在40年代,过程控制是基于3~15PSI的气动标准信号。其后,由于4~20mA模拟信号的使用,使得模拟控制器得到了广泛应用,但是并不是所有的传感仪表和驱动装置都使用统一的4~20mA信号。70年代,由于在检测、模拟控制和逻辑控制领域率先使用了计算机,从而产生了集中控制。进入80年代,由于微处理器的出现,促使工业仪表进入了数字化和智能化的时代,4~20mA模拟信号传输逐步被数字化通信代替,加之分布式控制以及网络技术的迅速发展,促进了控制、调度、优化、决策等功能一体化的发展。然而由于检测、变送、执行等机构大都采用模拟信号连接,其传送方式是一对一结构,这使得接线复杂,工程费用高,维护困难,而信号传输精度底,易受干扰,仪表互换性差,这都阻碍了上层系统的功能发挥。另一方面,由于智能仪表的功能远远超过了现场模拟仪表,如对量程和零点进行远方设定,仪表工作状态实现自诊断,能进行多参数测量和对环境影响的补偿等。由此可见,智能仪表和控制系统的发展,都要求上层系统和现场仪表实现数字通信。
Susol Cerus TS800HU 500 Amp 3p 65k 480v Breaker With 220 ~ 240v Shunt
Susol Cerus TS800HU 500 Amp 3p 65k 480v Circuit Breaker With 120v Shunt
Susol Cerus TS800HU 500 Amp 3p 65k 480v Circuit Breaker With 480v Shunt
Susol Cerus TS800HU 600 Amp 3p 65k 480v Breaker With 220 ~ 240v Shunt
Susol Cerus TS800HU 600 Amp 3p 65k 480v Circuit Breaker With 120v Shunt
Susol Cerus TS800HU 600 Amp 3p 65k 480v Circuit Breaker With 480v Shunt
Susol Cerus TS800HU 800 Amp 3p 65k 480v Breaker With 220 ~ 240v Shunt
Susol Cerus TS800HU 800 Amp 3p 65k 480v Breaker With 220 ~ 240v UVR
Susol Cerus TS800HU 800 Amp 3p 65k 480v Breaker With 380 ~ 440v UVR
Susol Cerus TS800HU 800 Amp 3p 65k 480v Breaker With 440 ~ 480v UVR
Susol Cerus TS800HU 800 Amp 3p 65k 480v Circuit Breaker With 120v Shunt
Susol Cerus TS800HU 800 Amp 3p 65k 480v Circuit Breaker With 480v Shunt
Susol Cerus TS800HU ATU 500 Amp 3p 65k 480v Circuit Breaker With 12v Shunt
Susol Cerus TS800HU ATU 500 Amp 3p 65k 480v Circuit Breaker With 24v Shunt
Susol Cerus TS800HU ATU 500 Amp 3p 65k 480v Circuit Breaker With 48v Shunt
Susol Cerus TS800HU ATU 500 Amp 3p 65k 480v Circuit Breaker With Auxiliary
Susol Cerus TS800HU ATU 600 Amp 3p 65k 480v Circuit Breaker With 12v Shunt
Susol Cerus TS800HU ATU 600 Amp 3p 65k 480v Circuit Breaker With 24v Shunt
Susol Cerus TS800HU ATU 800 Amp 3p 65k 480v Circuit Breaker
Susol Cerus TS800HU ATU 800 Amp 3p 65k 480v Circuit Breaker With 120v UVR
Susol Cerus TS800HU ATU 800 Amp 3p 65k 480v Circuit Breaker With 12v Shunt
Susol Cerus TS800HU ATU 800 Amp 3p 65k 480v Circuit Breaker With 24v Shunt
Susol Cerus TS800HU ATU 800 Amp 3p 65k 480v Circuit Breaker With 24v UVR
Susol Cerus TS800HU ATU 800 Amp 3p 65k 480v Circuit Breaker With 48v Shunt
Susol Cerus TS800HU ATU 800 Amp 3p 65k 480v Circuit Breaker With 48v UVR
Susol Cerus TS800HU ATU 800 Amp 3p 65k 480v Circuit Breaker With Auxiliary
Suss Microtec Standard Vespel Wedge Cam 200AA160-21
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switchgear section 1 of 2
Switchgear Section 2 of 2
SWT508-PX Compter Wire Cable Stripping Cutting Peeling Sub-line Machine
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