For example, almost all legacy computer systems need some form of design investigation, if for no other reason than to train new developers in the maintenance and extension of the system.
The major alarm maintenance signal of SDH transmission system are introduced and its implication and failure reason are described.
介绍了SDH传输系统主要告警维护信号，描述了告警维护信号的含义和故障产生原因。
3
Based on analyzing the common fault of belt conveyor system, the reason of the fault was found out. The settlement from design, installation, maintenance and producing management was put forward.