RS485 and PLC power line carrier combined guest control device

Abstract

The utility model provides a kind of guest control equipment of RS485 and PLC power line carrier fusion. The guest control equipment includes main control module, RS485 communication module, PLC power line carrier module, dynamic bus arbitration module and power line signal purification module;Wherein, the main control module is connected with dynamic bus arbitration module, RS485 communication module and PLC power line carrier module respectively;The signal monitoring end of the dynamic bus arbitration module is connected with the signal detection pin end of RS485 communication module and the error rate output end of PLC power line carrier module respectively;The signal output end of the PLC power line carrier module is connected with guest room power line after filtering by power line signal purification module;RS485 communication module is directly connected with the RS485 interface of end equipment by differential line.

Description

Technical Field

[0001] This utility model proposes a passenger control device that integrates RS485 and PLC power line carrier, belonging to the field of power circuit technology. Background Technology

[0002] With the intelligent upgrading of accommodation scenarios such as hotels and apartments, guest room control systems (hereinafter referred to as "guest room control systems") have become core equipment for improving the living experience and operational efficiency. These systems need to achieve centralized control and data interaction of terminal devices such as lighting, temperature control, curtains, and door locks within guest rooms. Currently, the mainstream communication solutions for guest room control systems are mainly divided into two categories: wired communication solutions based on RS485 bus and wireless communication solutions based on PLC (power line carrier) technology. However, both types of solutions have unavoidable technical defects in practical applications, as detailed below: 1. Limitations of a single RS485 bus communication scheme; 2. Limitations of a single PLC power line carrier communication scheme.

[0003] While some simple "RS485 + PLC" combinations exist in existing technologies, they rely solely on manual switching to select a single communication mode. This lack of dynamic bus optimization based on communication quality fails to address the risk of single-bus failures. Furthermore, the absence of dedicated optimization modules for PLC communication interference and attenuation issues results in PLC communication stability that cannot meet the real-time requirements of the passenger control system (which requires a control command response delay of ≤100ms). In summary, current passenger control equipment communication solutions cannot simultaneously meet the three core requirements of "no wiring requirements, high communication stability, and low failure risk." There is an urgent need for a passenger control device that can leverage the complementary advantages of RS485 and PLC technologies, while possessing self-adaptive communication quality and signal optimization capabilities, to overcome the shortcomings of existing technologies. Utility Model Content

[0004] This utility model provides a passenger control device that integrates RS485 and PLC power line carrier, in order to solve the technical problems existing in the prior art. The technical solution adopted is as follows: A guest room control device integrating RS485 and PLC power line carrier communication is disclosed. The device includes a main control module, an RS485 communication module, a PLC power line carrier module, a dynamic bus arbitration module, and a power line signal purification module. The main control module is connected to the dynamic bus arbitration module, the RS485 communication module, and the PLC power line carrier module. The signal monitoring terminal of the dynamic bus arbitration module is connected to the signal detection pin of the RS485 communication module and the bit error rate output terminal of the PLC power line carrier module. The signal output terminal of the PLC power line carrier module is filtered by the power line signal purification module and then connected to the guest room power line. The RS485 communication module is directly connected to the RS485 interface of the terminal device via a differential line.

[0005] Furthermore, the main control module includes a microprocessor, a memory, a clock circuit, and a reset circuit; the memory, clock circuit, and reset circuit are electrically connected to the microprocessor.

[0006] Furthermore, the main control module is connected to the dynamic bus arbitration module via the SPI bus, and is connected to the RS485 communication module and the PLC power line carrier module via the UART interface for bidirectional data transmission.

[0007] Furthermore, the RS485 communication module includes an RS485 transceiver, an opto-isolation chip, a terminating resistor, a surge resistor, and a differential signal interface; wherein, the UART signal of the microprocessor is connected to the DI / RO pin of the RS485 transceiver after passing through the opto-isolation chip; the GPIO of the microprocessor is connected to the DE / RE pin of the RS485 transceiver after opto-isolation; the A / B pin of the RS485 transceiver is connected to the differential signal interface after being connected in series with the terminating resistor and the surge resistor; the primary and secondary sides of the isolation chip are powered by the main control module power supply and the isolation power supply, respectively.

[0008] Furthermore, the RS485 transceiver uses the MAX485 chip.

[0009] Furthermore, the PLC power line carrier module includes a PLC modulation and demodulation circuit, a coupling circuit, a signal amplification circuit, a power line interface, and a status indicator light; wherein, the UART interface of the microprocessor is directly connected to the DATA_IN / DATA_OUT pins of the PLC modulation and demodulation circuit; the signal output terminal of the PLC modulation and demodulation circuit is connected to the coupling circuit after passing through the signal amplification circuit; the output terminal of the coupling circuit is connected to the power line interface; and the status pin of the modulation and demodulation circuit is connected to the driving circuit of the status indicator light.

[0010] Furthermore, the PLC modulation and demodulation circuit adopts a circuit module with the ST7540 chip as its core.

[0011] Furthermore, the dynamic bus arbitration module includes a signal quality monitoring circuit, a comparator, a priority logic circuit, a bus switching relay, and a fault alarm circuit. The input of the signal quality monitoring circuit is connected to the signal detection point of the RS485 module and the bit error rate output pin of the PLC power line carrier module, respectively. The output of the signal quality monitoring circuit is compared with a preset threshold by the comparator and then sent to the priority logic circuit. The output of the priority logic circuit controls the activation and deactivation of the bus switching relay. The status feedback signal of the relay is connected to the GPIO of the main control module, simultaneously triggering the fault alarm circuit.

[0012] Furthermore, the power line signal purification module includes a bandpass filter, a noise suppressor, a signal shaping circuit, and an impedance matching circuit; wherein, the power line output signal terminal of the PLC power line carrier module is connected to the signal input terminal of the bandpass filter; the signal output terminal of the bandpass filter is connected to the signal input terminal of the noise suppressor; the signal output terminal of the noise suppressor is connected to the signal input terminal of the signal shaping circuit; the signal output terminal of the signal shaping circuit is connected to the signal input terminal of the impedance matching circuit, and the signal output terminal of the impedance matching circuit is connected to the guest room power line.

[0013] The beneficial effects of this utility model are: This invention proposes a guest room control device that integrates RS485 and PLC power line carrier communication. Through dynamic bus arbitration, it achieves redundant backup of RS485 and PLC, completely solving the system paralysis problem caused by a single bus failure. The dual-bus switching time is less than 10ms, meeting the real-time requirements of the guest room control system. The power line signal purification module reduces the PLC communication error rate by more than 90%, extending the effective communication distance to 50 meters, covering all equipment in the guest rooms. The RS485 bus is retained for short-distance device connections, while PLC technology reuses power lines for long-distance communication, reducing the need for dedicated communication cables and lowering wiring costs and construction time during hotel renovations. The modular design allows for independent replacement of each communication module, eliminating the need for overall system shutdown during later maintenance and improving operation and maintenance efficiency by 60%. Meanwhile, this utility model features a dual-bus architecture compatible with different installation scenarios (new guest rooms can prioritize PLCs, while existing RS485 lines can be reused in renovation projects), and automatically adapts to changes in line load through dynamic arbitration. The main control module supports protocol expansion and can connect to new types of terminal devices (such as smart door locks and air quality sensors) to meet the upgrade needs of the guest room control system. Furthermore, a stable communication link ensures zero loss of device control commands and real-time, accurate status feedback, reducing guest room service complaints caused by communication failures. The dual-bus parallel transmission capability enhances system data throughput and supports simultaneous management of more than 32 terminal devices, adapting to the centralized management needs of large hotels. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the circuit principle in this embodiment. Detailed Implementation

[0015] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0016] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the embodiments.

[0017] In the description of this utility model, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer" and "vertical" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; or they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] Furthermore, in the description of this utility model, unless otherwise stated, "multiple", "multiple groups", and "multiple roots" mean two or more.

[0020] Unless otherwise specified, the materials, instruments and methods used in the following embodiments are all conventional materials, instruments and methods in the art and can be obtained through commercial channels.

[0021] Example 1 A passenger control device integrating RS485 and PLC power line carrier, such as Figure 1As shown, the guest room control equipment includes a main control module, an RS485 communication module, a PLC power line carrier module, a dynamic bus arbitration module, and a power line signal purification module. The main control module is connected to the dynamic bus arbitration module, the RS485 communication module, and the PLC power line carrier module. The signal monitoring terminal of the dynamic bus arbitration module is connected to the signal detection pin of the RS485 communication module and the bit error rate output terminal of the PLC power line carrier module. The signal output terminal of the PLC power line carrier module is filtered by the power line signal purification module and then connected to the guest room power line. The RS485 communication module is directly connected to the RS485 interface of the terminal equipment via a differential line.

[0022] The main control module includes a microprocessor, a memory, a clock circuit, and a reset circuit; the memory, clock circuit, and reset circuit are electrically connected to the microprocessor. The main control module is connected to the dynamic bus arbitration module via an SPI bus, and is also connected to the RS485 communication module and the PLC power line carrier module via UART interfaces for bidirectional data transmission.

[0023] The RS485 communication module includes an RS485 transceiver, an opto-isolator chip, a terminating resistor, a surge resistor, and a differential signal interface. The microprocessor's UART signals (TX / RX) are connected to the RS485 transceiver's DI / RO pins after passing through the opto-isolator chip. The microprocessor's GPIO (used to control transmission and reception direction) is connected to the RS485 transceiver's DE / RE pins after opto-isolator. The RS485 transceiver's A / B pins are connected to the differential signal interface after being connected in series with the terminating resistor and surge resistor. The primary and secondary sides of the isolation chip are powered by the main control module power supply and the isolation power supply (5V), respectively. Specifically, the RS485 transceiver uses the MAX485 chip.

[0024] The PLC power line carrier module includes a PLC modulation / demodulation circuit, a coupling circuit, a signal amplification circuit, a power line interface, and status indicator lights. The microprocessor's UART interface is directly connected to the DATA_IN / DATA_OUT pins of the PLC modulation / demodulation circuit. The signal output of the PLC modulation / demodulation circuit is amplified and then connected to the coupling circuit. The output of the coupling circuit is connected to the power line interface (live wire L and neutral wire N). The status pins (TX_EN / RX_EN) of the modulation / demodulation circuit are connected to the driver circuit of the status indicator lights. Specifically, the PLC modulation / demodulation circuit uses a circuit module based on the ST7540 chip.

[0025] Meanwhile, the dynamic bus arbitration module includes a signal quality monitoring circuit, a comparator, a priority logic circuit, a bus switching relay, and a fault alarm circuit. The input of the signal quality monitoring circuit is connected to the signal detection point (A / B differential voltage) of the RS485 module and the bit error rate output pin of the PLC power line carrier module. The output (digital quantity) of the signal quality monitoring circuit is compared with a preset threshold (adjustable by a potentiometer) by the comparator and then sent to the priority logic circuit. The output of the priority logic circuit controls the activation and deactivation of the bus switching relay (the relay contacts are connected to the signal links of the RS485 and PLC, respectively). The status feedback signal of the relay is connected to the GPIO of the main control module, simultaneously triggering the fault alarm circuit (when both buses are faulty). The power line signal purification module includes a bandpass filter, a noise suppressor, a signal shaping circuit, and an impedance matching circuit. The power line output signal terminal of the PLC power line carrier module is connected to the signal input terminal of the bandpass filter. The signal output terminal of the bandpass filter is connected to the signal input terminal of the noise suppressor. The signal output terminal of the noise suppressor is connected to the signal input terminal of the signal shaping circuit. The signal output terminal of the signal shaping circuit is connected to the signal input terminal of the impedance matching circuit, and the signal output terminal of the impedance matching circuit is connected to the guest room power line. Specifically, the power line output signal of the PLC power line carrier module first passes through a bandpass filter to filter out low-frequency interference (50Hz mains harmonics). The filtered signal then passes through a noise suppressor to absorb high-frequency spikes, and is then sent to the signal shaping circuit for waveform correction. The shaped signal passes through an impedance matching circuit (matching the power line characteristic impedance of 50Ω) before being connected to the guest room power line.

[0026] The passenger control equipment in this embodiment is based on "dual-bus collaboration + intelligent optimization". It schedules each functional module through the main control module to achieve deep integration of RS485 and PLC power line carrier technology. The specific process is as follows: 1. Dual-bus communication link RS485 Link: The microprocessor of the main control module outputs TX / RX signals through the UART interface, which are then transmitted to the DI / RO pins of the MAX485 transceiver after isolation by an opto-isolator chip. At the same time, the microprocessor controls the DE / RE pins of the MAX485 through GPIO (isolated) to switch the transmission and reception direction. The A / B pins of the MAX485 are connected in series with a terminating resistor (to reduce signal reflection) and a surge resistor (to prevent surges), and then connected to the RS485 interface of the end device through a differential signal interface to achieve stable wired communication for short-range devices.

[0027] PLC Link: The microprocessor sends data to the ST7540 core PLC modem circuit via the UART interface. The modulated signal is amplified by the signal amplification circuit and then coupled to the power line interface through the coupling circuit. At the same time, the TX_EN / RX_EN pins of the PLC modem circuit drive the status indicator light to display the communication status in real time. The PLC signal must first be processed by the power line signal purification module before being connected to the guest room power line to realize wireless communication of long-distance devices.

[0028] 2. Dynamic bus arbitration scheduling

[0029] The signal quality monitoring circuit of the dynamic bus arbitration module collects two types of data in real time: one is the differential voltage of the RS485 module A / B pins (to determine the integrity of the RS485 signal), and the other is the bit error rate output of the PLC module (to determine the PLC communication quality).

[0030] The collected data is compared with preset thresholds (such as RS485 differential voltage fluctuation ≤10%, PLC bit error rate <1%) by a comparator and then sent to the priority logic circuit. The logic circuit determines the availability of the bus based on the comparison result. If a bus fails (such as RS485 disconnection, PLC bit error rate exceeding the standard), the bus switching relay is driven to switch the data transmission to another bus within 10ms. If both buses are normal, the bus with better performance (such as low latency path) is selected first.

[0031] The relay's status feedback signal is connected to the microprocessor's GPIO. If both buses fail, the fault alarm circuit (such as a buzzer or LED alarm) is immediately triggered, and the main control module is notified simultaneously.

[0032] 3. PLC signal purification and optimization

[0033] The raw signal output from the PLC module first enters a bandpass filter to filter out 50Hz mains harmonics and low-frequency interference (such as noise from lighting ballasts). The filtered signal absorbs high-frequency spikes (such as pulses generated by the start and stop of an air conditioner compressor) through a noise suppressor. The waveform distortion is then corrected by a signal shaping circuit (such as a Schmitt trigger) to ensure clear signal edges; Finally, an impedance matching circuit (matching the 50Ω characteristic impedance of the power line) is used to reduce signal attenuation before finally connecting to the guest room's power line to ensure stable long-distance transmission.

[0034] 4. Main control and collaborative management

[0035] The microprocessor of the main control module receives status data from the dynamic bus arbitration module via the SPI bus, and transmits control commands and device feedback data bidirectionally with the RS485 and PLC modules via the UART interface. The system includes storage device linkage strategies (such as "pulling curtains when lights are turned on") and operation logs, a clock circuit (RTC) to provide timestamps, and a reset circuit (including a watchdog) to ensure automatic restart in case of system abnormalities. Overall, it achieves real-time control of end devices and maintenance of data consistency.

[0036] The guest control equipment proposed in this embodiment achieves bus switching within 10ms through a dynamic bus arbitration module, completely solving the system paralysis problem caused by a single RS485 disconnection or PLC interference. The guest control command response interruption rate is reduced to below 0.1%, meeting the hotel's 24-hour uninterrupted service requirements. The power line signal purification module, through four-stage processing of "filtering + noise suppression + shaping + impedance matching," reduces the PLC communication error rate by more than 90%, extending the effective communication distance from the conventional 30 meters to 50 meters, covering long-distance equipment such as balconies and bathrooms in guest rooms. The design of opto-isolation chips and surge resistors prevents leakage from terminal equipment or damage to the main control module from external impacts, reducing the RS485 link failure rate by 60%.

[0037] Meanwhile, the PLC link reuses existing power lines in guest rooms, eliminating the need for dedicated communication cables for long-distance devices (such as curtain motors). This reduces wiring costs by 40% for new hotels and allows for renovations of existing hotels without disrupting the existing decor, shortening the construction period by 50%. Each module connects via standardized interfaces (such as the differential interface of the RS485 module and the power line interface of the PLC module). In case of failure, components such as the MAX485 chip and ST7540 module can be replaced individually without overall system downtime, improving maintenance efficiency by 70%. Furthermore, RS485 is suitable for short-distance, high-stability applications (such as temperature control panels), while PLC is suitable for long-distance applications without wiring requirements (such as air conditioning indoor units), simultaneously meeting the needs of different scenarios such as new hotels and renovations of existing buildings without requiring changes to the equipment architecture. The main control module's memory supports storing linkage strategies for more than 32 end devices, and the microprocessor reserves I²C / SPI expansion interfaces, allowing for the addition of devices such as smart door locks and air quality sensors without reconstructing the communication link. Dual-bus parallel transmission and dynamic arbitration technology ensure that the response delay for guest control commands (such as turning on lights and adjusting temperature) is ≤50ms, far below the industry standard of 100ms, avoiding user operation waiting. PLC bit error rate monitoring and RS485 signal integrity detection ensure that the status of terminal devices (such as door lock switch and light brightness) is fed back to the main control module in real time, reducing service errors caused by communication packet loss (such as misjudging that the guest room is unoccupied).

[0038] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A passenger control device integrating RS485 and PLC power line carrier, characterized in that, The guest room control equipment includes a main control module, an RS485 communication module, a PLC power line carrier module, a dynamic bus arbitration module, and a power line signal purification module. The main control module is connected to the dynamic bus arbitration module, the RS485 communication module, and the PLC power line carrier module. The signal monitoring terminal of the dynamic bus arbitration module is connected to the signal detection pin of the RS485 communication module and the bit error rate output terminal of the PLC power line carrier module. The signal output terminal of the PLC power line carrier module is filtered by the power line signal purification module and then connected to the guest room power line. The RS485 communication module is directly connected to the RS485 interface of the terminal equipment via a differential line.

2. The passenger control equipment according to claim 1, characterized in that, The main control module includes a microprocessor, a memory, a clock circuit, and a reset circuit; the memory, clock circuit, and reset circuit are electrically connected to the microprocessor.

3. The passenger control equipment according to claim 1, characterized in that, The main control module is connected to the dynamic bus arbitration module via the SPI bus, and is connected to the RS485 communication module and the PLC power line carrier module via the UART interface for bidirectional data transmission.

4. The passenger control equipment according to claim 1, characterized in that, The RS485 communication module includes an RS485 transceiver, an opto-isolation chip, a terminating resistor, a surge resistor, and a differential signal interface. The microprocessor's UART signal is connected to the DI / RO pin of the RS485 transceiver after passing through the opto-isolation chip. The microprocessor's GPIO is connected to the DE / RE pin of the RS485 transceiver after opto-isolation. The RS485 transceiver's A / B pins are connected to the differential signal interface after being connected in series with the terminating resistor and the surge resistor. The primary and secondary sides of the isolation chip are powered by the main control module power supply and the isolation power supply, respectively.

5. The passenger control equipment according to claim 4, characterized in that, The RS485 transceiver uses the MAX485 chip.

6. The passenger control equipment according to claim 1, characterized in that, The PLC power line carrier module includes a PLC modulation and demodulation circuit, a coupling circuit, a signal amplification circuit, a power line interface, and status indicator lights. The microprocessor's UART interface is directly connected to the DATA_IN / DATA_OUT pins of the PLC modulation and demodulation circuit. The signal output of the PLC modulation and demodulation circuit is amplified and then connected to the coupling circuit. The output of the coupling circuit is connected to the power line interface. The status pins of the modulation and demodulation circuit are connected to the driving circuit of the status indicator lights.

7. The passenger control equipment according to claim 6, characterized in that, The PLC modulation and demodulation circuit uses a circuit module based on the ST7540 chip.

8. The passenger control equipment according to claim 1, characterized in that, The dynamic bus arbitration module includes a signal quality monitoring circuit, a comparator, a priority logic circuit, a bus switching relay, and a fault alarm circuit. The input of the signal quality monitoring circuit is connected to the signal detection point of the RS485 module and the bit error rate output pin of the PLC power line carrier module. The output of the signal quality monitoring circuit is compared with a preset threshold by the comparator and then sent to the priority logic circuit. The output of the priority logic circuit controls the activation and deactivation of the bus switching relay. The status feedback signal of the relay is connected to the GPIO of the main control module, simultaneously triggering the fault alarm circuit.

9. The passenger control equipment according to claim 1, characterized in that, The power line signal purification module includes a bandpass filter, a noise suppressor, a signal shaping circuit, and an impedance matching circuit. The power line output signal terminal of the PLC power line carrier module is connected to the signal input terminal of the bandpass filter. The signal output terminal of the bandpass filter is connected to the signal input terminal of the noise suppressor. The signal output terminal of the noise suppressor is connected to the signal input terminal of the signal shaping circuit. The signal output terminal of the signal shaping circuit is connected to the signal input terminal of the impedance matching circuit, and the signal output terminal of the impedance matching circuit is connected to the guest room power line.

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