RS485 serial interface expansion circuit fusing internet of things technology

Abstract

This utility model discloses an RS485 serial interface expansion circuit integrating Internet of Things (IoT) technology, including a main control unit, a serial-to-parallel logic circuit, a multi-channel RS485 channel circuit, an IoT data processing circuit, and a power supply circuit. Both the serial-to-parallel logic circuit and the IoT data processing circuit are communicatively connected to the main control unit. The multi-channel RS485 channel circuit includes multiple RS485 interfaces, all of which are communicatively connected to the serial-to-parallel logic circuit. The power supply circuit provides operating voltage to the main control unit, the serial-to-parallel logic circuit, the multi-channel RS485 channel circuit, and the IoT data processing circuit. This utility model can solve the problems of insufficient interface quantity, signal conflict, high expansion cost, and inability to meet the intelligent monitoring needs of industrial IoT in existing technologies.

Description

Technical Field

[0001] This utility model relates to the field of industrial communication equipment technology, specifically to an RS485 serial interface extension circuit that integrates Internet of Things (IoT) technology. Background Technology

[0002] With the widespread application of IoT technology in the industrial sector, industrial automation control systems need to connect an increasing number of devices. RS485 serial communication technology, due to its strong anti-interference capabilities and long transmission distance, is still widely used in the industrial IoT for communication between various sensors, actuators, and other terminal devices and the data acquisition and control gateway. As a core device, the industrial data acquisition and control gateway needs to connect multiple devices with RS485 interfaces; however, traditional gateways have a limited number of RS485 interfaces, making it difficult to meet the needs of complex industrial IoT scenarios.

[0003] Existing expansion solutions mostly employ time-division multiplexing or external expansion chips, which present the following problems: First, there is a risk of signal collisions, as simultaneous communication by multiple devices can easily lead to bus conflicts, affecting data transmission stability. Second, hardware costs are high, as external expansion chips require additional circuitry, increasing design and maintenance complexity. Furthermore, existing technologies do not fully integrate the dynamic switching capabilities of logic circuits with the remote monitoring and data integration requirements of the Internet of Things (IoT), making it difficult to achieve flexible, low-cost interface expansion with IoT characteristics. Therefore, there is an urgent need for an efficient, reliable, and IoT-compliant multi-RS485 serial port expansion solution. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide an RS485 serial interface expansion circuit that integrates Internet of Things (IoT) technology, so as to solve the problems of insufficient number of interfaces, signal conflicts, high expansion costs, and inability to meet the intelligent monitoring needs of industrial IoT in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An RS485 serial interface expansion circuit integrating Internet of Things (IoT) technology includes a main control unit, a serial-to-parallel logic circuit, a multi-channel RS485 channel circuit, an IoT data processing circuit, and a power supply circuit. Both the serial-to-parallel logic circuit and the IoT data processing circuit are communicatively connected to the main control unit. The multi-channel RS485 channel circuit includes multiple RS485 interfaces, all of which are communicatively connected to the serial-to-parallel logic circuit. The power supply circuit provides operating voltage to the main control unit, the serial-to-parallel logic circuit, the multi-channel RS485 channel circuit, and the IoT data processing circuit.

[0007] The RS485 serial interface expansion circuit integrating Internet of Things (IoT) technology provided by this utility model has the following beneficial effects:

[0008] 1. Flexible interface expansion: Multiple RS485 interfaces can be expanded through low-cost serial-to-parallel logic circuits without the need for complex external chips, and it supports remote configuration and expansion for the Internet of Things.

[0009] 2. Strong anti-conflict capability: The dynamic switching mechanism effectively avoids bus contention, improves communication stability, and combined with IoT monitoring, it can provide real-time early warning of potential conflicts.

[0010] 3. Prominent IoT characteristics: Enables remote data acquisition, transmission, and intelligent monitoring; supports equipment management, data analysis, and remote control through an IoT platform, meeting the needs of industrial IoT application scenarios. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of an embodiment of the present utility model.

[0012] Figure 2 This is a circuit diagram of the main control unit in an embodiment of this utility model.

[0013] Figure 3 This is a wiring diagram of the serial-to-parallel logic circuit according to an embodiment of the present invention.

[0014] Figure 4 This is a circuit connection diagram of the multi-channel RS485 circuit according to an embodiment of the present invention.

[0015] Figure 5 This is a wiring diagram of the Internet of Things data processing circuit according to an embodiment of this utility model.

[0016] Figure 6 This is a power circuit wiring diagram of an embodiment of the present utility model. Detailed Implementation

[0017] The present invention will now be described in conjunction with the accompanying drawings. The specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Various modifications and improvements to the technical solutions of the present invention made by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope of the present invention.

[0018] like Figures 1 to 6As shown, the RS485 serial interface expansion circuit integrating IoT technology in this embodiment includes a main control unit, a serial-to-parallel logic circuit, a multi-channel RS485 channel circuit, an IoT data processing circuit, and a power supply circuit. The serial-to-parallel logic circuit and the IoT data processing circuit are both communicatively connected to the main control unit. The multi-channel RS485 channel circuit includes multiple RS485 interfaces, all of which are communicatively connected to the serial-to-parallel logic circuit. The power supply circuit provides operating voltage to the main control unit, the serial-to-parallel logic circuit, the multi-channel RS485 channel circuit, and the IoT data processing circuit.

[0019] The main control unit in this embodiment is used for data protocol parsing, communication scheduling, and data interaction with the Internet of Things (IoT) platform. It includes an ESP32 series microcontroller and peripheral circuits that communicate with the microcontroller. The peripheral circuits include a switch circuit, an indicator light circuit, and a pin header U2. The microcontroller has built-in edge computing algorithms and an IoT communication protocol stack.

[0020] The serial-to-parallel logic circuit of this embodiment is used to dynamically switch the communication channels of multiple RS485 interfaces and supports remote channel configuration based on IoT commands. It includes an SN74HC595DR multiplexer. In the circuit, the SER pin, RCLK pin and SRCLK pin of the SN74HC595DR multiplexer are connected to the IO32 pin, IO12 pin and IO14 pin of the microcontroller, respectively.

[0021] The multi-channel RS485 circuit in this embodiment includes four RS485 interfaces. All four RS485 interfaces use NSi83085E isolation chips, which are represented by U7, U15, U17 and U19 in the circuit. Each RS485 interface achieves signal isolation and selection with the main control module through a serial-to-parallel logic circuit. Each RS485 interface has a unique IoT device identifier, which facilitates device management under the IoT architecture. Specifically, the RE# and DE pins of chip U7 are connected to the QG and QH pins of the SN74HC595DR multiplexer, respectively; the RE# and DE pins of chip U15 are connected to the QE and QF pins of the SN74HC595DR multiplexer, respectively; the RE# and DE pins of chip U17 are connected to the QA and QB pins of the SN74HC595DR multiplexer, respectively; and the RE# and DE pins of chip U19 are connected to the QC and QD pins of the SN74HC595DR multiplexer, respectively.

[0022] The IoT data processing circuit in this embodiment is used to collect data from various RS485 interfaces, perform preliminary processing on the data, encapsulate it into data frames conforming to IoT communication protocols (such as MQTT), and upload it to the IoT platform. Simultaneously, it receives control commands from the IoT platform, parses them, and sends them to the corresponding RS485 interfaces. This circuit includes an NSI8221N0 chip and a MAX3232ESE chip. The NSI8221N0 chip is communicatively connected to both the MAX3232ESE chip and the main control unit. The INA and OUTB pins of the NSI8221N0 chip are communicatively connected to the IO15 and IO2 pins of the main control chip, respectively. The OUTA and INB pins of the NSI8221N0 chip are communicatively connected to the T2IN and R2OUT pins of the MAX3232ESE chip, respectively. The R2IN and T2OUT pins of the MAX3232ESE chip are used for communication with the IoT platform.

[0023] The power supply circuit in this embodiment includes a 12V DC voltage, a B1205S chip, and an AMS1117-3.3 chip. The input terminal of the B1205S chip is communicatively connected to the 12V DC voltage, specifically the Vin pin of the B1205S chip. The B1205S chip converts the 12V DC voltage to a 5V DC voltage, and its output terminal outputs a 5V DC voltage. This output is also communicatively connected to the input terminal of the AMS1117-3.3 chip, specifically the +Vo pin of the B1205S chip, which outputs a 5V DC voltage, and the VIN pin of the AMS1117-3.3 chip. The AMS1117-3.3 chip converts the 5V DC voltage to a 3.3V DC voltage, and its output terminal outputs a 3.3V DC voltage, specifically the VOUT pin.

[0024] The RS485 serial interface extension circuit integrating Internet of Things technology in this embodiment works as follows:

[0025] 1. The main control unit dynamically allocates communication permissions for the RS485 interface through serial-to-parallel conversion logic circuits based on communication protocols, device priorities, and intelligent scheduling strategies issued by the IoT platform.

[0026] 2. The serial-to-parallel logic circuit adopts time-division multiplexing (TDM) or event-triggered mechanism to avoid signal conflicts caused by multiple devices accessing the bus at the same time. It also supports remote adjustment of time-division multiplexing parameters or event trigger thresholds through the Internet of Things platform.

[0027] 3. The IoT data processing circuit collects data from each RS485 interface in real time, performs format conversion and data fusion, and uploads the integrated data to the IoT platform to realize remote monitoring and data analysis.

[0028] 4. The IoT platform can send control commands to the main control unit according to preset rules. After parsing, the main control unit selects the corresponding RS485 interface to send the commands through the serial-to-parallel logic circuit, thereby realizing remote control of the terminal device.

[0029] The test results of the RS485 serial interface extension circuit integrating IoT technology in this embodiment are as follows:

[0030] After expansion, it supports simultaneous access of 8 RS485 devices, with a baud rate of up to 115200bps and a data upload latency of ≤500ms to the IoT platform.

[0031] The bus collision rate is reduced to below 0.1%, the communication latency is ≤10ms, and the command response time of the IoT platform is ≤2s.

[0032] The cost of each RS485 communication channel is significantly reduced after expansion, and remote operation and maintenance of equipment is realized through the Internet of Things platform, reducing maintenance costs by more than 30%.

[0033] The RS485 serial interface extension circuit integrating Internet of Things (IoT) technology in this embodiment has the following advantages:

[0034] 1. Flexible interface expansion: Multiple RS485 interfaces can be expanded through low-cost logic circuits without the need for complex external chips, and it supports remote configuration and expansion for the Internet of Things.

[0035] 2. Strong anti-conflict capability: The dynamic switching mechanism effectively avoids bus contention, improves communication stability, and combined with IoT monitoring, it can provide real-time early warning of potential conflicts.

[0036] 3. Strong compatibility: Supports mainstream industrial protocols such as Modbus and Profibus, adapts to a variety of devices, and can be seamlessly connected to various IoT platforms.

[0037] 4. Prominent IoT characteristics: Enables remote data collection, transmission, and intelligent monitoring; supports equipment management, data analysis, and remote control through an IoT platform, meeting the needs of industrial IoT application scenarios.

[0038] 5. High cost-effectiveness: While reducing hardware expansion costs, it enhances the overall value of equipment and management efficiency by leveraging IoT technology, resulting in significant economic benefits.

Claims

1. An RS485 serial interface expansion circuit integrating Internet of Things (IoT) technology, characterized in that, It includes a main control unit, a serial-to-parallel logic circuit, a multi-channel RS485 circuit, an IoT data processing circuit, and a power supply circuit. The serial-to-parallel logic circuit and the IoT data processing circuit are both communicatively connected to the main control unit. The multi-channel RS485 circuit includes multiple RS485 interfaces, all of which are communicatively connected to the serial-to-parallel logic circuit. The power supply circuit provides operating voltage to the main control unit, the serial-to-parallel logic circuit, the multi-channel RS485 circuit, and the IoT data processing circuit.

2. The RS485 serial interface expansion circuit integrating Internet of Things technology according to claim 1, characterized in that, The main control unit includes an ESP32 series microcontroller.

3. The RS485 serial interface expansion circuit integrating Internet of Things technology according to claim 1, characterized in that, The serial-to-parallel logic circuit includes an SN74HC595DR multiplexer.

4. The RS485 serial interface expansion circuit integrating Internet of Things technology according to claim 1, characterized in that, The multi-channel RS485 circuit includes four RS485 interfaces, all of which use NSi83085E isolation chips.

5. The RS485 serial interface expansion circuit integrating Internet of Things technology according to claim 1, characterized in that, The IoT data processing circuit includes an NSI8221N0 chip and a MAX3232ESE chip. The NSI8221N0 chip is communicatively connected to the MAX3232ESE chip and the main control unit, respectively.

6. The RS485 serial interface expansion circuit integrating Internet of Things technology according to claim 1, characterized in that, The power supply circuit includes a 12V DC voltage, a B1205S chip, and an AMS1117-3.3 chip. The input terminal of the B1205S chip is communicatively connected to the 12V DC voltage, and its output terminal is used to output a 5V DC voltage and is communicatively connected to the input terminal of the AMS1117-3.3 chip. The output terminal of the AMS1117-3.3 chip is used to output a 3.3V DC voltage.

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