus network, comprising:

The master device generates and transmits a broadcast frame, the broadcast frame includes response slave information, and the response slave information is used to indicate that the plurality of slave devices in the RS-485 bus network respond in response order, the response The order is an order in which the response frame is returned by the plurality of slave devices indicated by the response slave information;

The master device receives the response frame returned by the plurality of slave devices in response sequence.

A broadcast frame including the response slave information is generated and transmitted by the master device, indicating that multiple slave devices in the RS-485 bus network respond in response order, which can avoid broadcast response conflict between multiple slave devices, and improve broadcast communication success rate. To improve the performance of the RS-485 bus network.

In a first possible implementation of the second aspect, the generating, by the master device, the broadcast frame includes:

The master device determines an address of the plurality of slave devices;

Determining the response slave information according to an address of the plurality of slave devices and a preset condition;

Generating the broadcast frame based on the response slave information.

With reference to the first possible implementation of the second aspect, in a second possible implementation of the second aspect, the response slave information is a TLV format; the preset condition includes:

To specify that all slave devices in the RS-485 bus network respond in order, a response slave information of type 0 is used. Correspondingly, the value of the length field in the response slave information is 0, and the value field is empty;

To specify that multiple slaves with consecutive addresses respond in order, a response slave information of type 1 is used. Correspondingly, the value field in the response slave information includes a start address and a termination address, and the length field value is 2;

If the master device wants to specify that multiple slave devices whose addresses are not consecutive are answered in order, the type of the responding slave information may be determined according to the number of slave devices that need to be answered. When the number of slave devices that need to be answered is less than a preset threshold, it is determined that the type of the response slave information is 2. Accordingly, the value field includes the addresses of multiple slave devices that need to be answered. When the number of slave devices that need to be answered is greater than or equal to a preset threshold, it is determined that the type of the response slave information is 3. Correspondingly, the response indication bit corresponding to the slave device in the value field that needs to be acknowledged is set to 1.

The preset threshold may be

Where n is the number of bits of the address of the slave device.

The master device determines the response slave information according to the condition (number, address) of the slave device that needs to be answered, and specifies the response sequence to avoid the collision between the devices, and can shorten the length of the broadcast frame and improve the bandwidth utilization.

With reference to the second aspect, and any one of the foregoing possible implementations of the second aspect, in a third possible implementation of the second aspect, the method further includes: returning, by the master device, the multiple slave devices The response frame records status information of each slave device; the status information includes a device version, a transmit power, a sleep time, and the like.

With reference to the second aspect, and any one of the foregoing possible implementations of the second aspect, in a fourth possible implementation of the second aspect, the master device receives the response frame returned by the multiple slave devices in the response order, The method includes: determining, by the master device, a response waiting period according to a single point timeout duration and the number of the multiple slave devices, and receiving, in the response waiting period, a response frame sequentially returned by the multiple slave devices.

In a third aspect, a broadcast implementation apparatus is provided, which has the first slave device in the first aspect described above The function. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a fourth aspect, a slave device is provided for implementing the broadcast implementation method of the first aspect described above. The slave device includes a processor and a communication interface, the processor and the communication interface being connected to each other. The apparatus can also include a memory for storing a computer program, the computer program including program instructions, and the processor executing the program instructions to perform the broadcast implementation method of the first aspect described above.

In a fifth aspect, a computer storage medium is provided for storing computer software instructions for use in the first slave device described above, comprising a program designed to perform any of the first aspect described above and its possible implementations.

In a sixth aspect, a master device is provided, having the function of implementing the master device in the second aspect described above. The functions may be implemented by hardware or by corresponding software implemented by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a seventh aspect, a master device is provided for implementing the broadcast implementation method of the second aspect above. The master device includes a processor and a communication interface, and the processor and the communication interface are connected to each other. The apparatus can also include a memory for storing a computer program, the computer program comprising program instructions, the processor executing the program instructions, and performing the broadcast implementation method of the second aspect described above.

In an eighth aspect, a computer storage medium is provided for storing computer software instructions for use in the above-described host device, comprising a program designed to perform any of the above-described second aspects and possible implementations thereof.

According to a ninth aspect, there is provided an RS-485 bus network, comprising: a master device and a plurality of slave devices; the master device, as described in the sixth aspect or the seventh aspect, each of the plurality of slave devices As described in the third aspect or the fourth aspect above.

DRAWINGS

1 is a schematic flowchart of a broadcast implementation method according to an embodiment of the present invention;

2A is a schematic structural diagram of a type of response slave information according to an embodiment of the present invention;

2B is a schematic structural diagram of another type of response slave information according to an embodiment of the present invention;

2C is a schematic structural diagram of still another type of response slave information according to an embodiment of the present invention;

FIG. 3 is a schematic flowchart diagram of another broadcast implementation method according to an embodiment of the present invention;

4 is a schematic structural diagram of a broadcast implementation apparatus according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a slave device according to an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of a master device according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of another main device according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of an RS-485 bus network according to an embodiment of the present invention.

detailed description

The above described objects, features, and advantages of the embodiments of the present invention will become more apparent and understood.

Embodiments of the present invention provide a broadcast implementation method for an RS-485 bus network, where a master device sends The sent broadcast frame includes response slave information, and the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond to the broadcast frame in order, thereby avoiding conflicts when the multiple slave devices respond, and improving Communication efficiency and network performance. Moreover, each slave device can recalculate the response waiting time according to the response of the prior slave device, and shorten the response waiting time, thereby further improving communication efficiency.

FIG. 1 is a schematic flowchart of a broadcast implementation method according to an embodiment of the present invention. The method is used in an RS-485 bus network, and the method includes:

101. The first slave device receives a broadcast frame sent by the master device, where the broadcast frame includes response slave information, where the response slave information is used to indicate that multiple slave devices in the RS-485 bus network are in the order of Responding to the broadcast frame;

When the master device sends a broadcast frame, the slave device in the RS-485 bus network receives the broadcast frame. In the embodiment of the present invention, by extending the broadcast frame and carrying the response slave information, the master device may specify that the plurality of slave devices that need to communicate respond in order.

According to the response slave information, after receiving the broadcast frame from the slave device that does not need to communicate, there is no need to respond, avoiding the occupation of the RS-485 bus, and not consuming the resource to listen to whether the bus is idle, thereby improving the entire RS- Communication efficiency and performance of the 485 bus network.

The response slave information is a type-length-value (TLV) format. Referring to the schematic diagram of the response slave information shown in Figs. 2A, 2B and 2C, the response slave information in the embodiment of the present invention is explained as follows.

A Type field value of 0 means that all slave devices in the network need to respond in order (ie, in the order of the slave devices). At this time, the value of the Length field is 0 (byte), indicating that the length of the data contained in the Value field is 0 bytes, that is, the Value field is empty. Each slave device determines its own response order based on its own address.

A Type field value of 1 means that multiple slave devices within the address range contained in the Value field need to answer. At this time, the value of the Length field is 2 (bytes). The Value field includes a start address (1 byte) and a termination address (1 byte). For example, as shown in FIG. 2A, the start address is 0x02, and the end address is 0x1F, and the slave devices whose addresses are between 0x02 and 0x1F need to respond. Each slave device can determine its own response order based on the difference between its own address and the start address.

A Type field value of 2 means that the slave device of the specified address in the Value field needs to answer. The Value field includes all the addresses of the slaves that need to be answered. At this time, the value of the Length field is variable. If the number of slave devices to be answered is n, the value of the Length field is n (byte), indicating that the length of the data contained in the Value field is n. byte. For example, if the master device specifies four broadcast devices with addresses 0x11, 0x15, 0x43, and 0x78 to answer the broadcast frame, the above four addresses (0x11, 0x15, 0x43) are included in the value field of the response slave information. And 0x78), as shown in Figure 2B. Each slave device that needs to answer can use its own address in the value field as its own response order.

A Type field value of 3 indicates that the Answer Indicator bit in the Value field indicates that the slave device that needs to answer has replied. There are 247 addresses that can be assigned to slave devices in the RS-485 bus network. 0x01~0xF7, so the value field includes 247 response indication bits, and the length field has a value of 31 (bytes), as shown in FIG. 2C. In the Value field, the first to the 247th bits correspond to the address: 0x01 to 0xF7, that is, the first bit corresponding address: 0x01, the second bit corresponding address: 0x02, ..., the 247th bit corresponding address: 0x F7. A value of 1 for the response indication bit may indicate that a response is required, and a value of 0 indicates that no response is required. For example, if the 5th bit is set to 1, the slave device with the address 0x05 needs to answer the broadcast frame. The slave device that needs to respond can use its own response indication bit in the sequence of all response indication bits with a value of 1 as its own response sequence.

In a specific implementation, the master device can determine the type of the response slave information according to the number of slave devices that need to respond. When the addresses of multiple slave devices that need to respond are contiguous, the response slave information can be implemented with a Type field value of one. When the addresses of multiple slave devices that need to respond are not continuous, if the number is less than 31, the response slave information can be implemented with a Type field value of 2; if the number is greater than 31, the response slave information can be of type The (Type) field value is an implementation of 3.

102. If the first slave device determines, according to the response slave information, that the broadcast frame needs to be acknowledged, the first slave device determines a response start time according to the response slave information, and at the response start time. Respond.

Specifically, the first slave device determines, according to the answering slave information in the broadcast frame, whether the broadcast frame needs to be answered. If it is determined according to the response slave information that the broadcast frame does not need to be acknowledged, the information in the broadcast frame may be recorded, and then the broadcast frame is discarded. If it is determined that the broadcast frame needs to be answered according to the response slave information, the first slave device determines a response start time according to the response slave information, and responds at the response start time, the first slave The device is one of the plurality of slave devices.

The determining, by the first slave device, the response time according to the response slave information, specifically includes:

Obtaining, by the first slave device, a response order of the first slave device according to the response slave information, where the response sequence is the multiple slaves indicated by the first slave device in the response slave information The order in which the devices respond;

The first slave device calculates a response start time of the first slave device according to a single point timeout duration and a response order of the first slave device.

For example, the first slave device has a response order of N, N≥1. D represents the single point timeout duration, and the unit is usually microseconds (μs) or milliseconds (ms). The response start time Tsn=T0+(N-1)*D of the first slave device, where T0 is the time at which the first slave device receives the broadcast frame. In the embodiment of the present invention, the time difference between the received broadcast frame of each slave device and the broadcast frame sent by the master device may be ignored. In other words, T0 is also the time when the master device completes the transmission of the broadcast frame, and each slave device in the network starts to calculate the response start time from T0.

Optionally, the broadcast frame further includes a single point timeout duration. The single point timeout duration is the maximum duration required for each slave device designated by the master device to answer the broadcast frame for the broadcast frame. The master device may determine the single point timeout duration according to factors in the broadcast frame, slave processing speed, bus communication rate, and the like.

Of course, the single-point delay duration can also be pre-configured on the master device and each slave device. In this way, When receiving any broadcast frame including the response slave information, the slave device calculates the response start time according to the preset single-point timeout period.

The single point timeout duration is generally not less than the actual length of time required for the slave device to respond, and may be an empirical value. In the embodiment of the present invention, the single-point timeout period must be longer than the response time of the slave device with the slowest response in the network. For example, there are 200 slave devices in the RS-485 bus network, and the response duration may be 10ms, 20ms, 25ms, 50ms, 80ms, 95ms, and the longest response time is 95ms. In order to ensure that each slave device has enough time to complete the response, the single point timeout should be no less than 95ms.

Although the slave device waits sequentially in accordance with the response order and the single-point timeout duration, it is possible to avoid a response collision between the slave devices. However, the actual length of time required for different slave devices to respond in the network is different. Many slave devices usually have a response time that is less than the single-point timeout period. Therefore, the slave device in the response sequence can adjust its own response start time in real time according to the response order of the previous slave device, and avoid the delay caused by the fixed single-point timeout waiting time.

If the response sequence N of the first slave device is 1, that is, the first slave device is the first slave device to be replied, the response start time of the first slave device is Tsn=T0, ie, The first slave device starts to respond immediately after receiving the broadcast frame.

If the response order of the first slave device is N≥2, the first slave device may update its own according to the response end time of the second slave device in the response sequence (ie, the time when the response is completed and the response frame is sent) The start time of the response. Specifically, before reaching the response start time (Tsn) of the first slave device, the first slave device listens for communication on the RS-485 bus to determine whether there is a response from the prior slave device. . If the first slave device does not hear the response frame of the other slave device in the response order, the first slave device responds when the response start time Tsn is reached. If the first slave device detects the response frame of the second slave device in the response order before reaching the intermediate time before Tsn, the first slave device updates its response start time (Tsn) according to the intermediate time. . In this embodiment of the present invention, the time difference between the response frame of the second slave device and the response frame of the second slave device may be ignored. In other words, the intermediate time is equal to the time at which the second slave device completes the response frame transmission, that is, equal to the response end time of the second slave device.

For example, the first slave device listens to the response frame of the second slave device having the response order K (K<N) at the intermediate time Tek before reaching Tsn, and the first slave device updates the response start time Tsn=Tek+ (NK-1)*D. Before reaching the updated response start time Tsn, the first slave device continues to listen to the response frame of the prior slave device in the response order, and if it hears, continues to update Tsn, if not heard, then arrives at Tsn When an answer frame is sent.

The broadcast implementation method provided by the embodiment of the present invention is described below in conjunction with a specific example. Assume that the master device completes the transmission of the broadcast frame at time T0, the single-point timeout period is 100 ms, the type (Type) field value of the response slave information of the broadcast frame is 2, and the specified address in the Value field is 0x03, 0x06. The four slaves of 0x0A and 0x13 acknowledge the broadcast frame. After receiving the broadcast frame, each slave device in the network determines whether its own address is in the response slave information of the broadcast frame to determine whether it wants to answer the broadcast frame. After receiving the broadcast frame, the four slave devices 0x03, 0x06, 0x0A, and 0x13 determine that they want to answer the broadcast frame, respectively acquire respective response sequences, and calculate respective response start times. Specific The process is as follows:

(1) After receiving the broadcast frame from the device 3, it is determined that it wants to answer the broadcast frame, obtain the response sequence N=1, acquire the single-point timeout duration (from the broadcast frame or from the local), and calculate its own response. Start time:

Tr1=T0+(1-1)*100ms=T0

A response is received immediately after the device 3 receives the broadcast frame. Assuming that the response takes 10 ms, that is, the response duration is 10 ms, the slave device 3 completes the response at the end of its response: Te1 = Tr1 + 10 ms = T0 + 10 ms.

(2) The slave device 6 is the second slave device that needs to be answered. In this example, it is assumed that the slave device 6 has a failure and cannot respond. Therefore, the slave device 6 occupies a single point timeout of 100 ms.

(3) After receiving the broadcast frame from the device 10, it determines that it wants to answer the broadcast frame, obtains the response sequence N=3, acquires the single-point timeout duration, and calculates its own response start time:

Tr3=T0+(3-1)*100ms=T0+2*100ms

Before reaching Tr3=T0+2*100ms, the slave device 10 listens to the response frame of the prior slave device (slave device 3 and slave device 6); the slave device 10 listens at the intermediate time Te1=T0+10ms From the response frame of the device 3, the slave device 10 adjusts its own response start time to: Tr3 = Te1 + (3-1 - 1) * 100 ms = T0 + 110 ms.

The slave device 10 then continues to listen to the slave device (slave device 6) that responds in the prior order. Since the slave device 6 fails, the slave device 10 does not hear the response frame of the slave device 6 until it reaches Tr3=T0+110 ms, and cannot further adjust the response start time according to the response of the slave device 6. When the Tr3 = T0 + 110 ms is reached, the slave device 10 responds. Assuming that the slave device 10 responds with 20 ms, the slave device 10 completes the response at its response end time: Te3 = Tr3 + 20 ms = T0 + 110 ms + 20 ms = T0 + 130 ms.

(4) After receiving the broadcast frame from the device 18, it determines that it wants to answer the broadcast frame, obtains the response sequence N=4, acquires the single-point timeout duration, and calculates its own response start time:

Tr4=T0+(4-1)*100ms=T0+3*100ms

The slave device 18 listens to the slave devices (slave device 3, slave device 6 and slave device 10) that have responded in order before reaching Tr4 = T0 + 3 * 100 ms. The slave device 18 listens to the response frame of the slave device 3 at the intermediate time Te1 = T0 + 10 ms, so the slave device 18 adjusts its own response start time to: Tr4 = Te1 + (4-1-1) * 100 ms = T0 + 210 ms .

Then, the slave device 18 continues to listen to the slave devices (slave device 6 and slave device 10) that have responded in the prior order. Since the slave device 6 fails, the slave device 18 does not hear the response frame of the slave device 6. The slave device 18 listens to the response frame of the slave device 10 at the intermediate time Te3 = T0 + 130 ms, so the slave device 18 adjusts its own response start time to: Tr4 = Te3 + (4-3-1) * 100 ms = Te3 = T0 +130ms.

Since the response order of the slave device 18 is 4, the response order of the slave device 10 is 3, so no other slave device needs to respond between the slave device 18 and the slave device 10. Therefore, the response start time of the slave device 18 is the response of the slave device 10. End time. That is, the slave device 18 responds immediately after hearing the response frame of the slave device 10.

Assuming that the slave device 18 responds for 30 ms, the slave device 18 response end time is Te4 = Tr4 + 30 ms = T0 + 130 ms + 30 ms = T0 + 160 ms.

So far, the broadcast response process provided by the embodiment of the present invention ends.

It can be seen from the above process that at the time Te4 (T0+160ms), the four slave devices designated by the master device complete the response of the broadcast frame. If the response is made in such a way that the single point timeout period is not adjusted, the slave device 18 completes the response at time T0 + (4-1) * 100 ms + 30 ms = T0 + 330 ms. Therefore, in a manner of dynamically adjusting the start time of the response, the response of the four slave devices to complete the broadcast frame can be shortened by 170 ms. The slave device 6 has no response due to a fault, and the response duration is equal to the single-point delay duration. If the slave device 6 has no fault, the total response duration can be further shortened.

Further, the first slave device may first detect whether the RS-485 bus is occupied when the response start time is reached, and then send the response frame again if it is confirmed that the bus is idle.

According to the broadcast implementation method provided by the embodiment of the present invention, when the first slave device determines that the broadcast frame needs to be responded according to the response slave information in the broadcast frame, the response start time is calculated according to the single point timeout duration and the response order, and the response is reached. The response is answered at the beginning, which avoids the response conflict between the slave devices, and improves the resource utilization and communication efficiency of the slave device. In addition, the first slave device adjusts its own response start time in real time according to the response end time of the other slave devices in the response order, avoids the delay caused by the backoff collision according to the fixed single point timeout period, and improves the broadcast response efficiency. Thereby improving the performance of the entire RS-485 bus network.

FIG. 3 is a schematic flowchart diagram of another method for implementing a broadcast according to an embodiment of the present invention, where the method includes:

301. The master device generates and sends a broadcast frame, where the broadcast frame includes response slave information, where the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond in response order.

The slave device in the RS-485 bus network receives the broadcast frame sent by the master device. In the embodiment of the present invention, the master device specifies, by using the response slave information in the broadcast frame, that the multiple slave devices answer the broadcast frame according to the response order. The response order is an order in which the response frames are returned by the plurality of devices indicated by the response slave information.

The response slave information is in the TLV format. For details, refer to the description in step 101.

Optionally, the broadcast frame further includes a single point timeout duration. The master device may specify, for the broadcast frame, a maximum duration required for each slave device to answer the broadcast frame according to factors in the broadcast frame, a slave processing speed, a bus communication rate, and the like, ie, the Single point timeout period.

Of course, the single-point delay duration can also be pre-configured on the master device and each slave device. In this way, when receiving any broadcast frame including the response slave information, the slave device calculates the response start time according to the preset single-point timeout duration.

302. Receive a response frame that is returned by the multiple slave devices in response sequence.

The master device may determine a response waiting period according to a single point timeout period and a quantity of the plurality of slave devices (the slave device that specifies the broadcast frame to be answered), and in the response waiting period Receiving a response frame sequentially returned by the plurality of slave devices.

Optionally, when the response waiting period ends, if the slave device does not return the response frame, the master device may send the updated to the unacknowledged slave device of the multiple slave devices. Broadcast frame. Of course, the master device may also send a unicast frame to the slave devices that are not answered in the plurality of slave devices.

Further, the method may further include: the master device records status information of each slave device according to the response frame returned by the multiple slave devices, such as a device version, a transmit power, a sleep time, and the like.

Generating, by the master device, a broadcast frame, including: determining, by the master device, an address of the multiple slave devices; determining, according to an address and a preset condition of the multiple slave devices, the response slave information; The broadcast information is generated from the slave information.

Determining, by the master device, the answering slave information according to an address and a preset condition of the multiple slave devices, including:

If the master device wants to designate all slave devices to respond in order, it is preferred to use the responder slave information of type 0. Accordingly, each slave device can determine its own response order based on its own address.

If the master device is to specify a plurality of slave devices (a plurality of slave devices consecutive to each other) in a range of addresses to respond in order, it is preferable to use the response slave information of type 1 and in the value field of the response slave information. Includes start address and end address. Accordingly, each slave device can determine its own response order based on the difference between its own address and the start address. It is also possible to use the response slave information of type 1 to designate all slave devices to respond in order, and the start address in the value field of the response slave information is the minimum address of the slave device, and the termination address is the maximum address of the slave device.

If the master device wants to specify multiple slave devices whose addresses are not consecutive, the responder slave information may be of

type

2 or 3. Specifically, the master device may determine the type of the responding slave information according to the number of slave devices that need to be answered. When the number of slave devices that need to be answered is less than a preset threshold, it is determined that the type of the response slave information is 2 (ie, the response slave information includes addresses of multiple slave devices that need to be answered), and each of the responders needs to be answered. Slave devices can use their own address in the value field as their response order. When the number of slave devices that need to be answered is greater than or equal to a preset threshold, it is determined that the type of the response slave information is 3 (ie, the response slave information includes a response indication bit corresponding to each slave device), and needs to be answered. The slave device can set its own response indication bit in the order of all response indication bits with a value of 1 as its own response order.

The preset threshold may be

Where n is the number of bits of the address of the slave device. For example, when the number of bits of the address of the slave device in the RS-485 bus network is 8, the preset threshold is set to 32. When the number of slave devices to be answered is greater than or equal to 32, the type of the response slave information is 3. When the preset threshold is set to less than 32, the type of the response slave information is 2. In this way, when the number of slave devices to be answered is small, the address of the slave device that needs to be answered is directly carried in order, the length of the broadcast frame can be reduced, and the processing efficiency of the device can be improved, of course, except that the preset threshold is set to

It can also be set to a larger or smaller value.

Obviously, regardless of the above situation, the response slave information of type 3 can be used.

Other details in this embodiment may be described in the method shown in FIG. 1 of the embodiment of the present invention.

According to the broadcast implementation method provided by the embodiment of the present invention, the master device generates and transmits a broadcast frame including the response slave information, and the slave device information indicates that the plurality of slave devices in the RS-485 bus network respond in response order to broadcast Realizing a multicast-like communication mechanism, compared with the traditional unicast or broadcast mode, can improve the resource utilization and communication efficiency of the master device, and also avoid broadcast response conflicts between multiple slave devices, thereby improving RS-485. The performance of the bus network.

FIG. 4 is a schematic structural diagram of a broadcast implementation apparatus according to an embodiment of the present invention, which is used to implement the broadcast implementation method shown in FIG. 1 according to an embodiment of the present invention. The broadcast implementation device 40 includes a receiving module 401 and a processing module 402;

The receiving module 401 is configured to receive a broadcast frame sent by the master device, where the broadcast frame includes response slave information, where the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond in order Broadcast frame

The processing module 402 is configured to determine, according to the response slave information, that the broadcast frame needs to be answered, determine a response start time according to the response slave information, and respond at the response start time.

The broadcast implementation device 40 is deployed on a first of the plurality of devices.

The processing module 402 is specifically configured to determine, according to the response slave information in the broadcast frame, whether the broadcast frame needs to be acknowledged; if it is determined according to the response slave information that the broadcast frame does not need to be acknowledged, the recording station Decoding the information in the broadcast frame, and then discarding the broadcast frame; if it is determined that the broadcast frame needs to be answered according to the response slave information, determining a response start time according to the response slave information, and at the response start time Send an answer frame.

The processing module 402 is specifically configured to acquire, according to the response slave information, a response sequence of the first slave device, where the response sequence is that the first slave device indicates the multiple of the response slave information. The order in which the slave devices respond; the answer start time of the first slave device is calculated according to the single point timeout duration and the response order of the first slave device. For example, the first slave device has a response order of N, N≥1. D represents the single point timeout duration. The response start time Tsn=T0+(N-1)*D of the first slave device, where T0 is the time at which the first slave device receives the broadcast frame.

If the response sequence N of the first slave device is 1, that is, the first slave device is the first slave device to be replied, the response start time Tsn=T0, that is, the first slave The device starts responding immediately after receiving the broadcast frame.

If the response order of the first slave device is N≥2, the first slave device may update its response start time according to the response end time of the second slave device (ie, the time when the response frame is sent) according to the response order. .

The processing module 402 is further configured to adjust the response start time of the first slave device in real time according to the response end time of the second slave device in the response sequence. Specifically, the processing module 402 listens for communication on the RS-485 bus before determining the response start time (Tsn) of the first slave device to determine whether there is a response from the prior slave device. If the response frame of the other slave device whose response order is prior is not detected, the response is reached when the response start time Tsn is reached. If the response frame of the second slave device in the response order is detected at an intermediate time before the arrival of Tsn, the response start time (Tsn) of the first slave device is updated according to the intermediate time. For example, when the intermediate time Tek before the response start time Tsn of the first slave device is reached, the response frame of the second slave device having the response order K (K<N) is detected, and the first slave device is updated. The response start time is Tsn=Tek+(NK-1)*D.

Other details in this embodiment may be referred to in the broadcast implementation method shown in FIG. 1 of the embodiment of the present invention.

The broadcast implementation apparatus provided by the embodiment of the present invention may determine, according to the response slave information included in the broadcast frame, whether the broadcast frame needs to be acknowledged, and when determining that the broadcast frame needs to be answered, calculate according to the single point timeout duration and the response order. At the start of the response, the response is acknowledged at the start of the response, and the response conflict of the slave device is avoided. In addition, the broadcast implementing apparatus provided by the embodiment of the present invention adjusts its own response start time in real time according to the response end time of the other slave devices in the response order, thereby avoiding the delay caused by the fixed single-point timeout period backoff conflict, and improving The response efficiency improves the performance of the entire RS-485 bus network.

FIG. 5 is a schematic structural diagram of a slave device according to an embodiment of the present invention, which is applied to an RS-485 bus network, and is used to implement the broadcast implementation method shown in FIG. 1 according to an embodiment of the present invention. The slave device 50 includes a processor 501 and a communication interface 502.

The slave device 50 is configured to implement the first slave device in the method shown in FIG. 1 of the embodiment of the present invention.

The processor 501 and the communication interface 502 are connected to each other.

The communication interface 503 includes an RS-485 chip for communicating with other devices in the RS-485 bus network.

The processor 501 is configured to receive, by using the communication interface 502, a broadcast frame sent by a master device, where the broadcast frame includes response slave information, where the response slave information is used to indicate the RS-485 bus network. The plurality of slave devices respond to the broadcast frame in order. The processor 501 is further configured to determine, according to the responding slave information in the broadcast frame, whether the broadcast frame needs to be answered; when determining, according to the responding slave information, that the broadcast frame needs to be answered, according to the The response slave information determines the response start time and responds at the response start time.

The processor 501 is typically a microcontroller unit (MCU); it may also include a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device. .

Optionally, the processor 501 is further configured to: when determining, according to the responding slave information, that the broadcast frame does not need to be acknowledged, record information in the broadcast frame, and discard the broadcast frame.

The processor 501 may specifically acquire, according to the response slave information, a response sequence of the slave device 50 (ie, the first slave device), where the response sequence is that the first slave device is in the response slave The order in which the plurality of slave devices indicate the response is indicated by the information; and the response start time of the first slave device is further calculated according to the single point timeout duration and the response order of the first slave device. For example, the first slave device has a response order of N, N≥1. D represents the single point timeout duration, and the unit is usually microseconds (μs) or milliseconds (ms). The response start time Tsn=T0+(N-1)*D of the first slave device, where T0 is the time at which the first slave device receives the broadcast frame.

If the response order of the first slave device is N≥2, the processor 501 is further configured to adjust the slave device 50 in real time according to the response end time of the second slave device in the response sequence (ie, the first From the device) The start of the response.

The processor 501 is specifically configured to: after receiving the response start time (Tsn) of the first slave device, listen for communication on the RS-485 bus to determine whether there is a response from the prior slave device. . If the response frame of the second slave device in the response order is detected at an intermediate time before the arrival of Tsn, the response start time (Tsn) of the first slave device is updated according to the intermediate time. For example, when the intermediate time Tek before the response start time Tsn of the first slave device is reached, the response frame of the second slave device having the response order K (K<N) is detected, and the first slave device is updated. The response start time is Tsn=Tek+(NK-1)*D. If the response frame of the other slave device whose response order is prior is not detected, the response is reached when the response start time Tsn is reached.

The processor 501 further includes a memory for storing the single point timeout duration.

The communication interface 502 is further configured to send a response frame to the broadcast frame.

It will be understood by those skilled in the art that only a part of the structure related to the present invention from the device is shown in the embodiment of the present invention, and more components than those illustrated, or different component arrangements may be included.

FIG. 6 is a schematic structural diagram of a master device according to an embodiment of the present invention, which is used to implement the broadcast implementation method shown in FIG. 3 according to an embodiment of the present invention. The master device 60 includes a generating module 601, a sending module 602, and a receiving module 603.

The generating module 601 is configured to generate a broadcast frame, where the broadcast frame includes response slave information, where the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond in order;

The sending module 602 is configured to send the broadcast frame. The slave device in the RS-485 bus network will receive the broadcast frame. In the embodiment of the present invention, the broadcast implementing apparatus 60 specifies, by using the response slave information in the broadcast frame, that the multiple slave devices answer the broadcast frame in order.

The receiving module 603 is configured to receive a response frame returned by the multiple slave devices.

Optionally, the broadcast frame further includes a single point timeout duration.

The generating module 601 is configured to determine an address of the multiple slave devices, determine the responding slave information according to addresses and preset conditions of the multiple slave devices, and generate the broadcast frame according to the responding slave information .

The master device 60 can employ any type of response slave information to designate the plurality of slave devices to respond in order. The preset conditions include:

If the master device 60 is to designate all slave devices to respond in order, it is preferred to use answer slave information of type 0.

If the master device wants to specify multiple consecutive slave addresses to respond in order, it is preferable to use the responder slave information of type 1.

If the master device 60 wants to specify multiple slave devices whose addresses are not consecutive, the responder slave information of

type

2 or 3 can be used. Specifically, the broadcast implementing device 60 may determine the type of the response slave information according to a preset condition. The preset condition includes: when the number of slave devices that need to be answered is less than a preset threshold, determining that the type of the response slave information is 2, and each slave device that needs to respond The device can use its own address in the value field as its own response order. When the number of slave devices that need to be answered is greater than or equal to a preset threshold, it is determined that the type of the response slave information is 3, and the slave device that needs to respond may set its own response indicator to all the response indicator bits with a value of 1. The order is as its own response order.

The preset threshold may be

Where n is the number of bits of the address of the slave device. Of course, except that the preset threshold is set to

It can also be set to a larger or smaller value.

The receiving module 603 may determine a response waiting period according to a single point timeout duration and the number of the plurality of slave devices (specifying slave devices that need to answer the broadcast frame), and receive the multiple during the response waiting period. The response frame returned from the device.

The master device 60 may further include: a recording module, configured to record, according to the response frame returned by the multiple devices, status information corresponding to each device, such as a device version, a transmit power, a sleep time, and the like.

Other details in this embodiment may be described in the method shown in FIG. 1 and FIG. 3 of the embodiment of the present invention.

The master device provided by the embodiment of the present invention generates and sends a broadcast frame including the response slave information, by which the slave device information indicates that multiple devices respond in response order, and broadcasts a multicast-like communication mechanism. The traditional unicast or broadcast mode can improve the communication efficiency while avoiding the broadcast response conflict between multiple slave devices, thereby improving the performance of the entire RS-485 bus network.

FIG. 7 is a schematic structural diagram of another main device according to an embodiment of the present invention. The master device 70 includes a processor 701 and a communication interface 702. The master device 70 is configured to implement the broadcast implementation method shown in FIG. 3 of the embodiment of the present invention.

The processor 701 and the communication interface 702 are connected to each other.

The communication interface 702 includes an RS-485 chip for communicating with slave devices in the RS-485 bus network.

The processor 701 is configured to generate a broadcast frame and send the broadcast frame by using the communication interface 702. The broadcast frame includes response slave information, and the response slave information is used to indicate the RS-485 bus. Multiple slave devices in the network respond in order.

The processor 701 is further configured to receive, by using the communication interface 702, a response frame returned by the multiple slave devices.

The processor 701 is typically an MCU and may also include a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device.

The processor 701 is specifically configured to determine an address of the multiple slave devices, determine the response slave information according to an address and a preset condition of the multiple slave devices, and generate a location information according to the response slave information. Said broadcast frame.

The processor 701 further includes a memory for storing an address of the slave device in the RS-485 bus network.

The master device 70 may employ any type of response slave information to designate the plurality of slave devices to press Answer in order. The preset condition may be specifically referred to in the method step 302 shown in FIG.

Optionally, the broadcast frame further includes a single point timeout duration. The processor 701 is further configured to determine the single point timeout duration according to factors in the broadcast frame, a slave processing speed, a bus communication rate, and the like. The single point timeout duration is the maximum length of time required for the slave device to answer the broadcast frame.

Of course, the single-point delay duration can also be pre-configured on the master device and each slave device. The memory can also be used to store the single point timeout duration.

The processor 701 may determine a response waiting period according to the single-point timeout duration and the number of the plurality of slave devices (specifying slave devices that need to answer the broadcast frame), and receive the receiving period during the response waiting period. A response frame returned by multiple slave devices.

The processor 701 is further configured to record, according to the response frame returned by the multiple devices, status information corresponding to each device, such as a device version, a transmit power, a sleep time, and the like.

It will be understood by those skilled in the art that only a part of the structure of the main device related to the present invention is shown in the embodiment of the present invention, and more components than those illustrated, or different component arrangements may be included.

FIG. 8 is a schematic diagram of an RS-485 bus network according to an embodiment of the present invention, including a master device 801 and a plurality of slave devices 802. For details of the working principle, structure, and function of the main device 801, refer to FIG. 6 or 7 of the embodiment of the present invention, and details are not described herein again. For details of the working principle, structure, and function of the device 802, refer to FIG. 4 or 5 of the embodiment of the present invention, and details are not described herein again.

The broadcast implementation method provided by the embodiment of the present invention can also be applied to a low-rate wireless personal area network (LR-WPAN) in a star networking mode. The coordinator in the LR-WPAN is equivalent to the master device in the embodiment of the present invention. The non-coordinator device: a full-function device (FFD) and a reduced-function device (RFD) are equivalent. A slave device in an embodiment of the present invention. The embodiments of the present invention are described based on the RS-485 bus network and are not intended to limit the present invention.

A person skilled in the art can understand that all or part of the steps in implementing the foregoing method embodiments may be performed by a program to instruct related hardware, and the corresponding program may be stored in a computer readable storage medium, and the storage medium may be random. Access memory, read-only memory, flash memory, hard disk, solid state hard disk or optical disk.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed by the present invention. Alternatives are intended to be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

A broadcast implementation method for recommending a standard RS-485 bus network, characterized in that it comprises:

Receiving, by the first slave device, a broadcast frame sent by the master device, where the broadcast frame includes response slave information, where the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond in order;

When it is determined that the broadcast frame needs to be answered according to the response slave information, the first slave device acquires a response start time according to the response slave information, and responds when the response start time is reached.
The method according to claim 1, wherein the first slave device acquires a response start time according to the response slave information, and includes:

Obtaining, by the first slave device, the response sequence N of the first slave device according to the response slave information, where the response sequence N is that the first slave device answers the broadcast frame in the multiple slave devices Order

The first slave device calculates a response start time Tsn=T0+(N-1)*D of the first slave device according to a single point timeout duration D and a response sequence N of the first slave device, where T0 is The moment when the first slave device receives the broadcast frame.
The method according to claim 1 or 2, wherein N ≥ 2, the method further comprises:

The first slave device listens to the RS-485 bus before reaching the response start time Tsn of the first slave device;

Updating the response start time Tsn=Tek+(NK-1)*D of the first slave device according to the response end time Tek of the second slave device in the response order, where K is the response of the second slave device Order, N>K≥1.
The method according to any one of claims 1 to 3, wherein the response slave information is a type-length-value (TLV) format; the type of the response slave information is as follows Any one:

Type 0, indicating that all slave devices in the RS-485 bus network need to respond in order;

Type 1 indicates that multiple slave devices in the range of the start address to the end address in the value field need to respond in order;

The type is 2, indicating that the slave devices corresponding to each address in the value field need to respond in order;

The type is 3, and the response indication bit in the indication value field indicates that the slaves that need to answer are responsive in order.
A broadcast implementation method for recommending a standard RS-485 bus network, characterized in that it comprises:

The master device generates and transmits a broadcast frame, the broadcast frame includes response slave information, and the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond in response order;

Receiving, by the master device, a response frame returned by the multiple slave devices in response sequence;

The response order is an order in which the response frame is returned by the plurality of slave devices indicated by the response slave information.
The method according to claim 5, wherein said master device generates said broadcast frame, include:

The master device determines an address of the plurality of slave devices;

Determining the response slave information according to an address of the plurality of slave devices and a preset condition;

Generating the broadcast frame based on the response slave information.
The method according to claim 5 or 6, wherein the response slave information is a type-length-value (TLV) format; the preset condition includes:

To specify that all slave devices in the RS-485 bus network respond in order, using the responder slave information of type 0;

To specify that multiple slave devices with consecutive addresses respond in order, use response slave information of type 1;

If the master device wants to specify multiple slave devices whose addresses are not consecutively replied in order, when the number of slave devices that need to be answered is less than a preset threshold, it is determined that the type of the responding slave information is 2; When the number of devices is greater than or equal to a preset threshold, it is determined that the type of the response slave information is 3.
A broadcast implementation device for recommending a standard RS-485 bus network, comprising:

a receiving module, configured to receive a broadcast frame sent by the master device, where the broadcast frame includes response slave information, where the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond in order ;

a processing module, configured to: when determining, according to the response slave information, that the broadcast frame needs to be answered, the first slave device acquires a response start time according to the response slave information, and when the response start time is reached Answer

The broadcast implementation device is deployed on a first of the plurality of slave devices.
The apparatus according to claim 8, wherein the processing module is configured to acquire a response sequence N of the first slave device according to the response slave information, where the response sequence N is the first An order in which the slave device answers the broadcast frame in the plurality of slave devices; and calculates a response start time Tsn=T0+ of the first slave device according to the single-point timeout duration D and the response sequence N of the first slave device (N-1)*D, where T0 is the time at which the first slave device receives the broadcast frame.
The device according to claim 8 or 9, wherein N ≥ 2, the processing module is further configured to: the first slave device listens before reaching a response start time Tsn of the first slave device RS-485 bus; updating the response start time Tsn=Tek+(NK-1)*D of the first slave device according to the response end time Tek of the second slave device in the response sequence, where K is the number The order of response of the two slave devices, N>K≥1.
A master device for recommending a standard RS-485 bus network, characterized by comprising:

a generating module, configured to generate a broadcast frame, where the broadcast frame includes response slave information, where the response slave information is used to indicate that multiple slave devices in the RS-485 bus network respond in response order;

a sending module, configured to send the broadcast frame, where the response order is an order in which the response frame is returned by the multiple slave devices indicated by the response slave information;

And a receiving module, configured to receive the response frame returned by the multiple slave devices in the response sequence.
The master device according to claim 11, wherein the generating module is specifically configured to determine an address of the plurality of slave devices, and determine the response according to an address and a preset condition of the multiple slave devices The slave information; the broadcast frame is generated according to the response slave information.
The master device according to claim 11 or 12, wherein the response slave information is a type-length-value (TLV) format; the preset condition includes:

To specify that all slave devices in the RS-485 bus network respond in order, using the responder slave information of type 0;

To specify that multiple slave devices with consecutive addresses respond in order, use response slave information of type 1;

If the master device wants to specify multiple slave devices whose addresses are not consecutively replied in order, when the number of slave devices that need to be answered is less than a preset threshold, it is determined that the type of the responding slave information is 2; When the number of devices is greater than or equal to a preset threshold, it is determined that the type of the response slave information is 3.