Plug and play in-cabinet networking method

Abstract

The application discloses a cabinet networking strategy of plug and play. In order to overcome the problem that the existing networking strategy cannot realize plug and play due to the mixed insertion and misinsertion of normal Ethernet communication interfaces and the difficulty in corresponding address allocation and record of slaves, the application comprises the following steps: defining pins of interfaces of power supply equipment and power application equipment, setting a mixed insertion protection circuit in the power supply equipment to judge the mixed insertion and correct the pin configuration; deploying a host in the cabinet and connecting the host to a server, connecting a slave to the host through a network cable, and completing the networking configuration of field equipment; after the configuration is completed, the host sets a default address of the slave equipment, sends a query instruction to the default address, the slave receives the query instruction, judges a bus busy state, and sends a reply instruction to the host, and the host completes automatic address allocation. The strategy can automatically allocate an address for the slave when the slave is accessed, can accurately detect misinsertion, and can realize the effect of plug and play.

Description

Technical Field

[0001] This invention relates to the field of Power over Ethernet (PoE), and more particularly to a plug-and-play cabinet networking method. Background Technology

[0002] Network cables are a common and low-cost prefabricated cable, convenient for installation in industrial sites. However, the networking strategy based on power supply through network ports plus RS485 communication has the following drawbacks: network ports are easily misused with Ethernet communication ports, which can damage Ethernet communication equipment; RS485 communication requires bus devices to be assigned unique and independent addresses, and existing address allocation methods are mostly cumbersome and not conducive to on-site installation.

[0003] RS485 is a single-bus, half-duplex data communication technology commonly used in industrial applications. It typically consists of one master and multiple slave devices, each with a unique and distinct address. Therefore, slave addresses need to be assigned individually. Common practices include adding DIP switches to the slave devices for manual setting, or using appropriate tools to send commands to the slave devices to modify the address assignment. Typically, the slave devices need to be re-networked after address assignment; otherwise, the master cannot send commands or data to the corresponding slave, and duplicate slave addresses may cause bus conflicts.

[0004] Existing industrial systems are evolving towards intelligence and digitalization, making the monitoring of the internal environment of industrial field cabinets a growing trend. There are various types of monitoring modules for this internal environment, and to facilitate installation, these modules are typically designed to be small in size with standardized and convenient interfaces. Current cabinet monitoring modules use Ethernet ports, defined for DC power supply (24VDC or 48VDC) and RS485 communication, with the master device providing power and communication to the slave device. However, they lack corresponding detection and protection mechanisms for mis-insertion or incorrect plugging.

[0005] For example, a method, system, Modbus master station, and Modbus slave station for automatic address allocation disclosed in Chinese patent literature (publication number CN108737590B) includes: a Modbus master station sending a broadcast command to set the address of all Modbus slave station devices to the same fixed address; then sending a broadcast command to read the serial number of the Modbus slave station devices; the Modbus slave station devices returning a response message to read the serial number of the Modbus slave station devices; the Modbus master station, based on the list of received Modbus slave station device serial numbers, sequentially broadcasting slave address setting commands containing the slave station device serial numbers and slave station addresses; the Modbus slave station devices parsing out the slave station device serial number and slave station address, and if the slave station device serial number is equal to its own serial number, it modifies its own slave station address to achieve automatic address allocation. Although this solution can achieve the function of automatic slave station address allocation, it cannot improve the handling of mixed insertions and errors, and therefore still has shortcomings. Summary of the Invention

[0006] This invention primarily addresses the problems of mixed and incorrect insertion of normal Ethernet communication interfaces and the cumbersome slave address allocation process in existing networking strategies, which prevent plug-and-play functionality. It provides a plug-and-play cabinet networking method. This invention proposes a method that allows module networking to be completed with a single interface. It utilizes the electrical short-circuit characteristics of differential signals in network transformers for mixed insertion detection and associated protection circuits. Furthermore, slave devices determine the bus idle state after waiting for a random period before responding to the command, avoiding bus conflicts. Simultaneously, it utilizes the unique ID number of the slave device's MCU to map the assigned address, achieving power-off recovery networking. After power failure, the slave device restores its default address, avoiding address confusion caused by the same device networking multiple times on different buses. This enables plug-and-play functionality during engineering deployment, significantly improving on-site networking efficiency and reducing project construction costs.

[0007] The above-mentioned technical problems of the present invention are mainly solved by the following technical solutions: This invention includes: defining the pins of the interfaces of the power supply device and the power application device; setting a mis-plug protection circuit in the power supply device to judge the mis-plug situation and correct the pin configuration; deploying a host in the rack and connecting it to the server; the slave devices are connected to the host via network cables to complete the network configuration of the field devices; after the configuration is completed, the host sets the default address of the slave device and sends a query command to the default address; after receiving the query command, the slave device judges the bus busy status and sends a reply command to the host, which completes the automatic address allocation; the network transformer at the Ethernet communication interface is electrically short-circuited between the twisted pairs through the network transformer, so when any slave device's network port is mis-connected, the host can complete the mis-plug judgment by detecting the short circuit between pins 3 and 6.

[0008] Preferably, the power supply device and the power application device are each equipped with four sets of pins. Two sets of pins [n4, n5, n7, n8] are configured for power supply, one set of pins [n1, n2] is configured to connect to the built-in 485 communication module of the module device for communication, and one set of pins [n3, n6] is configured to connect to the built-in mis-plug protection circuit to complete the mis-plug detection. In the rack site, the mis-plugging situation of the network port refers to the mis-plugging between the network port and the Ethernet communication port. When the network port of the slave device is mis-plugged, the master device can accurately detect the mis-plugging by detecting the short circuit between n3 and n6.

[0009] Preferably, in the mixed-intervention protection circuit, the POWER_IN terminal is connected to one end of Q1, and the other end of Q1 is connected to the POWER_OUT terminal. The end of Q1 connected to POWER_IN is connected in sequence to protection resistors R3 and R4, and then to one end of Q2. The other end of Q2 is connected to the other end of Q1 through protection resistor R2. One end of Q2 is connected to interface n3 through R4. A network transformer is located at [n3, n6]. During mixed-intervention detection, if a mixed-intervention occurs, the mixed-intervention protection circuit automatically pulls down the level at the base of Q2, thus making Q1 open-circuited and POWER_OUT outputless, thereby completing the judgment. If no mixed-intervention occurs, POWER_OUT maintains normal output. By controlling the output of POWER_OUT in actual scenarios through the mixed-intervention protection circuit, the mixed-intervention detection can be completed more accurately, quickly, and safely.

[0010] Preferably, the master sets a fixed default address for all slave devices and sends a query command to the default address to check if there is already a slave device on the bus waiting for an address. If so, the slave device waiting for an address receives the query command and listens to see if the bus is idle, i.e., whether other slave devices are responding. If the bus is idle, it waits for a random time t (generated by a random function) and checks the bus again to see if it is idle. If the bus is idle, it sends a response command to the master. The random time t is less than the set maximum waiting time T. These design features, such as the master checking the slave devices waiting for address allocation and the slave listening to the bus for idle status before entering the preparation state, can prevent the slave device waiting for an address from repeatedly requesting addresses from other slave devices, thus avoiding bus congestion. Setting a random waiting time for the slave device waiting for an address is to stagger the address allocation times of different slave devices, ensuring that slave address allocation proceeds in an orderly manner.

[0011] Preferably, after sending a query command, the host waits for a response command from the slave device, setting a host waiting time tz. When tz exceeds the bus idle time threshold Tz, the host stops waiting and the address allocation ends. The response command includes the ID number of the current slave device's MCU. If the host waits too long for a response command when allocating an address to a slave, the address allocation process will be temporarily suspended to avoid wasting allocation time. Therefore, this solution imposes a certain limit on the host waiting time to ensure address allocation efficiency.

[0012] Preferably, after receiving the response command from the slave device, the host checks its cache. The host determines the ID allocation status and prioritizes allocating an ID number already in the cache. If the ID has already been allocated and is not currently occupied, it is allocated the original address. This operation allows the original network topology to be restored during a system reboot. For newly added ID numbers, unallocated addresses are prioritized. If no unallocated address is available, a currently unoccupied address is allocated. The range of addresses that the host can allocate is preset by the system. If a device connection exceeds this range, the system reports an error. Address allocation priority follows the order of unallocated addresses and then unoccupied addresses, effectively ensuring that slave devices do not receive duplicate address allocations.

[0013] Preferably, the host sends an address allocation confirmation command to the slave device. After receiving the confirmation command, the slave device compares the ID number. If the ID number matches its own ID number, the slave device modifies the communication address and replies with an allocation confirmation message to the host. If they do not match, the slave device sends a rejection message to the host. After receiving the allocation confirmation message, the host confirms the address allocation and weakly binds the address to the slave device ID number. After receiving the rejection message, the host re-verifies the allocated address and sends the confirmation command to the slave device again. The host updates and stores the address-ID number mapping table. Each address corresponds to only one slave device ID number. Storing the most recent mapping relationship helps verify the unique correspondence between the slave device and the address and improves the efficiency of slave device access.

[0014] As a preferred configuration, each rack is equipped with one host unit. The host unit uses Ethernet communication and connects to the server via a switch. Slave devices do not require separate configuration; they connect to the host unit via network cables and communicate, uploading communication information to the system software. Slave devices do not require separate configuration; they simply plug into the network port to complete the network setup, achieving a plug-and-play effect and greatly improving on-site deployment efficiency. Furthermore, the system software can determine the correspondence between the slave device addresses and on-site slave modules by viewing the access time sequence or the model type of the connected devices, increasing the convenience of on-site operations.

[0015] The beneficial effects of this invention are: 1. The present invention provides a plug-and-play cabinet networking method that uses a pair of spare twisted-pair wires of the network cable and a misconnection protection circuit to perform misconnection detection when networking field devices. After detecting a misconnection, the power output is shut off in less than 100ms, which can avoid damage to network devices and greatly increase networking security.

[0016] 2. The plug-and-play cabinet networking method of the present invention completes the mixed insertion detection by designing a mixed insertion monitoring circuit. It only changes the current in the circuit and performs a power-off design. Therefore, even if the Ethernet port is mis-inserted, it will not damage other devices.

[0017] 3. The present invention provides a plug-and-play cabinet networking method. Based on the inherent ID number of the slave device MCU, an automatic addressing strategy is proposed to solve the drawbacks caused by the need to pre-set the address of field devices, realize single interface pairing, improve field deployment and maintenance efficiency, and achieve the effect of plug-and-play devices.

[0018] 4. The plug-and-play cabinet networking method of the present invention automatically allocates addresses by the host software in conjunction with the bus, without the need to pre-set device addresses. Through the three-way response and mutual cooperation of the host, bus and slave, addresses can be set quickly and efficiently while avoiding slaves from repeatedly requesting addresses, thus increasing the security of address allocation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the interface definition with mixed-plug protection for a plug-and-play cabinet networking method according to the present invention. Figure 2 This is a circuit diagram of a plug-and-play cabinet networking method according to the present invention for mixed plug protection; Figure 3 This is a flowchart of the automatic address allocation master device for a plug-and-play cabinet networking method according to the present invention; Figure 4 This is a flowchart of the automatic address allocation process for a plug-and-play cabinet networking method according to the present invention. Detailed Implementation

[0020] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0021] Example: This embodiment provides a plug-and-play cabinet networking method, such as... Figure 1 As shown, to simplify on-site networking, all slave device monitoring modules use the Ethernet port as the sole interface. Pins 4, 5, 7, and 8 of the Ethernet port are used for 24V power supply; pins 1 and 2 are used for RS-485 communication; pins 3 and 6 are used to detect short circuits and determine if there is any mis-insertion. The mis-insertion protection circuit is as follows: Figure 2As shown. In the mixed insertion protection circuit, the POWER_IN terminal is connected to Q1, and the other end of Q1 is connected to the POWER_OUT terminal. The end of Q1 connected to POWER_IN is connected to protection resistors R3 and R4 in sequence and then connected to one end of Q2. The other end of Q2 is connected to the other end of Q1 through protection resistor R2. One end of Q2 is connected to interface 3 through R4. Network transformers are provided at interfaces 3 and 6.

[0022] In the server rack environment, mixed-connection situations occur between Ethernet ports and other communication ports. When a mixed-connection situation occurs on a slave device's network port, the mixed-connection protection circuit automatically pulls down the voltage level at the base of Q2, causing Q1 to open-circuit and POWER_OUT to have no output, thus completing the judgment. If no mixed-connection situation occurs, POWER_OUT maintains normal output. The host can efficiently, accurately, and safely detect mixed-connection / mixed-connection situations by detecting a short circuit between pins 3 and 6. Furthermore, by designing a separate mixed-connection monitoring circuit to perform mixed-connection detection, only changing the current within the circuit and implementing a power-off design, even if the Ethernet port is misconnected, it will not damage other devices.

[0023] The on-site equipment networking process includes: one host unit is deployed in each rack, using Ethernet communication and connected to the server via a switch; slave devices do not require individual configuration, but connect to the host via network cables and communicate, uploading communication information to the system software. The environmental monitoring modules of the slave devices within the rack are connected to the host via network cables, internally powered, and use RS-485 communication. Slave devices can be directly plugged into the network port to complete the network setup, achieving a plug-and-play effect and greatly improving on-site deployment efficiency. The system software allows users to determine the correspondence between slave device addresses and on-site slave modules by viewing the access time sequence or the model type of the connected devices. The protocol can be customized internally, increasing the convenience of on-site operations.

[0024] like Figure 3 and Figure 4 The diagram illustrates the process by which the master automatically assigns addresses to the slave device. The specific steps are as follows: All slave devices are assigned a fixed address 0X01 by default. This address is not saved when power is lost, and the default fixed address is restored. Each time the network is reconnected and powered on, the master automatically assigns an address. The master periodically sends a query command to the default fixed address 0X01 to check if there are any new slave devices on the bus that need to be assigned an address, preventing multiple slave devices from being assigned addresses at the same time.

[0025] After receiving a query command from the master, the slave device awaiting address allocation first listens to see if the bus is idle, i.e., whether other slave devices are responding. If the bus is busy, it waits until the bus is idle; if the bus is idle, it continues to wait for a random time generated by a random function, which is no greater than the set maximum waiting time, and then checks the bus status again. If the bus is still idle, it sends a response command to the master, which includes the ID number of the slave device's MCU. After the master sends a query command, it continues to receive reply commands from the slave until the bus idle time exceeds the set threshold, which means that there are no other new devices waiting to be assigned addresses on the bus.

[0026] The master's monitoring of slave address allocation status on the bus and the slave's listening for bus idle status before entering the ready state both prevent bus congestion caused by slaves requesting addresses repeatedly from other slaves. Setting random wait times for slaves awaiting address allocation is to stagger the address allocation times of different slaves, ensuring that slave address allocation proceeds in an orderly manner.

[0027] The host assigns addresses based on the ID numbers returned by the slave devices: It queries the host cache, determines the ID allocation status, and prioritizes allocating ID numbers already in the cache. If an ID has already been allocated and is not currently occupied, the original address is allocated. This operation allows the original network topology to be restored during a system reboot. For newly added ID numbers, it prioritizes allocating addresses that have not yet been allocated. If no unallocated addresses are available, it allocates currently unoccupied addresses. The range of addresses that the host can allocate is preset by the system. If a device connects outside this range, the system reports an error. This operation allows the original network topology to be restored during a system reboot, and the address allocation priority follows the order of unallocated addresses and unoccupied addresses, effectively avoiding duplicate address allocation.

[0028] The address range that the host can assign can be initially set by the system. If a device outside the address range connects, the system will report an error. After selecting an address, the host sends an address assignment confirmation command. The slave device receives the confirmation command and compares it with its ID number. If the ID number matches its own ID number, it modifies the communication address and replies with an assignment confirmation message to the host. If they do not match, it sends a rejection message to the host. After receiving the assignment confirmation message, the host confirms the address assignment and weakly binds the address to the slave device ID number. After receiving the rejection message, the host re-verifies the assigned address and sends the confirmation command to the slave device again. The host updates and stores the address-ID number mapping table. Each address corresponds to only one slave device ID number. The most recent mapping relationship is stored, which helps verify the unique correspondence between the slave device and the address and improves the efficiency of slave device access.

[0029] It should be understood that the embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A plug-and-play cabinet networking method, characterized in that, include: S1: Define the pins of the power supply device and the power application device interface, configure a set of pins [n3, n6] to connect to the interlock protection circuit, set up the interlock protection circuit in the power supply device to judge the interlock situation and correct the pin configuration; in the interlock protection circuit, the POWER_IN terminal is connected to Q1, the other end of Q1 is connected to the POWER_OUT terminal, the end of Q1 connected to POWER_IN is connected to the protection resistors R3 and R4 in sequence and connected to one end of Q2, the other end of Q2 is connected to the other end of Q1 through the protection resistor R2; one end of Q2 is connected to interface n3 through R4; a network transformer is provided at [n3, n6]; S2: The host is deployed in the rack and connected to the server. The slave devices are connected to the host via network cables to complete the network configuration of the field devices. S3: After configuration is complete, the host sets the default address of the slave device and sends a query command to the default address. After receiving the query command, the slave device checks the bus busy status. If the bus is idle, it waits for a random time t and checks the bus idle status again. If the bus is idle, it sends a reply command to the host including the ID number of the current slave device MCU, and the host completes the automatic address allocation. After receiving the reply command from the slave device, the host checks the host cache. The host checks the ID allocation status and prioritizes allocating the ID number that is already in the cache. If the ID has been allocated and is not occupied, the original address is still allocated. For newly added ID numbers, priority is given to allocating unassigned addresses. If there are no unassigned addresses, then currently unused addresses are allocated.

2. The plug-and-play cabinet networking method according to claim 1, characterized in that, In S1, four sets of pins are set for the power supply device and the power application device respectively. Two sets of pins [n4, n5, n7, n8] are configured to be paired for power supply. One set of pins [n1, n2] is configured to connect to the built-in 485 communication module of the module device to complete communication. One set of pins [n3, n6] is configured to connect to the built-in mis-insertion protection circuit to complete the mis-insertion judgment.

3. The plug-and-play cabinet networking method according to claim 1, characterized in that, S3.1.1: The master sets a fixed default address for all slave devices and sends a query command to the default address to check if there are any new slave devices waiting to be assigned addresses on the bus; S3.1.2: If there are, the slave device waiting to be assigned an address receives the query command, listens to whether the bus is idle, and if the bus is idle, waits for a random time t and checks whether the bus is idle again. If the bus is idle, it sends a reply command to the master. The random time t is less than the set maximum waiting time T.

4. The plug-and-play cabinet networking method according to claim 3, characterized in that, S3.2: After the host sends a query command, it waits for the slave's reply command and sets the host waiting time tz. When tz is greater than the bus idle time threshold Tz, the host stops waiting and ends the allocation. The reply command includes the ID number of the current slave device MCU.

5. A plug-and-play cabinet networking method according to claim 3 or 4, characterized in that, The range of addresses that can be assigned to the host is preset by the system. If a device connects outside the address range, the system will report an error.

6. A plug-and-play cabinet networking method according to claim 5, characterized in that, S3.4.1: The master sends an address allocation confirmation command to the slave. After receiving the confirmation command, the slave compares the ID number. If the ID number matches its own ID number, the slave modifies the communication address and replies to the master with an allocation confirmation message. If they do not match, the slave sends a rejection message to the master. S3.4.2: After receiving the confirmation allocation message, the host determines the address allocation and weakly binds the address with the slave ID number. After receiving the rejection message, the host re-verifies the allocated address and sends the confirmation command to the slave again. S3.5: The host updates the mapping table of the stored address and ID number.

7. A plug-and-play cabinet networking method according to claim 1, characterized in that, In S2, one host is deployed in each rack. The host uses Ethernet communication and connects to the server through a switch. The slave devices are not configured separately. They connect to the host via network cables and communicate with it, uploading communication information to the system software.

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