Dual-redundancy and high-reliability RS422 communication module and communication method

Abstract

The invention belongs to the field of data transmission, and relates to a dual-redundancy high-reliability RS422 communication module and a communication method, the communication module comprises a power supply 1, a resistor R1, a capacitor C1, a resistor R2, a power ground, a resistor R3, a capacitor C2, a transceiver 1, a main control chip, a transceiver 2, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9 and an interface module; according to the invention, the reliability of RS422 communication is improved by adopting dual redundancy; a series resistor is adopted to limit short-circuit current, a fault is isolated locally, and the reliability of the circuit is further improved; industrial-grade chip dual redundancy instead of a single-chip high-quality-grade chip is adopted, so that the device cost of the circuit is reduced; and a normal transceiver is selected to transmit data by adopting a method of feeding back the state of the transceiver through an external RS422. According to the dual-redundancy high-reliability RS422 communication method, the cost of a high-reliability RS422 communication circuit device can be effectively reduced, and meanwhile, the reliability can be improved.

Description

Technical Field

[0001] The invention belongs to the field of data transmission, in particular to the field of RS422 communication transmission, and specifically to a dual-redundancy, high-reliability RS422 communication module and a communication method. Background Art

[0002] RS422 communication is widely used in various industries, and highly reliable RS422 communication transmission is required in aerospace, aviation, military, medical and other industries. In the past, high-reliability RS422 communication used high-quality chips to implement RS422 communication circuits, using the reliability of the chip to improve the reliability of the circuit, thereby improving the reliability of RS422 communication. The advantage of this method is that the circuit is simple to implement and the communication software is simple, but the disadvantage is that the device cost is high, which is several times or even dozens of times that of ordinary industrial-grade products. Summary of the invention

[0003] Technical problem solved by the present invention: The present invention proposes a dual-redundancy, high-reliability RS422 communication module and communication method. In terms of circuit, ordinary industrial-grade chips are used to form a dual-redundancy circuit to improve circuit reliability. In terms of software, external RS422 is used to receive and judge the quality of the transceiver's sending function, and a transceiver with intact communication is selected to send and receive data. The present invention is characterized in that ordinary industrial-grade chips are used to form a dual-redundancy circuit, and measures are added to prevent the expansion of faults, allowing some components of the circuit to fail.

[0004] Technical solution of the present invention

[0005] A dual-redundancy, high-reliability RS422 communication module, comprising a power supply 1, a resistor R1, a capacitor C1, a resistor R2, a power ground, a resistor R3, a capacitor C2, a transceiver 1, a main control chip, a transceiver 2, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, and an interface module;

[0006] Power supply 1 is connected to one end of resistors R1 and R3, the other end of resistor R1 is connected to the VCC end of transceiver 1, the other end of resistor R3 is connected to the VCC end of transceiver 2, one end of capacitor C1 is connected to the VCC end of transceiver 1, and the other end is connected to the GND end of transceiver 1, one end of capacitor C2 is connected to the VCC end of transceiver 2, and the other end is connected to the GND end of transceiver 2, one end of resistor R2 is connected to the GND end and RE of transceiver 1 respectively, the other end of resistor R2 is grounded, the GND end of transceiver 1 is connected to the GND end of transceiver 2, and the RE end of transceiver 1 is connected to the RE1 end of the main control chip The RX end is connected to the RX1 end of the main control chip through a resistor R4, the D end is connected to the D1 end of the main control chip through a resistor R6, the DE end is connected to the DE1 end of the main control chip through a resistor R8, the RE end of the transceiver 2 is connected to the RE2 end of the main control chip, the RX end is connected to the RX2 end of the main control chip through a resistor R5, the D end is connected to the D2 end of the main control chip through a resistor R7, and the DE end is connected to the DE2 end of the main control chip through a resistor R9. The A, B, Y, and Z ports of transceiver 1 are respectively connected to the A, B, Y, and Z ports of transceiver 2, and are respectively connected to the A, B, Y, and Z ports of the interface module.

[0007] Furthermore, the transceiver 1 is a NCA3491-DSPKP transceiver.

[0008] Furthermore, the transceiver 2 adopts a transceiver of the NSIP83086V-DSWR model.

[0009] Furthermore, the model of the main control chip is QJ32F407VGT6.

[0010] Furthermore, the interface module adopts a DB9 model interface module.

[0011] A communication method for a dual-redundant, high-reliability RS422 communication module comprises the following steps: enabling transceiver 1, and transmitting to RS422 differential transmission ports Y and Z through transceiver 1; enabling transceiver 2, and transmitting to RS422 differential transmission ports Y and Z through transceiver 2; transceiver 1 receives data, and transceiver 2 receives data; judging whether the transmission of transceiver 1 is normal, if the transmission function of transceiver 1 is normal, enabling the transmission function of transceiver 1, and transmitting through transceiver 1; if the transmission function of transceiver 1 is abnormal, turning off the transmission function of transceiver 1, and stopping transmitting through transceiver 1; judging whether the transmission of transceiver 2 is normal, if the transmission function of transceiver 2 is normal, enabling the transmission function of transceiver 2, and transmitting through transceiver 2; if the transmission function of transceiver 2 is abnormal, turning off the transmission function of transceiver 2, and stopping transmitting through transceiver 2.

[0012] Furthermore, the communication method also includes a method for determining whether the number of transmissions of the transceiver is good or bad.

[0013] Further, the method for judging whether the number of transmissions of the transceiver is good or not is as follows: since the external receiving ports of the two receivers in the RS422 communication module are connected to each other through the interface module, the receiving end can work at the same time, and the transmitting end needs to be time-division multiplexed, so the data received by transceiver 1 and transceiver 2 are the same, when the number is transmitted through transceiver 1, a data is used in the transmitted data to indicate that it is the data sent by transceiver 1, and when the number is transmitted through transceiver 2, a data is used in the transmitted data to indicate that it is the data sent by transceiver 2, when the external RS422 receives the data sent by transceiver 1, the data is verified, and after verification, it is determined whether the number of transmissions of transceiver 1 is normal, and when the external RS422 receives the data sent by transceiver 2, the data is verified, and the verification is performed. After verification, determine whether the number of transmissions of transceiver 2 is normal. When no data is received, it is directly determined that the number of transmissions is abnormal. The external RS422 sends the results of whether the number of transmissions of transceiver 1 is normal and whether the number of transmissions of transceiver 2 is normal to the main control chip of the RS422 communication module. The main control chip of the RS422 communication module receives and reads the results fed back by the external RS422. If the external RS422 feeds back that the transmission of transceiver 1 is normal, the transmission function of transceiver 1 is enabled. If the feedback is that the transmission function of transceiver 1 is abnormal, the transmission function of transceiver 1 is disabled. If the external RS422 feeds back that the transmission of transceiver 2 is normal, the transmission function of transceiver 2 is enabled. If the feedback is that the transmission function of transceiver 2 is abnormal, the transmission function of transceiver 2 is disabled.

[0014] Beneficial Effects

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present invention proposes a dual-redundancy, high-reliability RS422 communication module and method, which adopts dual redundancy to improve the reliability of RS422 communication; adopts series resistors to limit short-circuit current, isolates faults locally, and further improves the reliability of the circuit; adopts industrial-grade chip dual redundancy instead of single-chip high-quality chips, reducing the device cost of the circuit; adopts an external RS422 method to feedback the transceiver status, and selects a normal transceiver for transmission. The dual-redundancy high-reliability RS422 communication method can effectively reduce the device cost of the high-reliability RS422 communication circuit, and can improve reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of dual redundant high reliability RS422 circuit;

[0018] Figure 2 Flowchart of dual redundant high-reliability RS422 communication method. DETAILED DESCRIPTION

[0019] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] An embodiment of the present invention is:

[0022] The present invention proposes a dual-redundancy, high-reliability RS422 communication module and method, which adopts circuit dual redundancy and external RS422 cooperation to achieve RS422 high-reliability communication, solving the problem of high cost and low reliability of high-reliability RS422 communication in the past. The circuit level adopts industrial-grade chips to form a dual-redundancy circuit, and the circuit includes a dual-redundancy transceiver circuit and a short-circuit current limiting circuit. The software level adopts an external RS422 cooperation check to determine whether the transceiver transmission function is normal, and selects the transceiver with normal transmission function to send data.

[0023] Dual-redundant high-reliability RS422 communication uses two industrial-grade RS422 transceiver chips in the circuit. The data differential sending end and the data differential receiving end of the two transceivers are connected together to form a dual-redundant RS422 circuit. If the sending and receiving function of one chip of the two transceivers is normal, the RS422 communication function will be normal; the single-ended data sending, data sending enable, and data receiving end of the two transceiver chips are connected to different pins of the main control, and the main control can communicate with the outside through the two transceiver chips; the RC filter circuit is connected to the power supply end of the two transceiver chips to supply power to the transceiver chip, and at the same time, the short-circuit current of the chip can be limited to prevent the expansion of the fault; the resistor is connected in series to the pins of the two transceiver chips to the main control, which can limit the short-circuit current of the transceiver chip pin to the ground, and prevent the fault short-circuit fault from affecting the main control; the resistor is connected in series to the power ground pin of the transceiver to limit the short-circuit current of the data differential sending and data differential receiving pins of the transceiver to the ground, and prevent the short-circuit fault from extending to the normal working transceiver in the two transceivers.

[0024] Dual redundant high-reliability RS422 communication uses a time-division multiplexing transmission enable method in software design to solve the problem of dual transceiver chips sharing data differential transmission cables. Only the transmission function of a single transceiver is enabled at any time. The simultaneous reception is enabled to enable the reception of two transceivers. The data of the two transmission channels of the dual redundant high-reliability RS422 communication is detected through an external RS422 to determine the quality of the transmission functions of the two transceivers, and enable the transceiver with normal dual redundant high-reliability RS422 communication to send data.

[0025] A second embodiment of the present invention is:

[0026] The RS422 schematic diagram corresponding to the present invention is as follows Figure 1 As shown. The dual redundant high-reliability RS422 communication circuit consists of 17 components, 1, power supply, 2, resistor R1, 3, capacitor C1, 4, resistor R2, 5, power ground, 6, resistor R3, 7, capacitor C2, 8, transceiver 1, 9, master control, 10, transceiver 2, 11, resistor R4, 12, resistor R5, 13, resistor R6, 14, resistor R7, 15, resistor R8, 16, resistor R9, 17, interface. The VCC and GND of transceiver 1 are connected to both ends of capacitor C1, and capacitor C1 and resistor R1 form an RC filter circuit; the VCC and GND of transceiver 2 are connected to both ends of C2, and resistors R3 and C2 form an RC circuit; one end of resistor R2 is connected to the power ground, and the other end is connected to RE of transceiver 1, RE of transceiver 2, capacitor C1, and one end of capacitor C2; RX of transceiver 1 is connected through resistor R4, D is connected through resistor R6, and DE is connected through resistor R8, respectively. Connected to RX1, D1 and DE1 of the master; RX of transceiver 2 is connected to RX2, D2 and DE2 of the master through resistor R5, D through resistor R7, and DE through resistor R9; A of transceiver 1 is connected to A and port A of transceiver 2, B of transceiver 1 is connected to B and port B of transceiver 2; C of transceiver 1 is connected to C and port C of transceiver 2; D of transceiver 1 is connected to D and port D of transceiver 2.

[0027] High reliability, dual redundancy principle:

[0028] 1) Transceiver 1 and transceiver 2 back up each other, and the input and output ports A, B, C and D of the differential signal are connected together, sharing the external communication interface. If one of transceiver 1 and transceiver 2 is damaged, RS422 communication will not fail;

[0029] 2) The RX1, D1 and DE1 of the master are connected to the RX, D and DE of transceiver 1 respectively, and the RX2, D2 and DE2 of the master are connected to the RX, D and DE of transceiver 2 respectively. The RX1, D1 and DE1 of the master are backed up with the RX2, D2 and DE2 ports, so the damage of one port will not cause communication failure.

[0030] 3) The VCC and GND of transceiver 1 are connected to the power supply and power ground through resistors R1 and R2 respectively, and the VCC and GND of transceiver 2 are connected to the power supply and power ground through resistors R3 and R2 respectively. On the one hand, the power quality of transceiver 1 and transceiver 2 can be improved, and the short-circuit current between VCC and GND of transceiver 1 and transceiver 2 can be limited, because even if the VCC and GND of one of the transceivers are short-circuited, there are still resistors R1, R3 and R2 between the power supply and the power ground;

[0031] 4) The master control RX1, D1, DE1, RX2, D2, and DE2 are respectively connected to the RX, D, and DE of the transceiver 1 and transceiver 2 through resistors, which can limit the short-circuit current between the master control, transceiver 1, and transceiver 2 chips and prevent the fault from expanding.

[0032] 5) When a functional failure or open circuit failure occurs in one of the ports of transceiver 1, transceiver 2 and the main control, the RS422 communication function will not be affected due to the existence of the dual backup circuit. When a short circuit failure occurs, the resistor can limit the short circuit current to prevent the short circuit failure from expanding.

[0033] This embodiment provides a communication method for the above RS422 communication module: the transmitting ends of the transceivers cannot be enabled at the same time, but the receiving ends can be enabled at the same time. The software needs to remove the damaged transmitting end. The program flow of RS422 communication is as follows: Figure 2 As shown, at the beginning of the method flow, transceiver 1 is enabled, and the RS422 differential transmission ports Y and Z are transmitted through transceiver 1; transceiver 2 is enabled, and the RS422 differential transmission ports Y and Z are transmitted through transceiver 2; transceiver 1 receives the data, and transceiver 2 receives the data; it is judged whether the transmission of transceiver 1 is normal, if the transmission function of transceiver 1 is normal, the transmission function of transceiver 1 is enabled, and the data is transmitted through transceiver 1, if the transmission function of transceiver 1 is abnormal, the transmission function of transceiver 1 is turned off, and the transmission through transceiver 1 is stopped; it is judged whether the transmission of transceiver 2 is normal, if the transmission function of transceiver 2 is normal, the transmission function of transceiver 2 is enabled, and the data is transmitted through transceiver 2, if the transmission function of transceiver 2 is abnormal, the transmission function of transceiver 2 is turned off, and the transmission through transceiver 2 is stopped.

[0034] The present embodiment also provides a method for judging whether the number of transmissions of a transceiver is good or bad: the method for judging whether the number of transmissions of a transceiver is good or bad is as follows: since the external receiving ports of the two receivers in the RS422 communication module are connected to each other through the interface module, the receiving end can work at the same time, and the sending end needs to be time-division multiplexed, so the data received by transceiver 1 and transceiver 2 are the same, when the number is transmitted through transceiver 1, a data is used in the transmitted data to indicate that it is the data sent by transceiver 1, and when the number is transmitted through transceiver 2, a data is used in the transmitted data to indicate that it is the data sent by transceiver 2, when the external RS422 receives the data sent by transceiver 1, the data is verified, and after verification, it is determined whether the number of transmissions of transceiver 1 is normal, and when the external RS422 receives the data sent by transceiver 2, , verify the data, and determine whether the number of transmissions of transceiver 2 is normal after verification. When no data is received, it is directly determined that the number of transmissions is abnormal; the external RS422 sends the results of whether the number of transmissions of transceiver 1 is normal and whether the number of transmissions of transceiver 2 is normal to the main control chip of the RS422 communication module, and the main control chip of the RS422 communication module receives and reads the results fed back by the external RS422. If the external RS422 feeds back that the transmission of transceiver 1 is normal, the sending function of transceiver 1 is enabled. If the feedback is that the transmission function of transceiver 1 is abnormal, the transmission function of transceiver 1 is disabled. If the external RS422 feeds back that the transmission of transceiver 2 is normal, the sending function of transceiver 2 is enabled. If the feedback is that the transmission function of transceiver 2 is abnormal, the transmission function of transceiver 2 is disabled.

[0035] In summary, the present invention adopts dual redundancy to improve the reliability of RS422 communication; adopts series resistors to limit short-circuit current, isolates faults locally, and further improves the reliability of the circuit; adopts industrial-grade chip dual redundancy instead of single-chip high-quality grade chips, reducing the device cost of the circuit; adopts an external RS422 method to feedback the transceiver status, and selects a normal transceiver for transmission. The dual-redundancy high-reliability RS422 communication method can effectively reduce the device cost of high-reliability RS422 communication circuits, and can improve reliability at the same time.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A dual-redundant, high-reliability RS422 communication module, characterized in that: Including power supply 1, resistor R1, capacitor C1, resistor R2, power ground, resistor R3, capacitor C2, transceiver 1, main control chip, transceiver 2, resistor R4, resistor R5, resistor R6, resistor R7, resistor R8, resistor R9, interface module; Power supply 1 is connected to one end of resistors R1 and R3, the other end of resistor R1 is connected to the VCC end of transceiver 1, the other end of resistor R3 is connected to the VCC end of transceiver 2, one end of capacitor C1 is connected to the VCC end of transceiver 1, and the other end is connected to the GND end of transceiver 1, one end of capacitor C2 is connected to the VCC end of transceiver 2, and the other end is connected to the GND end of transceiver 2, one end of resistor R2 is connected to the GND end and RE of transceiver 1 respectively, the other end of resistor R2 is grounded, the GND end of transceiver 1 is connected to the GND end of transceiver 2, and the RE end of transceiver 1 is connected to the RE1 end of the main control chip The RX end is connected to the RX1 end of the main control chip through a resistor R4, the D end is connected to the D1 end of the main control chip through a resistor R6, the DE end is connected to the DE1 end of the main control chip through a resistor R8, the RE end of the transceiver 2 is connected to the RE2 end of the main control chip, the RX end is connected to the RX2 end of the main control chip through a resistor R5, the D end is connected to the D2 end of the main control chip through a resistor R7, and the DE end is connected to the DE2 end of the main control chip through a resistor R9. The A, B, Y, and Z ports of transceiver 1 are respectively connected to the A, B, Y, and Z ports of transceiver 2, and are respectively connected to the A, B, Y, and Z ports of the interface module.

2. The dual redundant, high-reliability RS422 communication module according to claim 1, characterized in that: The transceiver 1 is a NCA3491-DSPKP transceiver.

3. The dual redundant, high reliability RS422 communication module according to claim 2, characterized in that: Transceiver 2 uses a NSIP83086V-DSWR transceiver.

4. The dual-redundancy, high-reliability RS422 communication module according to claim 3, characterized in that: The model of the main control chip is QJ32F407VGT6.

5. The dual-redundancy, high-reliability RS422 communication module according to claim 1, characterized in that: The interface module adopts a DB9 type interface module.

6. A communication method of the dual redundant, high-reliability RS422 communication module as claimed in claim 5, characterized in that: The communication method is: Enable transceiver 1, and transmit to RS422 differential transmission ports Y and Z through transceiver 1; enable transceiver 2, and transmit to RS422 differential transmission ports Y and Z through transceiver 2; transceiver 1 receives, and transceiver 2 receives; determine whether the transmission of transceiver 1 is normal, if the transmission function of transceiver 1 is normal, enable the transmission function of transceiver 1, and transmit through transceiver 1, if the transmission function of transceiver 1 is abnormal, turn off the transmission function of transceiver 1, and stop transmitting through transceiver 1; determine whether the transmission of transceiver 2 is normal, if the transmission function of transceiver 2 is normal, enable the transmission function of transceiver 2, and transmit through transceiver 2, if the transmission function of transceiver 2 is abnormal, turn off the transmission function of transceiver 2, and stop transmitting through transceiver 2.

7. The communication method according to claim 6, characterized in that: The communication method also includes a method for judging whether the number of transmissions of the transceiver is good or bad.

8. The communication method according to claim 7, characterized in that: The method for judging whether the number of transmissions of the transceiver is good or not is as follows: since the external receiving ports of the two receivers in the RS422 communication module are connected to each other through the interface module, the receiving end can work at the same time, and the transmitting end needs to be time-division multiplexed, so the data received by transceiver 1 and transceiver 2 are the same, when the number is transmitted through transceiver 1, a data is used in the transmitted data to indicate that it is the data sent by transceiver 1, and when the number is transmitted through transceiver 2, a data is used in the transmitted data to indicate that it is the data sent by transceiver 2. When the external RS422 receives the data sent by transceiver 1, the data is verified, and after verification, it is determined whether the number of transmissions of transceiver 1 is normal. When the external RS422 receives the data sent by transceiver 2, the data is verified, and after verification, it is determined whether the number of transmissions of transceiver 1 is normal. Determine whether the number of transmissions of transceiver 2 is normal. When no data is received, directly determine that the number of transmissions is abnormal; the external RS422 sends the results of whether the number of transmissions of transceiver 1 is normal and whether the number of transmissions of transceiver 2 is normal to the main control chip of the RS422 communication module. The main control chip of the RS422 communication module receives and reads the results fed back by the external RS422. If the external RS422 feeds back that the transmission of transceiver 1 is normal, the transmission function of transceiver 1 is enabled. If the feedback is that the transmission function of transceiver 1 is abnormal, the transmission function of transceiver 1 is disabled. If the external RS422 feeds back that the transmission of transceiver 2 is normal, the transmission function of transceiver 2 is enabled. If the feedback is that the transmission function of transceiver 2 is abnormal, the transmission function of transceiver 2 is disabled.

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