RS422 communication structure with isolation

Abstract

The utility model discloses an RS422 communication structure with isolation, which comprises an RS422 communication board, the RS422 communication board is provided with an isolation power supply module, an equipment communication module, an optocoupler isolation input module, an optocoupler isolation output module and an MCU chip communication module, the isolation power supply module is used for providing current of different voltage levels for each element on the RS422 communication board, the equipment communication module is used for providing current of different voltage levels for each element on the RS422 communication board, and the optocoupler isolation input module is used for providing current of different voltage levels for each element on the RS422 communication board. The equipment communication module is used for receiving data transmitted by the RS422 communication equipment and sending an instruction to the RS422 equipment; and the optical coupler isolation input module is used for receiving data transmitted by the equipment communication module. The RS422 communication structure disclosed by the utility model can physically isolate input and output signals through the photoelectric coupler, so that power supply interference of other circuits is prevented from entering serial port communication, and other parts in a system are protected from grounding interference; the situation that the communication circuit is interfered by grounding and electromagnetism, so that the circuit and elements are damaged and the communication is influenced is avoided, and the reliability and the stability of the whole system are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic communications, in particular to an isolated RS422 communication structure. Background Art

[0002] In a measurement and control system composed of multiple subsystems, data communication between or within subsystems generally uses serial communication. RS422 is an interface standard widely used in engineering equipment. Generally, the interface circuit adopts a non-isolated circuit. However, using this circuit for communication can increase the transmission speed of serial communication or cause high-frequency interference emitted by other devices to generate electromagnetic interference on the digital circuits within the system through the common ground cable, affecting the communication quality. In addition, due to the different potentials of different devices in serial communication, current may pass through the serial port channel and damage components in the circuit, causing heat generation and fire risks, which poses certain safety risks. Therefore, those skilled in the art provide an isolated RS422 communication structure to solve the problems raised in the above background technology. Utility Model Content

[0003] The purpose of the present invention is to provide an isolated RS422 communication structure to solve the problems raised in the above background technology.

[0004] To achieve the above objectives, the present invention provides the following technical solutions:

[0005] An isolated RS422 communication structure comprises: an RS422 communication board, on which is provided an isolated power supply module, a device communication module, an optocoupler isolation input module, an optocoupler isolation output module and an MCU chip communication module, wherein the isolated power supply module is used to provide currents of different voltage levels to various components on the RS422 communication board; the device communication module is used to receive data transmitted by the RS422 communication device and send instructions to the RS422 device; the optocoupler isolation input module is used to receive data transmitted by the device communication module and transmit the data in isolation to the MCU chip communication module; the MCU chip communication module is used to transmit data to the MCU main control chip and receive instruction data transmitted by the MCU main control chip; and the optocoupler isolation output module is used to receive instruction data transmitted by the MCU chip communication module and transmit the instruction data in isolation to the device communication module.

[0006] Preferably, the isolated power supply module is composed of four DC isolated power supplies, which are a DC3.3V isolated power supply, a DC5V isolated power supply, a DC12V isolated power supply and a DC24V isolated power supply.

[0007] Preferably, the optocoupler isolation input module and the optocoupler isolation output module are both photoelectric couplers 6N137.

[0008] Preferably, the MCU chip communication module includes TTL level RXD and TTL level TXD, and the RS422 communication board communicates with the MCU main control chip through TTL level RXD and TTL level TXD.

[0009] Preferably, the device communication module is a communication transceiver MAX490, and the RS422 communication board receives data transmitted by the RS422 communication device through the communication transceiver MAX490, and transmits instruction data of the MCU main control chip to the RS422 communication device.

[0010] Preferably, a transient voltage suppressor is provided on the RS422 communication board, and the transient voltage suppressor is used to protect various components on the RS422 communication board from voltage damage.

[0011] Preferably, the communication transceiver MAX490 is provided with RX+, RX-, TX+ and TX- signal differential lines, and the RX+, RX-, TX+ and TX- signal differential lines are connected in parallel to the transient voltage suppressor.

[0012] Compared with the prior art, the advantages of the present invention are: the RS422 communication structure proposed in the present application can physically isolate the input and output signals through the optocoupler, prevent the power interference of other circuits from entering the serial port communication, protect other components in the system from ground interference, avoid the situation where the communication circuit is damaged by the interference caused by grounding and electromagnetic, and the circuit and components are damaged and the communication quality is affected, thereby improving the reliability and stability of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a block diagram of an RS422 communication structure according to an embodiment of the present invention;

[0014] Figure 2 Schematic diagram of the communication process of the RS422 communication structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0015] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variations thereof are intended to cover non-exclusive inclusions.

[0016] Combine Figure 1 and Figure 2 As shown, an isolated RS422 communication structure includes: an RS422 communication board, on which an isolated power supply module, a device communication module, an optocoupler isolation input module, an optocoupler isolation output module and an MCU chip communication module are provided, wherein the isolated power supply module is composed of four DC isolated power supplies, namely a DC3.3V isolated power supply, a DC5V isolated power supply, a DC12V isolated power supply and a DC24V isolated power supply; when powering the RS422 communication board, the DC3.3V isolated power supply, the DC5V isolated power supply, the DC12V isolated power supply and the DC24V isolated power supply can provide currents of different voltage levels to various components on the RS422 communication board, thereby ensuring the use of various components on the RS422 communication board.

[0017] In one embodiment, the device communication module is a communication transceiver MAX490. The RS422 communication board receives data transmitted by the RS422 communication device through the communication transceiver MAX490, and transmits the instruction data of the MCU main control chip to the RS422 communication device. When transmitting data to the RS422 communication device, the communication transceiver MAX490 is used to receive the data transmitted by the RS422 communication device and transmit the instruction data of the MCU main control chip to the RS422 communication device. This can minimize electromagnetic interference (EMI) and reflections caused by incorrectly terminated cables, thereby ensuring the stability and reliability of data transmission.

[0018] In one embodiment, the coupling isolation input module is a photoelectric coupler 6N137, which is used to receive data transmitted by the device communication module and transmit the data in isolation to the MCU chip communication module; when transmitting the data of the RS422 communication device to the MCU main control chip, the photoelectric coupler 6N137 can convert the data signal received at its input end into an optical signal, and transmit the optical signal to its output end through the optical path thereon, and then convert the optical signal at its output end back into a data signal and transmit it to the MCU chip communication module, thereby physically isolating the input data signal, preventing the signal input from being subject to external electromagnetic interference, improving the stability and reliability of signal processing, and realizing isolated input of the RS422 communication signal.

[0019] In one embodiment, the MCU chip communication module includes a TTL level RXD and a TTL level TXD. The RS422 communication board transmits data to the MCU main control chip through the TTL level RXD, and receives the instruction data transmitted by the MCU main control chip through the TTL level TXD. When communicating with the MCU main control chip, the data signal can be converted into a TTL level signal through the TTL level RXD, and the level signal can be transmitted to the MCU main control chip through the RXD signal line for reception by the MCU main control chip. The MUC main control chip then transmits the data signal to the system host, allowing the system host to issue instructions to the MCU main control chip according to the data signal, and then converts the system-issued instruction data transmitted by the MCU main control chip into a TTL level signal through the TTL level TXD, and then converts the TTL level signal into an RS422 differential signal through the RS422 communication board for transmission on the RS422 communication link, thereby realizing communication between the RS422 communication board and the MCU main control chip.

[0020] In one embodiment, the optocoupler isolation output module is a photocoupler 6N137, which is used to receive the instruction data transmitted by the MCU chip communication module and isolate the instruction data and transmit it to the device communication module; when transmitting the instruction data signal sent by the MCU main control chip, the photocoupler 6N137 can convert the instruction data signal received at its input end into an optical signal, and transmit the optical signal to its output end through the optical path on it, and then convert the optical signal at its output end back into a data signal and transmit it to the device communication module, physically isolating the output data signal to prevent the signal input from being subject to external electromagnetic interference, thereby improving the stability and reliability of signal processing and realizing the isolated output of the RS422 communication signal.

[0021] In one embodiment, a transient voltage suppressor is provided on the RS422 communication board, and the transient voltage suppressor is used to protect the components on the RS422 communication board from voltage damage. In addition, the communication transceiver MAX490 is provided with RX+, RX-, TX+ and TX- signal differential lines, and the RX+, RX-, TX+ and TX- signal differential lines are connected in parallel to the transient voltage suppressor; when the transient voltage suppressor is connected, the RX+, RX-, TX+ and TX- signal differential lines provided on the communication transceiver MAX490 are connected in parallel to the transient voltage suppressor, The transient voltage suppressor protects both the RX and TX pairs of differential signal lines simultaneously, ensuring that transient overvoltages occurring during both the sending and receiving processes can be effectively suppressed. Moreover, when a transient overvoltage occurs on the RS422 communication board, the transient voltage suppressor can quickly turn on, clamping the overvoltage at a safe level, absorbing the energy generated by the transient overvoltage and directing it to the ground wire or other safe places, effectively blocking potential voltage damage and preventing it from damaging sensitive components on the communication board, thereby protecting circuits and equipment from damage and improving the stability and reliability of the RS422 communication board.

[0022] The working principle of the utility model is: the RS422 communication structure proposed in the present application first provides currents of different voltage levels to various components on the RS422 communication board through an isolated power supply module, and protects various components on the RS422 communication board from voltage damage through a transient voltage suppressor, thereby ensuring the use of various components on the RS422 communication board, and then receives the data transmitted by the RS422 communication device through the communication transceiver MAX490 in the device communication module, and transmits the data to the optocoupler isolation input module, and the photoelectric coupler 6N137 in the optocoupler isolation input module converts the data signal received at its input end into an optical signal, and transmits the optical signal to its output end through the optical path thereon, and then converts the optical signal at its output end back into a data signal and transmits it to the MCU chip communication module, so that the MCU chip communication module transmits the data signal to the MCU main control chip connected to it through the TTL level RXD, and then the MUC main control chip transmits the data signal to the system host, so that the system The host issues instructions to the MCU main control chip according to the data signal, and allows the main control chip to transmit the instruction data to the isolated output module through the TTL level TXD in the MCU chip communication module connected to it. The optocoupler 6N137 in the isolated output module converts the instruction data signal received at its input end into an optical signal, and transmits the optical signal to its output end through the optical path on it. The optical signal at its output end is then converted back into an instruction data signal and transmitted to the communication transceiver MAX490. The communication transceiver MAX490 sends the instruction data signal to the RS422 communication device, completing the transmission of data and instructions in the system. The optocoupler can physically isolate the input and output signals, prevent power interference from other circuits from entering the serial communication, protect other components in the system from ground interference, avoid the situation where the communication circuit is damaged by interference caused by grounding and electromagnetic interference, and affect the communication quality, thereby improving the reliability and stability of the entire system.

[0023] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An isolated RS422 communication structure, characterized in that: include: An RS422 communication board is provided with an isolated power supply module, a device communication module, an optocoupler isolation input module, an optocoupler isolation output module and an MCU chip communication module, wherein the isolated power supply module is used to provide currents of different voltage levels to various components on the RS422 communication board; the device communication module is used to receive data transmitted by the RS422 communication device and send instructions to the RS422 device; the optocoupler isolation input module is used to receive data transmitted by the device communication module and isolate the data and transmit it to the MCU chip communication module; the MCU chip communication module is used to transmit data to the MCU main control chip and receive instruction data transmitted by the MCU main control chip; the optocoupler isolation output module is used to receive instruction data transmitted by the MCU chip communication module and isolate the instruction data and transmit it to the device communication module.

2. A RS422 communication structure with isolation according to claim 1, characterized in that, The isolated power supply module is composed of four DC isolated power supplies, which are a DC3.3V isolated power supply, a DC5V isolated power supply, a DC12V isolated power supply and a DC24V isolated power supply.

3. A RS422 communication structure with isolation according to claim 1, characterized in that, The optocoupler isolation input module and the optocoupler isolation output module are both photoelectric couplers 6N137.

4. The isolated RS422 communication structure according to claim 1, wherein: The MCU chip communication module includes a TTL level RXD and a TTL level TXD, and the RS422 communication board communicates with the MCU main control chip through the TTL level RXD and the TTL level TXD.

5. The isolated RS422 communication structure according to claim 1, wherein: The device communication module is a communication transceiver MAX490. The RS422 communication board receives data transmitted by the RS422 communication device through the communication transceiver MAX490, and transmits instruction data of the MCU main control chip to the RS422 communication device.

6. The isolated RS422 communication structure according to claim 5, wherein: The RS422 communication board is provided with a transient voltage suppressor, which is used to protect various components on the RS422 communication board from voltage damage.

7. The isolated RS422 communication structure according to claim 6, wherein: The communication transceiver MAX490 is provided with RX+, RX-, TX+ and TX- signal differential lines, and the RX+, RX-, TX+ and TX- signal differential lines are connected in parallel to the transient voltage suppressor.

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