Abstract : This paper abandons the traditional host computer + PLC control mode and develops a high-performance, cost-effective in-place cleaning device control system for juice filling equipment based on the LabVIEW platform using an industrial computer and data acquisition board. This system satisfies different cleaning processes while stably and reliably achieving a high degree of automation in the cleaning process. Keywords : LabVIEW; CIP; juice filling equipment; data acquisition and processing 1. Introduction CIP stands for Clean In Place, which literally means cleaning in place. It refers to cleaning and sterilizing sealed, stationary containers using water and different washing solutions, relying on thermal, physical, and chemical energy, according to a certain program, through circulation and a certain action time. Currently, this cleaning method has become a necessary means to ensure product quality and normal equipment operation, and an indispensable part of the enterprise production process. Therefore, beer, beverage, and dairy product manufacturers at home and abroad generally use CIP systems to clean filling equipment. Traditional CIP control systems all adopt a host computer + PLC architecture and communicate via fieldbus. During development, based on the cleaning process, relevant control parameters such as cleaning time, acid/alkali concentration, cleaning temperature, and cleaning sequence are programmed and written into the PLC. Automatic or manual cleaning of the equipment is achieved through interaction between the operator and the host computer. However, the host computer typically uses a high-end industrial panel PC, serving only as a human-machine interface terminal for monitoring, resulting in significant resource waste. This system integrates advanced technologies from NI, including data acquisition, signal processing, and digital I/O. It operates using an industrial PC + data acquisition card model, seamlessly integrating the logic control and monitoring management functions of the CIP cleaning system with the software advantages of LabVIEW in industrial measurement and control. While ensuring reliability, it fully utilizes host computer resources, not only improving the accuracy of on-site analog quantity acquisition but also significantly reducing control system development costs and shortening the development cycle. 2. System Composition This system was developed for the automatic cleaning of bottling equipment in a domestic juice production company. Based on the cleaning process provided by the manufacturer, the overall architecture and related control requirements of the CIP cleaning system are as follows: [align=center] Figure 1 Overall Architecture of CIP Cleaning System[/align] Control Requirements: 1. Five liquid tanks display the liquid level in real time through level sensors, and provide high and low limit control; 2. Two-channel self-circulating alkali solution heating system, with temperature measured in real time by temperature sensors, automatically controlling the opening degree of the steam valve to control heating; 3. Detection of alkali solution reflux concentration using conductivity sensors (2 channels), thereby controlling alkali solution reflux; 4. Detection and control of digital I/O signals such as flow switches, air pressure switches, motor feedback, relays, and solenoid valves. Based on the overall structure and related control requirements of the CIP cleaning system, the hardware structure of the control system is designed as shown in Figure 2, mainly including an industrial panel PC with touch screen functionality, a PCI-6221 multi-function data acquisition card, a PCI-6513 industrial-grade digital output card, and related connecting accessories. [align=center]Figure 2 Hardware Structure Block Diagram of the Control System[/align] The control system software was developed using NI's LabVIEW 7.1 and NI-DAQmx driver software. NI-DAQmx is not limited to basic data acquisition drivers; it offers faster efficiency and superior performance in the development of data acquisition and control applications. Utilizing LabVIEW in conjunction with NI-DAQmx fully leverages the functionality of the data acquisition device, enabling rapid and flexible data acquisition and equipment control. The system software design adopts a modular approach, designing different functionalities into separate modules, mainly including six parts: data acquisition and processing module, logic control module, real-time monitoring module, formula management module, fault alarm module, and system management module. All modules are integrated into the same main program framework, allowing for flexible expansion, upgrades, and maintenance of functions, and facilitating portability to other applications. 3. Data Acquisition and Processing Liquid level, conductivity, and temperature are important parameters in the CIP automatic cleaning program, and their measurement accuracy directly affects the cleaning effect and product quality of the beverage filling equipment. To reduce external noise interference, the signal conditioning outputs from the level sensor, conductivity sensor, and temperature sensor are connected to the data acquisition card differentially via twisted-pair cables. Signal shielding, shielded cables and accessories for connecting test signals, and proper grounding of the data acquisition card are also crucial; these measures ensure the reliability of the system's data from a hardware perspective. On the software side, the system primarily uses low-pass filtering and mean filtering to reduce the impact of random noise on the measurement results. The NI PCI-6221 is a cost-effective, multi-functional data acquisition card. Its 16 analog inputs (16-bit, 250kS/s) fully meet the accuracy requirements for acquiring analog quantities such as level, conductivity, and temperature. Its 24 configurable digital I/O channels are mainly used for acquiring digital input signals such as motor feedback, pressure switches, and flow switches. Two 16-bit analog outputs (833kS/s) are used to control the opening of steam valves. The CIP automatic cleaning control system compares the data acquisition and processing results with the set thresholds. The results, along with digital input signals from the flow switch, air pressure switch, and motor feedback, constitute the key parameters for the entire system's logic control, and are used to control the actions of steam valves, solenoid valves, and relays. The CIP automatic cleaning system status display interface is shown in the following figures. [align=center] Figure 3.1 Status Display Interface 1[/align] [align=center] Figure 3.2 Status Display Interface 2 Figure 3 CIP Automatic Cleaning System Status Display Interface[/align] 4. Conclusion The development process and field application of the CIP automatic cleaning control system based on an industrial computer + data acquisition card show that this system fully meets the various requirements of the cleaning process for juice filling equipment, achieving stable and accurate control. Compared with the traditional host computer + PLC control mode, this system not only improves the accuracy of on-site analog quantity acquisition but also significantly reduces development costs. References: [1] Yang Leping, Li Haitao, Yang Lei. LabVIEW Programming and Application. Beijing: Electronic Industry Press, 2004. [2] National Instruments Corporation. LabVIEW Function and VI reference manual, January 1998 Edition. [3] Liu Junhua. Virtual Instrument Design Based on LabVIEW [M]. Beijing: Electronic Industry Press, 2003.