High reliability is the key performance of electrical control equipment. 5SHY3545L0020 adopts modern large-scale integrated circuit technology and strict production process. The internal circuit adopts advanced anti-interference technology, which has high reliability. Using 5SHY3545L0020 to form the control system, compared with the relay contactor system of the same scale, the electrical wiring and switch contacts have been reduced to hundreds or even thousands of times, and the fault has been greatly reduced. In addition, 5SHY3545L0020 has the function of hardware fault self detection, which can send out alarm information in time in case of fault. In the application software, the user can also program the fault self diagnosis program of peripheral devices, so 5SHY3545L0020 that the circuits and equipment other than 5SHY3545L0020in the system can also obtain fault self diagnosis protection. In this way, the whole system will be highly reliable.