The hottest Schneider twidoplc in large automatic

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Application of Schneider twidoplc in large automatic coating line

1 Overview according to the sizing process requirements and production program of double-sided waterproof adhesive for biodegradable dinner plates, we have designed, developed and manufactured an automatic coating line for double-sided waterproof adhesive for biodegradable dinner plates for our customers. This automatic coating line is composed of meal tray blanking, 3 times of spraying, 6 times of baking, turnover and transfer manipulator, blanking, automatic sorting and packaging, conveyor chain, etc., all of which need full-automatic control and convenient commissioning. All process equipment along the line are relatively independent, with a large number of i/o points (about 520 i/o points in total) and scattered distribution

based on the above, if PLC is used for centralized control, the amount of cable laying is large. Therefore, we are based on the use of distributed control. In order to achieve distributed control, if medium and large plc+ bus communication module and remote i/o module are used, the cost is high. Through comparison, Schneider Twido series PLC has built-in communication module, which has strong communication function, can meet the control requirements, and has high cost performance, And Schneider Electric can provide a low-cost integrated solution for seamless MODBUS serial communication between HMI and PLC, PLC and frequency converter

2. System hardware configuration

the electrical control system of this coating line is composed of two layers: the upper layer is the integrated monitoring layer, the main component is the industrial touch screen, which communicates with PLC through MODBUS bus to complete the graphic display and parameter setting of the equipment status of the whole line; The lower layer is the control layer, which is composed of six sets of Twido PLCs. The six sets of PLCs are slave stations relative to the upper touch screen. The six PLCs on site complete the automatic feeding of the dinner plate, the spraying of the three sets of automatic glue spraying system, the temperature of the drying and curing equipment, the control of the dinner plate turnover and transfer manipulator, automatic offline, sorting and packaging, and the conveyor chain. Among them, 1 × PLC communicates with the frequency converter driving the two conveyors through MODBUS bus, 6. PLC communicates with local industrial touch screen through MODBUS bus to complete the operation, parameter setting and monitoring of local equipment. The system structure is shown in Figure 1

Figure 1 Schematic diagram of the electrical control system of the automatic coating line for dinner plates

1) industrial touch screen

this machine selects one xbtg series touch screen of Schneider company with Ethernet communication port and monochrome STN as the graphic display unit, one of which has built-in Ethernet, leaving an interface for the later system update, and synchronously linking the communication functions such as uni telway, MODBUS and modbustcp/ip. The xbtg terminal can use vijeodesigner vjdspul software to configure and design pages in the environment of window, where the crack of the sample may occur at the position of strong force, and most of them are at the position of fracture force. Through the script written in Java language, various information can be processed in the xbtg terminal

as the central control equipment of the whole line, the touch screen is used to coordinate the coordination and data communication between the equipment controlled by the six slave PLC stations, so as to form an organically interrelated control system for the equipment of the whole line; Monitor and display the working status of equipment in the whole line; Provide action statistics, maintenance tips and alarms of each equipment; Set the operation authority of each institution through password

2) PLC configuration

each PLC is composed of DC power supply, CPU module, i/o and communication module. The main configurations of each PLC are as follows:

in order to prevent the impact of power fluctuation on PLC operation, isolation transformer and DC24V are used as the power supply and control of PLC, which is the power supply with slow temperature drop

due to the small extended i/o drive of Twido (the driving capacity of transistor do module above 16 points is only 0.1A), we choose MOSFET Tube solid-state relay board (see Figure 2) to amplify the output of PLC and then drive each load

the data exchange and correlation control between the six PLCs are completed through the script written in Java language on the upper xbtg touch screen. The whole line is equipped with many emergency stop buttons, and many innovative products have passed UL, CE, NSF and other third-party certification buttons and safety relay protection circuits to ensure the safety of operators and equipment

3) transmission frequency converter configuration

Schneider frequency converter ATV58 is used to give the conveyor speed. The ATV58 frequency converter has a Modbus communication interface, and 1 plc uses modibus bus bus to communicate with the two frequency converters to complete the speed synchronization, operation control and state monitoring of the two conveyors. Whether the two conveyors are fully synchronized is the key to the continuous operation of this automatic spraying line. Due to mechanical manufacturing and errors, the speed synchronization control must be carried out. The speed and position of the two conveyors are fed back to 1#plc through encoder, and the PLC will fine tune the speed of the two conveyors through PID operation to achieve fully synchronized operation

3. Conclusion

the electric control system of this line has the following advantages:

(1) complete the control of the complex large-scale self-zero time-lapse coating line through MODBUS serial communication, effectively reduce the cost

(2) the whole line runs smoothly, has high production efficiency, high degree of automation control, and has perfect protection and alarm functions

(3) human machine interface xbtg and Twido PLC support Modbus tcp/ip and CANopen communications, leaving an interface for future system updates

(4) perfect fault detection and alarm functions to ensure reliable operation of the equipment

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