SIS系统的故障安全? 求助:SIS系统一般都要求故障安全,请教在什么规范上提到过这个要求,特别是在哪儿出现过“ The Safety Systems shall be normally energized . A “1” logic signal is considered to be a normal state, and a “0” logic signal is an abnormal (trip or failure) state. Output signals shall go to a “0” (de-energized) state on power failure or on component failure ” 这句话。 查看更多5个回答 . 2人已关注