CAN communication and protection interface module of electric energy metering box assembly and verification all-in-one machine

Abstract

The utility model discloses a CAN communication and protection interface module of an electric energy metering box assembly and verification all-in-one machine, and the module comprises a CAN transceiver which is provided with a data transmitting end, a data receiving end, a standby control end, a differential output high end, and a differential output low end; the decoupling capacitor clings to the power supply end of the CAN transceiver and is connected with the ground end; the terminal resistor is directly bridged between the differential output high end and the differential output low end of the CAN transceiver; the TVS protection array adopts a bridge type structure and is used for respectively connecting the differential output high end and the differential output low end to a power supply and the ground through a diode array; and the differential signal pin is connected to the differential output high end and the differential output low end, and the plurality of parallel ground pins are connected with the system ground through wide wiring. The CAN communication and protection interface module of the electric energy metering box assembly and verification all-in-one machine has the characteristics of high anti-interference capability, low power consumption and high reliability.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of CAN communication and protection interface module of electric energy metering box assembly, verification integrated machine. BACKGROUND

[0002] Electric energy metering box production line is composed of multiple stations, including scanning code, screw locking, voltage resistance / insulation, verification table etc., and the above-mentioned stations need to realize data interaction and collaborative work through communication network.In industrial field environment, especially in electric energy metering box production workshop, there are complex electromagnetic environment such as static electricity, surge, common-mode interference, etc., and the above-mentioned interference sources often cause communication interruption, cause production line shutdown, cause low efficiency and quality problems.The existing CAN communication interface has deficiencies in anti-interference ability and energy consumption management, and it is difficult to meet the needs of high reliability and long-term stable operation of electric energy metering box production line. UTILITY MODEL CONTENTS

[0003] The utility model aims at providing a kind of CAN communication and protection interface module of electric energy metering box assembly, verification integrated machine.This kind of electric energy metering box assembly, verification integrated machine CAN communication and protection interface module has the characteristics of high anti-interference ability, low power consumption and high reliability.

[0004] The above technical purpose of the utility model is realized by the following technical scheme:

[0005] A kind of CAN communication and protection interface module of electric energy metering box assembly, verification integrated machine, comprising: CAN transceiver (U17), with data sending end (TXD), data receiving end (RXD), standby control end (STB), differential output high end (CANH) and differential output low end (CANL);Decoupling capacitor (C50), close to the power supply end (VCC) and ground end (GND) between the CAN transceiver (U17) connection;Terminal resistance (R68), directly across the differential output high end (CANH) and differential output low end (CANL) of the CAN transceiver (U17);TVS protection array (D9), using bridge structure, respectively the differential output high end (CANH) and differential output low end (CANL) are connected to power supply and ground by diode array;Bus interface seat (H6), including differential signal pin and multiple parallel ground pins, the differential signal pin is connected to the differential output high end (CANH) and differential output low end (CANL), and the multiple parallel ground pins are connected with system ground by wide wire.

[0006] The utility model is further provided as follows: the module is sequentially arranged MCU interface area, transceiver core area, protection and matching area and bus interface area from left to right, to form linear signal transmission path.

[0007] The utility model further sets up: TVS protection array (D9) is arranged immediately close to bus interface seat (H6), is used for intercepting outside interference for the first time.

[0008] The utility model further sets up: terminal resistance (R68) resistance value is 120Ω, is arranged in close to bus interface seat (H6) one side.

[0009] The utility model further sets up: the wire between the differential output high end (CANH) and differential output low end (CANL) of CAN transceiver (U17) adopts equal length parallel wiring mode.

[0010] The utility model further sets up: standby control end (STB) of CAN transceiver (U17) is connected to programmable output pin of microcontroller, is used for realizing the energy -conserving control of on -demand work.

[0011] The utility model further sets up: decoupling capacitor (C50) capacity value is 100nF, adopts surface mount technology and the shortest connection path of power end (VCC) and ground end (GND) of CAN transceiver (U17) is formed.

[0012] The utility model further sets up: the parallel ground pin of bus interface seat (H6) includes at least two ground pins, and the ground pin is connected with system ground through wide wire, forms low impedance discharge path.

[0013] The utility model further sets up: the differential signal pin and ground pin on bus interface seat (H6) are staggered arrangement, is used for improving electromagnetic interference suppression capability.

[0014] Summarized above, the utility model has following beneficial effect:

[0015] The layered protection setting of bridge type TVS protection: the utility model adopts bridge structure's TVS protection array (D9), and connects differential output high end (CANH) and differential output low end (CANL) through diode array to power and ground, and cooperates multiple parallel ground pin settings of bus interface seat (H6), forms the multi -level protection structure. This setting makes module can bear IEC standard specified ± 8kV contact discharge test, and ordinary interface usually can only bear ± 4kV, improves the anti -static ability. Meanwhile, through the surge energy diversion to power rail and ground two channels, and through parallel ground pin forms low impedance discharge path, ground pop noise reduces, and EMI radiation reduces. This layered protection setting significantly improves the reliability of module in the existence of multiple electrical interference environment such as electric energy metering box production workshop, reduces the production line downtime time caused by communication interruption.

[0016] Linear modular functional area layout: the utility model discloses the module from left to right MCU interface area, transceiver core area, protection and matching area and bus interface area are arranged in turn, form linear signal transmission path, and TVS protection array (D9) is arranged close to bus interface seat (H6). This layout minimizes signal transmission path, reduces crosstalk and radiation, and also facilitates debugging and fault location. Modular functional area division makes fault location simple and intuitive.

[0017] Optimized combination of decoupling and termination: the utility model discloses that the decoupling capacitor (C50) is 100nF, adopts surface mounting technology and the power supply end (VCC) and ground end (GND) of CAN transceiver (U17) form the shortest connection path, and the terminal resistance (R68) resistance is 120Ω, and is directly connected between differential output high end (CANH) and differential output low end (CANL). This optimized combination setting reduces power supply ripple, reduces signal reflection coefficient, reduces reflection interference, and improves common-mode rejection capability. The wire between differential output high end (CANH) and differential output low end (CANL) of CAN transceiver (U17) adopts equal-length parallel wiring mode, which further ensures the balance of differential signal and reduces differential mode noise.

[0018] Standby control function reduces power consumption: the standby control end (STB) of the utility model's CAN transceiver (U17) is connected to the programmable output pin of the microcontroller, realizing the energy-saving control of on-demand work. Compared with the always-on setting, standby power consumption is reduced, prolonging the service life of the equipment, and facilitating hot plug operation. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is the whole structure schematic diagram of the utility model. DETAILED DESCRIPTION

[0020] The utility model will be further explained in detail in combination with the drawings.

[0021] As Figure 1 Indicated, the utility model provides a kind of electric energy metering box assembly, and it is integrated machine CAN communication and protection interface module, which is arranged from left to right according to signal / energy flow direction, mainly including CAN transceiver (U17), decoupling capacitor (C50), terminal resistance (R68), TVS protection array (D9) and bus interface seat (H6).

[0022] The module is sequentially provided with an MCU interface area, a transceiver core area, a protection and matching area and a bus interface area from left to right, forming a linear signal transmission path. The MCU interface area is located on the left side of the module and is used for connecting the controller and the CAN transceiver (U17), mainly including three signal line connection points: the data output pin of the MCU is connected to the data transmission end (TXD) of the CAN transceiver (U17), the data input pin of the MCU is connected to the data receiving end (RXD) of the CAN transceiver (U17), and the control output pin of the MCU is connected to the standby control end (STB) of the CAN transceiver (U17). The above connection adopts a short direct wiring setting, minimizing signal transmission delay and interference coupling.

[0023] The transceiver core area is located in the center of the module. The CAN transceiver (U17) adopts an 8-pin package and is located in the center, with the left side connected to the MCU interface and the right side connected to the bus. The decoupling capacitor (C50) has a capacitance of 100nF and is closely connected between the power supply end (VCC) and the ground end (GND) of the CAN transceiver (U17) by using a surface mounting process, forming the shortest connection path and effectively suppressing power supply noise. The power supply wiring and the signal wiring are arranged in different areas, forming a star-shaped topology of the power supply distribution point, reducing common impedance coupling.

[0024] The protection and matching area is located on the right side of the module between the transceiver and the bus interface. The terminal resistor (R68) has a resistance of 120Ω and is directly connected between the differential output high end (CANH) and the differential output low end (CANL) of the CAN transceiver (U17), arranged close to one side of the bus interface seat (H6), used for suppressing signal reflection. The TVS protection array (D9) adopts a bridge structure, respectively connecting the differential output high end (CANH) and the differential output low end (CANL) to the power supply and the ground through a diode array, arranged close to the bus interface seat (H6), used for intercepting external interference in the first time.

[0025] The wiring between the differential output high end (CANH) and the differential output low end (CANL) of the CAN transceiver (U17) adopts an equal-length parallel wiring method, maintaining consistent characteristic impedance and reducing differential mode noise. The protection circuit grounding point is directly connected to the ground by using wide wiring, forming a low-impedance discharge path.

[0026] The bus interface area is located at the rightmost side of the module, and is used for connecting with an external network. The bus interface seat (H6) includes differential signal pins and a plurality of parallel ground pins. The differential signal pins (1, 2) are connected to the differential output high end (CANH) and the differential output low end (CANL) of the CAN transceiver (U17), and the plurality of parallel ground pins (4, 5) are connected to the system ground through wide traces to form a low-impedance discharge path. The parallel ground pins of the bus interface seat (H6) include at least two ground pins, which significantly reduce the contact impedance and the heating of the connection points. The differential signal pins and the ground pins on the bus interface seat (H6) are staggered, which improves the electromagnetic interference suppression capability.

[0027] The standby control end (STB) of the CAN transceiver (U17) is connected to a programmable output pin of the microcontroller, and is used for realizing energy-saving control in a demand mode. When the output pin of the microcontroller is at a low level, the CAN transceiver (U17) enters a normal working mode; when the output pin is at a high level, the CAN transceiver (U17) enters a low-power standby mode, which significantly reduces the power consumption and prolongs the service life of the device, and facilitates hot plug operation.

[0028] The layered protection setting bridge structure of the TVS protection array (D9) can effectively protect the CAN transceiver (U17) and the microcontroller from damage when encountering electrostatic discharge, induced surge or common mode spikes. External interference is first absorbed by the TVS protection array (D9), and the remaining amount is digested by the decoupling capacitor (C50) and the ground, forming a stepped protection structure.

[0029] The working principle of the utility model is as follows: an external microcontroller sends data to the CAN transceiver (U17) through a data sending end (TXD), the CAN transceiver (U17) converts the data into a CAN bus differential signal, and sends the CAN bus differential signal to the bus through a differential output high end (CANH) and a differential output low end (CANL); at the same time, the CAN transceiver (U17) receives the differential signal on the bus, converts the differential signal into a single-ended digital signal, and transmits the single-ended digital signal to the microcontroller through a data receiving end (RXD). A terminal resistor (R68) matches the bus characteristic impedance to suppress signal reflection; a TVS protection array (D9) provides overvoltage protection to prevent electrostatic and surge damage to the circuit; a decoupling capacitor (C50) filters power supply noise to ensure stable operation of the CAN transceiver (U17); and a plurality of parallel ground pins of the bus interface seat (H6) reduce the ground impedance and improve the system anti-interference capability. The microcontroller can control the working state of the CAN transceiver (U17) through a standby control end (STB) to realize energy-saving control.

[0030] The utility model discloses the implementation key points include: TVS protection array (D9) should be close to bus interface seat (H6) arrangement, maximum protection internal circuit, the connection between decoupling capacitor (C50) and CAN transceiver (U17) power end (VCC) and ground end (GND) should be as short as possible, maximum reduction power noise, differential signal line should adopt equal length parallel wiring, keep characteristic impedance consistency, terminal resistance (R68) should be close to bus interface seat (H6) arrangement, minimize the reflection point distance, the multiple ground pins of bus interface seat (H6) should be connected through wide wire and system ground, form low impedance discharge path.

[0031] The utility model discloses the bridge type TVS protection, linear modularization's functional area layout, the optimization combination setting of decoupling and termination, standby control function and mechanical connection reliability setting etc., solved the electric energy metering box production line communication interface's deficiency in anti -interference ability, energy consumption management, provided a kind of high reliability, low interference, easy maintenance, energy saving and environmental protection CAN communication and protection interface module for electric energy metering box assembly, verification integrated machine, especially suitable for electric energy metering box production line such high reliability requirement application scene of communication.

[0032] The utility model discloses the design as follows experimental evaluation electric energy metering box assembly, verification integrated machine CAN communication and protection interface module's technical effect.

[0033] 1. using contrast test method, the utility model module and traditional CAN interface module are compared in actual electric energy metering box production line environment performance. Test environment simulates production line actual working condition, including electrostatic interference, motor start-stop, welding machine interference and other typical electromagnetic interference source. Using electrostatic discharge generator, EMI receiver, oscilloscope, power analyzer and thermal imager and other equipment carry out data acquisition. Each test is repeated five times to take average value, guarantee test result accurate and reliable.

[0034] 2. technical effect comparison table

[0035]

[0036] 3. verification conclusion

[0037] Through comparison test in actual electric energy metering box production line environment, the utility model module bridge type TVS protection makes anti-static ability to improve one time, communication error rate reduces three orders of magnitude, greatly reduces the production line downtime caused by communication interruption;Optimized decoupling and termination setting makes power ripple suppression effect to improve 85%, significantly improves signal quality;Standby control function reduces non-working period power consumption 78%, meets energy saving requirement. In the production line actual operation test for three months, the station using the utility model module does not occur communication failure caused downtime. Experimental results fully verify the technical effect of the utility model, has wide application prospect.

Claims

1. A CAN communication and protection interface module for an electric energy metering box assembly and verification all-in-one machine, characterized in that, Comprise: CAN transceiver (U17) with data transmission end (TXD), data receiving end (RXD), standby control end (STB), differential output high end (CANH) and differential output low end (CANL); Decoupling capacitor (C50) connected between the power supply end (VCC) and the ground end (GND) of the CAN transceiver (U17); Terminal resistance (R68) directly across the differential output high end (CANH) and the differential output low end (CANL) of the CAN transceiver (U17); TVS protection array (D9) adopts bridge structure, respectively connecting the differential output high end (CANH) and the differential output low end (CANL) to the power supply and the ground through diode array; Bus interface seat (H6) includes differential signal pin and multiple parallel ground pins, the differential signal pin is connected to the differential output high end (CANH) and the differential output low end (CANL), and the multiple parallel ground pins are connected to the system ground through wide wiring.

2. The electric energy metering box assembling and calibrating all-in-one machine CAN communication and protection interface module according to claim 1, characterized in that, The modules are arranged in MCU interface area, transceiver core area, protection and matching area and bus interface area from left to right, forming a linear signal transmission path.

3. The electric energy metering box assembling and calibrating all-in-one machine CAN communication and protection interface module according to claim 1, characterized in that, The TVS protection array (D9) is arranged close to the bus interface seat (H6) for first-time interception of external interference.

4. The electric energy metering box assembling and calibrating all-in-one machine CAN communication and protection interface module according to claim 1, characterized in that, The terminal resistance (R68) has a resistance of 120Ω and is arranged close to one side of the bus interface seat (H6).

5. The electric energy metering box assembling and calibrating all-in-one machine CAN communication and protection interface module according to claim 1, characterized in that, The wiring between the differential output high end (CANH) and the differential output low end (CANL) of the CAN transceiver (U17) adopts equal-length parallel wiring mode.

6. The electric energy metering box assembling and calibrating all-in-one machine CAN communication and protection interface module according to claim 1, characterized in that, The standby control end (STB) of the CAN transceiver (U17) is connected to the programmable output pin of the microcontroller, for realizing energy-saving control of on-demand work.

7. The electric energy metering box assembling and calibrating all-in-one machine CAN communication and protection interface module according to claim 1, characterized in that, The decoupling capacitor (C50) has a capacitance of 100nF and adopts surface mounting process to form the shortest connection path with the power supply end (VCC) and the ground end (GND) of the CAN transceiver (U17).

8. The electric energy metering box assembling and calibrating all-in-one machine CAN communication and protection interface module according to claim 1, characterized in that, The parallel ground pins of the bus interface seat (H6) include at least two ground pins, which are connected to the system ground through wide wiring to form a low-impedance discharge path.

9. The electric energy metering box assembling and calibrating all-in-one machine CAN communication and protection interface module according to claim 1, characterized in that, The differential signal pins and the ground pins on the bus interface seat (H6) are staggered, for improving the electromagnetic interference suppression capability.

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