6GK5204-2AA00-2BD2 现场总线
在PLC控制系统中，电源占有极重要的地位。电网干扰串入PLC控制系统主要通过PLC系统的供电电源（如电源、I/O电源等）、变送器供电电源和与PLC系统具有直接电气连接的仪表供电电源等耦合进入的。现在，对于PLC系统供电的电源，一般都采用隔离性能较好电源，而对于变送器供电的电源和PLC系统有直接电气连接的仪表的供电电源，并没受到足够的重视，虽然采取了一定的隔离措施，但普遍还不够，主要是使用的隔离变压器分布参数大，抑制干扰能力差，经电源耦合而串入共模干扰、差模干扰。所以，对于变送器和共用信号仪表供电应选择分布电容小、抑制带大（如采用多次隔离和屏蔽及漏感技术）的配电器，以减少PLC系统的干扰。
位保证电网馈点不中断，可采用在线式不间断供电电源（UPS）供电，提高供电的安全可靠性。并且UPS还具有较强的干扰隔离性能，是一种PLC控制系统的理想电源。
2电缆选择的敖设
为了减少动力电缆辐射电磁干扰，尤其是变频装置馈电电缆。笔者在某工程中，采用了铜带铠装屏蔽电力电缆，从而降低了动力线生产的电磁干扰，该工程投产后取得了满意的效果。
上世纪60年代后期，根据当时汽车市场需求和计算技术的发展，在美国麻萨诸塞州Bedford的Bedford Associates,向美国汽车制造业提议开发一种Modular Digital Controller（MODICON）取代继电控制盘。其它一些公司也建议以计算机为基础的方案。其核心思想是采用软件编程方法代替继电控制的硬接线方式，并备有生产现场大量使用的输入传感器和输出执行器的接口，以便于进行大规模生产线的流程控制。这就是以后被称为Programmable Logic Controller的由来。MODICON 084是世界上种投入商业生产的PLC。
0年代是PLC崛起，首先在汽车工业获得大量应用，在其它产业部门也开始应用的时期。80年代是它走向成熟，全面采用微电子及微处理器技术；大量推广应用，并奠定其在工业控制中不可动摇地位的时期。在此阶段PLC销售始终以两位数百分点的速度增长，前六年的增长率超过35%，后四年稳定发展，年增长率约12%。90年代又开始了它的第三个发展时期。随着PLC的IEC 61131的正式颁布，推动了PLC在技术上发动新的突破：在系统体系结构上，从传统的单机向多和分布式及远程控制系统发展；在编程语言上，文本化和图形化的语言多样性，创造了更具表达控制要求、文字处理、通信能力的编程环境。
从应用范围和应用水平上，除了继续发展机械加工自动生产线的控制系统外，则是发展以PLC为基础的DCS系统、监控和数据采SCADA系统、柔性制造系统（FMS）、安全联锁保护（ESD）系统、运动控制系统等，全方位地产提高PLC的应用范围和水平。
进入90年代后期，由于用户对开放性的强烈要求和压力，由于信息技术的大力推动，PLC如果还停留在原有的专用而又封闭的系统概念上，它将坐以待毙。于是PLC进入了其发展的第四阶段。其特征是：
WIRE, BLU, 30AWG, 7/38AWG, 30.5M MPN: 3047 BL005 ALPHA WIRE
WIRE, BLU, 28AWG, 7/36AWG, 30.5M MPN: 3048 BL005 ALPHA WIRE
WIRE, BLU, 28AWG, 7/36AWG, 30.5M MPN: 2842/7 BL005 ALPHA WIRE
WIRE, BLU, 28AWG, 7/36AWG, 30.5M MPN: 1852 BL005 ALPHA WIRE
WIRE, BLU, 26AWG, 7/34AWG, 304.8M MPN: 1853 BL001 ALPHA WIRE
WIRE, BLU, 26AWG, 7/34AWG, 30.5M MPN: 2843/7 BL005 ALPHA WIRE
WIRE, BLU, 26AWG, 19/38AWG, 30.5M MPN: 2843/19 BL005 ALPHA WIRE
WIRE, BLU, 24AWG, 7/32AWG, 30.5M MPN: 3050 BL005 ALPHA WIRE
WIRE, BLU, 24AWG, 19/36AWG, 30.5M MPN: 2844/19 BL005 ALPHA WIRE
WIRE, BLU, 24AWG, 1/24AWG, 30.5M MPN: 2854/1 BL005 ALPHA WIRE
WIRE, BLU, 22AWG, 7/30AWG, 30.5M MPN: 3251 BL005 ALPHA WIRE
WIRE, BLU, 22AWG, 19/34AWG, 30.5M MPN: 5855 BL005 ALPHA WIRE
WIRE, BLU, 22AWG, 1/22AWG, 30.5M MPN: 3051/1 BL005 ALPHA WIRE
WIRE, BLU, 20AWG, 10/30AWG, 30.5M MPN: 3053 BL005 ALPHA WIRE
WIRE, BLU, 18AWG, 16/30AWG, 30.5M MPN: 3055 BL005 ALPHA WIRE
WIRE, BLU, 18AWG, 1/18AWG, 30.5M MPN: 3055/1 BL005 ALPHA WIRE
WIRE, BLU, 14AWG, 41/30AWG, 30.5M MPN: 3079 BL005 ALPHA WIRE
WIRE, BLU, 12AWG, 65/30AWG, 30.5M MPN: 3080 BL005 ALPHA WIRE
WIRE, BLK, 30AWG, 7/38AWG, 30.5M MPN: 2841/7 BK005 ALPHA WIRE
WIRE, BLK, 28AWG, 7/36AWG, 30.5M MPN: 2842/7 BK005 ALPHA WIRE
WIRE, BLK, 28AWG, 7/36AWG, 30.5M MPN: 1852 BK005 ALPHA WIRE
WIRE, BLK, 26AWG, 7/34AWG, 304.8M MPN: 3049 BK001 ALPHA WIRE
WIRE, BLK, 26AWG, 19/38AWG, 30.5M MPN: 5853/19 BK005 ALPHA WIRE
WIRE, BLK, 26AWG, 19/38AWG, 30.5M MPN: 2843/19 BK005 ALPHA WIRE
WIRE, BLK, 24AWG, 7/32AWG, 30.5M MPN: 3250 BK005 ALPHA WIRE
WIRE, BLK, 24AWG, 7/32AWG, 30.5M MPN: 1550 BK005 ALPHA WIRE
WIRE, BLK, 24AWG, 19/36AWG, 304.8M MPN: 1854/19 BK001 ALPHA WIRE
WIRE, BLK, 24AWG, 19/36AWG, 30.5M MPN: 1854/19 BK005 ALPHA WIRE
WIRE, BLK, 22AWG, 7/30AWG, 30.5M MPN: 5855/7 BK005 ALPHA WIRE
WIRE, BLK, 22AWG, 7/30AWG, 30.5M MPN: 3051 BK005 ALPHA WIRE
WIRE, BLK, 22AWG, 7/30AWG, 30.5M MPN: 1551 BK005 ALPHA WIRE
WIRE, BLK, 22AWG, 1/22AWG, 30.5M MPN: 2855/1 BK005 ALPHA WIRE
WIRE, BLK, 20AWG, 10/30AWG, 30.5M MPN: 1553 BK005 ALPHA WIRE
WIRE, BLK, 18AWG, 1/18AWG, 30.5M MPN: 3055/1 BK005 ALPHA WIRE
WIRE, BLK, 18AWG, 1/18AWG, 30.5M MPN: 2857/1 BK005 ALPHA WIRE
WIRE, BLK, 16AWG, 19/29AWG, 30.5M MPN: 5858 BK005 ALPHA WIRE
WIRE, BLK, 12AWG, 65/30AWG, 30.5M MPN: 3080 BK005 ALPHA WIRE
WIRE WIRE/CABLE ALPHA 3073 WH005 3073WH005
WIRE WIRE/CABLE ALPHA 3049 YL001 3049YL001
WIRE WIRE/CABLE ALPHA 3049 RD001 3049RD001
WIRE WIRE/CABLE ALPHA 3049 OR001 3049OR001
WIRE WIRE/CABLE ALPHA 3049 BK001 3049BK001
Wire Marker 42-ALPHA
WIRE MARKER 42-ALPHA
Wire Alpha 5874 24AWG 19/36 PTFE Teflon MIL-W-168780 EE Green 100 Ft Spool
WINCOR-NIXDORF USB KUNDENDISPLAY KUNDENANZEIGE GRAU ALPHANUMERISCH
Wilson Alpha Bracket Model # V-40 V40 For use with all Wilson Visors
Willson V-40 Alpha Bracket * IN BAG, LOT OF 4*
Willson V-40 Alpha Bracket
Willson Alpha Construction Hard Hat One Size Fits All. Black
Willson Alpha Construction Color Red Hard Hat One Size Fits All 0J 091
Wilbur Curtis WC-753 CONTROL BOARD 120/220V 50/60HZ ALPHA-DS
Wilbur Curtis Alpha G3 Two-Warmer Coffee Brewer
Wilbur Curtis Alpha 3GT Digital Automatic Coffee Brewer
Wilbur Curtis Alpha 3GT Automatic Coffee Brewer - Inline ALP3GT63A000
Wilbur Curtis Alpha 3DSR A102 Automatic Coffee Brewer Maker Machine w/ faucet
WHM Alpha Reseller £100.00 EU or US Based One Time Fee
Whittenstein, Inc Alpha LP 070-Mo1-3-110-000 Gearhead 3:1 Ratio 70mm Frame
White ALPHA INNOTECH MULTIIMAGE LIGHT CABINET TRANSILLUMINATOR MULTI IMAGE
Wellington Boots, Alpha S4 Safety Steel Toe Cap, Agriculture / Work Site,
Waxed Nylon Lacing Cord by Alpha Wire
Waveguide Freq. Multiplier X to K band Alpha/TRG?
Waters Alpha - WAT087198 - Cable, 3.3ft. (1M)
Warranty NIDEC TORIN ALPHA V TA450 CNC FAN A 30108-10 115V
WALTER Vollhartmetall-Spiralbohrer ALPHA 2 A3265TFL D = 13.3 NEU
WALTER Vollhartmetall-Kuehlkanalbohrer ALPHA 4 A3385TFL D = 13.5 NEU
WALTER TITEX CARBIDE AX196TFL-21.5 ALPHA DRILL DRILLING TIP COOLANT FED TOOL BIT
Walter Titex Alpha X-E #57 1.092mm Solid Carbide Stub Drill Bit A1547-NO57 1 bit
WALTER TITEX ALPHA 4 COOLANT FLOW THRU A3385TFL - 4.6 MM DRILL BIT SUPER CLEAN
Walter Titex Alpha 4 A3985TFL-15.8 Ø15,8 VHM Spiralbohrer mit Innenkühlung
Walter Titex Alpha 4 A3985TFL-12.5 Ø12,5 VHM Spiralbohrer mit Innenkühlung
Walter Titex Alpha 4 A3985TFL-12.2 Ø12,2 VHM Spiralbohrer mit Innenkühlung
WALTER TITEX A6785TFP 3/16 Alpha 4 XD20 Carbide Oil Drill
WALTER TITEX A6785TFP 1/4 Alpha 4 XD20 Carbide Oil Drill
Walter Titex 3.5 mm x 54 mm Carbide 140º Alpha 4 Spiral Drill Bit
WALTER TITEX 29/64 IN ALPHA 4 DEG COOLANT DRILL K30F TFL COAT A3385TFL
Walter / Titex A6485TFT-13/32, Alpha 4, XD8, Coolant Carbide Drill Bit - Regrind
Walkers WGE84976 Game Ear Alpha Carbon Power Muffs Compact Series Provides Up
Walkers WGE08442 Game Ear Alpha 360 Electronic Muffs Provides Up To 9 Times
Walkers WGE08182 Alpha Power Muffs Provides Up To 5 Times Hearing Enhancemen
Walker's Game WGE-PMA4LG Alpha Muffs & All Sports Glasses Combo Kit
Walker's Game WGE-GWP-AMPKCARB Alpha Power Muffs - Electric Pink
Walker's Game WGE-GWP-AMCARB Alpha Power Muffs - 5x Hearing Enhancement
Walker's Game WGE-GWP-AM360NXT Alpha Muffs 360 - 9x Hearing Enhancement
Walker Filtration Alpha Series Cast Aluminium Filters A018XA A018X1
Vtg Metal Rolodex V-FILE 4" x 6" Blank Cards w/ CUSTOM Alpha Poly Guides. Nice!
VPC Alpha-Flex 1-1/4" x 12" Floppy Conduit 11-12512 x 6
Vorrichter-Software Alpha Rohrleitungsbau Anlagenbau
Vorrichter-Software Alpha Plus Anlagen Rohrleitungsbau
Volume Slider Potentiometer (100KB)(Alpha) (2 pack)
VITEK VTC-IRLED24A ALPHA INFRARED CAMERA 12V-DC D508736
Vitek Alpha Series Indoor Color Dome Camera
Vitalograph ALPHA Touch Spirometer inkl. Spirotrac V Softwa
Vital Alpha Ice Pack Safety Wellington VW604
VITADUR Alpha Standard-Set # 1162
VITADUR ALPHA PORCELAIN 50g X 5, 12g X 7
Vitadur Alpha Keramikmassen Sortiment Art. Nr. 1459
Vitadur Alpha Keramikmassen Masterkit Art. Nr. 1458
VITADUR Alpha Keramikmassen # 1207
VITADUR Alpha + VITADURVEST Keramikmassen # 672
Vita Response Metallkeramik + Vitadur Alpha - Nr.300M85
VITA Keramikmassen VITADUR Alpha # 426
Vision Engineering Mantis Isis Alpha Stereo Microscope
VISION ENGINEERING ERGOWEDGE 25° HEAD ANGLE ADAPTOR for Lynx, Alpha, Beta, Cobra
Vision Engineering Dynascope Lynx Alpha Microscope Boom Bracket for Light Source
Vision Engineering C-069 Universal Camera Mount Adapter Lynx Alpha Beta Cobra
Vision Engineering Alpha Stereomikroskop Expanded-Pupil #9187
Vision Engineering Alpha Mantis Cobra Microscope Power Source Supply
Vision Engineering ALPHA ISIS Stereoscope Microscope.
Vision Engineering ALPHA ISIS Stereoscope Microscope WORKING
