This standard specifies the requirements for the use, design, manufacturing, and testing of electronic devices for rail transit locomotives and vehicles. It also specifies the basic software and hardware requirements for the durability and reliability of the devices. If appropriate, additional requirements in other standards or specifications can serve as supplementary requirements to this standard. The terms of this standard that can be negotiated and agreed upon by both parties can be found in Appendix B. This standard applies to all electronic devices such as control, regulation, protection, power supply, etc. installed on rail transit vehicles (including subway and urban rail vehicles). These devices can be powered by on-board batteries or generators, or by low-voltage power sources (transformers, voltage dividers, auxiliary power sources) directly or indirectly connected to the contact network; In this standard, electronic devices refer to devices mainly composed of semiconductor devices and other general components, which are usually installed on printed boards. Note: This standard also applies to trigger boards for sensors (current, voltage, speed, etc.) and power electronic devices, but the complete trigger device should comply with GB/T 25122,1. This standard does not apply to power electronic devices of the main and auxiliary circuits