The synchronization principle of IRIG-B code is analyzed.When applying IRIG-B code in substation IED,neither communication messages of fieldbus nor multiple pulse signals of GPS are needed.

• 分析了B码的对时机理,指出变电站的智能设备采用B码对时,就不再需要现场总线的通信报文对时,也不再需要GPS输出大量脉冲接点信号。