Abstract This paper briefly describes the performance of the FA361A drawing frame, highlighting its advanced electrical design and convenient process parameter changes. The machine operates stably and reliably, providing strong support for textile enterprises to ensure yarn quality. Keywords PLC, Touch screen, Frequency converter 1 Introduction The FA361A high-speed drawing frame is a key piece of equipment in the pre-spinning process. It uses a touch screen as the human-machine interface. The system utilizes a user-friendly programming software, specifically the Delta 1) VP series PLC, with motors and frequency converters as the main control objects. This system offers advantages such as simple operation, reliable control, convenient maintenance, short project development cycle, and high cost-effectiveness, making it highly competitive in the market. 2 System Requirements The FA316A high-speed drawing frame has control functions such as automatic stop upon sliver breakage, automatic stop upon full canister filling, automatic stop upon cotton slugging, and automatic stop upon entanglement fault. The touch screen allows real-time monitoring of the drawing frame's operating status, as well as the display of working parameters such as the current shift, length, sliver output speed, and pressure roller speed. The cotton spinning process parameters can be set via the touchscreen, including setting work shifts, presetting sliver output speed, setting extended protection time, and resetting the output for each shift. Sliver output speed is controlled by the touchscreen and communicates with the frequency converter via the touchscreen's RS485 serial port to control the frequency converter's operating frequency. 3. Hardware Configuration The control system uses the PLC's high-speed counting input points XO and Xl to count the pressure roller speed and yarn length, respectively. Including door switches, micro switches, photoelectric switches, thermal protection relays, and button signal inputs, a total of 17 input points and 10 output points are required. Additionally, one communication port is needed between the PLC and the touchscreen, and between the touchscreen and the Delta frequency converter. Because this control system is a small-scale system, the Delta economical DVP32E ProS type PLC is selected. The electrical control system structure is shown in Figure 1. 4. Software Development 4.1 Parameter Initialization To reduce the workload of on-site testing personnel, the power-off protection data memory used by the program is initialized upon the first power-on of the system. The ladder diagram is shown in Figure 2. 4.2 Setting Process Parameters In the process parameter setting page of the touchscreen (HMI), process parameters such as shift, preset length, yarn output speed, low-speed time, and over-length protection can be modified or reset. [b]4.3 Detection and Calculation of Pressure Roller Speed ​​and Spinning Length 4.3.1 Detection and Calculation Method of Pressure Roller Speed[/b] A high-speed counter (C235) is used to collect one detection pulse of the pressure roller within 35 seconds. The change in the value of the high-speed counter (C235) within 35 seconds is calculated. One counting pulse corresponds to one rotation of the pressure roller. Multiplying this by 20 gives the pressure roller speed (m/min). 4.3.2 Method for Detecting and Calculating Yarn Length A high-speed counter (C236) is used to collect and detect the yarn length counting pulses in real time. One counting pulse corresponds to one rotation of the pressure roller. The calculation formula is as follows: Where: L - yarn length (m); D - pressure roller diameter (mm). 4.4 Communication between Touch Screen and Inverter This program uses the macro instruction of the touch screen to communicate with the inverter via the RS458 serial port using the MODbus ASC protocol; controlling the inverter's operation, stop, fault initialization, and frequency changes. 5 Conclusion Since the FA361A drawing frame uses a touch screen as the human-machine interface and Zhongda's economical PLC as the control system, and all inverter operations are automatically completed by the touch screen, the system operation is more transparent to the user. It is not only simple to operate but also has a high cost-performance ratio and reliability. It has now been mass-produced and entered the market, receiving high praise from users. References : 1. Delta PLC Application Technology Manual [Z]. 2. Delta VFD-B Inverter User Manual [Z]. 3. HITECH Industrial-grade Human-Machine Interface Programming Manual [Z]. Application of Delta PLC on FA361A Drawing Mill: PDF