It is an inevitable trend to solve the outdated technical problems in automatic packaging projects. The factory area where the traditional automatic packaging equipment production line is located must ensure the safe operation throughout the year. Therefore, the attitude towards it is usually "if there is no fault, there is no need to repair". In recent years, due to outdated technology, manufacturers have to upgrade the packaging system. The challenges are mainly from two aspects
1. There has never been a good downtime window.
2. The appearance and performance of the system should be exactly the same as before shutdown to ensure that the operator can accept the system.
In view of the above two main problems, the automatic packaging system of a bread production line was upgraded to solve these problems. The old control system was upgraded to control and coordinate the packaging area of the bread factory. The packaging system consists of 7 production lines, handling more than 20 boxes per minute. The main technologies and Strategies of the automatic packaging equipment production line of the bread factory are as follows:
■ develop mitigation and contingency plans by identifying known risks in advance.
■ for old projects, especially in packaging applications where time is critical, pay close attention to sequence time when upgrading the system.
■ system upgrades need to be tracked and consistent across all production facilities.
该项目需要用4 个机架和超过60 个模块来替换PLC 5/25，这些模块通过远程输入/ 输出（I/O）和过时的数据高速公路通信协议，连接到工厂的其余部分。旧的处理器和系统被可编程的自动化控制器和基于以太网的I/O 所取代。此外，还涉及到软件转换、更新现有（破烂不堪的）电气设计文档。
The project required the replacement of PLC 5 / 25 with four racks and more than 60 modules, which were connected to the rest of the plant via remote input / output (I / O) and outdated data highway communication protocols. The old processors and systems were replaced by programmable automation controllers and Ethernet based I / O. In addition, it involves software conversion and updating of existing (dilapidated) electrical design documents.
The goal of the project is to replace all hardware (the existing processor is full and can no longer be edited), test the new I / O, and ensure the smooth implementation of existing functions before startup. As the project is based on hardware and lacks human machine interface (HMI) screen, it is impossible to fully simulate and test such projects before it is launched. In order to reduce the start-up risk, the project team takes extra care in quality management such as code conversion, cross check code, drawing review, etc.
停机时间选在了劳动节周末的3 天假日。电气团队从周六上午12 点开始接线，并在周日凌晨5 点结束。在周日，控制团队完成了所有I /O 检查，然后进行了功能测试。由于质量控制做的很好，代码测试进行得很顺利，经过漫长的一天，团队最终完成了工作。这样，就有星期一作为备用，可以进行更多测试，并有机会让团队休息。该系统在启动爬坡（2 秒内从0 到60 mph）内进行了调试，与项目相关的总停机时间仅为20 分钟。通过强有力的执行质量计划、严格的验收时间表和详细的现场验收测试清单，该项目的完成时间比预期提前，这为额外的测试留出了缓冲时间。
The downtime was selected on the 3-day holiday of the Labor Day weekend. The electrical team started wiring at 12 a.m. on Saturday and ended at 5 a.m. on Sunday. On Sunday, the control team completed all I / O checks and then conducted functional tests. Due to the good quality control, the code testing went smoothly, and after a long day, the team finally completed the work. That way, there's Monday as a backup, more testing and a chance to rest the team. The system was debugged within the start-up ramp (from 0 to 60 mph in 2 seconds), and the total project related downtime was only 20 minutes. Through a strong execution quality plan, strict acceptance schedule and detailed site acceptance test list, the completion time of the project is ahead of schedule, which provides buffer time for additional tests.
According to the different application requirements and environments, automation system integrators need to consider all possible difficulties for customers. Advanced automatic packaging equipment and control technology can help manufacturers realize the integration and upgrading of packaging system, and help enterprises achieve smooth upgrading and efficient operation of the system in the shortest time.