序言控制机的可靠性和在线效率,是衡量其性能的两个重要标志。可靠性就是连续无故障运行时间的长短;在线效率则是一年内在线控制生产时间和总时间的百分比,一般可用下式表达: Preamble Control machine reliability and online efficiency, is to measure the performance of the two important signs. Reliability is the length of continuous trouble-free operation; online efficiency is the percentage of online production in a year and the total time, which can be expressed as: