Slave device sending port protection circuit for RS422 communication system

Abstract

The utility model discloses a slave device sending port protection circuit for an RS422 communication system, and relates to the technical field of communication systems. The slave device sending port protection circuit used for the RS422 communication system comprises a master device, a slave device, a sending port protection circuit and a receiving port protection circuit, the plurality of slave devices are electrically connected with the master device; the switching tube is arranged between the master equipment and the slave equipment; wherein the switching tubes are respectively connected in series with the TX ends of the slave devices, so that the TX ends of the slave devices can directionally send data. According to the utility model, the problem that in practical application, when a plurality of slave devices send data to a bus at the same time, TXs of the slave devices are all connected together and interfere with one another, so that the reliability and the stability of communication are influenced is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of communication systems, and particularly relates to a protection circuit for the sending port of a slave device in an RS422 communication system. Background Art

[0002] RS422 is a differential signal transmission standard widely used in the fields of industrial automation and process control. This standard allows multiple slave devices to be connected to the same communication bus for data transmission. However, in practical applications, when multiple slave devices send data to the bus simultaneously, the TXs of the slave devices are all connected together, which will cause interference to each other, thus affecting the reliability and stability of communication. For the above problems that have occurred, no effective solution has been proposed yet. Content of the Utility Model

[0003] Purpose of the utility model: To provide a protection circuit for the sending port of a slave device in an RS422 communication system, so as to solve at least one of the problems existing in the above prior art.

[0004] Technical solution: A protection circuit for the sending port of a slave device in an RS422 communication system includes:

[0005] A master device;

[0006] Multiple slave devices, electrically connected to the master device; and

[0007] A switching tube, arranged between the master device and the slave device;

[0008] Wherein, by respectively connecting the switching tube in series at the TX end of the slave device, the TX end of the slave device can send data directionally.

[0009] Preferably, the switching tube is a Schottky diode.

[0010] Preferably, the number of the switching tubes is two. The two switching tubes are respectively connected to the slave device, and the directions of the two switching tubes are opposite.

[0011] Preferably, the model of the slave device is MAX3490ESA.

[0012] Preferably, a resistor is further arranged between the sending port and the receiving port of each slave device.

[0013] Preferably, the TX ports of multiple slave devices are respectively connected in series with the switching tube.

[0014] Preferably, one pin of the slave device is connected to the anode of the switching tube, and the other pin of the slave device is connected to the cathode of the other switching tube.

[0015] Preferably, it further includes: a power supply unit, and the power supply unit is electrically connected to the slave device.

[0016] Advantageous effects: In the embodiment of the present application, by adding a switching tube and connecting the switching tube in series at the TX end of the slave device respectively, the TX end of the slave device can send data in a directional manner, achieving the purpose of directional data transmission, thereby realizing the technical effect of avoiding mutual interference among other slave devices, and further solving the technical problem that in practical applications, when multiple slave devices send data to the bus simultaneously, the TXs of the slave devices are all connected together, which will cause mutual interference and affect the reliability and stability of communication. Description of the Drawings

[0017] Figure 1 is a schematic structural diagram of the slave device transmission port protection circuit for the RS422 communication system of the present utility model;

[0018] Figure 2 is the electrical schematic diagram of U40 of the slave device transmission port protection circuit for the RS422 communication system of the present utility model;

[0019] Figure 3 is the electrical schematic diagram of U42 of the slave device transmission port protection circuit for the RS422 communication system of the present utility model;

[0020] Figure 4 is the electrical schematic diagram of U44 of the slave device transmission port protection circuit for the RS422 communication system of the present utility model;

[0021] Figure 5 is the electrical schematic diagram of U45 of the slave device transmission port protection circuit for the RS422 communication system of the present utility model; and

[0022] Figure 6 is the electrical schematic diagram of U47 of the slave device transmission port protection circuit for the RS422 communication system of the present utility model.

[0023] Reference numerals are:

[0024] 10, master device;

[0025] 20, slave device;

[0026] 30, switching tube. Detailed Embodiments

[0027] To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances for the embodiments of this application described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0029] In addition, the terms "installed", "set up", "provided with", "connected", "connected to", "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or there can be internal communication between two devices, components or parts. For those of ordinary skill in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0030] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[0031] As Figure 1-6 shown, this application relates to a protection circuit for the slave device transmission port of an RS422 communication system. The protection circuit for the slave device transmission port of an RS422 communication system includes: a master device 10;

[0032] Multiple slave devices 20, electrically connected to the master device 10;

[0033] A switching tube 30, disposed between the master device 10 and the slave devices 20; capable of achieving good control effects.

[0034] Among them, by respectively connecting the switching tube 30 in series at the TX end of the slave device 20, the TX end of the slave device 20 can send data in a directed manner.

[0035] Specifically, a diode is connected in series at the TX end of the RS422 slave device 20. When the master device 10 reads the data of the slave device 20, all the slave devices 20 send data to the bus together. The TXs of all the slave devices 20 are connected together, which will cause interference to each other. After connecting the diode in series, the TX of the slave device 20 can only send data externally through the slave device 20 and cannot transmit data through the TX end, thus avoiding the interference of other slave devices 20.

[0036] From the above description, it can be seen that the present application achieves the following technical effects:

[0037] In the embodiment of the present application, by adding the switching tube 30 and connecting the switching tube 30 in series at the TX end of the slave device 20 respectively, the TX end of the slave device 20 is enabled to send data directionally, achieving the purpose of directional data transmission, thereby realizing the technical effect of avoiding the mutual interference of other slave devices 20, and further solving the technical problem that in practical applications, when multiple slave devices 20 send data to the bus at the same time, the TXs of the slave devices 20 are all connected together, which will cause interference to each other, thus affecting the reliability and stability of communication.

[0038] Furthermore, the switching tube 30 is a Schottky diode. It can be understood that it has good electrical performance and can ensure good data directional transmission effect at the same time.

[0039] Furthermore, the number of the switching tubes 30 is two. The two switching tubes 30 are respectively connected to the slave device 20, and the directions of the two switching tubes 30 are opposite.

[0040] Furthermore, the model of the slave device 20 is MAX3490ESA. It can be understood that the chip has the following functions including but not limited to: low power consumption, which is very suitable for battery-powered application scenarios. High data transmission rate: supports a data transmission rate of up to 12 Mbps, suitable for high-speed data communication. Wide power supply voltage range: the operating voltage range of this transceiver is 3V to 5.5V, adapting to different power supply systems. Short-circuit protection: built-in short-circuit protection function, effectively preventing device damage caused by line short-circuit or other abnormal conditions. Thermal shutdown function: when the device overheats, it will automatically shut down to prevent damage and restart after the temperature returns to normal. Electromagnetic interference (EMI) resistance: designed with EMI resistance characteristics, suitable for harsh industrial environments.

[0041] Furthermore, a resistor is also arranged between the sending port and the receiving port of each slave device 20.

[0042] Furthermore, the TX ports of multiple slave devices 20 are respectively connected in series with the switching tubes 30. It can be understood that good control effects can be achieved.

[0043] Further, one pin of the slave device 20 is connected to the anode of the switching transistor 30, and the other pin of the slave device 20 is connected to the cathode of the other switching transistor 30. It can be understood that a good electrical connection effect can be achieved, thereby ensuring a good control effect.

[0044] Further, it further includes: a power supply unit, and the power supply unit is electrically connected to the slave device 20. It can be understood that a good power supply effect can be achieved, thereby ensuring the normal operation effect of the device.

[0045] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept scope of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A transmission port protection circuit for a slave device in an RS422 communication system, characterized in that: include: A master device; A plurality of slave devices electrically connected to the master device; and A switch tube, arranged between the master device and the slave device; Wherein, the switch tubes are connected in series at the TX ends of the slave devices respectively, so that the TX ends of the slave devices can send data in a directionally manner.

2. The slave device transmission port protection circuit for RS422 communication system according to claim 1, characterized in that: The switch tube is a Schottky diode.

3. The slave device transmission port protection circuit for RS422 communication system according to claim 1, characterized in that: The number of the switch tubes is two, the two switch tubes are connected to the slave devices respectively, and the directions of the two switch tubes are opposite.

4. The slave device transmission port protection circuit for RS422 communication system according to claim 1, characterized in that: The model of the slave device is MAX3490ESA.

5. The slave device transmission port protection circuit for RS422 communication system according to claim 1, characterized in that: A resistor is also arranged between the sending port and the receiving port of each slave device.

6. The slave device transmission port protection circuit for RS422 communication system according to claim 1, characterized in that: The TX ports of the plurality of slave devices are respectively connected in series with switch tubes.

7. The slave device transmission port protection circuit for RS422 communication system according to claim 1, characterized in that: One pin of the slave device is connected to the anode of the switch tube, and another pin of the slave device is connected to the cathode of another switch tube.

8. The slave device transmission port protection circuit for RS422 communication system according to claim 1, characterized in that: Also includes: A power supply unit is electrically connected to the slave device.

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