Description
从时间调度上来说。
PLC的程序一般不能按事先设定的循环周期运行。PLC程序是从头到尾执行一次后又从头开始执行。（现在一些新型PLC有所改进，不过对任务周期的数量还是有限制）而DCS可以设定任务周期。比如，快速任务等。同样是传感器的采样，压力传感器的变化时间很短，我们可以用200ms的任务周期采样，而温度传感器的滞后时间很大，我们可以用2s的任务周期采样。这样，DCS可以合理的调度控制器的资源。
Nortel Passport 8310 2x 8393SF Ethernet Routing Switch
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Nokia NIF4450 4Port Gigabit Eth ADP Interface IP1280
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Extreme Black Diamond 8800 10G4Xa 41612 4-port 10G XFP
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Alcatel 3EZ00902DB AA01 8-Port Gig LX SFP 7470 Router?
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Alcatel OS8-GNI2-C24 Omniswich 8800 2nd Gen 1000BaseT
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Spirent Smartbits SMB-2000 GX-1420B ML-7710 GX-1405Bs
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Cisco MGX8800 1 Port OC-48cSTM-16c SMF-SR SMFSR-1-
