Abstract: Current communication protocol consistency test methods between the charger and battery management system (BMS) is mainly designed according to expert experience, which lacks theoretical support, resulting in weak test coverage and unconvincing test results. To effectively solve the above problem, a communication protocol consistency test method was designed here based on a finite state machine (FSM). First, through a detailed interpretation of Protocol GB/T 27930—2015, the communication process between the charger and BMS was analyzed using the proposed method to ensure the consistency of communication between different entities of the protocol. Secondly, the unique input/output (UIO) was exploited on FSM to get the test sequence and the final test case set. The recursive algorithm was adopted to consider the pre-test cases so that each test case had complete input and output. The results show that the consistency testing method based on FSM not only provides theoretical support for the communication protocol consistency testing process between charger and BMS, but also has strong reuse ability compared to the experience-based method.

Key words: finite state machine, charger, battery manage system, consistency test