DC loop signaling (Dirrect Current)

同义词释义

1)DC loop signaling (Dirrect Current),直流环路信令2)LDDC Long Distance D.C. line signaling,远距离直流线路信令3)loop signalling limit,环路信令极限4)loop start signaling,环路启动信令5)LSR Loop Signaling Repeater,环路信令中继器6)loop disconnect signalling,环路断续信令