Reconfigurable CAN switching box device

Abstract

Due to the fact that display and control console groups and cabins are relatively scattered in position and far in distance, when a traditional CAN networking technology is applied, the problems that bus topology is too complex, reliability is reduced, the number of hitching nodes is limited, and long-distance transmission is achieved are often caused. Therefore, the invention provides a brand-new reconfigurable CAN exchange box device so as to meet the application scene requirements of a multi-cabin display and control console group network. A CAN transceiver-isolator-CAN transceiver and a CAN transceiver-isolator-photoelectric module are utilized to convert CAN nodes of a plurality of display and control console groups in a cabin into a single node from the physical interface characteristic, and the single node is hung on a CAN bus in a reconfigurable CAN exchange box device. For a cabin or a display and control console group needing long-distance transmission, long-distance transmission of data is achieved through the CAN transceiver-isolator-photoelectric module.

Description

Technical Field

[0001] The invention belongs to the technical field of field bus, and in particular relates to a reconfigurable CAN exchange box device. Background Art

[0002] The display and control console is an important part of the radar system and a key platform for radar system control input and status display. With the increasing complexity of radar system functions and the background of multi-system linkage and collaboration, the functional division of the display and control console is becoming more and more detailed and the number is increasing, gradually developing into a display and control console group and a multi-cabin display and control console group. Therefore, the control command synchronization and status monitoring between display and control console groups, as well as the need for reconfiguration and switchable master and slave devices are extremely urgent. The controller area network (CAN) can fully meet the networking needs of the display and control console group because of its reliable communication, network broadcasting and multi-master control capabilities. However, the locations of each display and control console group and each cabin are relatively scattered and far apart. The application of traditional CAN network networking technology often faces problems such as overly complex bus topology, reduced reliability, limited number of connected nodes, and long-distance transmission. Summary of the invention

[0003] To this end, the present invention proposes a new reconfigurable CAN exchange box device to meet the application scenario requirements of a multi-cabin display and control console group network, and can achieve the following functions: first, the basic working principle of the reconfigurable CAN exchange box device; second, the master-slave mode switching implementation and function of the reconfigurable CAN exchange box device; third, the application topology of the reconfigurable CAN exchange box device; fourth, the basic protocol framework of the reconfigurable CAN exchange box device.

[0004] The basic working principle of the reconfigurable CAN exchange box device of the present invention is: using "CAN transceiver-isolator-CAN transceiver" and "CAN transceiver-isolator-photoelectric module" to transform the CAN nodes of multiple display and control console groups inside the cabin into a "single" node from the physical interface characteristics, and hang it on the CAN bus inside the reconfigurable CAN exchange box device. For cabins or display and control console groups that require long-distance transmission, "CAN transceiver-isolator-photoelectric module" is used to achieve long-distance transmission of data.

[0005] Implementation and function of the master-slave mode switching of the reconfigurable CAN exchange box device: The reconfigurable CAN exchange box device has two working modes, master and slave, which can be flexibly switched through the dial code on the device. When the reconfigurable CAN exchange box device works in the master mode, the built-in MCU collects bus data and packages it for external transmission, and can also respond to external instructions to distribute control instructions; when the reconfigurable CAN exchange box device works in the slave mode, the built-in MCU only completes the monitoring of the bus. In the CAN bus topology structure built with multiple reconfigurable CAN exchange box devices, only one reconfigurable CAN exchange box device works in the master mode, and the rest of the devices work in the slave mode.

[0006] Application topology of reconfigurable CAN exchange box device: The internal CAN bus topology of a single reconfigurable CAN exchange box device is a daisy chain topology structure connected end to end. After using the reconfigurable CAN exchange box device, the CAN nodes of multiple display and control console groups inside the cabin are networked into a local small CAN bus network, which can be regarded as a "single" node from the physical interface characteristics to the outside. Therefore, for the networking of equipment in multiple cabins, the cabin bus can be arbitrarily connected to the main network (the CAN bus network where the main working mode reconfigurable CAN exchange box device is located) without considering complex matching impedance calculations.

[0007] Basic protocol framework of the reconfigurable CAN switch box device: Based on the standard CAN communication protocol, the reconfigurable CAN switch box device customizes the control frame, status frame and heartbeat frame using the CANID and data frame parts.

[0008] The beneficial effects of the present invention are

[0009] It solves the complex networking problem of multiple equipment compartments and avoids the impedance matching problem in complex CAN bus topology, truly achieving the access and use of the local CAN bus network. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is the principle block diagram of the reconfigurable CAN switch box device.

[0011] Figure 2 Schematic diagram of the master-slave mode switching of the reconfigurable CAN switch box device.

[0012] Figure 3 Schematic diagram of the internal topology of the reconfigurable CAN switch box device.

[0013] Figure 4 This is a schematic diagram of the networking topology of multiple reconfigurable CAN switch box devices.

[0014] Figure 5 It is a schematic diagram of the protocol frame of the reconfigurable CAN switch box device. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] like Figure 1 As shown, the hardware of the present invention is mainly composed of five parts: MCU control circuit, master-slave identification circuit, "CAN transceiver-signal isolation-CAN transceiver" circuit, "CAN transceiver-signal isolation-photoelectric module" circuit, and CAN bus. The MCU control circuit is the central part of the device data processing and control, and realizes the analysis and processing of bus data, external interaction and equipment control. The master-slave identification circuit realizes the identification of the master-slave mode setting of the device. The "CAN transceiver-signal isolation-CAN transceiver" circuit realizes the interface conversion of the local CAN bus network where it is located. The "CAN transceiver-signal isolation-photoelectric module" circuit realizes the photoelectric conversion of the device's external interface, which mainly meets the use of long-distance data transmission. The CAN bus topology circuit adopts a daisy chain topology structure.

[0017] like Figure 2 As shown, the 8-bit DIP switch on the reconfigurable CAN exchange box device can be used to set the master-slave working mode of the device, and the CANID number of the device can also be set. The 1st to 7th bits of the DIP switch correspond to the device CANID number, corresponding to the CANID number range of 0x00 to 0x7F; the 8th bit of the DIP switch corresponds to the device working mode, and the DIP switch is turned to "ON" for the master working mode and turned to "OFF" for the slave working mode. The device defaults to the slave working mode. After the device is powered on, the DIP setting status is identified during the initialization process, and the device is set.

[0018] like Figure 3 As shown, the reconfigurable CAN exchange box device adopts a daisy chain topology, with 120 ohm matching impedance installed at the head and tail. Each external CAN interface (electrical) or CAN interface (optical) in the bus is equivalent to a CAN node for the reconfigurable CAN exchange box device. The CAN interface (electrical) is composed of a "CAN transceiver-isolator-CAN transceiver" circuit. The two CAN communication interfaces are isolated from each other to solve the problem of multi-cabin equipment communication interfaces not sharing the same ground. The CAN interface (optical) is composed of a "CAN transceiver-isolator-photoelectric module" circuit, which realizes signal isolation and long-distance transmission through optical signal transmission.

[0019] like Figure 4As shown, multiple reconfigurable CAN exchange box devices are used in the networking topology of multiple cabins. Among them, the reconfigurable CAN exchange box device located in the command cabin is set to the master working mode. In addition to monitoring the bus data, it also interacts with the scheduling equipment in the cabin through Ethernet, responds to control instructions and query instructions, and forwards them in the CAN bus network. The reconfigurable CAN exchange box devices located in the combat support cabin and the detection cabin are set to the slave working mode, with a monitoring mode, forming a CAN bus local area network in the cabin, and various devices in the cabin.

[0020] like Figure 5 As shown in the figure, based on the CAN bus standard protocol, the arbitration area CANID number and the data frame area are used to customize the reconfigurable CAN switch box device protocol frame, including control frame, status frame and heartbeat frame. The control frame CANID is fixed at 0x100 and is sent by the reconfigurable CAN switch box device working in the main working mode to distribute control instructions. The status frame CANID is fixed at 0x200 and the heartbeat frame CANID is fixed at 0x300, which are used by the reconfigurable CAN switch box device to monitor the device status and then send them regularly.

[0021] The present invention is not limited to the above specific implementations, and the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made to the above implementations based on the technical essence of the present invention shall be included in the protection scope of the present invention.

Claims

1. A reconfigurable CAN switch box device, characterized in that: It includes an MCU control circuit, a master-slave identification circuit, a "CAN transceiver-signal isolator-CAN transceiver" combination circuit, a "CAN transceiver-signal isolator-photoelectric module" combination circuit and a CAN bus; the MCU control circuit is the central part of data processing and control, and realizes the analysis and processing of CAN bus data, external interaction and equipment control. The MCU control circuit is connected to the signal isolator and then hung on the CAN bus through the CAN transceiver; the master-slave identification circuit is connected to the MCU control circuit to realize the identification of the master-slave mode of the CAN exchange box device; the "CAN transceiver-signal isolator-CAN transceiver" combination circuit realizes the interface conversion of the CAN bus local area network where it is located; the "CAN transceiver-signal isolator-photoelectric module" circuit realizes the photoelectric conversion of the external interface; the "CAN transceiver-signal isolation-CAN transceiver" combination circuit and the "CAN transceiver-signal isolation-photoelectric module" combination circuit are both hung on the CAN bus.

2. A reconfigurable CAN switch box device according to claim 1, characterized in that: The internal topology of the reconfigurable CAN switch box adopts a daisy chain topology. Each external electrical or optical CAN interface in the bus is equivalent to a CAN node for the reconfigurable CAN switch box device, and 120 ohm matching impedance is added at the beginning and end.

3. The reconfigurable CAN switch box device according to claim 1, characterized in that: The reconfigurable CAN exchange box device also includes an 8-bit dip switch, and the master-slave working mode and the CANID number of the device are set by the dip switch.

4. A reconfigurable CAN switch box device according to claim 3, characterized in that: The 1st to 7th positions of the dip switch correspond to the CANID number of the device, corresponding to the CANID number range of 0x00 to 0x7F; the 8th position of the dip switch corresponds to the master and slave working modes of the device, and when it is turned to "ON", it is the master working mode, and when it is turned to "OFF", it is the slave working mode. The device defaults to the slave working mode. The setting state of the dip switch is identified during the initialization process after the device is powered on.

5. The reconfigurable CAN switch box device according to claim 1, characterized in that: The reconfigurable CAN switch box device set to the master working mode, in addition to monitoring the bus data, also interacts with the dispatching equipment through Ethernet, responds to control instructions and query instructions, and forwards them in the CAN bus network; the reconfigurable CAN switch box device set to the slave working mode has a monitoring mode to form a CAN bus local area network.

6. A reconfigurable CAN switch box device according to any one of claims 1 to 5, characterized in that: Based on the CAN bus standard protocol, the CAN ID number and data frame area are used to customize the reconfigurable CAN switch box device protocol frame, including control frame, status frame and heartbeat frame; The control frame CANID is fixed at 0x100 and is sent by the reconfigurable CAN switch box device working in the main working mode to distribute control instructions. The status frame CANID is fixed at 0x200 and the heartbeat frame CANID is fixed at 0x300 and is sent periodically after the reconfigurable CAN switch box device monitors the device status.

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