CAN communication system, working method thereof and knitting machine control system

Abstract

The present application relates to the field of knitting control technology, and discloses a CAN communication system, its working method, and a knitting machine control system. The CAN communication system includes a first CAN network and an adjustment module; the first CAN network includes a first node, a second node, several groups of third nodes, and three groups of terminal resistors. The first node is used to receive a first signal and output it through the third node, and is used to receive a second signal and output it through the second node. The second node is used to receive a third signal and output it through the first node. The third node is used to receive a fourth signal and output it through the first node. The adjustment module connects the terminal resistor on one side of each third node to the CAN bus of the first CAN network when the third nodes are both suspended, and disconnects the terminal resistor on the one side of the third node from the CAN bus of the first CAN network when the third nodes are not suspended. The embodiment of the present application can automatically adjust the terminal resistor of the CAN network.

Description

Technical Field

[0001] The present application relates to the field of knitting control technology, and in particular to a CAN communication system, a working method thereof, and a knitting machine control system. Background Art

[0002] Currently, knitting machine control systems use parallel communication and CAN communication. Parallel communication requires numerous connecting wires, which overburdens the chip's IO ports and complicates the circuitry. This leads to drawbacks such as poor anti-interference performance, high cost, and low reliability. While CAN communication simplifies circuit complexity, the two nodes at the end of the CAN bus have terminal resistors between the CANH signal and the CAN signal to ensure proper CAN bus communication. When users select or leave the relevant nodes unconnected based on the actual usage scenario, they need to manually re-identify all CAN nodes as terminal nodes and manually connect the terminal resistors. This can result in the terminal resistors not being properly connected, impacting the normal operation of other nodes. Summary of the Invention

[0003] The purpose of this application is to provide a CAN communication system, its working method and knitting machine control system, aiming to solve the technical problem that the existing method of adjusting the terminal resistance requires manual re-identification of whether all CAN nodes are terminal nodes and manual connection of the terminal resistance.

[0004] The present invention provides a CAN communication system, including:

[0005] A first CAN network includes a first node, a second node, several groups of third nodes, and three groups of terminal resistors; the first node, as a terminal node, is used to receive a first signal and output it through the third node, and is used to receive a second signal and output it through the second node; the second node, as an intermediate node, is used to receive a third signal and output it through the first node; the third node, as a terminal node or an intermediate node, is used to receive a fourth signal and output it through the first node;

[0006] an adjustment module, detecting a connection status of each third node, connecting a terminal resistor located on one side of the third node to the CAN bus of the first CAN network when each third node is suspended, and disconnecting the terminal resistor located on one side of the third node from the CAN bus of the first CAN network when the third node is not suspended;

[0007] Among them, the first signal is a signal for controlling the needle selector, the second signal is a signal for controlling the power supply of the power supply device, the third signal is a signal for the working state of the needle selector, and the fourth signal is a signal for representing the working state of the power supply device.

[0008] Furthermore, the regulating module includes a switch unit and a detection unit;

[0009] The switch unit is connected in series with the terminal resistor located at one side of the second node;

[0010] The detection unit is connected to the switch unit, and closes the switch unit when each third node is suspended, and turns off the switch unit when the third node is not suspended.

[0011] Furthermore, the number of the third nodes is n, where n∈[1, 36].

[0012] Furthermore, the resistance of the terminal resistor is 120Ω.

[0013] Furthermore, the CAN communication system further includes:

[0014] The second CAN network includes a fourth node, several groups of fifth nodes and two groups of terminal resistors;

[0015] The fourth node, as a terminal node, is connected in parallel with one terminal resistor of the second CAN network and is used to receive the first signal and output it through the fifth node;

[0016] The fifth node, serving as a terminal node or an intermediate node, is connected in parallel with another terminal resistor of the second CAN network, and is used to receive the fourth signal and output it through the fourth node.

[0017] Furthermore, the number of the second CAN networks is 7 groups.

[0018] An embodiment of the present application further provides a working method of a CAN communication system, which is applied to the above-mentioned CAN communication system. The working method of the CAN communication system includes:

[0019] The regulating module determines whether each third node is suspended;

[0020] If all third nodes are left floating, the regulating module regulates the terminal resistor located on one side of the second node to connect to the CAN bus of the first CAN network, so that the first node, the second node and the two sets of terminal resistors of the first CAN network form a CAN network structure;

[0021] On the contrary, the adjustment module adjusts the terminal resistor located on the second node side not to be connected to the CAN bus of the first CAN network, so that the first node, the second node, the non-suspended third node and the terminal resistor located on the first node side form a CAN network structure.

[0022] Furthermore, the adjustment module determines whether all third nodes are suspended, including:

[0023] The regulating module detects the level status of each third node, and determines whether each third node is suspended according to a preset judgment rule and the level status information obtained by the detection.

[0024] The present application also provides a knitting machine control system, comprising:

[0025] The above-mentioned CAN communication system;

[0026] a controller, connected to the first node, configured to output the first signal and / or the second signal to the first node and receive the third signal and / or the fourth signal output by the first node;

[0027] a power supply device, connected to the second node, configured to receive the second signal output by the second node and output a third signal to the second node;

[0028] The needle selector is connected to at least one group of third nodes and is used to receive the first signal output by the third node and output a fourth signal to the third node.

[0029] The present application also provides a knitting machine control system, comprising:

[0030] The above-mentioned CAN communication system;

[0031] a controller connected to the first node and the fourth node, configured to output the first signal and / or the second signal to the first node and receive the third signal and / or the fourth signal output by the first node, and / or output the first signal to the fourth node and receive the fourth signal output by the fourth node;

[0032] a power supply device, connected to the second node, configured to receive the second signal output by the second node and output a third signal to the second node;

[0033] The needle selector is connected to at least one group of third nodes, and is used to receive the first signal output by the third node and output the fourth signal to the third node, and / or receive the first signal output by the fifth node and output the fourth signal to the fifth node.

[0034] The beneficial effects of the present application are as follows: a CAN network is constructed based on a first node, a second node, a third node and two groups of terminal resistors to realize signal transmission between the first node and the second node and signal transmission between the first node and the third node, and whether the third nodes are all in a suspended state is automatically adjusted to connect the terminal resistors on one side of the third node to the CAN network, so that the CAN network can normally transmit signals when the third nodes are all suspended or not, avoiding interference between each other, and solving the technical problem that the existing method of adjusting the terminal resistors requires manual re-identification of whether all CAN nodes are terminal nodes and manual connection of the terminal resistors. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural diagram of the CAN communication system provided in the first embodiment of this application.

[0036] Figure 2 It is a structural diagram of the CAN communication system provided in the second embodiment of the present application.

[0037] Figure 3 It is a structural diagram of the CAN communication system provided in the third embodiment of the present application.

[0038] Figure 4 This is a flowchart of a working method of a CAN communication system provided by an embodiment of the present application.

[0039] Figure 5 It is a structural diagram of the knitting machine control system provided in the first embodiment of the present application.

[0040] Figure 6 It is a structural diagram of a knitting machine control system provided in the second embodiment of the present application. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the present invention will be further described below in conjunction with the embodiments and drawings.

[0042] In the embodiments of the present invention, "several" means an indefinite quantity, "multiple" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, and "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0043] In embodiments of the present invention, the terms "comprises," "includes," or any other variations thereof are intended to cover a non-exclusive inclusion, ie, including not only the listed elements but also other elements not explicitly listed.

[0044] In the related art, knitting machine control systems use parallel communication and CAN communication. Parallel communication requires numerous connecting cables, resulting in excessive chip IO port usage and complex circuits. It also suffers from poor anti-interference performance, high cost, and low reliability. CAN, short for Controller Area Network (CAN), is a serial communication network capable of distributed real-time control. It transmits data via the voltage difference generated by two communication lines (the CAN bus). All nodes in a CAN network are connected to these two communication lines, using differential signaling and half-duplex communication. The CAN bus is a multi-node parallel network communication network based on differential cables. Only two-core cables, CANH and CANL, are required to connect each CAN node. This connection is simple and easy to expand, making it widely used in industry. The CAN bus relies on the differential voltage levels on the CANH and CANL cables to achieve communication. To eliminate signal reflections at the CAN cable terminals, a termination resistor is required at each terminal node at each end of the CAN bus, while the intermediate nodes located in the middle of the CAN bus do not have this matching resistor. The CAN nodes connected to the CAN bus usually change dynamically. When a new CAN node is connected to the existing CAN bus network or a CAN terminal node is removed, the terminal node of the CAN bus network will change. At this time, the terminal resistance of the new CAN terminal node needs to be readjusted.

[0045] In order to achieve the above-mentioned purpose of adjusting the terminal resistance, there are two existing methods. The first is to manually identify the terminal node and then manually connect the terminal resistance to the terminal node or control the connection of the terminal resistance by other communication means; the second is to input the power supply voltage through the CAN intermediate node to drive the relay to connect the terminal resistance.

[0046] However, both of the above methods have some defects that cannot be ignored: First, it is necessary to manually identify whether the CAN node is an intermediate node or a terminal node, and manually connect or disconnect the terminal resistors of each CAN node based on the identification results; Second, it is impossible to automatically adapt to the access of new CAN nodes or the disconnection of existing CAN nodes. At this time, the CAN terminal node changes, and it is necessary to manually re-identify whether all CAN nodes are terminal nodes and manually connect the terminal resistors; Third, the power supply is output through the CAN intermediate node to drive the relay of the next CAN node to connect the terminal resistor. The power line and ground line need to be added to the CAN bus cable. Mutual interference will occur between the power line, ground line and CAN signal line, which requires the addition of corresponding interference removal devices in the power supply and CAN signal line of each CAN node, which will reduce the transmission rate of the CAN bus signal and increase the transmission bit error rate.

[0047] Based on this, an embodiment of the present application provides a CAN communication system, its working method and a knitting machine control system, which determines whether a terminal resistor needs to be connected by identifying whether a CAN node that is preset to be a terminal node is floating, and automatically connects the terminal resistor or not, so as to solve the technical problem that the existing method of adjusting the terminal resistor requires manual re-identification of whether all CAN nodes are terminal nodes and manual connection of the terminal resistor.

[0048] See Figure 1 , an embodiment of the present application provides a CAN communication system.

[0049] like Figure 1 As shown, in the first embodiment, the CAN communication system includes a first CAN network 100 and a regulating module 200, and is suitable for a knitting control system.

[0050] The first CAN network 100 includes a first node 110, a second node 120, several groups of third nodes 130, and three groups of terminal resistors. The first node 110 serves as a terminal node, the second node 120 serves as an intermediate node, the last group of third nodes 130 serves as another terminal node, and the remaining third nodes 130 serve as intermediate nodes, connected between the second node 120 and the last group of third nodes 130. The first node 110 is used to receive a first signal and output it through the third node 130, and to receive a second signal and output it through the second node 120. The second node 120 is used to receive a third signal and output it through the first node 110. The third node 130 is used to receive a fourth signal and output it through the first node 110.

[0051] Among them, the first signal is a signal for controlling the needle selector, the second signal is a signal for controlling the power supply of the power supply device, the third signal is a signal for the working state of the needle selector, and the fourth signal is a signal for representing the working state of the power supply device.

[0052] In the knitting control system, the first node 110 is connected to an external controller, the second node 120 is connected to an external power supply, and the third node 130 is connected to an external needle selector. During operation, the first node 110, the second node 120, and the third node 130 transmit signals via the differential level of the CAN bus. When the first node 110 receives a first signal, it transmits the first signal to the corresponding third node 130 via the CAN bus, and outputs the first signal to the needle selector via the third node 130. When the first node 110 receives a second signal, it transmits the second signal to the corresponding second node 120 via the CAN bus, and outputs the second signal to the power supply via the second node 120. When the second node 120 receives a fourth signal, it transmits the fourth signal to the corresponding first node 110 via the CAN bus, and outputs the fourth signal to the controller via the first node 110. When the third node 130 receives a third signal, it transmits the third signal to the corresponding first node 110 via the CAN bus, and outputs the third signal to the controller via the first node 110.

[0053] The controller generates a first signal to control the needle selector to select needles and generates a second signal to control the power supply device to supply power. The needle selector receives the first signal to perform corresponding needle selection operations according to the level information of the first signal and generates a third signal during operation. The power supply device receives the second signal to perform corresponding power supply operations according to the level information of the second signal and generates a fourth signal during operation. The controller receives the third signal to determine whether the working state of the needle selector is abnormal (for example, needle selection error) according to the level information of the third signal and receives the fourth signal to determine whether the working state of the power supply device is abnormal (for example, the fuse is on or off, the power supply is on or off) according to the level information of the fourth signal.

[0054] The adjustment module 200 detects the connection status of each third node 130, and when each third node 130 is suspended, the terminal resistor located on the side of the second node 120 is connected to the CAN bus of the first CAN network 100; when the third node 130 is not suspended, the terminal resistor located on the side of the second node 120 is not connected to the CAN bus of the first CAN network 100.

[0055] After the first CAN network 100 is powered on, the adjustment module 200 detects whether the third nodes 130 are floating. When the adjustment module 200 detects that all third nodes 130 in the first CAN network 100 are floating, the terminal resistor located on the side of the second node 120 is connected to the CAN bus of the first CAN network 100. This allows the first node 110, the second node 120, the terminal resistor located on the side of the first node 110, and the terminal resistor located on the side of the second node 120 to form a CAN network structure. The first node 110 and the second node 120 serve as terminal nodes, respectively, to ensure normal communication between the first node 110 and the second node 120. When the adjustment module 200 detects that there is at least one group of third nodes 130 in the first CAN network 100 that is not suspended, the terminal resistor located on the side of the second node 120 is not connected to the CAN bus of the first CAN network 100, so that the first node 110, the second node 120, the third node 130 that is not suspended, the terminal resistor located on the side of the first node 110, and the terminal resistor located on the side of the third node 130 constitute a CAN network structure. The first node 110 and the last group of third nodes 130 that are not suspended serve as terminal nodes, respectively, and the second node 120 and the remaining suspended third nodes 130 serve as intermediate nodes, thereby avoiding mutual interference between the communication between the first node 110 and the second node 120 and the communication between the first node 110 and the third node 130.

[0056] It should be noted that the third node 130 and the terminal resistor located on one side of the third node 130 can be regarded as a whole. When each third node 130 is suspended, the terminal resistor located on one side of the third node 130 is not connected to the first CAN network 100.

[0057] like Figure 2 As shown, in the second embodiment, the regulating module 200 includes a switch unit 210 and a detection unit 220 .

[0058] Among them, the switch unit 210 is connected in series with the terminal resistor located on one side of the second node 120, and the detection unit 220 is connected to the switch unit 210, so that the switch unit 210 is closed when each third node 130 is suspended, and the switch unit 210 is turned off when the third node 130 is not suspended.

[0059] Specifically, the detection unit 220 detects the connection status of each third node 130, obtains the level of each third node 130, and determines whether each third node 130 is suspended based on the detected level information. When the detected level status indicates that each third node 130 is suspended, the detection unit 220 triggers the switch unit 210 to close, so that the terminal resistor located on the side of the second node 120 is connected to the CAN bus of the first CAN network 100. Conversely, when the detected level status indicates that the third node 130 is not suspended, the detection unit 220 triggers the switch unit 210 to close, so that the terminal resistor located on the side of the second node 120 is not connected to the CAN bus of the first CAN network 100.

[0060] In the above embodiment, the number of the third nodes 130 is n, where n∈[1, 36].

[0061] In the above embodiment, the resistance of the terminal resistor is 120Ω.

[0062] like Figure 3 As shown, in the third embodiment, the CAN communication system further includes a second CAN network 300 .

[0063] Among them, the second CAN network 300 includes a fourth node 310, several groups of fifth nodes 320 and two groups of terminal resistors, the fourth node 310 serves as a terminal node, the last group of fifth nodes 320 serves as another terminal node, and the remaining fifth nodes 320 serve as intermediate nodes. The fourth node 310 is connected in parallel with one of the terminal resistors of the second CAN network 300, for accessing the first signal and outputting it through the fifth node 320, and the fifth node 320 is connected in parallel with another terminal resistor of the second CAN network 300, for accessing the fourth signal and outputting it through the fourth node 310.

[0064] In the knitting control system, the first node 110 and the fourth node 310 are respectively connected to an external controller, the second node 120 is connected to an external power supply, and the third node 130 and the fifth node 320 are respectively connected to an external needle selector. Regarding the first CAN network 100, the first node 110, the second node 120, and the third node 130 transmit signals via the differential level of the CAN bus of the first CAN network 100. When the first node 110 receives a first signal, it transmits the first signal to the corresponding third node 130 via the CAN bus, and outputs the first signal to the needle selector via the third node 130. When the first node 110 receives a second signal, it transmits the second signal to the corresponding second node 120 via the CAN bus, and outputs the second signal to the power supply via the second node 120. When the second node 120 receives a fourth signal, it transmits the fourth signal to the corresponding first node 110 via the CAN bus, and outputs the fourth signal to the controller via the first node 110. When the third node 130 receives a third signal, it transmits the third signal to the corresponding first node 110 via the CAN bus, and outputs the third signal to the controller via the first node 110. For the second CAN network 300, the fourth node 310 and the fifth node 320 transmit signals through the differential level of the CAN bus of the second CAN network 300. When the fourth node 310 receives the first signal, it transmits the first signal to the corresponding fifth node 320 through the CAN bus, and outputs the first signal to the needle selector through the fifth node 320. When the fifth node 320 receives the third signal, it transmits the third signal to the corresponding fourth node 310 through the CAN bus, and outputs the third signal to the controller through the fourth node 310.

[0065] In the above embodiment, the number of the second CAN networks 300 is 7.

[0066] See Figure 4 , an embodiment of the present application provides a working method of a CAN communication system, which is applied to the above-mentioned CAN communication system.

[0067] like Figure 4 As shown, in one embodiment, the working method of the CAN communication system includes but is not limited to steps S401 to S403.

[0068] In step S401, the regulating module determines whether all third nodes are suspended. If all third nodes are suspended, step S402 is executed; otherwise, step S403 is executed.

[0069] In step S402 , the regulating module regulates the terminal resistor located at one side of the second node to connect to the CAN bus of the first CAN network, so that the first node, the second node and the two sets of terminal resistors of the first CAN network form a CAN network structure.

[0070] In step S403, the regulating module regulates the terminal resistor located on the second node side to disconnect it from the CAN bus of the first CAN network, so that the first node, the second node, the non-suspended third node and the terminal resistor located on the first node side form a CAN network structure.

[0071] In some embodiments, step S401 specifically includes: the adjustment module detects the level status of each third node, and determines whether each third node is suspended according to a preset judgment rule and the detected level status information.

[0072] See Figure 5 , an embodiment of the present application provides a knitting machine control system, comprising:

[0073] The CAN communication system provided by the first embodiment above;

[0074] a controller, connected to the first node 110, configured to output the first signal and / or the second signal to the first node 110 and receive the third signal and / or the fourth signal output by the first node 110;

[0075] a power supply device, connected to the second node 120, configured to receive the second signal output by the second node 120 and output a third signal to the second node 120;

[0076] The needle selector is connected to at least one group of third nodes 130 and is used to receive the first signal output by the third node 130 and output the fourth signal to the third node 130 .

[0077] See Figure 6 , an embodiment of the present application provides a knitting machine control system, comprising:

[0078] The CAN communication system provided by the third embodiment above;

[0079] a controller connected to the first node 110 and the fourth node 310, configured to output the first signal and / or the second signal to the first node 110 and receive the third signal and / or the fourth signal output by the first node 110, and / or output the first signal to the fourth node 310 and receive the fourth signal output by the fourth node 310;

[0080] a power supply device, connected to the second node 120, configured to receive the second signal output by the second node 120 and output a third signal to the second node 120;

[0081] The needle selector is connected to at least one group of third nodes 130 and is used to receive the first signal output by the third node 130 and output the fourth signal to the third node 130 , and / or receive the first signal output by the fifth node 320 and output the fourth signal to the fifth node 320 .

[0082] The working method of the CAN communication system and the specific implementation of the knitting machine control system are basically the same as the specific embodiment of the CAN communication system mentioned above, and will not be repeated here.

[0083] The CAN communication system, its working method and knitting machine control system provided in the embodiments of the present application construct a CAN network based on a first node 110, a second node 120, a third node 130 and two groups of terminal resistors to realize signal transmission between the first node 110 and the second node 120 and signal transmission between the first node 110 and the third node 130. By identifying whether the third node 130 is in a suspended state, the terminal resistor located on the side of the second node 120 is automatically adjusted to be connected to the CAN network. Therefore, the CAN network can normally transmit signals whether the third node 130 is suspended or not, avoiding interference between each other, and solving the technical problem that the existing method of adjusting the terminal resistor requires manual re-identification of whether all CAN nodes are terminal nodes and manual connection of the terminal resistor.

[0084] The embodiments described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0085] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0086] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0087] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0088] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0089] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0090] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the above-mentioned units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0091] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0092] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0093] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention should be within the scope of the present invention.

Claims

1. A CAN communication system, characterized in that: include: A first CAN network (100) comprises a first node (110), a second node (120), a plurality of third nodes (130) and three groups of terminal resistors; the first node (110) is used as a terminal node for receiving a first signal and outputting it through the third node (130), and for receiving a second signal and outputting it through the second node (120); the second node (120) is used as an intermediate node for receiving a third signal and outputting it through the first node (110); the third node (130) is used as a terminal node or an intermediate node for receiving a fourth signal and outputting it through the first node (110); The regulating module (200) detects the connection status of each third node (130), and when each third node (130) is suspended, connects the terminal resistor located on the side of the second node (120) to the CAN bus of the first CAN network (100), so that the first node (110), the second node (120), the terminal resistor located on the side of the first node (110), and the terminal resistor located on the side of the second node (120) constitute a CAN network structure, and the first node (110) and the second node (120) serve as terminal nodes respectively, ensuring normal communication between the first node (110) and the second node (120). , when the third node (130) is not suspended, the terminal resistor located on the side of the second node (120) is not connected to the CAN bus of the first CAN network (100), so that the first node (110), the second node (120), the third node (130) that is not suspended, the terminal resistor located on the side of the first node (110) and the terminal resistor located on the side of the third node (130) constitute a CAN network structure, the first node (110) and the last group of third nodes (130) that are not suspended serve as terminal nodes, respectively, and the second node (120) and the remaining third nodes (130) that are suspended serve as intermediate nodes; Among them, the first signal is a signal for controlling the needle selector, the second signal is a signal for controlling the power supply of the power supply device, the third signal is a signal for representing the working state of the power supply device, and the fourth signal is a signal for representing the working state of the needle selector.

2. The CAN communication system according to claim 1, characterized in that The regulating module (200) comprises a switch unit (210) and a detection unit (220); The switch unit (210) is connected in series with a terminal resistor located on one side of the second node (120); The detection unit (220) is connected to the switch unit (210), and closes the switch unit (210) when each third node (130) is suspended, and turns off the switch unit (210) when the third node (130) is not suspended.

3. The CAN communication system according to claim 1, characterized in that The number of the third nodes (130) is n, n∈[1, 36].

4. The CAN communication system according to claim 1, characterized in that The resistance of the terminal resistor is 120Ω.

5. The CAN communication system according to any one of claims 1 to 4, characterized in that: Also includes: A second CAN network (300) includes a fourth node (310), a plurality of groups of fifth nodes (320), and two groups of terminal resistors; The fourth node (310), as a terminal node, is connected in parallel with one of the terminal resistors of the second CAN network (300), and is used to receive the first signal and output it through the fifth node (320); The fifth node (320), as a terminal node or an intermediate node, is connected in parallel with another terminal resistor of the second CAN network (300) and is used to receive the fourth signal and output it through the fourth node (310).

6. The CAN communication system according to claim 5, characterized in that: The number of the second CAN networks (300) is 7 groups.

7. A working method of a CAN communication system, applied to the CAN communication system according to any one of claims 1 to 6, characterized in that: The working method of the CAN communication system includes: The regulating module (200) determines whether each third node (130) is suspended; If all third nodes (130) are suspended, the regulating module (200) regulates the terminal resistor located on one side of the second node (120) to connect to the CAN bus of the first CAN network (100), so that the two sets of terminal resistors of the first node (110), the second node (120) and the first CAN network (100) form a CAN network structure; Conversely, the regulating module (200) regulates the terminal resistor located on one side of the second node (120) so as not to be connected to the CAN bus of the first CAN network (100), so that the first node (110), the second node (120), the non-suspended third node (130) and the terminal resistor located on one side of the first node (110) form a CAN network structure.

8. The operating method of the CAN communication system according to claim 7, characterized in that: The regulating module (200) determines whether each third node (130) is suspended, including: The regulating module (200) detects the level status of each third node (130), and determines whether each third node (130) is suspended according to a preset judgment rule and the level status information obtained by the detection.

9. A knitting machine control system, characterized in that: include: The CAN communication system according to any one of claims 1 to 4; a controller connected to the first node (110), configured to output a first signal and / or a second signal to the first node (110) and to receive a third signal and / or a fourth signal output by the first node (110); A power supply device, connected to the second node (120), configured to receive a second signal output by the second node (120) and output a third signal to the second node (120); The needle selector is connected to at least one group of third nodes (130) and is used to receive the first signal output by the third node (130) and output a fourth signal to the third node (130).

10. A knitting machine control system, characterized in that: include: The CAN communication system according to claim 5 or 6; a controller connected to the first node (110) and the fourth node (310), configured to output the first signal and / or the second signal to the first node (110) and receive the third signal and / or the fourth signal output by the first node (110), and / or output the first signal to the fourth node (310) and receive the fourth signal output by the fourth node (310); A power supply device, connected to the second node (120), configured to receive a second signal output by the second node (120) and output a third signal to the second node (120); A needle selector is connected to at least one group of third nodes (130), and is used to receive the first signal output by the third node (130) and output a fourth signal to the third node (130), and / or receive the first signal output by the fifth node (320) and output the fourth signal to the fifth node (320).

Images