A.10S B.5S C.3S
A.多點(diǎn)串聯(lián) B.多點(diǎn)環(huán)形 C.點(diǎn)對(duì)點(diǎn)
A.壓板未投入 B.開關(guān)的遙信輔助接點(diǎn)永遠(yuǎn)合的故障 C.有某個(gè)輔助接點(diǎn)抖動(dòng)造成通道里不斷上送遙信變位包和SOE包 D.上行通道故障