Introduction Air-jet looms are a type of shuttleless loom, characterized by high production efficiency and the ability to weave a wide variety of products. However, they require sophisticated processes, demanding strong coordination of the entire machine's movements and resulting in a complex control system. Currently, most air-jet looms manufactured in China rely heavily on Japanese technology, with their electrical control systems also primarily imported from Japan. This hinders production cost reduction, makes it difficult to guarantee delivery times, and directly impedes product sales. To improve this situation, many manufacturers and related research institutions have undertaken extensive work over the years on the localization of electrical control systems for air-jet looms. The main approach has been to completely imitate the control methods of Japanese air-jet looms, employing multiple microcontroller systems to control the entire loom's movements and perform data processing. However, during the long-term research and development process, we have found that this method is time-consuming, involves cumbersome modifications, and suffers from poor system stability. Consequently, the localization of electrical control systems for air-jet looms has consistently failed to achieve satisfactory results. In response to this situation, our company, in its work on the localization of the electrical control system for the Japanese-made LA51VS air-jet loom, decided to abandon the previous imitation approach and adopt a new type of intelligent controller, the B&R Programmable Computer Controller (PCC). Designed according to the product's functional and operational requirements, we completed the entire process from development to successful prototype debugging in just three and a half months, opening up a new research and development path. Application of B&R PCC in Air-Jet Loom Control Systems Currently, the electrical control system of a conventional air-jet loom mainly includes the following aspects: 1. Basic motion control of the air-jet loom, including starting, running, and stopping the loom, detecting various process and equipment faults during operation, issuing relevant instructions according to process requirements, and controlling the loom's movements. 2. Weft insertion system control mainly refers to the coordinated control of the main nozzle solenoid valve, auxiliary nozzle solenoid valve, and yarn-stopping pin of the loom. 3. Warp feed system control, i.e., the electronic warp feed control system. Parameters are set according to the loom's process requirements, calculating the warp feed amount, warp feed compensation amount, and warp feed speed, thereby controlling the servo motor to achieve precise warp feed and effectively prevent stoppage. 4. Functional Parameter Settings, Fault Alarm Prompts, and Production Management Statistics: This function sets all parameters for the air-jet loom, provides detailed and accurate fault and alarm information, monitors the loom's operating status, and collects necessary information for production management. All actions of the air-jet loom are closely related to the loom's angle. It places high demands on the system's I/O signal response speed, processing time, positioning and stopping locations, the accuracy of solenoid valve opening and closing angles, and the control precision of the warp feed system. Taking a 600 rpm loom as an example, its rotation angle is 3.6 degrees per millisecond, while the loom's angle control accuracy requires ±2 degrees. This means the system must process multiple signals within one millisecond. These signals include high-frequency encoder signals from the main unit and servo motors, millivolt-level analog signals from the tension sensor, and analog control signals from the servo motors, among other non-switching signals. In summary, using a traditional Programmable Logic Controller (PLC) cannot meet the control requirements of an air-jet loom. This is because the primary function of a PLC is logic control, i.e., switching control. While it may have some special function modules, these are supplementary modules with an interface between the PLC and the hardware, and cannot be uniformly programmed and controlled within the PLC program. Furthermore, conventional PLC operating systems mostly use single-task clock scanning or monitoring programs to handle the program's own logic operations and the acquisition and updating of external I/O channel status. This directly results in the true "control speed" depending on the size of the application program, a consequence that undoubtedly contradicts the high real-time control requirements of the air-jet loom's I/O channels. Additionally, PLCs have only tens of kilobytes of memory, and their data processing capabilities are relatively limited. Therefore, using a PLC to perform such complex control in an air-jet loom control system is somewhat inadequate. The B&R Programmable Computer Controller (PCC) is a dedicated control system for motion control, process control, and network control. It is an intelligent controller that integrates the performance characteristics of a standard PLC, CNC system, and industrial computer. Its modular hardware and software structure allows for the combination of specialized control systems tailored to the designer's control needs, providing flexible networking and expansion capabilities. All modules (including intelligent modules such as motion modules) communicate with the PCC via a system bus, eliminating inter-module interfaces. Furthermore, the PCC's system software employs a time-sharing multi-tasking mechanism to build its application software's runtime platform. This means the application's runtime cycle is independent of program length, determined by the operating system's cycle time. This distinguishes the application's scan cycle from the actual external control cycle, fulfilling the requirements of true real-time control. Based on this operating system, the PCC's application program consists of multi-task modules, greatly facilitating project application software development. This allows for the easy creation of control program modules (tasks) based on the different functional requirements of each part of the control project, such as data acquisition, alarms, PID control calculations, and communication control. These modules operate independently while maintaining a certain degree of interrelationship between data. After independent development and debugging in stages, these modules can be downloaded together to the PCC's CPU and run in parallel under the scheduling and management of the multi-task operating system to jointly achieve the project's control requirements. PCC offers flexibility in using different programming languages ​​when developing individual task modules. This means that not only can the ladder diagram and instruction list languages ​​familiar to conventional PLCs be used on PCC, but users can also employ more efficient and intuitive high-level languages ​​(PL2000). PL2000 is a text-based language entirely geared towards control; those familiar with BASIC will find its syntax familiar, and its description of control requirements is very simple and intuitive. Furthermore, PCC application software development has the ability to integrate C language programs, providing powerful data processing capabilities. In terms of hardware structure, PCC is quite distinctive. Within its core computing module, PCC equips its CPU with a storage capacity several times larger than that of conventional PLCs (100K-16M), undoubtedly providing a robust hardware foundation for powerful systems and application software monitoring. PCC's hardware features are also reflected in its many dedicated interface modules designed for various signals in industrial settings, such as high-frequency pulse, incremental encoder, temperature, weighing signal, and ultrasonic signal interface modules. These systems easily integrate various forms of field signals into the PCC-based digital control system. Users can expand and network the hardware I/O channels of the application system as needed, using single channels, multiple channels, or dozens of channels as modules, from tens to hundreds or even thousands of points. In the machinery industry, the PCC integrates high-precision motion control functions such as high-speed encoder counting, speed and position compensation, electronic gear transmission, and electronic cams as dedicated modules, greatly improving control accuracy while making programming more convenient. Our company uses the B&R 2005 series PCC in the development of the electrical control system for air-jet looms. Below, we will describe the overall system control overview. This control system uses the B&R PCC as the main controller. The human-machine interface adopts a multi-functional touch screen display, which is connected to the PCC via communication, making operation more convenient and the interface more user-friendly. 1. Basic motion control. The PCC encoder module samples the angle sensor signal of the loom, performs frequency multiplication to improve control accuracy, and then converts it into a loom angle signal, which serves as the basic reference for various loom movements. Various parameters of the loom are set through the human-machine interface. During loom operation, the system status is monitored in real time, controlling every action of the loom, and simultaneously displaying the current loom status and fault causes on the touch screen. The weft detection range signal is output by the PCC high-speed digital I/O module, with an accuracy of ±1 degree. 2. Weft insertion control system. The PCC CPU is connected to the solenoid valve control board via RS232 interface, and the opening and closing angles of the solenoid valves are set through the human-machine interface. The solenoid valve control board receives instructions from the main controller and drives the solenoid valves to work according to the angle sensor signals. This system is a dual-jet arbitrary weft selection system, and the weft insertion system has normal operation weft insertion, slow weft insertion, and single weft insertion functions. All functions are operated through the touch screen. 3. Warp feed control system. The main controller calculates the speed of the servo motor of the warp feed system based on the parameters set by the system, such as the warp beam diameter, weft density, and loom speed. During loom operation, the warp tension is detected by the PCC tension full-bridge measurement module. After calculation by the CPU, the servo motor speed is adjusted by the analog output module to ensure relatively constant warp tension during loom operation. Additionally, the PCC allows setting whether the loom uses fast start, adjusting the servo motor's start delay, start time, stop delay, and stop time, and adjusting the weaving position before the loom starts, effectively preventing stoppages. 4. Production Management Statistics. The PCC's powerful data processing and computing capabilities make production efficiency statistics, operating status recording, and fabric doffing recording simple and effective. Current practice has proven that the new generation B&R PCC programmable computer controller is perfectly suited for high-end loom control systems. It not only ensures the original machine's functionality but also improves the system's overall control performance and reduces the failure rate (PCC can achieve 500,000 hours of trouble-free operation). Coupled with an economical and practical human-machine interface, operation becomes simpler and more convenient, significantly improving the overall quality of the equipment. Furthermore, due to the PCC's powerful network communication capabilities, it can easily achieve remote centralized computer monitoring of the loom, enhancing the scientific nature of weaving workshop management and improving management efficiency. B&R's powerful PCC features in industrial control embody the trend of integration between programmable logic controllers, industrial control computers, and DCS (distributed industrial control systems) technologies. Our company is willing to work with B&R to develop high-performance textile machinery equipment with unique style and technical characteristics for the textile machinery industry.