busy lamp

基本解释占有线指示灯

网络释义

1)busy lamp,占有线指示灯2)hold lamp,占线指示灯3)visual busy-lamp,占线灯信号，占线指示灯4)trunk congestion lamp,中继线占用指示灯5)busy indicator,占线指示器，占用指示器6)line signal,线路指示灯