Abstract : This paper introduces the capacity expansion and transformation of the automatic batching system for sintering at Xinsteel, based on PROFIBUS-DP fieldbus control, which fully utilizes the openness of the fieldbus. The transformed control system is more standardized and reasonable, with a significantly improved degree of automation, greatly enhancing the quality of sinter and production efficiency. Keywords: PROFIBUS-DP, fieldbus, frequency converter, batching ratio [b]0 Introduction[/b] Sintering batching is the core of sintering production and an important link in the entire steel production process. Reasonable batching of various materials is key to improving the grade of sinter. The original batching workshop of Xinsteel's sintering machine adopted a distributed process control system based on PROFIBUS-DP fieldbus to achieve automatic batching by microcomputer. PROFIBUS fieldbus is an open, digital, bidirectional, multi-branch communication network used in production sites to connect intelligent field devices and automation systems, enabling rapid communication between devices. Due to a technical upgrade project, a new 90m² sintering machine will also need to use this batching workshop. This increases the load, and the outdoor raw material silo, conveyor belt scales, and indoor frequency converters and control systems cannot meet the requirements. Therefore, based on fieldbus control, the workshop needs to be expanded, upgraded, and a high-performance automatic batching system established. 1. Composition and Principle The batching workshop currently has nine conveyor belt scales (1#-9#). The rotary motors of scales 1#, 3#, 7#, 8#, and 9# have a rated power of 2.2kW and a rated current of 5.0A, while the motors of scales 2#, 4#, 5#, and 6# have a rated power of 3.0kW and a rated current of 6.8A. The motors drive the weighing belts, resulting in a uniform material layer. The faster the motor rotates, the greater the material flow and the higher its proportion in the batch; conversely, the slower the motor rotates, the smaller the material flow and the lower its proportion in the batch. Each motor is driven by a frequency converter, and the frequency of the frequency converter is controlled by a PLC via a PROFIBUS-DP fieldbus. The PLC calculates the actual flow rate of each material based on automatically collected data on its load and instantaneous flow rate, compares this calculation with the set value, and completes closed-loop regulation. [b][align=center]For details, please click: Retrofitting the Sintering Machine Batching Control System Based on Fieldbus[/align][/b]