Abstract: USS is a communication protocol developed by Siemens for frequency converters. In small-scale automation systems, the USS protocol communication method is a good solution. This paper presents a standardized design for communication between S7-200 and Siemens variable frequency speed control devices based on the USS protocol, which can be universally applied to automation control systems. Keywords: USS protocol; frequency converter; PLC; standardization In recent years, computer and communication technologies have gradually become the core part of most solutions in industrial environments. Communication and networking have become an indispensable and important component of control systems, and also one of the key points and difficulties in the design and maintenance of control systems. In industrial control, the drive control of AC motors is increasingly accomplished using frequency converters. These converters are not only independent actuators, but with their increasing intelligence, they can be integrated with host computers through various communication methods to form an organic whole. In actual engineering implementation, communication requires the writing and development of communication programs. To save development costs and improve efficiency, it is necessary to standardize and universalize the written communication programs as much as possible, so that they can be directly called in similar projects. In small-scale control systems, the USS protocol is a very successful automation system solution. This paper standardizes the communication programs required for it. This program was developed from an automated control system project for a large copper drawing machine. After on-site testing, its control performance was excellent. For details, please click: Standardized Communication between PLC and Frequency Converter Based on USS