Long-distance communication device

Abstract

According to the long-distance communication device provided by the utility model, the receiving module and the transmitting module are independently designed, so that the receiving and transmitting performances of the device can be respectively optimized. The receiving module is always in a receiving state; in addition, the sending module is in a sending state all the time, the state switching operation in communication is reduced through the design of the mode, and the data transmission efficiency is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to wired communication technical field especially relates to a long distance communication device. BACKGROUND

[0002] In the field of long distance communication, especially in the application scenarios of industrial automation, security monitoring, intelligent building, etc., reliable data transmission becomes a key element for the normal operation of the system. In the process of long distance transmission, the traditional communication equipment is easily affected by electromagnetic interference, signal attenuation and voltage fluctuation, resulting in unstable communication link and even data loss. Therefore, how to design a communication device with good anti-interference ability, which can guarantee data integrity and has long transmission distance, has become a problem to be solved.

[0003] Currently, most communication systems use RS485 protocol for data transmission, which has the advantages of long transmission distance and strong anti-interference ability. However, with the increase of communication distance, power fluctuation, high-frequency noise and transient voltage interference may affect the receiving and transmitting units in the communication equipment, and further cause communication failure. At the same time, the A and B signal lines of RS485 bus are prone to be in a suspended state when idle, which may cause false triggering or interference.

[0004] In summary, the problems in the prior art need to be solved. UTILITY MODEL CONTENT

[0005] The utility model provides a long distance communication device to solve the defects in the prior art, realize long distance communication.

[0006] The utility model provides a long distance communication device, comprising: receiving data module and sending data module,

[0007] The receiving data module comprises a first power filter unit, a low-voltage receiving unit, a first data protection unit, a first signal transmission unit and a first pull-up and pull-down resistor unit.

[0008] The sending data module comprises a second power filter unit, a low-voltage sending unit, a second data protection unit, a second signal transmission unit and a second pull-up and pull-down resistor unit.

[0009] The output end of the first signal transmission module is connected to the input end of the low-voltage receiving unit through the first data protection unit and the first pull-up and pull-down resistor unit, and the output end of the low-voltage receiving unit is connected to the microprocessor.

[0010] The output end of the second signal transmission module is connected with the output end of the low-voltage sending unit through the second data protection unit and the second up-down pull resistance unit, and the input end of the low-voltage sending unit is connected with a microprocessor.

[0011] According to the long-distance communication device, the low-voltage receiving unit and the low-voltage sending unit are both MAX485 chips.

[0012] According to the long-distance communication device, the DE pin of the low-voltage receiving unit is grounded, so that the low-voltage sending unit is in a data receiving mode; and the DE pin of the low-voltage sending unit is connected to the positive pole of a power supply, so that the low-voltage sending unit is in a data sending mode.

[0013] According to the long-distance communication device, the first power supply filtering module comprises a first magnetic bead and a first bypass capacitor, so as to reduce the interference of high-frequency noise on the power supply line on the low-voltage receiving unit and stabilize the working voltage of the low-voltage receiving unit.

[0014] The second power supply filtering module comprises a second magnetic bead and a second bypass capacitor, so as to reduce the interference of high-frequency noise on the power supply line on the low-voltage sending unit and stabilize the working voltage of the low-voltage sending unit.

[0015] According to the long-distance communication device, the first data protection unit and the second data protection unit both comprise a PTC thermistor and a transient suppression diode, and the PTC thermistor and the transient suppression diode are used for protecting the communication chip in the circuit from being damaged when the current is too large or the transient voltage is too high.

[0016] According to the long-distance communication device, the first up-down pull resistance module comprises a first pull-up resistance and a first pull-down resistance, the first pull-up resistance is connected with the first pin of the first signal transmission unit, and the first pull-down resistance is connected with the second pin of the first signal transmission unit.

[0017] According to the long-distance communication device, the first signal transmission unit and the second signal transmission unit perform data transmission through an 8-core copper mesh wire.

[0018] The long-distance communication device provided by the utility model, the receiving module and the sending module are independently designed, so that the equipment can optimize the performance of receiving and sending respectively. In the receiving module, always in the receiving state; in the sending module, always in the sending state, the design of this mode reduces the state switching operation in communication, and improves the data transmission efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0020] Figure 1 is a module schematic diagram of the long-distance communication device provided by the present application;

[0021] Figure 2 is a specific circuit diagram of the long-distance communication device provided by the present application. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present application more clear, the technical scheme of the present application will be described clearly and completely in the following with reference to the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] In order to solve the problems in the prior art, the present application provides a long-distance communication device to realize long-distance communication. The long-distance communication device will be described as follows, as shown in Figure 1 including but not limited to the following modules:

[0024] receiving data module and sending data module;

[0025] The receiving data module comprises a first power filter unit, a low-voltage receiving unit, a first data protection unit, a first signal transmission unit and a first pull-up and pull-down resistor unit.

[0026] The sending data module comprises a second power filter unit, a low-voltage sending unit, a second data protection unit, a second signal transmission unit and a second pull-up and pull-down resistor unit.

[0027] The output end of the first signal transmission module is connected to the input end of the low-voltage receiving unit through the first data protection unit and the first pull-up and pull-down resistor unit, and the output end of the low-voltage receiving unit is connected to the microprocessor.

[0028] The output end of the second signal transmission module is connected to the output end of the low-voltage sending unit through the second data protection unit and the second pull-up and pull-down resistor unit, and the input end of the low-voltage sending unit is connected to the microprocessor.

[0029] Specifically,

[0030] The receiving data module comprises:

[0031] The first power filter unit comprises a first magnetic bead L1 and a first bypass capacitor C1, which are used for filtering noise from the power supply and reducing high-frequency noise interference on the circuit. The magnetic bead L1 is connected in series with the power supply, and the bypass capacitor C1 is connected in parallel between the power supply and the ground, thereby effectively filtering out high-frequency interference signals in the power supply line and ensuring the working stability of the low-voltage receiving unit U1.

[0032] The low-voltage receiving unit adopts a MAX485 chip as a receiver, which receives A and B signals and outputs a received signal after differential demodulation through an RO pin. The DE pin is grounded to ensure that the chip is in a receiving mode, so that the device can stably receive external data signals.

[0033] The first data protection unit comprises a PTC thermistor R1 and a transient suppression diode D1. The PTC thermistor is used to prevent the circuit from being burned out when the current is too large, and the transient suppression diode is used to protect the receiving chip from the impact of transient voltage. The PTC thermistor is connected in series on the signal line, and the transient suppression diode is connected in parallel between the signal line and the ground. When the current or voltage exceeds the safe range, the circuit can be quickly responded to protect the circuit.

[0034] The first signal transmission unit comprises a signal transmission line, which is used for receiving external RS485 signals and transmitting the signals to the A and B input terminals of the MAX485 chip. A first pull-up and pull-down resistance unit is arranged on the A and B signal lines respectively to stabilize the level state of the signal line and prevent false actions or interference signals caused by the idle state of the line.

[0035] The first pull-up and pull-down resistance unit comprises a first pull-up resistance R2 and a first pull-down resistance R3. The pull-up resistance is connected with the signal line A, and the pull-down resistance is connected with the signal line B, so as to ensure that the A and B signal lines are pulled to high and low levels respectively when the signal transmission line is idle, thereby maintaining the stability of the RS485 bus.

[0036] The sending data module comprises:

[0037] The second power filter unit comprises a second magnetic bead L2 and a second bypass capacitor C2. The magnetic bead L2 is connected in series on the power supply line to filter out high-frequency noise on the power supply line, and the bypass capacitor C2 is connected in parallel between the power supply and the ground to provide a bypass path for power supply noise, thereby ensuring the working stability of the low-voltage sending unit U2.

[0038] Low-voltage sending unit: also uses MAX485 chip as the sender, receives data from the microprocessor through the DI pin, and sends it out through the A and B signal lines. The DE pin is connected to the positive pole of the power supply to make the chip in the sending mode, so that the signal from the microprocessor is stably transmitted to the RS485 bus.

[0039] Second data protection unit: including PTC thermistor R4 and transient suppression diode D2, which plays the same protective role as the receiving module, preventing chip damage caused by excessive current or transient voltage when sending data.

[0040] Second signal transmission unit: including signal transmission lines, for outputting differential signals from MAX485 to external devices through A and B lines. Similar to the receiving data module, the sending data module also has an upper and lower pull resistance unit to prevent interference caused by the floating state of the signal line.

[0041] Second upper and lower pull resistance unit: including second pull-up resistor R5 and second pull-down resistor R6, the pull-up resistor is connected with the signal line A, and the pull-down resistor is connected with the signal line B, which is used to stabilize the signal line level and prevent external noise from interfering with the communication signal.

[0042] In the working process of the embodiment, the receiving and sending data modules transmit data through the RS485 bus. The specific operation steps are as follows:

[0043] Working process of the receiving data module: when the data sent by the external device is transmitted to the receiving data module through the RS485 bus, the data first passes through the first signal transmission unit and stabilizes the signal line level through the first upper and lower pull resistance unit. Then, the signal enters the first data protection unit, which is protected by the PTC thermistor and the transient suppression diode, to ensure that the signal will not damage the chip before entering the low-voltage receiving unit U1. After the low-voltage receiving unit U1 receives the differential signal, it outputs the decoded signal through the RO pin and transmits it to the microprocessor for further processing.

[0044] Working process of the sending data module: the working principle of the sending data module is similar to that of the receiving data module. When the microprocessor needs to send data, the data is input through the DI pin of the low-voltage sending unit U2, encoded, and output to the RS485 bus through the A and B signal lines. In this process, the second data protection unit protects the sending signal from the influence of abnormal current and voltage, and the second upper and lower pull resistance unit is used to stabilize the signal level in the idle state, ensuring the stability of the communication link.

[0045] As a further optional embodiment, the low-voltage receiving unit and the low-voltage sending unit are both MAX485 chips.

[0046] Low-voltage receiving unit:

[0047] In this embodiment, the low-voltage receiving unit in the receiving data module adopts a MAX485 chip, which decodes the received differential signal into a TTL level signal through its RO (receive output) pin, and then transmits it to the microprocessor for processing. Since MAX485 has strong anti-noise ability, it can realize stable data reception in complex electromagnetic environment, especially suitable for industrial control, remote communication and other scenes that require high reliability.

[0048] Low-voltage sending unit:

[0049] The low-voltage sending unit in the sending data module also adopts a MAX485 chip. The microprocessor transmits the data to be sent to the MAX485 chip through the DI (data input) pin, and the chip converts the TTL level signal into a differential signal for long-distance transmission through the A and B signal lines. MAX485 has strong driving ability, supports communication distance up to hundreds of meters, and effectively suppresses common-mode noise through differential transmission, improving the reliability of communication.

[0050] As a further optional embodiment, the DE pin of the low-voltage receiving unit is grounded to make the low-voltage sending unit in data receiving mode; the DE pin of the low-voltage sending unit is connected to the positive pole of the power supply to make the low-voltage sending unit in data sending mode.

[0051] Specifically, the DE pin of the low-voltage receiving unit is grounded:

[0052] When receiving data, the DE pin of the low-voltage receiving unit is grounded. The DE pin of the MAX485 chip is used to control the enablement of the driver, and grounding disables the sending driver, making MAX485 in receiving mode, and the chip receives differential signals from the A and B pins and outputs the received TTL level signal through the RO pin.

[0053] The DE pin of the low-voltage sending unit is connected to the positive pole of the power supply:

[0054] When sending data, the DE pin of the low-voltage sending unit is connected to the positive pole of the power supply. At this time, the DE pin is high, and the sending driver of the MAX485 chip is enabled, making it in sending mode. The chip converts the TTL level signal input from the DI pin into a differential signal and sends it to the receiving end through the A and B signal lines, realizing long-distance transmission of data.

[0055] As a further optional embodiment, the first power supply filtering module includes a first magnetic bead and a first bypass capacitor to reduce the interference of high-frequency noise on the power supply line on the low-voltage receiving unit and stabilize the working voltage of the low-voltage receiving unit;

[0056] The second power filter module includes a second magnetic bead and a second bypass capacitor to reduce high-frequency noise on the power line and stabilize the working voltage of the low-voltage transmitting unit.

[0057] As a further optional embodiment, the first data protection unit and the second data protection unit each include a PTC thermistor and a transient suppression diode, which are used to protect the communication chip in the circuit from damage when the current is too large or the transient voltage is too high.

[0058] In this embodiment, the first data protection unit and the second data protection unit are respectively used for signal line protection in the receiving data module and the transmitting data module. Each data protection unit contains two PTC thermistors (SP1, SP2, SP3, and SP4) and two transient suppression diodes (U1, U2, U3, and U4), which work together to ensure that the communication chip is protected from overcurrent or transient voltage during operation.

[0059] Specifically, when the external circuit is short-circuited or overcurrent, the PTC thermistor will quickly heat up and increase the resistance, limiting the current flowing into the chip and preventing the chip from being burned out by overcurrent; when the external voltage abnormally rises, the transient suppression diode will conduct, quickly absorbing the high-voltage surge and leading it to the ground terminal, avoiding damage to the chip by high-voltage impact.

[0060] Specifically, in the receiving data module and the transmitting data module, one PTC thermistor is respectively connected in series on the positive and negative lines (A and B lines) of the signal, so that both lines can be protected at the same time when the current is too large.

[0061] Therefore, each data protection unit usually contains two PTC thermistors, which are respectively used to protect the two communication signal lines (A line and B line), thereby providing more comprehensive current protection. Similarly, the transient suppression diode is also correspondingly paired with each PTC thermistor, further improving the ability to resist transient voltage.

[0062] As a further optional embodiment, the first up-down pull resistance module includes a first pull-up resistor and a first pull-down resistor, the first pull-up resistor is connected to the first pin of the first signal transmission unit, and the first pull-down resistor is connected to the second pin of the first signal transmission unit.

[0063] Specifically, the first pull-up resistor R1 is connected between the first pin (A line) of the first signal transmission unit and the positive pole of the power supply, so that the A line remains in a high level state when there is no data transmission. The first pull-down resistor R2 is connected between the second pin (B line) of the first signal transmission unit and the ground, so that the B line remains in a low level state when there is no data transmission.

[0064] Similarly, the second pull-up resistor R3 is connected between the first pin (A line) of the second signal transmission unit and the positive pole of the power supply, so that the A line remains in a high level state when there is no data transmission. The second pull-down resistor R4 is connected between the second pin (B line) of the second signal transmission unit and the ground, so that the B line remains in a low level state when there is no data transmission.

[0065] As a further optional embodiment, the first signal transmission unit and the second signal transmission unit perform data transmission through an 8-core copper mesh wire.

[0066] Specifically, each core of the 8-core copper mesh wire is independently shielded, which can effectively reduce the interference between signals and improve the stability and anti-interference ability of data transmission. Using such a copper mesh wire for transmission can ensure multi-point control within a range of one kilometer in a classroom, conference room or the like without the need for a switch, thereby reducing the laying cost of the system.

[0067] Through such a design, not only can long-distance data transmission be supported, but also the reliability and real-time performance of communication can be ensured in a complex electromagnetic environment.

[0068] The beneficial effects of the utility model are as follows:

[0069] Stable power supply filtering: the receiving data module and the sending data module in the utility model each include a power supply filtering unit, through the configuration of a magnetic bead and a bypass capacitor, the interference of high-frequency noise on the power line on a low-voltage receiving unit and a sending unit is effectively reduced, it is ensured that a communication chip can stably work in a high-noise environment, and the stability and anti-interference ability of the entire communication system are improved.

[0070] Reliable data protection: the receiving and sending data modules are each configured with a data protection unit composed of a PTC thermistor and a transient suppression diode. When the current in the circuit is too large or the transient voltage is too high, the PTC thermistor can automatically limit the current, protecting the communication equipment from being damaged; the transient suppression diode can quickly clamp the excessively high voltage to a safe range, preventing the chip from being impacted by high voltage, thereby prolonging the service life of the equipment.

[0071] Stable signal transmission: in the receiving data and sending data module, the pull-up and pull-down resistance unit is configured, the signal line is stabilized at high level or low level state when idle, the problem of mis-triggering or noise interference caused by RS485 bus in idle state is avoided, and the communication reliability of the system is further improved.

[0072] Long distance transmission performance: the utility model discloses a data transmission is carried out with RS485 protocol, and through 8 core copper network line as signal transmission medium. This transmission mode not only has strong anti-interference ability, but also can realize long distance data transmission under the condition of keeping low error rate, is suitable for the scene of industrial automation and other needs wide range communication.

[0073] Modular design: the utility model discloses a receiving module and sending module are independently designed, so that the equipment can optimize the performance of receiving and sending respectively. In the receiving module, DE pin is grounded, to ensure that the equipment is always in receiving state, in the sending module, DE pin is connected to the positive pole of power supply, so that the equipment is always in sending state, the design of this mode reduces the state switching operation in communication, improves the data transmission efficiency.

[0074] Finally, it should be noted that: the above examples are used to illustrate the technical scheme of the utility model, but not limited to it; although the utility model is described in detail with reference to the foregoing examples, those skilled in the art should understand that: it still can modify the technical scheme recorded in the foregoing each embodiment, or equivalent replacement is carried out to part of technical features, and these modifications or replacements do not make the essence of corresponding technical scheme deviate from the spirit and scope of the technical scheme of each embodiment of the utility model.

Claims

1. A long-distance communication device, characterized in that: include: Receive data module and send data module; The data receiving module includes a first power supply filtering unit, a low voltage receiving unit, a first data protection unit, a first signal transmission unit and a first pull-up and pull-down resistor unit; The data sending module includes a second power supply filtering unit, a low voltage sending unit, a second data protection unit, a second signal transmission unit, and a second pull-up and pull-down resistor unit; The output end of the first signal transmission module is connected to the input end of the low voltage receiving unit through the first data protection unit and the first pull-up and pull-down resistor units. The output end of the low voltage receiving unit is connected to the microprocessor. The first power supply filter unit is connected to the low voltage receiving unit. The output end of the second signal transmission module is connected to the output end of the low voltage sending unit through the second data protection unit and the second pull-up and pull-down resistor units. The input end of the low voltage sending unit is connected to the microprocessor. The second power supply filter unit is connected to the low voltage sending unit.

2. The long-distance communication device according to claim 1, wherein: The low voltage receiving unit and the low voltage sending unit are both MAX485 chips.

3. The long-distance communication device according to claim 1, wherein: The DE pin of the low voltage receiving unit is grounded, so that the low voltage sending unit is in data receiving mode; the DE pin of the low voltage sending unit is connected to the positive pole of the power supply, so that the low voltage sending unit is in data sending mode.

4. The long-distance communication device according to claim 1, wherein: The first power supply filter unit includes a first magnetic bead and a first bypass capacitor to reduce the interference of high-frequency noise on the power line on the low-voltage receiving unit and stabilize the operating voltage of the low-voltage receiving unit; The second power supply filter unit includes a second magnetic bead and a second bypass capacitor to reduce interference of high-frequency noise on the power line on the low-voltage sending unit and stabilize the operating voltage of the low-voltage sending unit.

5. The long-distance communication device according to claim 1, wherein: The first data protection unit and the second data protection unit both include a PTC thermistor and a transient suppression diode. The PTC thermistor and the transient suppression diode are used to protect the communication chip in the circuit from damage when the current is too large or the transient voltage is too high.

6. The long-distance communication device according to claim 1, wherein: The first pull-up resistor unit includes a first pull-up resistor and a first pull-down resistor, the first pull-up resistor is connected to the first pin of the first signal transmission unit, and the first pull-down resistor is connected to the second pin of the first signal transmission unit.

7. The long-distance communication device according to claim 1, wherein: The first signal transmission unit and the second signal transmission unit perform data transmission via an 8-core copper network cable.

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