The distributed system has developed from an industrial automation instrument control system to a distributed system centered on an industrial control computer.Therefore,it has certain advantages in analog quantity processing and loop regulation.In the initial stage,it was mainly used in continuous process control,focusing on the loop regulation function.PLC is developed from the relay logic system and is mainly used in discrete manufacturing and process control.In the initial stage,it was mainly used to replace the relay control system,focusing on switching sequence control.
集散系统从工业自动化仪表控制系统发展到以工业控制计算机为中心的集散系统，所以其在模拟量处理、回路调节方面具有一定优势，初期主要用在连续过程控制，侧重回路调节功能。PLC是由继电器逻辑系统发展而来，主要用在离散制造、工序控制，初期主要是代替继电器控制系统，侧重于开关量顺序控制方面。
HP/Agilent 53132A/OPT:001 Universal Frequency Counter,
HP/Agilent E4400-60718 Assembly Board Sampler
HP/Agilent 53150A CW Microwave Frequency Counter, 20 GH
HP/Agilent E8356-60006 Signal Processing ADC Module(SPA
HP/Agilent E8364-60099 Fractional-N Synthesizer Board
HP/Agilent E4400-60659 Board Assembly – Output
