Extended IO module fault communication system and method based on double bus PLC

Abstract

The application discloses an extended IO module fault communication system and method based on a double-bus PLC, comprising a PLC controller, a plurality of extended IO modules and terminal modules; the PLC controller serves as a control port of the whole system and is used for acquiring input voltage and output voltage of a sampling resistor reported by each node of the extended IO modules, performing state monitoring of each module according to the input voltage and the output voltage, determining the number of fault extended IO modules and the positions of the fault extended IO modules, collecting analog and digital signals by the extended IO modules, receiving monitoring results output by the PLC commands, processing faults according to the monitoring results, determining the positions and the number of fault modules by processing voltage data in a communication process, switching a bus network through a control switch, and skipping the fault modules, so that subsequent extended IO modules can realize bus communication and do not affect normal functions.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and specifically to a fault communication system and method for extended I / O modules based on a dual-bus PLC. Background Technology

[0002] PLCs are the main controller devices in industrial automation, commonly used in equipment control in industrial manufacturing, aerospace, and power industries. They employ programmable memory to execute logic operations, timing, motion control, and other operational instructions internally. Simultaneously, PLCs acquire analog and digital signals through their own or extended I / O modules, and control other equipment through these modules.

[0003] In existing PLC solutions, the PLC itself has limited I / O resources, requiring the use of expanded I / O modules to obtain more data acquisition and control resources. Most existing PLCs and expanded I / O modules use CAN bus or CANFD bus, but the maximum baud rate of CAN bus is 1Mbps, and that of CANFD bus is 10Mbps. Considering the application scenarios of PLCs and expanded I / O modules, and to reduce communication cables, the LVDS communication between PLCs and expanded I / O modules mainly uses a 2-transmit, 2-receive interface. However, after expansion, the communication rate can reach 100Mbps. The expanded I / O uses single-wire transmission, which offers the advantages of rapid expansion and high cable utilization. However, during transmission, the signal must pass through each chip sequentially to reach the designated location. In this linear transmission scenario, if one I / O expansion module fails, it will affect the communication of subsequent modules, leading to communication interruption and thus communication failure. Summary of the Invention

[0004] The technical problem this invention aims to solve is that signals must pass through each chip sequentially. When one I / O expansion module fails, it affects the communication of subsequent modules, causing communication interruption and thus a communication failure. The goal is to provide a fault communication system and method for expansion I / O modules based on a dual-bus PLC. By processing voltage data during communication, the location and number of faulty modules are determined. The bus network is then switched by controlling a SWITCH switch to skip the faulty module, allowing subsequent expansion I / O modules to achieve bus communication without affecting their normal function.

[0005] This invention is achieved through the following technical solution:

[0006] The first aspect of the present invention provides a fault communication system for extended I / O modules based on a dual-bus PLC, including a PLC controller, several extended I / O modules and a terminal module;

[0007] The PLC controller serves as the control port for the entire system, receiving sampled data from each extended I / O module, monitoring the communication status of each extended I / O module, and commanding the corresponding extended I / O module to perform corresponding actions.

[0008] The extended I / O module serves as an analog / digital input / output channel for the PLC, used to acquire analog and digital signals, receive monitoring results from PLC command outputs, and handle faults based on the monitoring results.

[0009] Furthermore, the PLC controller includes a main CPU, a first communication chip, a slave MCU2 of the PLC controller, and a reference voltage source;

[0010] The main CPU is connected to the first communication chip and the slave MCU2 of the PLC controller, respectively;

[0011] The main CPU is used to process the data received by the first communication chip and output the processed data to the first communication chip.

[0012] The first communication chip is used to receive data from the main CPU and forward it to the high-speed bus network;

[0013] The slave MCU2 of the PLC controller is used to manage the network status of each module in the extended IO module, and to isolate and skip the slave MCU2 of the faulty extended IO module according to the network status.

[0014] The reference voltage source is used to power the sampling resistor of the subsequent series-connected extended IO module.

[0015] Furthermore, the extended I / O module includes a main MCU1, a second communication chip, a slave MCU2 of the extended I / O module, switches SW1-SW4, and sampling resistors;

[0016] The main MCU1 is used to communicate with the second communication chip, and forward the collected data to the high-speed bus network through the second communication chip, and receive corresponding data output from the bus network;

[0017] The second communication chip is used to send and receive bus data and communicate with the main MCU1 to forward field data;

[0018] The switches SW1-SW4 are single-pole double-throw (SPDT) switches used to switch the bus, skip the faulty module and establish communication with the next module.

[0019] The slave MCU2 of the extended IO module is used to send the network status of this module, the status of the second communication chip and the status of the master MCU1, and is also used to control the switches SW1-SW4 to switch the bus.

[0020] Each of the extended I / O modules includes a sampling resistor, and the voltage system of the sampling resistor is used to determine the number of extended I / O modules and the location of the faulty extended I / O module.

[0021] Furthermore, the main MCU1 is connected to the second communication chip, the main MCU1 is connected to the slave MCU2, and the slave MCU2 is connected to switches SW1-SW4 respectively; the slave MCU2 is connected to the input and output terminals of the sampling resistor respectively.

[0022] The second communication chip is connected to switches SW1-SW4 respectively. Among switches SW1-SW4, switches SW1-SW2 are connected to the output of the previous level expansion IO module or PLC high-speed bus, and switches SW3-SW4 are connected to the input of the next level expansion IO module high-speed bus.

[0023] Furthermore, controlling the switches SW1-SW4 of the extended I / O module includes:

[0024] When a fault is detected in this extended I / O module, the MCU2 slave of the extended I / O module controls the SW1-SW4 switches to switch directions, connecting the adjacent module above the faulty module with the next module to establish communication.

[0025] Furthermore, it also includes a high-speed bus and a low-speed bus, wherein the high-speed bus is used for application data communication and the low-speed bus is used for network management.

[0026] Furthermore, the extended I / O module is also used to report the high-speed bus status, the second communication chip status, and the main MCU1 status of the extended I / O module to the PLC controller via the low-speed bus, and at the same time receive commands from the PLC controller to control the switches SW1-SW4 of the extended I / O module.

[0027] Furthermore, the PLC controller's slave MCU2 and each extended IO module are connected to the low-speed bus via the slave MCU2.

[0028] The first communication chip is connected in series with each of the extended I / O modules until it is connected to the last extended I / O module.

[0029] Furthermore, the extended I / O module also includes a termination module, which serves as the last extended module for placing the bus termination resistor and the last grounded sampling resistor.

[0030] The second aspect of this invention provides a fault communication method for extended I / O modules based on a dual-bus PLC, applied to a fault communication system for extended I / O modules based on a dual-bus PLC, comprising the following specific steps:

[0031] Obtain the input and output voltages of the sampling resistors reported by each node of the extended I / O module;

[0032] The status of each module is monitored based on the input and output voltages to determine the number and location of the faulty extended I / O modules.

[0033] Based on the number and location of the faulty extended I / O modules, a switching control command is issued to switch the bus network and restore communication for subsequent extended I / O modules.

[0034] Furthermore, determining the number of faulty extended I / O modules includes:

[0035] Obtain the input voltage of the sampling resistor from the extended I / O module. Output voltage and the reference voltage of the PLC controller The number of extended I / O modules was calculated. ;

[0036] Determining the location of the faulty extended I / O module includes:

[0037] Obtain the location number of the nearest extended I / O module of the PLC controller, and so on until the last extended I / O module. .

[0038] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0039] By processing the voltage data during the communication process, the location and number of faulty modules are determined. The bus network is then switched by controlling the SWITCH switch to skip the faulty modules, thus enabling subsequent expansion IO modules to achieve bus communication without affecting their normal functions.

[0040] By employing a high-speed and low-speed bus scheme, with the high-speed bus used for application data communication and the low-speed bus used for network management, the dual-redundant bus communication scheme solves the problem of network management being impossible after a single high-speed bus interruption. This achieves separation of application data and network management data, improving network management capabilities.

[0041] By using sampling resistors connected in series to sample the voltage across each extended I / O module, the location of the extended I / O module and the fault point can be determined. This method is characterized by high efficiency and fast response. Even in the event of a high-speed bus fault, it can remain unaffected and still report the location of the faulty extended I / O module. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0043] Figure 1 For existing extended I / O modules;

[0044] Figure 2 This is a fault communication method in an embodiment of the present invention;

[0045] Figure 3 This is a fault communication system in an embodiment of the present invention;

[0046] Figure 4 This is the extended I / O module in the embodiments of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are only for explaining this invention and are not intended to limit this invention.

[0048] like Figure 1 The existing technology shown depicts various extended I / O modules connected via an LVDS bus. Each extended I / O module's LVDS communication chip employs a 2-transmit, 2-receive scheme: RX1 and TX1 communicate with the preceding extended I / O module, while RX2 and TX2 communicate with the next extended I / O module. Communication data flows in from extended I / O module 1. Extended I / O module 1 determines if it receives the data it needs; if not, it forwards the data to the next extended I / O module. After forwarding, extended I / O module 2 receives the data, determines if it receives the data it needs, and if so, retains it; otherwise, it continues forwarding the data to the next extended I / O module, and so on, completing the entire communication process.

[0049] Such a communication network has a drawback: when one of the extended I / O modules fails, for example, if extended I / O module 2 fails, then extended I / O modules 3 and 4 will be unable to establish a communication connection with the master PLC, resulting in extended I / O modules 3 and 4 going offline, thus affecting their normal function and data communication.

[0050] As one possible implementation method, such as Figure 3As shown, the first aspect of this embodiment provides a fault communication system for extended I / O modules based on a dual-bus PLC, including a PLC controller, several extended I / O modules, and a terminal module;

[0051] The PLC controller serves as the control port for the entire system, receiving sampled data from various extended I / O modules, monitoring the communication status of each extended I / O module, and commanding the corresponding extended I / O modules to perform corresponding actions.

[0052] The extended I / O module serves as an analog / digital input / output channel for the PLC, used to acquire analog and digital signals, receive monitoring results from PLC command outputs, and handle faults based on the monitoring results.

[0053] In some possible implementations, the PLC controller includes a main CPU, a first communication chip, a slave MCU2 of the PLC controller, and a reference voltage source;

[0054] The main CPU is connected to the first communication chip and the slave MCU2 of the PLC controller, respectively;

[0055] The main CPU is used to process the data received by the first communication chip and output the processed data back to the first communication chip.

[0056] The first communication chip is used to receive data from the main CPU and forward it to the high-speed bus network;

[0057] The slave MCU2 of the PLC controller is used to manage the network status of each module in the extended IO module, and to isolate and skip the slave MCU2 of the faulty extended IO module according to the network status.

[0058] The reference voltage source is used to power the sampling resistor of the extended I / O module connected in series in the subsequent stage.

[0059] In some possible implementations, such as Figure 4 As shown, the extended I / O module includes a main MCU1, a second communication chip, a slave MCU2 of the extended I / O module, switches SW1-SW4, and sampling resistors;

[0060] The main MCU1 is used to communicate with the second communication chip, and forwards the collected data to the high-speed bus network through the second communication chip, and receives the corresponding data output from the bus network;

[0061] The second communication chip is used to send and receive bus data and communicate with the main MCU1 to forward field data.

[0062] Switches SW1-SW4 are single-pole double-throw (SPDT) switches used to switch the bus, skipping faulty modules and establishing communication with the next module;

[0063] The slave MCU2 of the extended IO module is used to send the network status of this module, the status of the second communication chip and the status of the master MCU1, and is also used to control the switches SW1-SW4 to switch the bus.

[0064] Each extended I / O module includes a sampling resistor. The voltage system of the sampling resistor is used to determine the number of extended I / O modules and the location of the faulty extended I / O module. The sampling resistor value is the same for all extended I / O modules.

[0065] In some possible implementations, the main MCU1 is connected to the second communication chip, the main MCU1 is connected to the slave MCU2 of the extended IO module, the slave MCU2 of the extended IO module is connected to switches SW1-SW4 respectively; the slave MCU2 of the extended IO module is connected to the input and output terminals of the sampling resistor respectively.

[0066] The second communication chip is connected to switches SW1-SW4 respectively. Among switches SW1-SW4, switches SW1-SW2 are connected to the output of the previous level expansion IO module or PLC high-speed bus, and switches SW3-SW4 are connected to the input of the next level expansion IO module high-speed bus.

[0067] In some possible implementations, controlling the switches SW1-SW4 of the extended I / O module includes:

[0068] When a fault is detected in this extended I / O module, the MCU2 slave of the extended I / O module controls the SW1-SW4 switches to switch directions, connecting the adjacent module above the faulty module with the next module to establish communication.

[0069] In some possible implementations, a high-speed bus and a low-speed bus are also included, with the high-speed bus used for application data communication and the low-speed bus used for network management.

[0070] In some possible implementations, the high-speed bus can be LVDS, and the low-speed bus can be CAN.

[0071] In some possible implementations, the extended I / O module is also used to report the high-speed bus status, the second communication chip status, and the main MCU1 status of the extended I / O module to the PLC controller via a low-speed bus, and at the same time receive commands from the PLC controller to control the switches SW1-SW4 of the extended I / O module.

[0072] In some possible implementations, the PLC controller's slave MCU2 and each of the extended I / O modules are connected to a low-speed bus from MCU2.

[0073] The first communication chip is connected in series with each of the extended I / O modules until it is connected to the last extended I / O module.

[0074] In some possible implementations, the extended I / O module also includes a termination module, which serves as the last extension module for placing the bus termination resistor and the last grounded sampling resistor.

[0075] As one possible implementation method, such as Figure 2 As shown, the second aspect of this embodiment provides a fault communication method for an extended I / O module based on a dual-bus PLC, including the following specific steps:

[0076] Obtain the input and output voltages of the sampling resistors reported by each node of the extended I / O module;

[0077] The status of each module is monitored based on the input and output voltages to determine the number and location of the faulty extended I / O modules.

[0078] Based on the number and location of the faulty extended I / O modules, a switching control command is issued to switch the bus network and restore communication for subsequent extended I / O modules.

[0079] in,

[0080] The number of extended I / O modules that were identified as faulty includes:

[0081] Obtain the input voltage of the sampling resistor from the extended I / O module. Output voltage and the reference voltage of the PLC controller The number of extended I / O modules was calculated. ;

[0082] Determining the location of the faulty extended I / O module includes:

[0083] Obtain the location number of the nearest extended I / O module of the PLC controller, and so on until the last extended I / O module. ;

[0084] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fault communication system for extended I / O modules based on a dual-bus PLC, characterized in that, Includes a PLC controller, several expansion I / O modules, terminal modules, high-speed bus and low-speed bus; The high-speed bus is used for application data communication, and the low-speed bus is used for network management. The PLC controller serves as the control port for the entire system, receiving sampled data from each extended I / O module, monitoring the communication status of each extended I / O module, and commanding the corresponding extended I / O module to perform corresponding actions. The PLC controller includes a main CPU, a first communication chip, a slave MCU2 of the PLC controller, and a reference voltage source; The main CPU is connected to the first communication chip and the slave MCU2 of the PLC controller, respectively; The main CPU is used to process the data received by the first communication chip and output the processed data to the first communication chip. The first communication chip is used to receive data from the main CPU and forward it to the high-speed bus network; The slave MCU2 of the PLC controller is used to manage the network status of each module in the extended IO module, and to isolate and skip the slave MCU2 of the faulty extended IO module according to the network status. The reference voltage source is used to power the sampling resistor of the subsequent series-connected extended IO module; The extended I / O module serves as an analog / digital input / output channel for the PLC, used to acquire analog and digital signals, receive monitoring results from PLC command outputs, and handle faults based on the monitoring results. The extended I / O module includes a main MCU1, a second communication chip, a slave MCU2 of the extended I / O module, switches SW1-SW4, and sampling resistors; The main MCU1 is used to communicate with the second communication chip, and forward the collected data to the high-speed bus network through the second communication chip, and receive corresponding data output from the bus network; The second communication chip is used to send and receive bus data and communicate with the main MCU1 to forward field data; The switches SW1-SW4 are single-pole double-throw (SPDT) switches used to switch the bus, skip the faulty module and establish communication with the next module. The slave MCU2 of the extended IO module is used to send the network status of this module, the status of the second communication chip and the status of the master MCU1, and is also used to control the switches SW1-SW4 to switch the bus. Each of the extended I / O modules includes a sampling resistor, and the voltage system of the sampling resistor is used to determine the number of extended I / O modules and the location of the faulty extended I / O module; The main MCU1 is connected to the second communication chip, and the main MCU1 is connected to the slave MCU2 of the extended IO module. The slave MCU2 of the extended IO module is connected to switches SW1-SW4 respectively. The slave MCU2 of the extended IO module is connected to the input and output terminals of the sampling resistor respectively. The second communication chip is connected to switches SW1-SW4 respectively. Among switches SW1-SW4, switches SW1-SW2 are connected to the output of the previous level expansion IO module or PLC high-speed bus, and switches SW3-SW4 are connected to the input of the next level expansion IO module high-speed bus. Controlling the switches SW1-SW4 of the extended I / O module includes: When a fault is detected in this extended I / O module, the MCU2 slave of the extended I / O module controls the SW1-SW4 switches to switch directions, connecting the adjacent module above the faulty module with the next module to establish communication.

2. The fault communication system for the extended I / O module based on a dual-bus PLC according to claim 1, characterized in that, The extended I / O module is also used to report the high-speed bus status, the second communication chip status, and the main MCU1 status of the extended I / O module to the PLC controller via the low-speed bus, and at the same time receive commands from the PLC controller to control the switches SW1-SW4 of the extended I / O module.

3. The fault communication system for the extended I / O module based on a dual-bus PLC according to claim 2, characterized in that, The PLC controller's slave MCU2 and each of its extended IO modules are connected to the low-speed bus via the slave MCU2. The first communication chip is connected in series with each of the extended I / O modules until it is connected to the last extended I / O module.

4. The fault communication system for the extended I / O module based on a dual-bus PLC according to claim 1, characterized in that, The extended I / O module also includes a terminal module, which serves as the last extended module for placing the bus terminating resistor and the last grounded sampling resistor.

5. A fault communication method for extended I / O modules based on a dual-bus PLC, applied to the fault communication system for extended I / O modules based on a dual-bus PLC as described in any one of claims 1-4, characterized in that, The specific steps include the following: Obtain the input and output voltages of the sampling resistors reported by each node of the extended I / O module; The status of each module is monitored based on the input and output voltages to determine the number and location of the faulty extended I / O modules. Based on the number and location of the faulty extended I / O modules, a switching control command is issued to switch the bus network and restore communication for subsequent extended I / O modules.

6. The fault communication method for extended I / O modules based on a dual-bus PLC according to claim 5, characterized in that, The number of extended I / O modules that were identified as faulty includes: Obtain the input voltage of the sampling resistor from the extended I / O module. Output voltage and the reference voltage of the PLC controller The number of extended I / O modules was calculated. ; Determining the location of the faulty extended I / O module includes: Obtain the location number of the nearest extended I / O module of the PLC controller, and so on until the last extended I / O module. .

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