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。
NEW SEAL Giddings and Lewis M.1016.9710 R0 M10169710
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GIDDINGS & LEWIS 502-03518-02R2 PIC 900 D/A NIB
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GIDDINGS & LEWIS COUNSEL TRIERFACE CUP BOARD 501-03201
Giddings & Lewis DSA 030-230 Digital Servo
GIDDINGS & LEWIS 810-21979-00 POWER SUPPLY GOOD TAKEOUT
EK-1320 GIDDINGS & LEWIS 98.491 MM DIA MAX 2 UNITS
GIDDINGS & LEWIS 502-03551-02 (PIC900) OUTPUT (REMAN)
GIDDINGS & LEWIS 502-03550-00R3 (PIC900) INPUT (REMAN)