A.SNTP對(duì)時(shí) B.B碼對(duì)時(shí) C.1588對(duì)時(shí) D.PPS、PPM
A.檢修壓板 B.出口壓板 C.功能壓板 D.接收壓板
A.250us B.500us C.1ms D.2ms