Protection system for conveyor

Abstract

The utility model discloses a protection system for a conveyor, which belongs to the technical field of conveyor comprehensive protection, and comprises an embedded comprehensive protection instrument, a PLC (programmable logic controller) and a plurality of address encoders, the embedded comprehensive protection instrument is in communication connection with the PLC, the embedded comprehensive protection instrument is electrically connected with the address encoders through two non-polar POWERBUS buses, all the address encoders are connected in parallel with the POWERBUS buses, and the POWERBUS buses are electrically connected with the embedded comprehensive protection instrument. The physical form of the POWERBUS bus is an unshielded twisted pair, due to the fact that the POWERBUS bus with the two-core cable is adopted, compared with an RS485 bus, at least two-core cables can be saved, the length of a single belt conveyor can reach thousands of meters, the cost of the cable can be greatly reduced, the POWERBUS bus adopts the carrier signal communication principle, the anti-interference capacity is high, and the service life of the POWERBUS bus is prolonged. Good signal stability can be realized only by using the unshielded twisted pair, and a shielded cable is required by a bus scheme based on RS485, so that the communication stability under the same cable condition is higher.

Description

Technical Field

[0001] This utility model belongs to the field of comprehensive protection technology for conveyors, and specifically relates to a protection system for conveyors. Background Technology

[0002] Currently, the address encoders and integrated protection devices used in the field of belt conveyor integrated protection typically communicate using RS485. The communication cable is a four-core cable, with two cores for communication and two cores for power supply. Power supply and communication are independent of each other. The power supply voltage is usually 24V. Shielded twisted-pair cables are usually required as communication cables. Without adding a repeater, the maximum communication distance is 1200m. The core part of the PCB is a single-chip microcomputer combined with an RS485 signal conversion circuit. Master-slave communication usually uses a polling mechanism, resulting in a slow alarm response time, which usually exceeds 1 second. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a protection system for conveyors that can achieve rapid alarm response, effectively improve transmission distance, and reduce cable and construction costs.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0005] A protection system for a conveyor includes: an embedded protection device, a PLC, and multiple address encoders. The embedded protection device is communicatively connected to the PLC. The embedded protection device is electrically connected to the address encoders via two non-polar POWERBUS buses. All the address encoders are connected in parallel to the POWERBUS buses. The physical form of the POWERBUS bus is unshielded twisted pair cable.

[0006] Furthermore, the embedded integrated protection device includes a housing, a power supply module, a signal control module, an embedded main control module, and a serial port screen. The power supply module is connected to the signal control module, the embedded main control module is connected to both the signal control module and the serial port screen, the signal control module is connected to the POWERBUS bus, and the embedded main control module is communicatively connected to the PLC.

[0007] Furthermore, the signal control module includes: a main communication circuit with preemptive communication function, a step-down filter circuit, a power signal modulation and demodulation circuit, and a main communication feedback circuit. The main communication circuit is connected to the embedded main control module via serial communication. The main communication circuit is connected to the power supply module through the step-down filter circuit and to the POWERBUS bus through the power signal modulation and demodulation circuit.

[0008] Furthermore, the embedded main control module includes a main control core circuit, at least three sets of USART peripheral interfaces, and at least one set of RS485 / TTL circuit. The main control core circuit is connected to the main communication circuit via a serial port through one set of the USART peripheral interfaces, to the serial port screen through another set of the USART peripheral interfaces, and to the RS485 / TTL circuit through yet another set of the USART peripheral interfaces. The RS485 / TTL circuit is connected to the PLC.

[0009] Furthermore, the main control core circuit includes a No. 1 main control chip and a No. 2 main control chip. The pins PB6 and PB7 of the No. 1 main control chip are connected to the main communication circuit through a set of USART peripheral interfaces. The pins PA1 and PA2 of the No. 1 main control chip are connected to the RS485 / TTL circuit through another set of USART peripheral interfaces. The No. 2 main control chip is connected to the pins PB6 and PB7 of the No. 1 main control chip through two rx pins in two other sets of USART peripheral interfaces. The No. 2 main control chip is connected to the serial port screen through yet another set of USART peripheral interfaces.

[0010] Furthermore, the address encoder includes: a top cover, a housing, a circuit board, a gland, and a hinge. The top cover and the housing are respectively connected to the hinge by bolts, the gland is connected to the housing by threads, and the circuit board is installed inside the housing.

[0011] Furthermore, the circuit board includes: a DC / DC step-down circuit, a rectification and signal modulation circuit, a slave communication circuit with preemptive communication function, and a core control circuit. The DC / DC step-down circuit and the rectification and signal modulation circuit are respectively connected to the POWERBUS bus. The core control circuit is electrically connected to the DC / DC step-down circuit and the slave communication circuit. The slave communication circuit is connected to the rectification and signal modulation circuit.

[0012] Furthermore, the circuit board also includes peripheral control circuitry, which includes digital tube circuitry or DIP switch circuitry.

[0013] Furthermore, the communication circuit includes a communication chip and a communication feedback circuit.

[0014] Furthermore, the rectification and signal modulation circuit includes a rectification and voltage regulation circuit, a resistor voltage divider circuit, and a transistor driving circuit. The rectification and voltage regulation circuit consists of a fuse, a Zener diode, and a rectifier bridge.

[0015] After adopting the above technical solution, the beneficial effects of this utility model are:

[0016] The protection system for conveyors disclosed in this utility model uses a POWERBUS bus with two-core cables, which saves at least two cores of cable compared to an RS485 bus. Since a single conveyor belt can be several kilometers long, this application can significantly reduce cable costs. Furthermore, the POWERBUS bus uses a carrier signal communication principle, which has strong anti-interference capabilities. It only requires unshielded twisted-pair cables to achieve good signal stability, while RS485-based bus solutions require shielded cables. Therefore, this application has higher communication stability under the same cable conditions.

[0017] In this invention, the POWERBUS bus based on the master communication circuit and slave communication circuit has a preemptive communication function, which can realize that the address encoder uplink information is in a certain priority order. By setting the number order to the priority order, it can ensure that at least the high priority alarm signal is not lost under extreme working conditions (different slaves act simultaneously within 20ms). Under normal circumstances, if one set of alarms is triggered, the machine will stop. Therefore, it has sufficient redundancy for practical application scenarios.

[0018] In this invention, the address encoder has a rectifier bridge, eliminating the need to distinguish the connection order between the address encoder and the POWERBUS bus, thereby effectively reducing construction costs. Attached Figure Description

[0019] Figure 1 This is a structural block diagram of the protection system for the conveyor in this application;

[0020] Figure 2 This is a bus layout diagram of the protection system for the conveyor in this application;

[0021] Figure 3 This is a schematic diagram of the step-down filter circuit for the signal control module.

[0022] Figure 4 This is the schematic diagram of the main communication circuit of the signal control module;

[0023] Figure 5 This is a schematic diagram of the power signal modulation and demodulation circuit for the signal control module.

[0024] Figure 6 This is the schematic diagram of the main communication feedback circuit of the signal control module;

[0025] Figure 7 This is the circuit schematic of the No. 1 main control chip of the embedded main control module;

[0026] Figure 8 This is the circuit schematic of the No. 2 main control chip in the embedded main control module;

[0027] Figure 9Schematic diagram of RS485 / TTL conversion circuit for embedded main control module;

[0028] Figure 10 This is a diagram of the external structure of the address encoder;

[0029] Figure 11 This is a diagram of the internal structure of an address encoder;

[0030] Figure 12 Schematic diagram of a DC / DC step-down circuit for an address encoder;

[0031] Figure 13 This is a schematic diagram of the rectification and signal modulation circuit for an address encoder.

[0032] Figure 14 This is a schematic diagram of the slave communication circuit for an address encoder.

[0033] Figure 15 This is the schematic diagram of the core control circuit of the address encoder;

[0034] Figure 16 This is a schematic diagram of the peripheral control circuit for an address encoder.

[0035] In the diagram, 1-Embedded integrated protection device, 2-PLC, 3-POWERBUS bus, 4-Address encoder, 41-Top cover, 42-Housing, 43-Circuit board, 44-Glander head, 45-Hinge, 46-Fasting bolt. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the textual part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0037] like Figure 1 and Figure 2 As shown, a protection system for a conveyor includes: an embedded protection device 1, a PLC 2, and multiple address encoders 4. The embedded protection device 1 is communicatively connected to the PLC 2 to achieve linkage with other industrial control systems. The embedded protection device 1 is electrically connected to the address encoders 4 via two non-polarity POWERBUS buses 3. The embedded protection device 1 is connected to the POWERBUS buses 3 to transmit carrier signals and provide DC voltage. All address encoders 4 are connected in parallel to the POWERBUS buses 3. No polarity distinction is required during wiring, supporting any form of parallel bus topology.

[0038] When the address length of address encoder 4 is set to one byte, address encoder 4 acts as a slave station, with a maximum of 255 slave stations connected to each bus, numbered from 001 to 255. All slave stations draw power from the bus, which serves as both a power supply cable and a communication cable. Downlink communication signals are transmitted from embedded protection unit 1 to address encoder 4, and uplink communication signals are transmitted from address encoder 4 to embedded protection unit 1. The physical form of POWERBUS bus 3 is unshielded twisted pair cable, with a theoretical maximum bus voltage of 48V.

[0039] The embedded integrated protection device 1 includes a housing, a power module, a signal control module, an embedded main control module, and a serial port screen. The serial port screen is mounted on the surface of the housing, while the power module, signal control module, and embedded main control module are installed inside the housing. The housing protects the internal components. 220V AC power is used as the system power supply. The power module takes in 220V AC power and outputs 48V DC power. The power module is connected to the signal control module, and the embedded main control module is connected to both the signal control module and the serial port screen. The signal control module is connected to the POWERBUS bus 3, and the embedded main control module communicates with PLC 2.

[0040] Specifically, the functions of each part in the embedded integrated protection device 1 are as follows: the signal control module is directly connected to the power supply module to obtain the system operating voltage; the signal control module is directly connected to the embedded main control module to realize communication and power supply between the two, the signal is transmitted through the serial port, and the power supply is 5V; the embedded main control module is directly connected to the serial port screen, the signal is transmitted through the serial port, and the power supply is 5V.

[0041] like Figures 3 to 6 As shown, the signal control module includes: a main communication circuit with preemptive communication function, a step-down filter circuit, a power signal modulation and demodulation circuit, and a main communication feedback circuit. The main communication circuit is connected to the embedded main control module via serial communication. The main communication circuit is connected to the power supply module via the step-down filter circuit and to the POWERBUS bus 3 via the power signal modulation and demodulation circuit.

[0042] Specifically, the step-down filter circuit steps down and filters the 48V output voltage from the power module, providing 5V and 3.3V operating voltages for the system. The main communication circuit consists of the PB621 chip and its peripheral circuits, serving as the main control circuit for signal conversion. The PB621 chip provides an external communication interface via a pair of serial port pins, RX and TX, connecting to the embedded main control module for serial communication. The power signal modulation and demodulation circuit primarily uses two parallel MOSFETs, Q1 and Q2, to achieve modulation, and a circuit composed of transistors T4 and T5 to perform preliminary sampling. The modulated signal is then output to the POWERBUS bus 3 via the interface. The main communication feedback circuit uses LEDs to provide real-time feedback on the power supply and communication status.

[0043] The signal control module works as follows: the PB621 chip in the main communication circuit communicates with the embedded main control module via a serial port, with a baud rate of 9600bps. During downlink data transmission, the PB621 chip receives the signal from the embedded main control module, modulates the voltage signal through the peripheral circuit, and transmits it to the POWERBUS bus 3. During uplink data transmission, the current signal on the POWERBUS bus 3 is converted by the peripheral circuit, the PB621 chip acquires the signal, and transmits the signal to the embedded main control module via the serial port.

[0044] like Figures 7 to 9 As shown, the embedded main control module includes a main control core circuit and at least three sets of USART peripheral interfaces for data transmission and reception in three directions. PLC 2 needs to have an RS485 or other interface, which can communicate with the microcontroller via serial port after signal conversion. In this application, PLC 2 and the embedded main control module preferably communicate via an RS485 bus. Therefore, the embedded main control module also needs to include at least one RS485 / TTL circuit, which is connected to PLC 2 for communication between the microcontroller and PLC 2. The main control core circuit can use an STM32 series or other type of microcontroller. The main control core circuit is connected to the main communication circuit via a USART peripheral interface, to the serial port screen via another USART peripheral interface, and to the RS485 / TTL circuit via yet another USART peripheral interface.

[0045] The RS485 / TTL conversion circuit can achieve power supply voltage isolation through an isolation transformer and signal isolation through an optocoupler, and convert the TTL signal to an RS485 signal through an SP485 chip.

[0046] PLC 2 also has at least another RS485 communication interface for industrial control systems. The action signals obtained by PLC 2 through the embedded integrated protection device 1 can be used to control the start and stop of the actuator or to transmit alarm signals to other systems to realize the function of system linkage.

[0047] Specifically, this application preferably uses a dual STM32 microcontroller solution, and the main control core circuit includes, for example: Figure 7 The No. 1 main control chip U22 shown and Figure 8 The second main control chip, U23, is shown. Both main control chips use STM32F103C8T6 chips. The first main control chip, U22, serves as the core signal transceiver unit, used to issue broadcast and polling commands and receive feedback commands. It is used to realize communication between the embedded main control module and the signal control module. Pins PB6 and PB7 of the first main control chip, U22, are connected to the main communication circuit through a set of USART peripheral interfaces. Pins PA1 and PA2 of the first main control chip, U22, are connected to the RS485 / TTL circuit through another set of USART peripheral interfaces, transmitting signals to the RS485 / TTL circuit and then to PLC 2.

[0048] The second main control chip, U23, is connected to pins PB6 and PB7 of the first main control chip, U22, via two RX pins from two other sets of USART peripheral interfaces. The second main control chip, U23, communicates with the serial screen via another set of USART peripheral interfaces. The second main control chip, U23, reads the communication content of the first main control chip, U22, without disturbing the communication of the first main control chip, U22, or experiencing any additional delay. After processing the information, it communicates with the serial screen. This scheme can minimize the signal processing time of the first main control chip, U22, thereby improving the system's response speed.

[0049] like Figure 11 and Figure 12 As shown, the address encoder 4 includes: a top cover 41, a housing 42, a circuit board 43, a gland 44, and a hinge 45. The top cover 41 has a sealing strip and fastening bolts 46. The top cover 41 can be locked to the housing 42 by the fastening bolts 46 for easy installation. The sealing strip provides a seal. The top cover 41 and the housing 42 are respectively connected to the hinge 45 by bolts to prevent the top cover 41 from falling out when the cover is opened. The gland 44 is connected to the housing 42 by threads. The gland 44 has a cable hole to seal the cable. The circuit board 43 is the core functional component, installed inside the housing 42, and directly connected in parallel to the POWERBUS bus 3. It draws power through bus communication and does not need to distinguish between positive and negative terminals when connected. The housing 42 provides support and protection for the internal components.

[0050] like Figures 12 to 15As shown, the circuit board 43 includes: a DC / DC step-down circuit, a rectification and signal modulation circuit, a slave communication circuit with preemptive communication function, and a core control circuit. The DC / DC step-down circuit and the rectification and signal modulation circuit are respectively connected to the POWERBUS bus 3. The core control circuit is electrically connected to the DC / DC step-down circuit and the slave communication circuit. The slave communication circuit is connected to the rectification and signal modulation circuit.

[0051] Specifically, the DC / DC step-down circuit uses the ZH7463 chip, with an input voltage range of 5V to 52V and an output voltage of 3.3V, serving as the operating voltage for the core control circuit. The rectification and signal modulation circuit includes a rectification and regulation circuit, a resistor divider circuit, and a transistor driver circuit. The rectification and regulation circuit consists of a fuse U1, a Zener diode D1, and a rectifier bridge D2. The rectification and signal modulation circuit rectifies the voltage of the POWERBUS bus 3 to provide system power to the circuit board 43, and modulates and acquires the signal through the subsequent transistor and resistor divider circuit.

[0052] The core control circuit consists of an STM32 microcontroller minimum system, including the STM32F030K6T6 microcontroller chip and its peripheral circuitry. It acquires input I / O signals, processes data, and controls output. A reset button is provided, allowing manual reset after the switch sensor connected to address encoder 4 is activated, or a reset of all address encoders 4 can be performed by powering down the POWERBUS bus 3.

[0053] The communication circuit includes a communication chip and a communication feedback circuit. The communication chip is a PB332 chip, which is the core control component for signal conversion. It has a preemption control pin, and the core control circuit controls the transmitted signal format. Together with the PB621 chip in the embedded integrated protection device 1, it realizes a communication mode with preemption functionality. The PB332 chip communicates with the STM32F030K6T6 microcontroller via a USART peripheral interface serial port. The output pins of the STM32F030K6T6 microcontroller control whether the PB332 chip outputs a preemption signal to prevent uplink signal corruption. The communication feedback circuit uses LEDs to provide real-time feedback on the power supply and communication status.

[0054] like Figure 16 As shown, circuit board 43 also includes peripheral control circuitry, which includes either a digital tube circuit or a DIP switch circuit. In practical applications, one of these circuits is selected for use. In this application, a digital tube circuit is preferred as the peripheral control circuitry.

[0055] Based on extensive engineering experience, feedback indicates that on-site construction personnel often have limited knowledge and struggle to master the use of binary DIP switches. Furthermore, address encoders cannot be pre-coded before being fixed, making binary DIP switches unsuitable for on-site construction when there are many address encoders. Similarly, the DIP method for infrared remote controls has drawbacks; for example, infrared diodes must emit infrared signals within a specific angle for successful communication, and setting addresses is cumbersome and inconvenient for on-site construction. Therefore, this application preferably uses a four-digit common cathode LED display combined with a mobile terminal and ST-Link for address programming. The mobile terminal uses ST-Link software to program the address content, achieving address fixing. Wired connection provides more stable information transmission and is simpler to operate than infrared remote control solutions; only the corresponding hex or bin file needs to be found for one-click programming. Modifications only require re-programming the corresponding file. Additionally, the address encoder in this solution is equipped with an LED display, providing direct feedback on program programming success. Therefore, the address fixing solution provided by this invention has significant advantages in facilitating on-site construction.

[0056] Overall, the main communication flow of this application is as follows:

[0057] (1) The No. 1 main control chip in the embedded main control module of the embedded integrated protection device 1 is used as the system main control to send broadcast requests and polling requests;

[0058] (2) The No. 1 main control chip in the embedded main control module transmits the signal to the PB621 chip in the signal control module through a serial port.

[0059] (3) The PB621 chip and its peripheral circuit in the signal control module are connected to the power signal modulation and demodulation circuit, which modulates the serial port signal received by the PB621 chip into a bus signal and transmits it to the POWERBUS bus 3.

[0060] (4) The modulated signal is transmitted to each address encoder 4 via the POWERBUS bus 3. Each address encoder 4 demodulates and samples the modulated signal on the bus through a unified rectification and signal modulation circuit.

[0061] (5) The PB332 chip converts the signal, converts the modulation signal on the bus into a TTL signal, and transmits the signal to the microcontroller of the address encoder 4 through the direct serial port.

[0062] (6) The microcontroller of address encoder 4 judges and processes the received signal, and outputs a response signal or silence signal in combination with the sampled signal;

[0063] (7) When the address encoder 4 microcontroller outputs a response signal, the signal is transmitted to the PB332 chip via the serial port, and the microcontroller controls whether to reply with the preemption signal.

[0064] (8) The PB332 chip transmits the TTL signal to the rectification and signal modulation circuit of the address encoder 4, modulates the response signal and transmits it to the POWERBUS bus 3.

[0065] (9) The modulated response signal is transmitted to the signal control module of the embedded integrated protection instrument 1. After demodulation, the PB621 chip obtains the response signal and converts it into a TTL format signal. Through serial communication, the response signal is transmitted back to the No. 1 main control chip of the embedded main control module to complete the most important signal transmission and reception function.

[0066] This application achieves extremely fast alarm response speed through a master-slave interaction method of broadcast combined polling. The measured alarm response speed is about 14ms-30ms, while the alarm response time of the polling scheme based on RS485 bus can exceed 1 second. It can be seen that the slowest alarm response time of this application is only about 30ms, which is significantly better than the polling scheme based on RS485 bus.

[0067] The protection system for conveyors of this utility model connects an embedded integrated protection device to the address encoders via two non-polar POWERBUS buses. All address encoders are connected in parallel to the POWERBUS buses. The embedded integrated protection device communicates with the PLC. The POWERBUS bus uses a two-core cable, which can significantly reduce cable costs. Furthermore, the POWERBUS bus uses a carrier signal communication principle, which has strong anti-interference capabilities and higher communication stability under the same cable conditions.

[0068] In the description of this specification, unless otherwise expressly defined, the terms "setup", "installation", "connection", etc. should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in combination with the specific content of the technical solution.

[0069] While specific embodiments of this utility model have been described above, those skilled in the art should understand that the described embodiments are merely some, not all, embodiments of this utility model. These are merely illustrative examples, and the scope of protection of this utility model is defined by the claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model and without any inventive effort, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A protection system for a conveyor, characterized in that, include: The system includes an embedded protection device, a PLC, and multiple address encoders. The embedded protection device is communicatively connected to the PLC. The embedded protection device is electrically connected to the address encoders via two non-polar POWERBUS buses. All the address encoders are connected in parallel to the POWERBUS buses, which are in the form of unshielded twisted-pair cables.

2. The protection system for conveyors according to claim 1, characterized in that, The embedded integrated protection device includes a housing, a power supply module, a signal control module, an embedded main control module, and a serial port screen. The power supply module is connected to the signal control module, the embedded main control module is connected to both the signal control module and the serial port screen, the signal control module is connected to the POWERBUS bus, and the embedded main control module is communicatively connected to the PLC.

3. The protection system for conveyors according to claim 2, characterized in that, The signal control module includes: a main communication circuit with preemptive communication function, a step-down filter circuit, a power signal modulation and demodulation circuit, and a main communication feedback circuit. The main communication circuit is connected to the embedded main control module via serial communication. The main communication circuit is connected to the power supply module through the step-down filter circuit and to the POWERBUS bus through the power signal modulation and demodulation circuit.

4. The protection system for conveyors according to claim 3, characterized in that, The embedded main control module includes a main control core circuit, at least three sets of USART peripheral interfaces, and at least one set of RS485 / TTL circuit. The main control core circuit is connected to the main communication circuit via serial communication through one set of the USART peripheral interfaces, to the serial screen via another set of the USART peripheral interfaces, and to the RS485 / TTL circuit via yet another set of the USART peripheral interfaces. The RS485 / TTL circuit is connected to the PLC.

5. The protection system for conveyors according to claim 4, characterized in that, The main control core circuit includes a No. 1 main control chip and a No. 2 main control chip. The pins PB6 and PB7 of the No. 1 main control chip are connected to the main communication circuit through a set of USART peripheral interfaces. The pins PA1 and PA2 of the No. 1 main control chip are connected to the RS485 / TTL circuit through another set of USART peripheral interfaces. The No. 2 main control chip is connected to the pins PB6 and PB7 of the No. 1 main control chip through two rx pins in two other sets of USART peripheral interfaces. The No. 2 main control chip is connected to the serial port screen through yet another set of USART peripheral interfaces.

6. The protection system for a conveyor according to any one of claims 1 to 5, characterized in that, The address encoder includes: a top cover, a housing, a circuit board, a gland, and a hinge. The top cover and the housing are respectively connected to the hinge by bolts, the gland is connected to the housing by threads, and the circuit board is installed inside the housing.

7. The protection system for a conveyor according to claim 6, characterized in that, The circuit board includes: a DC / DC step-down circuit, a rectification and signal modulation circuit, a slave communication circuit with preemptive communication function, and a core control circuit. The DC / DC step-down circuit and the rectification and signal modulation circuit are respectively connected to the POWERBUS bus. The core control circuit is electrically connected to the DC / DC step-down circuit and the slave communication circuit. The slave communication circuit is connected to the rectification and signal modulation circuit.

8. The protection system for a conveyor according to claim 7, characterized in that, The circuit board also includes peripheral control circuitry, which includes digital tube circuitry or DIP switch circuitry.

9. The protection system for a conveyor according to claim 7, characterized in that, The communication circuit includes a communication chip and a communication feedback circuit.

10. The protection system for a conveyor according to claim 7, characterized in that, The rectification and signal modulation circuit includes a rectification and voltage regulation circuit, a resistor voltage divider circuit, and a transistor drive circuit. The rectification and voltage regulation circuit consists of a fuse, a Zener diode, and a rectifier bridge.

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