描述
ESD也不单是实现联锁关系,它应该凌驾于生产过程控制之上,具有独立性,这样降低了两者同时失效的概率,ESD的安全等级要高于DCS。DCS主要是:动态控制,故障自动显示,维修时间不太关键,可以进行自动/手动切换;ESD主要是:静态监测、保护,必须测试潜在故障,维修时间非常关键,必须始终在线,不允许离线。
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