A communication device, a tower placement device and an automatic switching circuit thereof

Abstract

The present application discloses a communication device, a tower device and an automatic switching circuit thereof, wherein the automatic switching circuit comprises a modem, a switching chip, an inverter and a level conversion circuit, wherein the modem is coupled to the switching chip and the level conversion circuit, and the level conversion circuit is coupled to the switching chip through an inverter; the level conversion circuit obtains an output signal from the transmitting end of the modem and generates a control signal according to the output signal; the switching chip obtains the control signal through the inverter and automatically switches to a receiving mode or a transmitting mode according to the control signal. The level conversion circuit of the present application can generate different control signals according to different output signals output by the modem, thereby realizing the automatic switching of the transceiver mode of the control switching chip, without the need for software intervention and additional integrated chips, thereby reducing costs.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a communications device, a tower placement device and an automatic switching circuit thereof. Background Art

[0002] The RS485 bus is a serial half-duplex one-master-multiple-slave communication bus, that is, when the master station (base station) sends through the RS485 bus, it has the bus control right, the slave station (tower or antenna) cannot send, and the RS485 bus is in sending mode; when the slave station (antenna) sends through the RS485 bus, the master station cannot send, and the RS485 bus is in receiving mode.

[0003] The existing RS485 bus controls the switching of the sending mode and the receiving mode through the built-in function pins of the integrated chip, such as the integrated AISG modem, which leads to high cost. Summary of the invention

[0004] The present application provides a communication device, a tower placement device and an automatic switching circuit thereof to solve the problem of high cost in the prior art.

[0005] To solve the above technical problems. A technical solution adopted by the present application is: to provide an automatic switching circuit, which includes a modem, a switching chip, an inverter and a level conversion circuit, the modem is coupled with the switching chip and the level conversion circuit, the level conversion circuit is coupled to the switching chip through the inverter; the level conversion circuit obtains an output signal from the transmitting end of the modem and generates a control signal according to the output signal; the switching chip obtains the control signal through the inverter, and switches to a receiving mode or a transmitting mode according to the control signal.

[0006] Among them, the level conversion circuit includes a first capacitor, a second capacitor, a first resistor and a first diode, the first end of the inverter is connected to one end of the first capacitor, one end of the first resistor and the positive electrode of the first diode, the other end of the first capacitor is grounded, the other end of the first resistor receives a first voltage, the cathode of the first diode is connected to the transmitting end of the modem, the second end of the inverter is grounded, the third end of the inverter receives the second voltage, and the fourth end of the inverter is respectively connected to the first enable end and the second enable end of the switching chip.

[0007] When the transmitting end of the modem is in an idle state, the first capacitor is charged, the first end of the inverter is at a high level, the fourth end of the inverter outputs a low level, and the switching chip enters a receiving mode.

[0008] When data is sent at the transmitting end of the modem and the data is at a low level, the first capacitor discharges through the first diode, the first end of the inverter is at a low level, the fourth end of the inverter outputs a high level, and the switching chip enters the sending mode.

[0009] Among them, when data is sent at the transmitting end of the modem and the data is at a high level, the first capacitor is charged through the first resistor, the voltage of the first capacitor is less than the threshold voltage of the inverter, the first end of the inverter is at a low level, and the fourth end of the inverter outputs a high level, and the switching chip maintains the sending mode.

[0010] When the transmitting end of the modem stops sending data, the first capacitor is charged through the first resistor, the voltage of the first capacitor is greater than the threshold voltage of the inverter, the first end of the inverter is high level, the fourth end of the inverter outputs a low level, and the switching chip enters the receiving mode.

[0011] The first capacitor is charged through the first resistor for a preset charging time, the voltage of the first capacitor is greater than the threshold voltage of the inverter, and the charging time is greater than the transmission time of the modem sending one byte of data.

[0012] The inverter further includes a second capacitor, the third end of the inverter is connected to one end of the second capacitor, and the other end of the second capacitor is grounded.

[0013] To solve the above technical problems, another technical solution adopted in the present application is: to provide a tower-mounted device, the tower-mounted device includes a filter, a low-noise amplifier and an automatic switching circuit as described above, the filter is coupled to the low-noise amplifier, and the low-noise amplifier is coupled to the automatic switching circuit.

[0014] In order to solve the above technical problems, another technical solution adopted by the present application is: to provide a communication device, the communication device includes a power module and the tower placement device as mentioned above, and the power module is coupled to the tower placement device.

[0015] The beneficial effects of the present application are as follows: Different from the prior art, the present application provides an automatic switching circuit, which includes a modem, a switching chip, an inverter, and a level conversion circuit. The modem is coupled to the switching chip and the level conversion circuit, and the level conversion circuit is coupled to the switching chip through an inverter; the level conversion circuit obtains an output signal from the transmitting end of the modem and generates a control signal according to the output signal; the switching chip obtains the control signal through the inverter and switches to a receiving mode or a sending mode according to the control signal. The level conversion circuit of the present application can generate different control signals according to different output signals output by the modem, thereby realizing the automatic switching of the transceiver mode of the control switching chip, without the need for software intervention or additional integrated chips, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 is a circuit diagram of an embodiment of the automatic switching circuit of the present application;

[0018] Figure 2 is a circuit diagram of another embodiment of the automatic switching circuit of the present application;

[0019] Figure 3 This is the working waveform diagram of the automatic switching circuit of this application;

[0020] Figure 4 It is a circuit diagram of an embodiment of the tower release device of the present application;

[0021] Figure 5 It is a circuit diagram of an embodiment of the communication device of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0024] In order to enable those skilled in the art to better understand the technical solution of the present application, the automatic switching circuit provided by the invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0025] See also Figure 1 , Figure 1 The automatic switching circuit 100 includes a level conversion circuit 110 , an inverter U1 , a switching chip 120 and a modem 130 .

[0026] The modem 130 is coupled to the switching chip 120 and the level conversion circuit 110, and the level conversion circuit 110 is coupled to the switching chip 120 through the inverter U1; the level conversion circuit 110 obtains the output signal from the transmitting end of the modem 130 and generates a control signal according to the output signal; the switching chip 120 obtains the control signal through the inverter U1, and automatically switches to the receiving mode or the sending mode according to the control signal.

[0027] The level conversion circuit 110 generates a first level or a second level according to the output signal, and the inverter U1 inverts the generated level signal, that is, inverts the first level to the second level, and inverts the second level to the first level. The first enable terminal and the second enable terminal of the switching chip 120 are connected to the output terminal of the inverter U1; when the control signal is the first level, that is, the switching chip 120 receives the second level output by the inverter U1, the first enable terminal of the switching chip 120 works, and the switching chip 120 enters the receiving mode; when the control signal is the second level, that is, the switching chip 120 receives the first level output by the inverter U1, the second enable terminal of the switching chip 120 works, and the switching chip 120 enters the sending mode.

[0028] Optionally, the first level is a low level and the second level is a high level, or the first level is a high level and the second level is a low level.

[0029] Different from the prior art, the automatic switching circuit 100 of the embodiment of the present application generates different control signals according to the different states of the modem 130 through the level conversion circuit 110, and outputs the control signal to the switching chip 120 through the inverter U1, thereby controlling the switching mode of the switching chip 120. No software intervention or additional integrated chip is required, thereby realizing automatic control of the transmission and reception of the switching chip 120 and reducing costs.

[0030] Further reading Figure 2 , Figure 2 1 is a circuit diagram of another embodiment of the automatic switching circuit of the present application. The level conversion circuit 110 includes a first capacitor C1, a first resistor R1 and a first diode D1.

[0031] The first end of the inverter U1 is connected to one end of the first capacitor C1, one end of the first resistor R1 and the positive electrode of the first diode D1, the other end of the first capacitor C1 is grounded, the other end of the first resistor R1 receives the first voltage U1, the cathode of the first diode D1 is connected to the transmitting end TX of the modem 130, the second end of the inverter U1 is grounded, the third end of the inverter U1 receives the second voltage U2, and the fourth end of the inverter U1 is connected to the first enable end RE and the second enable end DE of the switching chip 120 for outputting a control signal. The second voltage U2 is the power supply voltage of the inverter U1. Optionally, the first voltage U1 and the second voltage U2 can be +5V.

[0032] Optionally, the inverter U1 is further provided with a second capacitor C2, which is a bypass capacitor of the power supply terminal of the inverter U1, one end of the second capacitor C2 is connected to the third end of the inverter U1, and the other end of the second capacitor C2 is grounded.

[0033] The first terminal R of the switch chip 120 is connected to the receiving terminal RX of the modem 130; the second terminal RE of the switch chip 120 is a first enabling terminal, which works when receiving a low level; when the second terminal RE of the switch chip 120 receives a low level, the first terminal R and the second terminal RE of the switch chip 120 work at the same time, the switch chip 120 switches to the receiving mode, and the sixth terminal B and the seventh terminal A of the switch chip 120 receive the data of the RS485 bus. The fourth terminal D of the switch chip 120 is connected to the transmitting terminal TX of the modem 130; the third terminal DE of the switch chip 120 is a second enabling terminal, which works when receiving a high level; when the third terminal DE of the switch chip 120 receives a high level, the third terminal DE and the fourth terminal D of the switch chip 120 work at the same time, the switch chip 120 is in the sending mode, and the sixth terminal B and the seventh terminal A of the switch chip 120 send data to the RS485 bus. The eighth terminal GND of the switching chip 120 is the ground terminal; the sixth terminal B and the seventh terminal A of the switching chip 120 are connected to the RS485 bus for receiving data from the RS485 bus or sending data to the RS485 bus; the fifth terminal VCC of the switching chip 120 is the power supply terminal for receiving the third voltage U3.

[0034] The third voltage U3 is a power supply voltage of the switching chip 120. Optionally, the third voltage U3 may be +5V.

[0035] Optionally, the fifth terminal VCC of the switch chip 120 is further provided with a third capacitor C3, which is a bypass capacitor of the fifth terminal VCC. One end of the third capacitor C3 is connected to the fifth terminal VCC, and the other end of the third capacitor C3 is grounded.

[0036] The switch chip 120 is an RS485 driver chip. Optionally, the switch chip 120 can be SN75176, SN75276, SN75LBC184, MAX485, MAX1487, MAX3082, MAX1483 or other chips, and the circuit connection is performed according to the design of the PIN pins of the chip itself.

[0037] Different from the prior art, the automatic switching circuit 100 of the embodiment of the present application only uses an inverter U1, a first capacitor C1, a first resistor R1 and a first diode D1, and utilizes a small number of simple components to realize automatic control of transmission and reception of the switching chip 120, which can simplify the circuit and reduce production costs.

[0038] See also Figure 2 and Figure 3 , Figure 3 This is a working waveform diagram of the automatic switching circuit of this application, which has five main nodes.

[0039] Node 1, according to the AISG protocol, when the transmitter TX of the modem 130 is in an idle state, that is, when no data is sent, TX is in a high level state. At this time, the first diode D1 is not conducting, and the first capacitor C1 is charged via the first resistor R1; when the first capacitor C1 is fully charged, it is at a high level, that is, the first end of the inverter U1 is at a high level, and the high level is inverted by the inverter U1, and the fourth end of the inverter U1 outputs a low level; the switching chip 120 receives the low level output by the inverter U1, and the second end RE of the switching chip 120 works. At this time, the switching chip 120 is in a receiving mode, and can receive data from the RS485 bus at any time.

[0040] Node 2, when the transmitter TX of the modem 130 starts to transmit the first falling edge of the data, that is, when the data is at a low level, the first capacitor C1 is discharged through the first diode D1, and the voltage difference between the voltage after discharge and the voltage before discharge is greater than the threshold voltage of the inverter U1, that is, the threshold voltage from a high level to a low level. At this time, the first end of the inverter U1 is a low level, and the fourth end of the inverter U1 outputs a high level, and the output signal of the inverter U1 is reversed from a low level to a high level; the switching chip 120 receives the high level output by the inverter U1, and the third end DE of the switching chip 120 works. At this time, the switching chip 120 is in a sending mode and sends data to the RS485 bus.

[0041] Node 3, when the data sent by the transmitter TX of the modem 130 is converted from a low level to a high level, due to the unidirectional conductivity of the first diode D1, the first capacitor C1 is no longer discharged through the first diode D1, but is charged through the first resistor R1; when the input voltage of the inverter U1 slowly increases but has not reached the threshold voltage of the inverter U1 from a low level to a high level, the data sent by the transmitter of the modem 130 is inverted to a low level, and the first capacitor C1 is discharged through the first diode D1 again. At this time, the first end of the inverter U1 is a low level, and the fourth end of the inverter U1 outputs a high level, so that the inverter U1 keeps outputting a high level, and the switching chip 120 keeps the sending mode unchanged.

[0042] Node 4, when the transmitter TX of the modem 130 finishes sending data and returns to an idle state, the first capacitor C1 continues to be charged through the first resistor R1.

[0043] At node 5, when the input voltage of the inverter U1 reaches the threshold voltage of the inverter U1 from low level to high level, the first end of the inverter U1 is at a high level, the fourth end of the inverter U1 outputs a low level, the output signal of the inverter U1 is inverted from a high level to a low level, and the switching chip 120 enters the receiving mode.

[0044] The delay between node 4 and node 5 is the charging time T. The first capacitor C1 is charged to a preset charging time T through the first resistor R1. At this time, the voltage of the first capacitor C1 is greater than the threshold voltage of the inverter U1.

[0045] The charging time T must be at least greater than the transmission time of one byte of data, so that the output level of the inverter U1 will not be reversed during the data transmission process of the modem 130, so that the switching chip 120 can keep the output state unchanged. Among them, one byte of data includes 9 bits, 8 valid bits and a stop bit. According to the AISG protocol, when the RS485 communication is in the sending state, it should be switched to the receiving state within 20 bits after the demodulator outputs the last valid bit. Therefore, the charging time T should be less than the transmission time of 20 bits and greater than the transmission time of 9 bits.

[0046] Optionally, the inverter U1 may be an inverter composed of other discrete devices and logic devices. The threshold voltage is determined by the parameters of the inverter U1 itself, and the charging time can be changed by changing the parameters of the first resistor R1 and the first capacitor C1 to meet the condition that the charging time is less than the transmission time of 20 bits and greater than the transmission time of 9 bits.

[0047] Different from the prior art, the embodiment of the present application realizes the change of the level signal by using the first capacitor C1 to charge and discharge according to the change of the TX state of the modem 130 transmitting end, thereby controlling the working state of the switching chip 120. At the same time, through the charging and discharging of the first capacitor C1, the input voltage of the inverter U1 can be kept below the inversion threshold voltage to maintain the sending state of the switching chip 120.

[0048] See also Figure 4 , Figure 4 The tower-mounted device 10 includes an automatic switching circuit 100 , a low noise amplifier 200 and a filter 300 .

[0049] The filter 300 is coupled to the low noise amplifier 200, and the low noise amplifier 200 is coupled to the automatic switching circuit 100. The filter 300 filters the input signal, the low noise amplifier 200 amplifies the filtered signal, and the automatic switching circuit 100 receives the amplified input signal, demodulates the input signal, and switches the receiving and transmitting state according to the demodulated output signal.

[0050] See also Figure 5 , Figure 5 The communication device 1 includes a tower device 10 and a power module 20 , the tower device 10 and the power module 20 are coupled, and the power module 20 provides the tower device 10 with an operating voltage.

[0051] The above are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An automatic switching circuit, characterized in that: The automatic switching circuit comprises a modem, a switching chip, an inverter and a level conversion circuit, wherein the modem is coupled to the switching chip and the level conversion circuit, and the level conversion circuit is coupled to the switching chip through the inverter; The level conversion circuit obtains the output signal from the transmitting end of the modem and generates a control signal according to the output signal; the switching chip obtains the control signal through the inverter and automatically switches to a receiving mode or a transmitting mode according to the control signal; Wherein, the level conversion circuit includes a first capacitor, a first resistor and a first diode, the first end of the inverter is connected to one end of the first capacitor, one end of the first resistor and the positive electrode of the first diode, the other end of the first capacitor is grounded, the other end of the first resistor receives a first voltage, the cathode of the first diode is connected to the transmitting end of the modem, the second end of the inverter is grounded, the third end of the inverter receives a second voltage, and the fourth end of the inverter is respectively connected to the first enable end and the second enable end of the switching chip; The second voltage is the supply voltage of the inverter, the first capacitor is charged through the first resistor to a preset charging time, the voltage of the first capacitor is greater than the threshold voltage of the inverter, and the charging time is greater than the transmission time of the modem to send one byte of data.

2. The automatic switching circuit according to claim 1, characterized in that: When the transmitting end of the modem is in an idle state, the first capacitor is charged, the first end of the inverter is at a high level, the fourth end of the inverter outputs a low level, and the switching chip enters the receiving mode.

3. The automatic switching circuit according to claim 2, characterized in that: When data is sent at the transmitting end of the modem and the data is at a low level, the first capacitor discharges through the first diode, the first end of the inverter is at a low level, the fourth end of the inverter outputs a high level, and the switching chip enters the sending mode.

4. The automatic switching circuit according to claim 3, characterized in that: When the data is sent at the transmitting end of the modem and the data is at a high level, the first capacitor is charged through the first resistor, the voltage of the first capacitor is less than the threshold voltage of the inverter, the first end of the inverter is at a low level, the fourth end of the inverter outputs a high level, and the switching chip maintains the sending mode.

5. The automatic switching circuit according to claim 4, characterized in that: When the transmitting end of the modem stops sending the data, the first capacitor is charged through the first resistor, the voltage of the first capacitor is greater than the threshold voltage of the inverter, the first end of the inverter is a high level, the fourth end of the inverter outputs a low level, and the switching chip enters the receiving mode.

6. The automatic switching circuit according to claim 1, characterized in that: The inverter is further provided with a second capacitor, the third end of the inverter is connected to one end of the second capacitor, and the other end of the second capacitor is grounded.

7. A tower placing device, characterized in that: The tower equipment comprises a filter, a low noise amplifier and an automatic switching circuit as described in any one of claims 1 to 6, wherein the filter is coupled to the low noise amplifier, and the low noise amplifier is coupled to the automatic switching circuit.

8. A communication device, characterized in that: The communication device comprises a power module and the tower placement device as claimed in claim 7, wherein the power module is coupled to the tower placement device.

Images