Multichannel digital quantity transmission method and device based on serial coding

Abstract

The invention provides a multi-channel digital quantity transmission method and device based on serial coding, which are applied to the technical field of industrial control and automation, and are used for sampling multi-channel parallel input signals in a first period and carrying out serial coding on sampling values in a second period to generate coded signals. And transmitting the coded signal to a decoding circuit through a sending / receiving channel, and finally recovering the original multi-channel parallel signal. According to the method, the number of hardware channels is remarkably reduced, the cost and the hardware complexity are reduced, meanwhile, the anti-noise capability of the system and the stability of data transmission are improved through multiple sampling and coding technologies, and efficient and low-cost multi-channel digital quantity transmission is achieved.

Description

Technical Field

[0001] This application relates to the field of industrial control and automation technologies, and particularly relates to a multi-channel digital quantity transmission method and device based on serial encoding. Background Art

[0002] In the field of industrial control and automation, the transmission of digital control signals (such as motor start / stop, forward / reverse, limit switch, position calibration, etc.) highly depends on multi-channel I / O interfaces. Traditional multi-channel digital quantity transmission methods mainly rely on parallel transmission, that is, each signal channel requires independent transmit (TX) and receive (RX) modules. Due to the huge area of TX and RX modules, for scenarios where dozens or even hundreds of signals need to be transmitted, a large amount of PCB area needs to be occupied, and the hardware cost significantly increases.

[0003] Currently, the following two schemes are mainly adopted to transmit digital control signals: One is the low-cost scheme: using multiple low-speed optocouplers as the input of digital isolation quantities. However, optocouplers have problems such as poor temperature coefficient, low stability, optical decay, and poor inter-chip consistency, seriously affecting the system stability and lifespan.

[0004] The other is the high-stability scheme: inputting signals through analog diodes and then transmitting the signals through TX / RX. Although it can solve the temperature characteristics, stability, and randomness problems of optocouplers, each signal still requires a corresponding pair of TX / RX channels, resulting in high hardware costs.

[0005] Based on this, a new multi-channel digital quantity transmission scheme that can both reduce costs and ensure transmission stability and anti-interference ability is needed. Summary of the Invention

[0006] In view of this, embodiments of this specification provide a multi-channel digital quantity transmission method and device based on serial encoding. By using serial encoding and decoding technologies, signals of multiple parallel channels are encoded serially and then transmitted through the same TX and RX paths, which not only effectively solves the defects of traditional optocouplers in terms of stability and randomness but also significantly reduces the high cost caused by using multiple TX / RX channels.

[0007] Embodiments of this specification provide the following technical solutions: Embodiments of this specification provide a multi-channel digital quantity transmission method based on serial encoding, including: In the first cycle, sampling multiple parallel input signals to obtain sampling values; In the second cycle, encoding the sampling values of the first cycle in sequence to generate encoded signals; Transmitting the encoded signals to a decoding circuit through a first transmit / receive channel; The decoding circuit restores the original multi-channel parallel signal according to the encoded signal.

[0008] An embodiment of this specification also provides a multi-channel digital quantity transmission device based on serial encoding, including: A sampling module, configured to sample the multi-channel parallel input signal in the first cycle to obtain sampling values; An encoding module, configured to sequentially encode the sampling values in the first cycle in the second cycle to generate an encoded signal; A transmission module, including a first transmitting / receiving module, configured to transmit the encoded signal to a decoding circuit; A decoding module, configured to restore the original multi-channel parallel signal according to the encoded signal.

[0009] Compared with the prior art, the at least one technical solution adopted in the embodiment of this specification can achieve at least the following beneficial effects: By sampling the multi-channel parallel input signal in the first cycle, serially encoding the sampling values in the second cycle to generate an encoded signal, transmitting the encoded signal to the decoding circuit through a transmitting / receiving channel, and finally restoring the original multi-channel parallel signal, the number of hardware transmission channels is significantly reduced, the cost and the circuit board area are reduced. At the same time, the anti-noise ability of the system and the stability of data transmission are improved through multiple sampling and encoding technologies, realizing efficient and low-cost multi-channel digital quantity transmission. Description of the Drawings

[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0011] Figure 1 is a traditional method for realizing digital quantity transmission using optocoupler technology; Figure 2 is a traditional method for realizing digital quantity transmission using TX / RX; Figure 3 is the transmission method in this application; Figure 4 is a flowchart of the multi-channel digital quantity transmission method based on serial encoding in this application; Figure 5 is a timing diagram of the transmission method in this application; Figure 6 is an encoding waveform diagram of the transmission method in this application; Figure 7It is the decoded waveform diagram of the transmission method in this application. Detailed implementation manners

[0012] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0013] The following uses specific specific examples to illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0014] It should be noted that the following describes various aspects of the embodiments within the scope of the appended claims. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects described herein can be used to implement the device and / or practice the method. In addition, this device and / or practice this method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0015] It should also be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present application schematically. The drawings only show the components related to the present application, rather than being drawn according to the number, shape and size of the components in actual implementation. The type, quantity and proportion of each component in its actual implementation can be an arbitrary change, and the component layout type may also be more complex.

[0016] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the examples can be practiced without these specific details.

[0017] In the field of industrial control and automation, the transmission of digital signals (such as controlling the start, stop, forward and reverse rotation of motors, limit switches, position calibration, etc.) requires a large number of I / O interfaces.

[0018] Currently, there are some obvious deficiencies in traditional digital signal transmission methods. Some methods only consider cost and ignore stability. For example, Figure 1 As shown in the optocoupler isolation scheme, by using multiple low-speed optocouplers as the input of digital isolation quantities, although optocouplers have the advantage of low cost, their temperature coefficient is very poor. For example, the performance fluctuates significantly at -40°C to 85°C; the stability of optocouplers is not high, there is optical decay, which affects the lifespan; in addition, the difference between optocouplers is large and the randomness is high, so it cannot meet the requirements of industrial scenarios for long-term reliability.

[0019] Some other methods consider stability, but the cost is high. For example, Figure 2 As shown in the multi-channel TX / RX scheme, by simulating the input of diodes and then transmitting the signals through TX and RX, although the temperature characteristics, stability and randomness problems of optocouplers are solved, each signal still needs to correspond to a pair of TX / RX channels, resulting in high hardware costs. For example, transmitting 8 signals requires 8 pairs of TX / RX modules, with large cost and area overhead. For scenarios that need to transmit dozens or even hundreds of signals (such as PLC control or industrial robots), this scheme requires a large amount of PCB area, and there is a risk of signal interference during high-density integration, and the hardware cost increases significantly.

[0020] In view of this, the inventor has found through research and improvement exploration that: existing low-cost schemes (such as optocoupler isolation) have poor stability, and high-stability schemes (such as multi-channel TX / RX) have too high costs.

[0021] Based on this, the embodiments of this specification propose a multi-channel digital quantity transmission method based on serial coding. The overall idea is: by introducing serial coding technology, compress the signals of multiple parallel channels to a few TX / RX channels for transmission, which not only solves the defects of poor stability, short lifespan and high randomness of traditional optocouplers, but also avoids the high-cost problem of multi-channel TX / RX, meeting the requirements of the industrial control field for efficient and reliable signal transmission.

[0022] The following will describe the technical solutions provided by the embodiments of this application with reference to the accompanying drawings.

[0023] As Figure 4 shown, the embodiments of this specification provide a multi-channel digital quantity transmission method based on serial coding, including: Step S1, in the first cycle, sample the multiple parallel input signals to obtain sampling values; Generally, the multiple parallel signals come from different sensors or control devices, such as the start / stop signal, forward / reverse signal, limit switch signal of a motor, etc. Sample each signal channel in the first cycle and store the sampling results in a register for use in the encoding stage.

[0024] Step S2: In the second cycle, encode the sampled values of the first cycle in sequence to generate an encoded signal; In implementation, arrange the sampled values obtained in the first cycle in order, and encode the sampled values in sequence to generate an encoded signal. During the encoding process, header information is usually added. The header information is usually a specific pattern (such as a synchronization flag) used to identify the start position of the data frame. The encoded signal needs to distinguish the header information from the signal information so that the decoding module can distinguish the header and decode successfully.

[0025] Step S3: Transmit the encoded signal to the decoding circuit through the first transmit / receive channel; In implementation, the first transmit / receive channel includes a data channel responsible for transmitting the encoded data frame and the header information.

[0026] Step S4: The decoding circuit restores the original multi-channel parallel signal according to the encoded signal.

[0027] In implementation, the decoding circuit determines the start position of the data frame by identifying the header information (such as a synchronization flag). According to the header information, the decoding circuit sequentially analyzes the data bits in the encoded signal to restore the original multi-channel parallel signal. The restored multi-channel parallel signal is output to the subsequent processing circuit or control device.

[0028] Therefore, by introducing serial encoding technology, compared with the traditional multi-channel digital quantity transmission method, it significantly reduces the occupation of hardware resources and costs, and also improves the stability and anti-interference ability of the signal, and is particularly suitable for the efficient transmission of a large number of signals in the fields of industrial control and automation.

[0029] The core idea of this application is to use serial encoding and decoding technology to transmit the signals of multi-channel parallel channels through serial encoding and use the same TX and RX paths.

[0030] In some embodiments, in the sampling stage, each signal is sampled multiple times, and a majority voting mechanism is used to determine the final sampled value.

[0031] In implementation, within the first cycle, each parallel input signal is sampled multiple times. For example: each signal is sampled 3 times, 5 times or more times. The specific number of times can be determined according to actual requirements and hardware capabilities. By sampling multiple times, the influence of noise in a single sampling is reduced.

[0032] Then, the multiple sampled values of each signal are statistically analyzed, and the value that appears the most times is selected as the final sampled value, filtering the input signal, which can effectively reduce the influence of noise and interference in sampling and improve the stability of the signal.

[0033] For example, if the three sampling values of a certain signal are 1, 0, 1 respectively, the final sampling value is 1 (majority value).

[0034] In some embodiments, during the encoding process, parity bits are added. If the parity check fails, the output signal is pulled low.

[0035] In implementation, parity bits are added at the end of encoding to detect the security of the transmitted data during the transmission process. During data transmission or decoding, when the receiving end detects that the parity of the encoded signal is inconsistent with the indication of the parity bit, the system will pull the output signal low (i.e., set to logic "0") to prevent the transmission of incorrect data.

[0036] For example, after sampling is completed, the sampling values of the first cycle are encoded in the second cycle. The 8 input values are encoded in 8 time bits in sequence. One clock corresponds to one bit of data and is stored in a register. The last bit is subjected to parity check. When the parity bit cannot be matched, the output is pulled low. The waveform of the encoding is as Figure 6 shown, and the rising edge of the clock locks the sampling value.

[0037] In some embodiments, after encoding is completed, the encoded clock signal is transmitted to the decoding circuit through the second transmit / receive channel to maintain time synchronization.

[0038] In implementation, the decoding circuit uses the clock signal to synchronize the data parsing in the data channel, locks the data bits according to the rising edge or falling edge of the clock, so as to correctly restore the original signal.

[0039] In some embodiments, the encoded clock signal transmitted by the second transmit / receive channel is phase-shifted by 90 degrees to distinguish the frame header information and signal information in the encoded signal; When the clock signal is at a high level, the value of the frame header information flips, and the value of the signal information remains unchanged.

[0040] In implementation, before transmitting the encoded information to the RX, the encoded clock also needs to be phase-shifted by 90 degrees, as Figure 7 shown. In this way, the decoding circuit can accurately distinguish the frame header bit and the data bit, avoiding signal confusion. When the clock is high, the data of the frame header bit flips, while the data of the data bit does not flip when the clock is high. According to the above method, the decoding circuit can decode the 8-channel signals into the register in sequence and then output them synchronously.

[0041] In some embodiments, the encoding and decoding processes adopt pipelining operation. While encoding the sampling values of the first cycle in the second cycle, the next sampling is performed in parallel.

[0042] In implementation, as Figure 5As shown, while encoding the sampled values of the first cycle in the second cycle, the system will perform the next sampling in parallel, thereby improving the efficiency of data transmission.

[0043] For example: In the first cycle, the first sampling is performed on multiple parallel input signals to obtain sampled values (Sampling 1).

[0044] In the second cycle, two parallel operations are performed: The second sampling is performed on multiple parallel input signals to obtain new sampled values (Sampling 2); The sampled values of the first cycle (Sampling 1) are encoded to generate an encoded signal (Encoding 1).

[0045] The encoded signal (Encoding 1) is transmitted to the decoding circuit (Output 1) through the first transmit / receive channel.

[0046] In the third cycle, and so on.

[0047] By adopting pipeline operation in this embodiment, sampling and encoding operations are performed in parallel in different cycles, significantly improving the data processing efficiency, reducing latency, optimizing resource utilization, and increasing the system throughput.

[0048] In some embodiments, as Figure 3 shown, after encoding is completed, the data of 8 channels and the encoded clock are transmitted to the decoding circuit through two sets of transmit / receive (TX / RX) circuits. The advantage of transmitting the clock is that the decoding circuit can directly use the received encoded clock to parse the data, eliminating the step of clock resynchronization, effectively preventing transmission errors. The functions of the traditional 8 transmission channels can be achieved only by using 2 transmission channels, significantly reducing the required number of channels and significantly reducing the high cost brought by the multi-channel TX / RX configuration.

[0049] Based on the same inventive concept, the present application also provides a multi-channel digital quantity transmission device based on serial encoding corresponding to the foregoing method embodiment, including: A sampling module, configured to perform sampling on multiple parallel input signals in the first cycle to obtain sampled values; An encoding module, configured to sequentially encode the sampled values of the first cycle in the second cycle to generate an encoded signal; A transmission module, including a first transmit / receive module, configured to transmit the encoded signal to the decoding circuit; A decoding module, configured to restore the original multiple parallel signals according to the encoded signal.

[0050] In some embodiments, the sampling module performs multiple samplings on each signal and uses a majority voting mechanism to determine the final sampled value.

[0051] In some embodiments, the transmission module further includes: a second transmitting / receiving module; configured to transmit the encoded clock signal to a decoding circuit so that the decoding circuit performs data synchronization and parsing according to the clock signal; or, configured to transmit the encoded clock signal with a 90-degree phase shift to a decoding circuit to distinguish the frame header information and signal information in the encoded signal.

[0052] In some embodiments, the encoding module adds parity check bits during the encoding process. If the check bits fail, the output signal is pulled low.

[0053] In some embodiments, the sampling module, the encoding module, the transmission module, and the decoding module are integrated into the same chip, reducing the volume and occupied space of the system, lowering the power consumption, improving the reliability, and ultimately achieving multi-channel digital quantity transmission with low cost and high stability.

[0054] This application is applied to the serial encoding and decoding technology for multi-channel digital quantity transmission. For the multi-channel signals that originally required multiple TX / RX channels for transmission, now only two TX / RX channels are needed to accurately transmit 8 digital quantities without error, significantly reducing the hardware cost and occupied area, solving the disadvantages of poor stability, short lifespan, and high randomness of traditional optocoupler transmission, and at the same time improving the problem of excessive cost of traditional TX / RX transmission methods.

[0055] In this specification, the same or similar parts among the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for the embodiments described later, since the description is relatively simple, the relevant parts can be referred to the partial description of the foregoing embodiments.

[0056] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A multi-channel digital quantity transmission method based on serial coding, characterized in that: include: In the first cycle, multiple parallel input signals are sampled to obtain sampled values; In the second cycle, the sampled values ​​of the first cycle are encoded in sequence to generate a coded signal; transmitting the encoded signal to a decoding circuit via a first transmitting / receiving channel; The decoding circuit restores the original multi-path parallel signal according to the encoded signal.

2. The multi-channel digital quantity transmission method based on serial coding according to claim 1 is characterized in that: During the sampling phase, each signal is sampled multiple times, and a majority voting mechanism is used to determine the final sampling value.

3. The multi-channel digital quantity transmission method based on serial coding according to claim 1 is characterized in that: During the encoding process, a parity bit is added. If the parity bit fails, the output signal is pulled low.

4. The multi-channel digital quantity transmission method based on serial coding according to claim 1 is characterized in that: After the encoding is completed, the encoded clock signal is transmitted to the decoding circuit through the second sending / receiving channel to maintain time synchronization.

5. The multi-channel digital quantity transmission method based on serial coding according to claim 4 is characterized in that: The encoding clock signal transmitted by the second sending / receiving channel is phase-shifted by 90 degrees to distinguish the frame header information and the signal information in the encoding signal; When the clock signal is at a high level, the value of the frame header information is flipped, and the value of the signal information remains unchanged.

6. The multi-channel digital quantity transmission method based on serial coding according to claim 1 is characterized in that: The encoding and decoding process adopts pipeline operation, and the next sampling is performed in parallel while the sampling value of the first cycle is encoded in the second cycle.

7. A multi-channel digital quantity transmission device based on serial coding, characterized in that: include: The sampling module is used to sample multiple parallel input signals in the first cycle to obtain sampling values; The encoding module is used to encode the sampled values ​​of the first cycle in sequence in the second cycle to generate an encoded signal; A transmission module, comprising a first sending / receiving module, configured to transmit the encoded signal to a decoding circuit; The decoding module is used to restore the original multi-channel parallel signal according to the encoded signal.

8. The multi-channel digital quantity transmission device based on serial coding according to claim 7, characterized in that: The sampling module samples each signal multiple times and uses a majority voting mechanism to determine the final sampling value.

9. The multi-channel digital quantity transmission device based on serial coding according to claim 7, characterized in that: The transmission module further includes: a second sending / receiving module; Used to transmit the encoded clock signal to the decoding circuit so that the decoding circuit performs data synchronization and analysis according to the clock signal; Or, it is used to transmit the encoded clock signal with a 90-degree phase shift to a decoding circuit to distinguish the frame header information and signal information in the encoded signal.

10. The multi-channel digital quantity transmission device based on serial coding according to claim 7, characterized in that: The sampling module, encoding module, transmission module and decoding module are integrated into the same chip.

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