网络控制信号装置
network controlling signal unit
共电制电话
central battery telephone
船内电气信号装置
inner electric signalling system
光电信号电压
photoelectric signal voltage
失聪者用电信装置
telecommunications device for the deaf
TDD
通信信号电缆
Communication and Signal Cable
保护性压力信号装置
protective pressure signaling unit
监视信号装置
supervisory signalling apparatus
佩带者不适信号装置
personal distress signal unit