A communication component and a communication system

Abstract

The present invention discloses a communication component, which includes a main control chip, a 485 chip, a protection capacitor and a transmission bus; the main control chip is connected to the OE terminal of the 485 chip, and the 485 chip is connected to the transmission bus through the A terminal and the B terminal of the 485 chip; the protection capacitor is arranged between the main control chip and the OE terminal, wherein the plate of the protection capacitor close to the main control chip is the main control plate, and the plate of the protection capacitor close to the OE terminal is the OE plate; the OE plate is connected to the common terminal; between the OE plate and the common terminal, a charging resistor is included. By adding the protection capacitor on the connection path connecting the main control chip and the OE terminal of the 485 chip, the present invention avoids the 485 chip from being locked due to continuous sending of redundant information caused by a front-end fault. The technical solution provided by the present invention has a simple structure and low process difficulty. The present invention also provides a communication system having the above beneficial effects.

Description

Technical Field

[0001] The present invention relates to the field of communications, and particularly to a communication component and a communication system. Background Art

[0002] RS485 is a standard that defines the electrical characteristics of drivers and receivers in a balanced digital multi-point system, which is defined by the Telecommunications Industry Association and the Electronic Industries Alliance. Digital communication networks using this standard can effectively transmit signals under long-distance conditions and in environments with high electronic noise. RS-485 enables the configuration of inexpensive local networks and multi-branch communication links.

[0003] In the existing technology, in order to prevent damage to the 485 circuit node, the commonly used method is to add various external protections to prevent damage to the 485 circuit node. However, this method has a high cost and the effect is not obvious. Once the 485 circuit node is damaged, in the existing technology, only software can be used to selectively reset the deadlock circuit, and of course this requires the program to work properly and the main control chip to be undamaged. Once the main control chip is damaged, there is currently no way to effectively solve the phenomenon that the 485 chip continuously sends redundant signals, resulting in the blocking of the transmission bus and causing deadlocks. [[ID=!2]]

[0004] Therefore, it is an urgent problem for those skilled in the art to find a method that does not require complex modification of the circuit, has a simple process, and can solve the problem of bus deadlock caused by damage to the main control chip. Summary of the Invention

[0005] The object of the present invention is to provide a communication component and a communication system to solve the problems in the existing technology that the bus deadlock caused by damage to the main control chip cannot be solved and that complex modification of the system is required to handle the bus deadlock, resulting in a high process difficulty.

[0006] To solve the above technical problems, the present invention provides a communication component, including a main control chip, a 485 chip, a protection capacitor, and a transmission bus;

[0007] The main control chip is connected to the OE terminal of the 485 chip, and the 485 chip is connected to the transmission bus through the A terminal and B terminal of the 485 chip;

[0008] A protection capacitor is provided between the main control chip and the OE terminal. Among them, the plate of the protection capacitor close to the main control chip is the main control plate, and the plate of the protection capacitor close to the OE terminal is the OE plate;

[0009] The OE plate is connected to the common terminal; between the OE plate and the common terminal, a charging resistor is included.

[0010] Optionally, in the communication component, between the OE electrode plate and the common terminal, a unidirectional conduction circuit parallel to the charging resistor is included;

[0011] The unidirectional conduction circuit can pass the current in the direction from the OE electrode plate to the common terminal, and the resistance value of the unidirectional conduction circuit when conducting is less than the resistance value of the charging resistor.

[0012] Optionally, in the communication component, the unidirectional conduction circuit includes a discharge diode, the positive electrode of the discharge diode is connected to the OE electrode plate, and the negative electrode is connected to the common terminal.

[0013] Optionally, in the communication component, the fast discharge circuit further includes an adjusting resistor, and the adjusting resistor is connected in series with the discharge diode.

[0014] Optionally, in the communication component, the communication component further includes a first isolation resistor and a second isolation resistor;

[0015] The first isolation resistor is arranged between the A end and the transmission bus, and the second isolation resistor is arranged between the B end and the transmission bus.

[0016] Optionally, in the communication component, the 485 chip is a MAX485 chip.

[0017] A communication system, the communication system includes the communication component as described in any one of the above.

[0018] The communication component provided by the present invention includes a main control chip, a 485 chip, a protection capacitor, and a transmission bus; the main control chip is connected to the OE terminal of the 485 chip, and the 485 chip is connected to the transmission bus through the A terminal and the B terminal of the 485 chip; a protection capacitor is arranged between the main control chip and the OE terminal, wherein the plate of the protection capacitor close to the main control chip is the main control plate, and the plate of the protection capacitor close to the OE terminal is the OE plate; the OE plate is connected to the common terminal; between the OE plate and the common terminal, a charging resistor is included. By adding the protection capacitor on the connection path connecting the main control chip and the OE terminal of the 485 chip, when the main control chip is damaged or the program runs wild, causing the MCU_RDE signal sent from the main control chip to the 485 chip to be at a high level, the protection capacitor will discharge after being fully charged, thereby forcing the signal at the OE terminal to become a low-level signal, enabling the 485 chip to enter the data receiving state and no longer send data to the transmission bus, thus avoiding the 485 chip from being locked due to continuous sending of redundant information caused by a front-end fault. The technical solution provided by the present invention has little change to the original circuit, simple structure and low process difficulty. The present invention also provides a communication system having the above beneficial effects. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is a circuit schematic diagram of a specific implementation manner of a selective reset deadlock sub-station circuit in the prior art;

[0021] Figure 2 It is a partial circuit schematic diagram of a specific implementation manner of the communication component provided by the present invention;

[0022] Figure 3 It is a partial circuit schematic diagram of another specific implementation manner of the communication component provided by the present invention;

[0023] Figure 4 It is a partial circuit schematic diagram of yet another specific implementation manner of the communication component provided by the present invention. Detailed Implementation Manner

[0024] Figure 1It is an existing selective reset deadlock slave station circuit. It utilizes the characteristic that when the RS-485 bus is deadlocked, the transmit enable DE of the corresponding deadlock slave station is "1", and a circuit for selectively resetting the deadlock slave station is implemented in the slave station. During normal operation, P1.1 of the master station is set to "0". At this time, regardless of the state of DE of each slave station, the output of their NAND gates is high level, the triode T1 is cut off, and RST is low level, and no slave station will be reset. When detecting the RS-485 bus deadlock, the master station only needs to set P1.1 to "1". Only the NAND gate output of the slave station with DE being "1" is low level, the triode T1 is turned on, RST is high level, and the corresponding slave station is reset. The NAND gate outputs of other slave stations are high level and will not be wrongly reset.

[0025] The existing circuit can only solve the deadlock caused by the program running wild, and cannot solve the deadlock caused by device damage. This solution requires adding a line connection (P1.1) between the master station and each slave station, which increases the system complexity and the wiring difficulty.

[0026] It should be pre-stated that the 485 chip is a communication chip using the rs485 standard.

[0027] The main control chip controls the transceiver state of the 485 chip through the sent MCU_RDE signal. When MCU_RDE is at high level, the 485 chip is in the data transmission state. When MCU_RDE is at low level, the 485 chip is in the data reception state.

[0028] In order to enable the personnel in the technical field to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] The core of the present invention is to provide a communication component, and the circuit schematic diagram of a specific embodiment thereof is as Figure 2 shown, which is called the first specific embodiment, and includes a main control chip 100, a 485 chip 200, a protection capacitor 300 and a transmission bus;

[0030] The main control chip 100 is connected to the OE end of the 485 chip 200, and the 485 chip 200 is connected to the transmission bus through the A end and B end of the 485 chip 200;

[0031] A protection capacitor 300 is provided between the main control chip 100 and the OE terminal. Among them, the plate of the protection capacitor close to the main control chip 100 is the main control plate, and the plate of the protection capacitor close to the OE terminal is the OE plate;

[0032] The OE plate is connected to the common terminal; between the OE plate and the common terminal, a charging resistor 500 is included.

[0033] The transmission bus is not drawn in the figure, but the part connected to the A end and the B end on the right side of the figure is the transmission bus.

[0034] Among them, the communication component further includes a first isolation resistor 610 and a second isolation resistor 620.

[0035] The first isolation resistor 610 is arranged between the A end and the transmission bus, and the second isolation resistor 620 is arranged between the B end and the transmission bus. When the 485 chip 200 has its own fault, the most common situation is that the voltage difference between the A end and the B end is fixed, and this problem can be solved by adding the first isolation resistor 610 and the second isolation resistor 620.

[0036] Furthermore, the 485 chip 200 is a MAX485 chip 200.

[0037] The communication component provided by the present invention includes a main control chip 100, a 485 chip 200, a protection capacitor 300 and a transmission bus; the main control chip 100 is connected to the OE terminal of the 485 chip 200, and the 485 chip 200 is connected to the transmission bus through the A end and the B end of the 485 chip 200; a protection capacitor 300 is provided between the main control chip 100 and the OE terminal. Among them, the plate of the protection capacitor close to the main control chip 100 is the main control plate, and the plate of the protection capacitor close to the OE terminal is the OE plate; the OE plate is connected to the common terminal; between the OE plate and the common terminal, a charging resistor is included. By adding the protection capacitor on the connection path connecting the main control chip 100 and the OE terminal of the 485 chip 200, when the main control chip 100 is damaged or the program runs wild, causing the MCU_RDE signal sent from the main control chip 100 to the 485 chip 200 to be at a high level, the protection capacitor will discharge after being fully charged, thereby forcing the signal at the OE terminal to become a low-level signal, making the 485 chip 200 enter the data reception state and no longer send data to the transmission bus, thus avoiding the 485 chip 200 from being locked due to continuous sending of redundant information caused by a front-end fault. The technical solution provided by the present invention has little change to the original circuit, simple structure and low process difficulty.

[0038] On the basis of the first specific implementation manner, the communication component is further improved to obtain the second specific implementation manner. The circuit schematic diagram is as follows Figure 3 shown, including a main control chip 100, a 485 chip 200, a protection capacitor 300, and a transmission bus;

[0039] The main control chip 100 is connected to the OE terminal of the 485 chip 200, and the 485 chip 200 is connected to the transmission bus through the A terminal and the B terminal of the 485 chip 200;

[0040] A protection capacitor 300 is arranged between the main control chip 100 and the OE terminal. Among them, the plate of the protection capacitor close to the main control chip 100 is the main control plate, and the plate of the protection capacitor close to the OE terminal is the OE plate;

[0041] The OE plate is connected to the common terminal; between the OE plate and the common terminal, a charging resistor 500 is included;

[0042] Between the OE plate and the common terminal, a unidirectional conduction circuit 400 in parallel with the charging resistor 500 is included;

[0043] The unidirectional conduction circuit 400 can pass the current in the direction from the OE plate to the common terminal, and the resistance value of the unidirectional conduction circuit 400 when conducting is less than the resistance value of the charging resistor 500.

[0044] The difference between this specific implementation manner and the above specific implementation manner is that in this specific implementation manner, the charging resistor 500 and the unidirectional conduction circuit 400 are added to the energization circuit of the protection capacitor, and the rest of the structures are the same as those in the above specific implementation manner, so they will not be elaborated here.

[0045] Furthermore, the unidirectional conduction circuit 400 includes a discharge diode 410. The positive pole of the discharge diode 410 is connected to the OE plate, and the negative pole is connected to the common terminal. The structure of the discharge diode 410 is simple, the cost is low, and it is convenient for installation.

[0046] In this specific embodiment, a unidirectional conduction circuit 400 is connected in parallel with the charging resistor 500 between the OE electrode plate and the common terminal. At the same time, it is specified that the resistance value of the unidirectional conduction circuit 400 during conduction is less than the resistance value of the charging resistor 500. This results in two paths for current during the charging and discharging process of the OE electrode plate of the protection capacitor. During charging, the unidirectional conduction circuit 400 is not conducting, so charging can only occur through the circuit where the charging resistor 500 is located. When the protection capacitor discharges, since the resistance of the unidirectional conduction circuit 400 is usually much smaller than that of the charging resistor 500, the current is quickly released through the unidirectional conduction circuit 400, causing the voltage of the OE signal to quickly return to the low level. The 485 chip 200 quickly returns from the data transmission state to the data reception state, without affecting the data reception of subsequent nodes. By adjusting the resistance value of the charging resistor 500 and the capacitance value of the protection capacitor 300, the maximum duration of the high level at the OE terminal can also be adjusted.

[0047] Based on the second specific embodiment, the communication component is further improved to obtain the third specific embodiment, and its circuit schematic diagram is as Figure 4 shown, including a main control chip 100, a 485 chip 200, a protection capacitor 300, and a transmission bus;

[0048] The main control chip 100 is connected to the OE terminal of the 485 chip 200, and the 485 chip 200 is connected to the transmission bus through the A terminal and B terminal of the 485 chip 200;

[0049] A protection capacitor 300 is provided between the main control chip 100 and the OE terminal. Among them, the electrode plate of the protection capacitor close to the main control chip 100 is the main control electrode plate, and the electrode plate of the protection capacitor close to the OE terminal is the OE electrode plate;

[0050] The OE electrode plate is connected to the common terminal; between the OE electrode plate and the common terminal, there is a charging resistor 500;

[0051] Between the OE electrode plate and the common terminal, there is a unidirectional conduction circuit 400 connected in parallel with the charging resistor 500;

[0052] The unidirectional conduction circuit 400 can conduct current in the direction from the OE electrode plate to the common terminal, and the resistance value of the unidirectional conduction circuit 400 during conduction is less than the resistance value of the charging resistor 500;

[0053] The fast discharge circuit further includes an adjustment resistor 420, and the adjustment resistor 420 is connected in series with the discharge diode 410.

[0054] The difference between this specific embodiment and the above-mentioned specific embodiment is that in this specific embodiment, the regulating resistor 420 is added to the unidirectional conduction circuit 400, and the rest of the structures are the same as those in the above-mentioned specific embodiment, so they will not be elaborated here.

[0055] In this specific embodiment, the regulating resistor 420 is added to the unidirectional conduction circuit 400 to adjust the resistance of the unidirectional conduction circuit 400, so that the electrical properties of the unidirectional circuit match those of other components better, and at the same time, the discharge speed of the protection capacitor 300 is adjusted.

[0056] The present invention also provides a communication system, which includes the communication component as described in any one of the above. The communication component provided by the present invention includes a main control chip 100, a 485 chip 200, a protection capacitor 300 and a transmission bus; the main control chip 100 is connected to the OE terminal of the 485 chip 200, and the 485 chip 200 is connected to the transmission bus through the A terminal and the B terminal of the 485 chip 200; the protection capacitor 300 is arranged between the main control chip 100 and the OE terminal, wherein the plate of the protection capacitor close to the main control chip 100 is the main control plate, and the plate of the protection capacitor close to the OE terminal is the OE plate; the OE plate is connected to the common terminal; between the OE plate and the common terminal, there is a charging resistor. By adding the protection capacitor to the connection path connecting the OE terminal of the main control chip 100 and the 485 chip 200, when the MCU_RDE signal sent from the main control chip 100 to the 485 chip 200 is at a high level due to damage or program runaway of the main control chip 100, the protection capacitor will discharge after being fully charged, thereby forcing the signal at the OE terminal to become a low-level signal, making the 485 chip 200 enter the data receiving state and no longer sending data to the transmission bus, thus avoiding the 485 chip 200 from being locked due to continuous sending of redundant information caused by a front-end fault. The technical solution provided by the present invention has little change to the original circuit, simple structure and low process difficulty.

[0057] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is the difference from other embodiments. For the same or similar parts between each embodiment, reference can be made to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and reference can be made to the description of the method part for related parts.

[0058] It should be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0059] The communication component and communication system provided by the present invention have been introduced in detail above. Specific examples are used herein to illustrate the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A communication component, characterized in that, It includes a main control chip, a 485 chip, a protection capacitor and a transmission bus; The main control chip is connected to the OE terminal of the 485 chip, and the 485 chip is connected to the transmission bus through the A terminal and the B terminal of the 485 chip; A protection capacitor is arranged between the main control chip and the OE terminal. Among them, the plate of the protection capacitor close to the main control chip is the main control plate, and the plate of the protection capacitor close to the OE terminal is the OE plate; The OE plate is connected to the common terminal; between the OE plate and the common terminal, a charging resistor is included; Between the OE plate and the common terminal, a one-way conduction circuit parallel to the charging resistor is included; The one-way conduction circuit can pass the current in the direction from the OE plate to the common terminal, and the resistance value of the one-way conduction circuit when it is conducting is less than the resistance value of the charging resistor; The one-way conduction circuit includes a discharge diode, the positive electrode of the discharge diode is connected to the OE plate, and the negative electrode is connected to the common terminal; The fast discharge circuit further includes an adjustment resistor, and the adjustment resistor is connected in series with the discharge diode.

2. The communication component according to claim 1, wherein The communication component further includes a first isolation resistor and a second isolation resistor; The first isolation resistor is arranged between the A terminal and the transmission bus, and the second isolation resistor is arranged between the B terminal and the transmission bus.

3. The communication component according to claim 1, characterized in that, The 485 chip is a MAX485 chip.

4. A communication system, characterized in that, The communication system includes the communication component according to any one of claims 1 to 3.

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