Pressing plate data transmission system for multi-terminal peer-to-peer real-time communication based on RS485 network

Abstract

The invention relates to a multi-end peer-to-peer real-time communication pressure plate data transmission system based on an RS485 network, which comprises a pressure plate data acquisition circuit, a peer-to-peer 485 interface circuit, an RS485 hard sending time control window circuit, a main control circuit, a power supply circuit and an indicator lamp circuit, the pressing plate data acquisition circuit is arranged below a monitored pressing plate, the pressing plate is provided with a magnet, the magnet and the pressing plate data acquisition circuit are located on the same axis, and the pressing plate data acquisition circuit is used for detecting the strength of a magnetic line of force of the hard pressing plate magnet installed on the protection screen cabinet penetrating through the Hall sensor so as to acquire the state of the hard pressing plate; the indicating lamp circuit adopts two red and green LED lamps and is used for indicating data transmission and pressing plate information reporting states. According to the RS485 bus communication network realized by the invention, polling is not needed when real-time data is uploaded once, only one second is needed when pressure plate data change is uploaded, and the communication time is prolonged by 956 times compared with that of a traditional mode.

Description

Technical Field

[0001] The present invention relates to the technical field of substation equipment data monitoring, and specifically to a pressure plate data transmission system based on RS485 network for multi-terminal peer-to-peer real-time communication. Background Art

[0002] With the increasing demand for electricity, the substation, as a core component of the power system, its safe and stable operation is crucial for ensuring power supply. The traditional substation equipment condition-based maintenance mainly relies on manual inspections and regular maintenance, which has problems such as low work efficiency, high risk, and high cost. Therefore, it has become an inevitable trend to introduce advanced monitoring technologies to achieve real-time monitoring, analysis, and prediction of the substation equipment status.

[0003] The data monitoring of substation equipment requires reliability, real-time performance, and accuracy. Based on these high requirements, most substation equipment currently uses an RS485 wired system to transmit data. The RS485 system is basically based on a master-slave structure, and the communication mechanism is that the master end initiates polling and the slave end responds. When there are many slave nodes connected to the master end, the real-time performance of the data will be greatly reduced, and the data response of this system is very slow. Summary of the Invention

[0004] The present invention mainly solves the problems that the data response time of the entire communication network during communication of the existing substation pressure plate equipment information acquisition and transmission equipment is uncontrollable and the invisible problems such as the increased cost caused by avoiding this problem. Therefore, a pressure plate data transmission system based on RS485 network for multi-terminal peer-to-peer real-time communication is proposed.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A pressure plate data transmission system based on RS485 network for multi-terminal peer-to-peer real-time communication, the system includes a pressure plate data acquisition circuit, a peer-to-peer 485 interface circuit, an RS485 hard transmission time control window circuit, a main control circuit, a power supply circuit, and an indicator light circuit:

[0007] The pressure plate data acquisition circuit includes a switch-type Hall sensor, which is arranged below the monitored pressure plate. The pressure plate is equipped with a magnet, and the magnet and the pressure plate data acquisition circuit are on the same axis, and is used to detect the intensity of the magnetic force line of the magnet passing through the Hall sensor installed on the hard pressure plate of the protection screen cabinet, so as to collect the status of the hard pressure plate;

[0008] The peer-to-peer 485 interface circuit is implemented by using RS485 communication mode and its GPIO pin interrupt monitoring;

[0009] The main control circuit uses a single-chip microcomputer with a 32-bit ARM architecture;

[0010] The power supply circuit uses a DCDC power supply to supply power to the communication node;

[0011] The indicator light circuit uses two red and green LED lights to indicate the data transmission and the status of the press plate information reporting.

[0012] As a further technical solution of the present invention, the main control circuit uses a 32-bit ARM architecture low-power MCU, with the model number FM33LC026N.

[0013] As a further technical solution of the present invention, when the node transmits the press plate data, the indicator light in the indicator light circuit will flash to indicate that the status has changed. After successful reporting, the indicator light will flash. If the reporting is not successful, the warning indicator light will flash.

[0014] As a further technical solution of the present invention, the network topology of the system has no central node, nor the distinction between the traditional master end and slave end. All nodes in the network have equal control rights over the network bus. Any node that needs to send data to other nodes on the bus only needs to monitor the bus status through the peer 485 interface circuit and use the bus as needed, and release the bus after use.

[0015] As a further technical solution of the present invention, the RS485 hard transmission time control window circuit serves to limit the time for each node to occupy the bus to send data through a hardware circuit. The longest transmission time for each node is configured by the resistance and capacitance parameters of the hardware circuit. When the required transmission time is less than the time controlled by the hardware, the node only needs to control the GPIO pin to output a low level to release the bus and make the node in the receiving state.

[0016] As a further technical solution of the present invention, the configuration parameter is that when the node needs to occupy the bus to send data, the GPIO outputs a high level. After circuit conversion, there will be a high-level window period of about 50 ms at the control direction end of the 485 chip. Then the hardware circuit will forcibly pull the control direction end of the 485 chip to a low level. The node needs to send the data within this 50-ms transmission window period;

[0017] The entire circuit achieves the control purpose through the charging and discharging of resistors and capacitors. The charging time T = RCIn((U - Uc) / U), and the discharging time T = RCIn(Uc / U). When the GPIO is at a high level, D3 conducts, and Q2 is in a non-conducting state. The current passes through D3 and the RC circuit to make Q1 conduct. When the GPIO is at a low level, due to the existence of D2, the charge in C1 quickly flows through D2 to the E pole of Q2. At this time, the E pole is about 0.7V. The existence of R4 makes the B of Q2 low, and Q2 conducts. The charge in C1 is quickly released through D2 and Q2. After the charge is released, both Q1 and Q2 are disconnected, thus ensuring the effective required window time for this circuit.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a pressure plate data transmission system for multi-terminal peer-to-peer real-time communication based on the RS485 network, which has higher real-time performance and accuracy of data transmission compared with the prior art. Taking a 110 kV substation as an example, for a traditional master-slave wired communication network, if there is 1 master node and multiple slave nodes, when the master queries the data of each slave node in one round, it needs to poll each slave node once. If it takes 1 second for each poll, then it takes 956 seconds (15.9 minutes) to poll 956 slave nodes. For the communication network implemented by the present invention, it does not need to poll when uploading real-time data once. When there is a change in the pressure plate data, it only takes 1 second to upload, which is 956 times faster than the traditional communication method. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a block diagram of a pressure plate data transmission system for multi-terminal peer-to-peer real-time communication based on the RS485 network.

[0020] Figure 2 It is the entire communication network topology diagram of a pressure plate data transmission system for multi-terminal peer-to-peer real-time communication based on the RS485 network.

[0021] Figure 3 It is the circuit diagram of the RS485 hard transmission time control window in a pressure plate data transmission system for multi-terminal peer-to-peer real-time communication based on the RS485 network. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] The embodiment of the present invention provides a pressure plate data transmission system for multi-terminal peer-to-peer real-time communication based on the RS485 network (hereinafter also referred to as a multi-terminal peer-to-peer communication network for convenience of description). The system includes a pressure plate data acquisition circuit, a peer-to-peer 485 interface circuit, an RS485 hard transmission time control window circuit, a main control circuit, a power supply circuit and an indicator light circuit:

[0024] The pressure plate data acquisition circuit includes a switch-type Hall sensor, which is arranged under the monitored pressure plate. The pressure plate is equipped with a magnet, and the magnet and the pressure plate data acquisition circuit are on the same axis, and are used to detect the intensity of the magnetic force line of the magnet passing through the Hall sensor installed in the protection panel cabinet hard pressure plate, so as to collect the state of the hard pressure plate;

[0025] The peer-to-peer 485 interface circuit is implemented by using the RS485 communication method and its GPIO pin interrupt monitoring;

[0026] The main control circuit uses a single-chip microcomputer with a 32-bit ARM architecture;

[0027] The power supply circuit uses a DCDC power supply to supply power to the communication nodes;

[0028] The indicator light circuit uses two red and green LED lights to indicate the data transmission and the status of the pressure plate information reporting.

[0029] In this embodiment, the main control circuit uses a low-power MCU with a 32-bit ARM architecture, and the model is FM33LC026N.

[0030] In this embodiment, please refer to Figure 1 , the indicator light circuit is used to indicate the status of the pressure plate data transmission. When the node transmits the pressure plate data, the indicator light in the indicator light circuit will flash to indicate that the status has changed. After the successful report, the indicator light will flash. If the report is not successful, the alarm indicator light will flash.

[0031] As Figure 2 shown is the entire communication network topology diagram of the pressure plate data transmission system for multi-terminal peer-to-peer real-time communication in the RS485 network. The network topology of the system has no central node and no distinction between traditional master and slave ends. All nodes in the network have equal control rights over the network bus. Any node that needs to send data to other nodes on the bus only needs to monitor the bus status through the peer 485 interface circuit and use the bus as needed, and release the bus after use. This bus network topology structure has very high real-time performance for data transmission, and the network system has strong scalability. Adding nodes does not affect the data response speed of the entire network.

[0032] As Figure 3 shown is the circuit diagram of the RS485 hard sending time control window. The RS485 hard sending time control window circuit plays a role in limiting the time for each node to occupy the bus when sending data through the hardware circuit, avoiding the hidden danger of long-term occupation of the bus caused by software algorithm control. Through the RS485 hard sending time control window circuit, the entire communication network is guaranteed high reliability from the hardware. The longest sending time of each node is configured by the resistance and capacitance parameters of the hardware circuit, and specific parameters can be set according to the requirements of the data transmission of the entire system. When the required sending time is less than the time controlled by the hardware, only software needs to control the GPIO pin to output a low level to make the node release the bus and make the node in the receiving state.

[0033] Currently, according to the actual application configuration parameters of the substation pressure plate monitoring data system, when a node needs to occupy the bus to send data, the GPIO outputs a high level. After circuit conversion, there will be a high-level window period of about 50 ms at the control direction end of the 485 chip. After that, the hardware circuit will force the control direction end of the 485 chip to be pulled low. The node needs to send all the data within this 50-ms sending window period. This circuit ensures that even if the GPIO pin of the MCU keeps outputting a high level to preempt the bus due to invisible reasons, the high level will not appear at the 485 transceiver end for a long time, thus preventing the entire network bus from being occupied by this node all the time, greatly improving the reliability of the entire network;

[0034] The entire circuit achieves the control purpose through resistor-capacitor charging and discharging. The charging time T = RCIn((U - Uc) / U), and the discharging time T = RCIn(Uc / U). When the GPIO is at a high level, D3 conducts, and Q2 is in the non-conducting state. The current passes through D3 and the RC circuit to make Q1 conduct. When the GPIO is at a low level, due to the existence of D2, the charge in C1 quickly flows through D2 to the E pole of Q2. At this time, the E pole is about 0.7 V. The existence of R4 makes the B of Q2 low, and Q2 conducts. The charge in C1 is quickly released through D2 and Q2. After the charge is released, both Q1 and Q2 are disconnected, thus ensuring the effective required window time for this circuit.

[0035] It should be noted that in this article, the term "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or device including a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article, or device. Without more limitations, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article, or device including that element.

[0036] The above is only the preferred embodiment of the present invention, and it does not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A multi-terminal peer-to-peer real-time communication platen data transmission system based on RS485 network, characterized in that: The system includes a platen data acquisition circuit, a peer-to-peer 485 interface circuit, an RS485 hard-send time control window circuit, a main control circuit, a power supply circuit and an indicator light circuit: The pressure plate data acquisition circuit includes a switch type Hall sensor, which is arranged below the monitored pressure plate. The pressure plate is equipped with a magnet, and the magnet and the pressure plate data acquisition circuit are located on the same axis, which is used to detect the strength of the magnetic force lines of the magnet installed on the hard pressure plate of the protection screen cabinet passing through the Hall sensor, so as to collect the state of the hard pressure plate; The peer-to-peer 485 interface circuit is implemented by RS485 communication mode and GPIO pin interrupt monitoring; The main control circuit adopts a 32-bit ARM architecture single-chip microcomputer; The power supply circuit uses a DCDC power supply to supply power to the communication node; The indicator light circuit uses two red and green LED lights to indicate the data transmission and pressure plate information reporting status.

2. A platen data transmission system based on multi-terminal peer-to-peer real-time communication of RS485 network according to claim 1, characterized in that: The main control circuit adopts a 32-bit ARM architecture low-power MCU, model FM33LC026N.

3. A platen data transmission system based on multi-terminal peer-to-peer real-time communication of RS485 network according to claim 1, characterized in that: When the node transmits the pressure plate data, the indicator light in the indicator light circuit will flash to indicate that the status has changed. The indicator light will flash after successful reporting, and the alarm indicator light will flash if the reporting is unsuccessful.

4. A platen data transmission system based on multi-terminal peer-to-peer real-time communication of RS485 network according to claim 1, characterized in that: The network topology of the system has no central node, and all nodes in the network have equal control over the network bus. Any node that needs to send data to other nodes on the bus only needs to monitor the bus status through the peer-to-peer 485 interface circuit and use the bus as needed, and release the bus after use.

5. A platen data transmission system based on multi-terminal peer-to-peer real-time communication of RS485 network according to claim 1, characterized in that: The RS485 hard sending time control window circuit plays the role of limiting the bus time occupied by each node to send data through the hardware circuit, wherein the maximum sending time of each node is configured by the resistance and capacitance parameters of the hardware circuit. When the required sending time is less than the time controlled by the hardware, the node can be released from the bus by simply controlling the GPIO pin to output a low level through software, so that the node is in a receiving state.

6. A platen data transmission system based on multi-terminal peer-to-peer real-time communication of RS485 network according to claim 5, characterized in that: The configuration parameters are that when the node needs to occupy the bus to send data, the GPIO outputs a high level. After the circuit conversion, there will be a high level window period of about 50ms at the 485 chip control direction end. After that, the hardware circuit will force the 485 chip control direction end to be pulled down. The node needs to send the data within this 50ms sending window period.

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