Mitsubishi QPLC application in fiber processing line

1. company introduction

 

The QPLC application Mitsubishi equipment QPLC application Mitsubishi manufacturer for high security company, the company for large scale chemical fiber machinery manufacturing plant, FA product has a widely used, in the industry have a certain degree of visibility. The equipment for 5000 tons of fiber post processing production line project, the owner for a Japanese chemical fiber factory.

 

 

2. device description

 

For controlling the size of.I/O repeatedly the equipment used in the fiber tensile, curled before processing production, mainly by the guide wire frame, eight roller guide wire machine, hot water tank, a first drawing machine, water bath, the second drawing machine, steam box, the third drawing machine, stack machine, tension frame, crimping machine, curling side motor and oil pump electric machine, vibration motor, circulating water pump, vibration detection equipment for 103 points, wherein the switch quantity input 61 points, switch output is 39, analog input 3. Main control requirements for chemical fiber speed, drawing ratio, steam and water temperature, the interlock logic control. The control system is the key to ensure the guide wire, a pull, pull, three lead, crimp Wutai motor speed synchronization.

 

 

3. System configuration

 

As the figure, the system uses the Mitsubishi Co's Q series PLC as the main controller, transmission control for Emerson's EV2000 series inverter, the man-machine interface is F940GOT.

 

 

System configuration is as follows:

 

The main controller: q00cpu: speed and drawing ratio is given. Through the I / O module, field testing machine emergency stop, limit position switch and analog signal, complete linkage control and alarm function.

 

Input module: QX40: the completion of the field of switch control collection.

 

Output module: QY10: complete the switch output.

 

Module input: Q64AD: to complete the field simulation test.

 

Serial communication module: QJ71C24N-R4: inverter communication link.

 

Driving unit: Emerson EV2000 series inverter.

 

In view of the length of the paper, the paper mainly describes the design and implementation of key control system, to ensure that the guide wire, a pull, pull pull two, three, five sets of synchronous motor speed. Crimp customers based on the cost factor, drive unit uses Emerson EV2000 series inverter, and the requirements of the main controller and its constitute a the RS485 as the communication medium low cheap communication link. Although the guide wire, a pull, pull two, three pull, curling 5 inverters use of common DC bus operation mode, and install the incremental encoder form the closed-loop speed to improve the speed and accuracy, crimping machine inverter tension sensor to control stable tension, improve the fiber quality. But in the process of starting and stopping equipment especially adjust running speed and drawing during operation than the technological parameters such as real-time low speed communication link problem is shown.

 

 

In design, although a communication module can be composed of 485 networks, but because of a large amount of communication, we must send the speed of the motor speed and stop information, but also read the frequency converter operating voltage, current, frequency and other parameters, so if the use of a module, the communication cycle will increase, the 485 communication ports simultaneously on a pull, three traction, four sets of frequency communication, the communication protocol frame length is 18 bytes, the maximum speed command response 19200Bit/s transmission rate, the maximum time delay 20ms response when the maximum speed is 200M/Min, although the guide wire is slightly lagging behind, but in the process is acceptable. The synchronization ability of the starting and stopping process is realized by the synchronous speed of the instruction and the speed of the five motors and the uniformity of the tension of the fiber.

 

4. Debugging and understanding

 

In the actual debugging process, the system is basically in line with our expectations, but in the communication debugging, we found that the Q series PLC equipped with multiple communication module system, the stability of the communication and the length of the PLC scan cycle. With the continuous enhancement of function, the continuous improvement of the process, the scan cycle is also increased, when the maximum scan cycle is greater than 25ms, the communication began to unstable phenomenon.

 

 

Phenomenon: we use the QJ71C24 special communication instructions to accept communications data, when the scan cycle is greater than 25ms, in the 4 ports in the same communication, the last port of the program will occasionally have a communication error, when the acceptance flag has jumped to ON, said the data has been accepted, but the data area is no data. We have four mouth of the process of communication and found that the situation is still, the error occurred only in the last one.

 

Analysis reason: we think that the communication timing problems, the system accepts the flag bit jump and system data transmission is not synchronous, which is the system internal communication sign establishment, the communication buffer data has not yet had time to transfer. So we judge the system communication timing extension will affect the timing of the system communication. But because the system program is larger, finally in order to ensure the reliability of the system CPU from Q02 to Q00, improve the system processing speed, the scan cycle reduced to 10ms below.

 

 

5. User feedback

 

The system has been put into operation more than three months, the current system is very stable and reliable, reliable, technical indicators have reached the design effect.