Half-duplex communication transfer circuit

Abstract

The half-duplex communication transfer circuit provided by the utility model is suitable for adjusting the switching of the working modes of a transmitting modulation circuit and a receiving demodulation circuit between a communication master station and a communication slave station through an upper computer, and comprises a level switching module which is used for switching the working modes of the transmitting modulation circuit and the receiving demodulation circuit according to the type of a control signal of the upper computer, when the control signal is at a low level, the signal transmitted by the communication master station is sent to the communication slave station through the sending modulation circuit, and the receiving demodulation circuit is in a forbidden state; when the control signal is at a high level, the signal transmitted from the communication slave station to the communication master station is received through the receiving demodulation circuit, and the sending modulation circuit is in a disable state, so that the communication efficiency of the two can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a half-duplex communication relay circuit. Background Art

[0002] With the continuous development of communication technologies, the demand for the flexibility of communication between devices under different electrical conditions is increasing. The existing communication slave electrical module needs to communicate with the master station and also requires power supply from the master station. Therefore, it is required that the communication master station can deliver power to the slave electrical module. For example, a simple communication master station built with a single-chip microcomputer or DSP for serial port transceiver cannot output enough power to enable the slave station to work properly. Moreover, due to its fixed power supply voltage, the communication level cannot be flexibly switched, which cannot meet the requirements and results in a decrease in communication efficiency. Summary of the Utility Model

[0003] In view of this, the half-duplex communication relay circuit provided by the utility model solves the technical problem that the communication efficiency between the communication slave station and the communication master station is reduced by the existing technology.

[0004] A half-duplex communication relay circuit is applicable to switching the working modes of a transmission modulation circuit and a reception demodulation circuit between a communication master station and a communication slave station through a host computer, and includes a level switching module, which is used to switch the working modes of the transmission modulation circuit and the reception demodulation circuit according to the type of the host computer control signal, so as to realize that when the control signal is at a low level, the signal transmitted by the communication master station is sent to the communication slave station through the transmission modulation circuit, and the reception demodulation circuit is in a disabled state; when the control signal is at a high level, the signal transmitted from the communication slave station to the communication master station is received through the reception demodulation circuit, and the transmission modulation circuit is in a disabled state.

[0005] Preferably, the level switching module includes a diode V1, a PNP type triode Q1 and an NPN type triode Q2, wherein,

[0006] The collector of the triode Q2 is connected to the BUS pin of the communication slave station. The BUS pin is connected to the positive pole of the bus of the communication slave station. The emitter of the triode Q2 is grounded and connected to the AGND pin of the communication slave station. The AGND pin is connected to the negative pole of the bus of the communication slave station. The base of the triode Q2 is connected to the pin of the negative output terminal of the transmission modulation circuit;

[0007] The collector of the triode Q1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the collector of the triode Q2, the emitter of the triode Q1 is connected to the output end of the resistor R2, the input end of the resistor R2 is connected to the anode of the diode V1, the cathode of the diode V1 is connected to the BO pin of the positive output end of the sending modulation circuit, and the base of the triode Q1 is connected to the output end of the resistor R3, and the input end of the resistor R3 is connected to the anode of the diode V1;

[0008] The positive input end and the negative input end of the receiving demodulation circuit are respectively connected to the BUS pin and the AGND pin of the communication slave station, where

[0009] When the control signal is at a low level, the triodes Q1 and Q2 are turned on, and the signal transmitted by the communication master station is sent to the communication slave station through the sending modulation circuit, and the receiving demodulation circuit is in a disabled state.

[0010] Preferably, the level switching module includes an NPN-type triode Q3, and the triode Q3 is used to control the disabling or enabling of the triode Q1, where

[0011] The collector of the triode Q3 is connected to the cathode of the diode V1, the emitter of the triode Q3 is grounded, and the base of the triode Q3 is connected to the BO pin.

[0012] Preferably, the resistor R1 is used to suppress the generation of high-frequency clutter, absorb the reflected signal and reduce signal reflection.

[0013] Preferably, the resistance value of the resistor R1 is 50 ohms.

[0014] Preferably, a voltage stabilizing module is further included, where

[0015] A preset voltage is provided to the sending modulation circuit through the voltage converter inside the voltage stabilizing module, and the output end of the stable output power supply in the voltage stabilizing module is connected to the output end of the resistor R2 to ensure the stability of the operation of the transistor Q1.

[0016] Beneficial effects

[0017] The level switching module is used to change the output level of the voltage conversion circuit and change the modulation level to meet the requirements of output power and communication matching. For example, according to the type of the host computer control signal, the working modes of the sending modulation circuit and the receiving demodulation circuit are switched, so as to realize that when the control signal is at a low level, the signal transmitted by the communication master station is sent to the communication slave station through the sending modulation circuit, and the receiving demodulation circuit is in a disabled state; when the control signal is at a high level, the signal transmitted by the communication slave station to the communication master station is received through the receiving demodulation circuit, and the sending modulation circuit is in a disabled state. Description of the drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the accompanying drawings required for the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0019] Figure 1 This is the circuit diagram of the present utility model. Specific embodiments

[0020] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0021] The following illustrates the embodiments of the present disclosure through specific examples. Those skilled in the art can easily understand other advantages and effects of the present disclosure from the content disclosed in this specification. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of them. The present disclosure can also be implemented or applied through other different specific embodiments. 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 disclosure. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts belong to the scope of protection of the present disclosure.

[0022] 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 merely illustrative. Based on the present disclosure, 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 of aspects described herein can be used to implement a device and / or practice a method. Additionally, this device and / or method can be implemented using other structures and / or functionality in addition to one or more of the aspects described herein.

[0023] It should also be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present disclosure in a schematic manner. The diagrams only show the components related to the present disclosure and are not drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0024] 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 aspects can be practiced without these specific details.

[0025] See Figure 1 The half-duplex communication relay circuit shown is applicable to switching the working modes of the transmission modulation circuit and the reception demodulation circuit between a communication master station and a communication slave station through a host computer. It includes a level switching module, which is used to switch the working modes of the transmission modulation circuit and the reception demodulation circuit according to the type of the host computer control signal, so as to achieve that when the control signal is at a low level, the signal transmitted by the communication master station is sent to the communication slave station through the transmission modulation circuit, and the reception demodulation circuit is in a disabled state; when the control signal is at a high level, the signal transmitted from the communication slave station to the communication master station is received through the reception demodulation circuit, and the transmission modulation circuit is in a disabled state, and the output of the transmission modulation circuit is always high, thereby realizing half-duplex communication, that is, a half-duplex communication relay circuit applied to the occasion where transmission can be modulated and reception can be demodulated. By switching the level of the mode switching pin, the working mode of the relay circuit can be switched, and by changing the value of the received demodulation voltage input, the level value of the received signal can be changed.

[0026] As a specific implementation manner provided in this case, the level switching module includes a diode V1, a PNP-type triode Q1, and an NPN-type triode Q2, where

[0027] The collector of the triode Q2 is connected to the BUS pin of the communication slave station. The BUS pin is connected to the positive pole of the bus of the communication slave station. The emitter of the triode Q2 is grounded and connected to the AGND pin of the communication slave station. The AGND pin is connected to the negative pole of the bus of the communication slave station. The base of the triode Q2 is connected to the pin of the negative output terminal of the transmission modulation circuit;

[0028] The collector of the triode Q1 is connected to one end of a resistor R1. The other end of the resistor R1 is connected to the collector of the triode Q2. The emitter of the triode Q1 is connected to the output terminal of a resistor R2. The input terminal of the resistor R2 is connected to the anode of the diode V1. The cathode of the diode V1 is connected to the BO pin of the positive output terminal of the transmission modulation circuit. The base of the triode Q1 is connected to the output terminal of a resistor R3. The input terminal of the resistor R3 is connected to the anode of the diode V1;

[0029] The positive input terminal and the negative input terminal of the reception demodulation circuit are respectively connected to the BUS pin and the AGND pin of the communication slave station, where

[0030] When the control signal is at a low level, the triode Q1 and the triode Q2 are turned on, and the signal transmitted by the communication master station is sent to the communication slave station through the transmission modulation circuit, and the reception demodulation circuit is in a disabled state.

[0031] Further, the triode Q1 is configured with a switch, and the level switching module includes an NPN-type triode Q3, which is used to control the disabling or enabling of the triode Q1. Among them,

[0032] The collector of the triode Q3 is connected to the cathode of the diode V1, the emitter of the triode Q3 is grounded, and the base of the triode Q3 is connected to the BO pin.

[0033] As a specific implementation provided in this case, in the case of long-distance fast transmission, signal reflection and communication anomalies may occur due to high-frequency interference. Therefore, the resistance value of the resistor R1 is preferably 50 ohms, which is used to suppress the generation of high-frequency clutter, absorb the reflected signal and reduce signal reflection.

[0034] As a specific implementation provided in this case, the communication slave station needs to draw power from the bus to maintain its normal operation. If the power output on the bus is insufficient, it may cause the slave station to fail to work properly, resulting in the inability to perform reception and demodulation. Therefore, a voltage stabilization module or a voltage stabilization circuit is set up. The voltage stabilization module or the voltage stabilization circuit adopts a circuit in the prior art. Among them,

[0035] A preset voltage is provided to the transmission modulation circuit through the voltage converter inside the voltage stabilization module. Preferably, the voltage converter converts to a voltage of VCC_3.3V to provide a stable working voltage to the transmission modulation circuit. The output end of the stable output power supply (V_BUS) in the voltage stabilization module is connected to the output end of the resistor R2 to ensure the stability of the operation of the transistor Q1. Preferably, the VIN pin of the voltage stabilization module is connected to the external power supply positive line, and the voltage is +15V to +28V. The GND pin of the voltage stabilization module is connected to the external power supply negative line.

[0036] As a specific implementation provided in this case, the level switching module further includes a main control chip of the host computer. The main control chip includes an R / TEN pin, an RTX pin, and a TXD pin. The R / TEN pin is used to select the working mode of the main control chip and is connected to the control ends of the transmission modulation circuit and the reception demodulation circuit through the switching input line respectively; the RTX pin is connected to the signal receiving line of the host computer, and the TXD pin is connected to the signal sending line of the host computer. Among them,

[0037] When the R / TEN pin is at a low level, it is in the transmission mode, enabling the transmission modulation circuit and disabling the reception demodulation circuit, and the level of the RXD pin is always high. When the system is idle, this pin should be placed in the transmission state, and the TXD always sends a high level when idle, so that the "BUS" bus maintains a high-level power supply state;

[0038] When the R / TEN pin is at a high level, it is in the reception state, the reception demodulation circuit works and the transmission modulation circuit is disabled, the triode Q1 is always turned on, and the triode Q2 is always turned off.

[0039] As a specific implementation manner provided in this case, the VDD pin of the receiving demodulation circuit is connected to the positive pole of the external receiving demodulation voltage, and the voltage range is 3.3V - 5V, and there is no need to provide a stable voltage through a voltage stabilizing circuit. The power supply voltages of the sending modulation circuit and the receiving demodulation circuit are separated, and there will be no phenomenon that the two circuits cannot work properly due to abnormal power supply of one path.

[0040] Further, in the above circuit, except that the resistor R1 is a fixed-value resistor, the other circuits are preferably adjustable resistors. On the premise that the topological structure remains unchanged and normal communication is maintained, only by changing the resistance value, the high-level value of the bus voltage can be changed to adapt to the working conditions of different slave stations.

[0041] The above is only the specific implementation manner of the present disclosure, but the protection scope of the present disclosure 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 the present disclosure should be covered by the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A half-duplex communication transfer circuit, suitable for adjusting the switching of the working modes of the sending modulation circuit and the receiving demodulation circuit between the communication master station and the communication slave station through the host computer, characterized in that: It includes a level switching module, which is used to switch the working modes of the sending modulation circuit and the receiving demodulation circuit according to the type of the upper computer control signal, so that when the control signal is at a low level, the signal transmitted by the communication main station is sent to the communication slave station through the sending modulation circuit, and the receiving demodulation circuit is in a disabled state; when the control signal is at a high level, the signal transmitted from the communication slave station to the communication main station is received through the receiving demodulation circuit, and the sending modulation circuit is in a disabled state.

2. The half-duplex communication relay circuit according to claim 1, characterized in that: The level switching module includes a diode V1, a PNP transistor Q1 and an NPN transistor Q2, wherein: The collector of the transistor Q2 is connected to the BUS pin of the communication slave station, the BUS pin is connected to the positive pole of the bus of the communication slave station, the emitter of the transistor Q2 is grounded and connected to the AGND pin of the communication slave station, the AGND pin is connected to the negative pole of the bus of the communication slave station, and the base of the transistor Q2 is connected to the negative output end of the sending modulation circuit. Pin connections; The collector of the transistor Q1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the collector of the transistor Q2, the emitter of the transistor Q1 is connected to the output end of the resistor R2, the input end of the resistor R2 is connected to the anode of the diode V1, the cathode of the diode V1 is connected to the BO pin of the forward output end of the transmission modulation circuit, the base of the transistor Q1 is connected to the output end of the resistor R3, and the input end of the resistor R3 is connected to the anode of the diode V1; The positive input terminal and negative input terminal of the receiving demodulation circuit are connected to the BUS pin and AGND pin of the communication slave station respectively. When the control signal is at a low level, transistors Q1 and Q2 are turned on, and the signal transmitted by the communication master station is sent to the communication slave station through the sending modulation circuit, and the receiving demodulation circuit is in a disabled state.

3. The half-duplex communication relay circuit according to claim 2, characterized in that: The level switching module also includes an NPN transistor Q3, which is used to control the disablement or enablement of the transistor Q1. The collector of the transistor Q3 is connected to the cathode of the diode V1 , the emitter of the transistor Q3 is grounded, and the base of the transistor Q3 is connected to the BO pin.

4. The half-duplex communication relay circuit according to claim 2, characterized in that: The resistor R1 is used to suppress the generation of high-frequency clutter, absorb reflected signals and reduce signal reflection.

5. The half-duplex communication relay circuit according to claim 4, characterized in that: The resistance of the resistor R1 is 50 ohms.

6. The half-duplex communication relay circuit according to claim 2, characterized in that: It also includes a voltage regulator module, wherein: A preset voltage is provided to the transmission modulation circuit through a voltage converter inside the voltage stabilizing module, and the output end of the stable output power supply in the voltage stabilizing module is connected to the output end of the resistor R2 to ensure the working stability of the transistor Q1.

7. The half-duplex communication relay circuit according to claim 6, characterized in that: The stable output power of the voltage stabilizing module is V_BUS.

8. The half-duplex communication relay circuit according to claim 6, characterized in that: The VIN pin of the voltage stabilizing module is connected to an external positive power supply line, the voltage is +15V to +28V, and the GND pin of the voltage stabilizing module is connected to an external negative power supply line.

9. The half-duplex communication relay circuit according to claim 1, characterized in that: The level switching module also includes a main control chip of the host computer, and the main control chip includes an R / TEN pin, an RTX pin and a TXD pin. The R / TEN pin is used to select the working mode of the main control chip, and is connected to the control end of the sending modulation circuit and the receiving demodulation circuit respectively by switching the input line; the RTX pin is connected to the signal receiving line of the host computer, and the TXD pin is connected to the signal sending line of the host computer, wherein, When the R / TEN pin is at a low level, it is in the transmit mode, enabling the transmit modulation circuit and disabling the receive demodulation circuit, and the RXD pin level is always high; When the R / TEN pin is at a high level, it is in the receiving state, the receiving demodulation circuit works and the transmitting modulation circuit is disabled.

10. The half-duplex communication relay circuit according to claim 1, characterized in that: The VDD pin of the receiving demodulation circuit is connected to the positive pole of the external receiving demodulation voltage, and the voltage range is 3.3V-5V.

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