Resistance welding machine controller with EtherCAT communication function

Abstract

The utility model discloses a resistance welding machine controller with an EtherCAT communication function, which comprises a welding machine controller and a communication protocol conversion module, the communication protocol conversion module comprises a Modbus communication unit, a protocol conversion unit and an EtherCAT communication unit, the Modbus communication unit is electrically connected with the welding machine controller through an RS485 interface, the protocol conversion unit is electrically connected with the welding machine controller through an RS485 interface, and the EtherCAT communication unit is electrically connected with the welding machine controller through an RS485 interface. The Modbus communication unit is electrically connected with the protocol conversion unit, the protocol conversion unit is electrically connected with the EtherCAT communication unit, and the EtherCAT communication unit is electrically connected with the upper computer through an RJ45 interface. According to the utility model, the communication protocol conversion module is adopted to convert a communication protocol and convert a Modbus protocol into an EtherCAT protocol, so that the welding machine controller only provided with a serial port can carry out EtherCAT communication with the PLC, and I / O action connection and welding data transmission between the PLC and the welding machine controller are realized.

Description

Technical Field

[0001] The utility model relates to a resistance welding machine controller with EtheCAT communication function. Background Art

[0002] At present, in the field of resistance welding, the application of automatic welding is becoming more and more widespread. Automatic welding integrates the welding machine into the automated production equipment. The upper computer sends welding instructions to the welding machine controller, and the welding machine controller feeds back the welding results to the upper computer, and the upper computer takes the next action according to the results. This requires a certain amount of data interaction between the welding machine controller and the upper computer, which is generally achieved by communication. Different welding methods have their own characteristics. Some welding methods may communicate with upper computers such as PLCs or robots even during single-machine operation, such as multi-spot welding, flash welding, energy storage welding, etc.

[0003] Flash welding belongs to a type of resistance welding. Its welding principle is that current passes through the two end faces of the workpiece to generate an arc. The heat generated by the arc melts the end faces of the workpiece, and then pressure is applied to both ends of the workpiece to fuse the workpiece together. Its welding process is usually divided into three stages: preheating, flashing, and tempering. The preheating and tempering stages are the same as those of ordinary spot welding machines. The flashing stage is an important stage in flash welding. Whether the arc is stable will directly affect the welding quality. During the flashing process, the distance between the two end faces of the workpiece plays a crucial role in the stability of the arc. If the distance is too far, the arc cannot be started or will be interrupted. If the distance is too close, the two end faces of the workpiece are prone to direct short circuit, which will also interrupt the arc. Once the arc is interrupted during the welding process, it means that the current welding fails and the workpiece will be scrapped.

[0004] Since the flash welding machine has many actions, it is usually controlled by a PLC, and the welding is the responsibility of the welding machine controller. The two need to cooperate closely to achieve perfect welding. The usual method is to use proximity switches to determine the distance of the workpiece, but this method does not work well in actual use and has high requirements for the shape and placement position of the workpiece.

[0005] In order to meet the welding requirements, a method of detecting the flash current and changing the workpiece distance according to the magnitude of the current is adopted. When the workpiece distance becomes farther, the flash current also decreases; when the workpiece distance is too close, the flash current will also increase. The distance between the workpieces is changed by judging the magnitude of the flash current. In order to implement the above method, it is required that the welding machine controller and the PLC communicate with each other to transmit the flash current data. However, for a welding machine controller with only a serial port, it cannot directly communicate with the PLC. Summary of the Utility Model

[0006] The technical problem to be solved by the utility model is that a resistance welding machine controller with only a serial port cannot directly perform EtheCAT communication with a PLC.

[0007] To solve the above problems, the technical solutions adopted by the present utility model are as follows:

[0008] A resistance welding machine controller with EtheCAT communication function includes a welding machine controller and a communication protocol conversion module. The communication protocol conversion module includes a Modbus communication unit, a protocol conversion unit, and an EtheCAT communication unit. Among them, the Modbus communication unit is electrically connected to the welding machine controller through an RS485 interface, the Modbus communication unit is electrically connected to the protocol conversion unit, the protocol conversion unit is electrically connected to the EtheCAT communication unit, and the EtheCAT communication unit is electrically connected to the upper computer through an RJ45 interface; the welding machine controller converts the communication protocol through the communication protocol conversion module, converts the Modbus protocol into the EtheCAT protocol, and realizes the EtheCAT communication function between the upper computer and the welding machine controller.

[0009] The following is a further limited technical solution of the present utility model. The communication protocol conversion module includes a serial port part and an Ethernet part; the serial port part uses an RS485 interface and the protocol is Modbus RTU; the Ethernet part uses an RJ45 general interface and the protocol is EtheCAT. The communication protocol conversion module maps the data of the Modbus communication unit to the buffer area of the EtheCAT communication unit for EtheCAT communication with the upper computer.

[0010] The following is a further limited technical solution of the present utility model. The upper computer is a PLC controller.

[0011] The following is a further limited technical solution of the present utility model. The communication protocol conversion module includes a main IC chip, a power supply, an RS485 interface, an RS485 / TTL conversion chip, and an RJ45 interface. The power supply supplies power to the main IC chip and the RS485 / TTL conversion chip. The RS485 interface is electrically connected to the RS485 / TTL conversion chip, the RS485 / TTL conversion chip is electrically connected to the main IC chip, and the main IC chip is electrically connected to multiple RJ45 interfaces.

[0012] Compared with the prior art, the present utility model has the following technical effects:

[0013] The present utility model adopts a communication protocol conversion module to convert the communication protocol, converts the Modbus protocol into the EtheCAT protocol, enables the welding machine controller with only a serial port to perform EtheCAT communication with the PLC, and realizes the I / O action connection and welding data transmission between the PLC and the welding machine controller.

[0014] The present utility model will be further described below in conjunction with the accompanying drawings and embodiments. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the accompanying drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, other accompanying drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 is the communication schematic diagram of the present utility model;

[0017] Figure 2 is the communication schematic diagram of the specific modularization of the communication protocol conversion module in the present utility model;

[0018] Figure 3 is the schematic diagram of the hardware part of the communication protocol conversion module in the present utility model;

[0019] Figure 4 is the interface connection relationship diagram of the present utility model;

[0020] Figure 5 is the communication flow chart of the application of the present utility model. Detailed Embodiment

[0021] In order to make the above-mentioned objects, features, and advantages of the present utility model more obvious and understandable, the following will describe the detailed embodiments of the present utility model in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present utility model. However, the present utility model can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0022] As Figure 1 shown, this embodiment provides a resistance welding machine controller with EtheCAT communication function, including a welding machine controller and a communication protocol conversion module. The welding machine controller converts the communication protocol through the communication protocol conversion module, converts the Modbus protocol into the EtheCAT protocol, and realizes the EtheCAT communication function between the upper computer and the welding machine controller.

[0023] 1. Composition

[0024] As Figure 2 shown, the communication protocol conversion module mainly consists of a Modbus communication unit, a protocol conversion unit, and an EtheCAT communication unit.

[0025] As Figure 3 and 4 shown, the hardware part of the communication protocol conversion module consists of a main IC chip, a power supply, an RS485 interface, an RS485 / TTL conversion chip, an RJ45 interface, etc.

[0026] For the Modbus communication unit, the welding machine controller is the slave station and the communication module is the master station; for the EtherCAT communication unit, the PLC is the master station and the communication module is the slave station. To improve the reliability of communication, some main signals are transmitted in bytes, and a state is represented by 8 bits.

[0027] The communication data is divided into 8-byte (4-word) input and 8-byte (4-word) output, as shown in Table 1:

[0028] Table 1:

[0029]

[0030] 2. Working Principle

[0031] The communication protocol conversion module is divided into two parts: a serial port part and an Ethernet part. The serial port part uses an RS485 interface, and the protocol is Modbus RTU. The communication protocol conversion module serves as the master station, and the welding machine controller serves as the slave station. The communication format is a baud rate of 38.4 Kbit / s, 8 data bits, even parity, and 1 stop bit. The Ethernet part uses an RJ45 general interface, and the protocol is EtherCAT. The communication protocol conversion module maps the data of the Modbus communication unit to the buffer area of the EtherCAT communication unit to communicate with the PLC via EtherCAT. The input and output lengths are both 8 bytes.

[0032] 3. Working Process

[0033] As Figure 4 and 5 shown, after turning on the 24V DC power supply, initialization is first performed, and then the communication protocol conversion module establishes a connection with the PLC: the communication protocol conversion module communicates with the PLC via EtherCAT; at the same time, the communication protocol conversion module establishes a connection with the welding machine controller: it communicates with the welding machine controller via Modbus in a polling manner.

[0034] It should be noted that the control programs or algorithms involved in the working process of this embodiment are not within the protection scope of the present utility model and are only used for those skilled in the art to understand the application of this embodiment.

[0035] The above are only the preferred embodiments of the present utility model, and do not impose any form of limitation on the present utility model. Any person skilled in the art can, without departing from the scope of the technical solution of the present utility model, make many possible changes and modifications to the technical solution of the present utility model by using the methods and technical contents disclosed above, or modify it into equivalent embodiments with equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the present utility model without departing from the content of the technical solution of the present utility model shall be covered by the protection scope of the present utility model.

Claims

1. A resistance welding machine controller with EtheCAT communication function, characterized in that, It includes a welding machine controller and a communication protocol conversion module. The communication protocol conversion module includes a Modbus communication unit, a protocol conversion unit, and an EtherCAT communication unit. Among them, the Modbus communication unit is electrically connected to the welding machine controller through an RS485 interface, the Modbus communication unit is electrically connected to the protocol conversion unit, the protocol conversion unit is electrically connected to the EtherCAT communication unit, and the EtherCAT communication unit is electrically connected to the host computer through an RJ45 interface; the welding machine controller converts the communication protocol through the communication protocol conversion module, converts the Modbus protocol into the EtherCAT protocol, and realizes the EtherCAT communication function between the host computer and the welding machine controller.

2. The resistance welding machine controller with EtheCAT communication function according to claim 1, characterized in that, The communication protocol conversion module includes a serial port part and an Ethernet part; the serial port part uses an RS485 interface and the protocol is ModbusRTU; the Ethernet part uses an RJ45 general interface and the protocol is EtherCAT. The communication protocol conversion module maps the data of the Modbus communication unit to the buffer area of the EtherCAT communication unit for EtherCAT communication with the host computer.

3. The resistance welder controller with EtheCAT communication function according to claim 2, characterized in that, The host computer is a PLC controller.

4. The resistance welder controller with EtheCAT communication function according to claim 1, characterized in that, The communication protocol conversion module includes a main IC chip, a power supply, an RS485 interface, an RS485 / TTL conversion chip, and an RJ45 interface. The power supply supplies power to the main IC chip and the RS485 / TTL conversion chip. The RS485 interface is electrically connected to the RS485 / TTL conversion chip, the RS485 / TTL conversion chip is electrically connected to the main IC chip, and the main IC chip is electrically connected to multiple RJ45 interfaces.

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