PLC是以微处理器为基础，综合了计算机技术、自动控制技术和通信技术，用面向控制过程面向用户的“自然语言”编程，适应工业环境，简单易懂、操作方便、可靠性高的新一代通用工业控制装置。PLC是在继电器顺序控制基础上发展起来的以微处理器为核心的通用自动控制装置。

可编程序控制器是一种数字运算操作电子系统，专为在工业环境下应用而设计。它采用了可编程序的存储器，用来在其内部存储执行逻辑运算、顺序控制、定时、计数和算术运算等操作指令，并通过数字的、模拟的输入和输出，控制各种类型的机械或生产过程。可编程序控制器及其有关的外围设备，都应按易于与工业控制系统形成一个整体、易于扩充其功能的原则设计。

PLC产品种类繁多，其规格和性能也各不相同。对于PLC，通常根据其结构形式的不同、功能的差异和I/O点数的多少等进行大致分类。

按结构形式分类

根据PLC的结构形式，可将PLC分为整体式和模块式两类。

整体式PLC

整体式PLC是将电源、CPU、I/O接口等部件都集中装在一个机箱内，如图所示。具有结构紧凑、体积小、价格低的特点。小型PLC一般采用这种整体式结构。整体式PLC由不同I/O点数的基本单元（又称主机）和扩展单元组成，基本单元内有CPU、I/O接口、与I/O扩展单元相连的扩展口以及与编程器或EPROM写入器相连的接口等；扩展单元内只有I/O和电源等，而没有CPU。基本单元和扩展单元之间一般用扁平电缆连接。整体式PLC一般还可配备特殊功能单元，如模拟量单元、位置控制单元等，使其功能得以扩展。

2）模块式PLC

模块式PLC将PLC的各组成部分分别做成若干个单独的模块，如CPU模块、I/O模块、电源模块（有的含在CPU模块中）以及各种功能模块。模块式PLC由框架或基板和各种模块组成，模块装在框架或基板的插座上，如图所示。这种模块式PLC的特点是配置灵活，可根据需要选配不同规模的系统，而且装配方便，便于扩展和维修。大、中型PLC一般采用模块式结构。

还有一些PLC将整体式和模块式的特点结合起来，构成所谓的叠装式PLC。叠装式PLC的CPU、电源、I/O接口等也是各自独立的模块，但它们之间是靠电缆进行连接的，并且各模块可以一层层地叠装。这样，不但系统可以灵活配置，还可做得体积小巧。

2.2.按功能分类

根据PLC的功能不同，可将PLC分为低档、中档、。

RESISTOR METAL FILM, 68OHM, 5%, AXIAL Part # PANASONIC ERG5SJ680
RESISTOR METAL FILM, 68KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ683
RESISTOR METAL FILM, 680 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ681
RESISTOR METAL FILM, 6.8KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ682
RESISTOR METAL FILM, 56OHM, 5%, AXIAL Part # PANASONIC ERG5SJ560
RESISTOR METAL FILM, 56KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ563
RESISTOR METAL FILM, 560 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ561
RESISTOR METAL FILM, 5.6KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ562
RESISTOR METAL FILM, 47OHM, 5%, AXIAL Part # PANASONIC ERG5SJ470
RESISTOR METAL FILM, 47KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ473
RESISTOR METAL FILM, 470 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ471
RESISTOR METAL FILM, 4.7OHM, 5%, AXIAL Part # PANASONIC ERX5SJ4R7
RESISTOR METAL FILM, 39OHM, 5%, AXIAL Part # PANASONIC ERG5SJ390
RESISTOR METAL FILM, 39KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ393
RESISTOR METAL FILM, 390 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ391
RESISTOR METAL FILM, 33OHM, 5%, AXIAL Part # PANASONIC ERG5SJ330
RESISTOR METAL FILM, 33KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ333
RESISTOR METAL FILM, 330 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ331
RESISTOR METAL FILM, 3.9KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ392
RESISTOR METAL FILM, 3.3KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ332
RESISTOR METAL FILM, 27OHM, 5%, AXIAL Part # PANASONIC ERG5SJ270
RESISTOR METAL FILM, 27KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ273
RESISTOR METAL FILM, 22OHM, 5%, AXIAL Part # PANASONIC ERG5SJ220
RESISTOR METAL FILM, 220 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ221
RESISTOR METAL FILM, 2.7KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ272
RESISTOR METAL FILM, 2.2KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ222
RESISTOR METAL FILM, 1OHM, 5%, AXIAL Part # PANASONIC ERX5SJ1R0
RESISTOR METAL FILM, 1KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ102
RESISTOR METAL FILM, 18KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ183
RESISTOR METAL FILM, 180 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ181
RESISTOR METAL FILM, 15KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ153
RESISTOR METAL FILM, 150 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ151
RESISTOR METAL FILM, 12OHM, 5%, AXIAL Part # PANASONIC ERG5SJ120
RESISTOR METAL FILM, 12KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ123
RESISTOR METAL FILM, 10KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ103
RESISTOR METAL FILM, 100KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ104
RESISTOR METAL FILM, 100 OHM, 5%, AXIAL Part # PANASONIC ERG5SJ101
RESISTOR METAL FILM, 1.8OHM, 5%, AXIAL Part # PANASONIC ERX5SJ1R8
RESISTOR METAL FILM, 1.8OHM, 5%, AXIAL Part # PANASONIC ERX3SJ1R8
RESISTOR METAL FILM, 1.8KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ182
RESISTOR METAL FILM, 1.5KOHM, 5%, AXIAL Part # PANASONIC ERG5SJ152
RESISTOR METAL FILM, 0.56 OHM, 5%, AXIAL Part # PANASONIC ERX5SJR56
RESISTOR METAL FILM, 0.39 OHM, 5%, AXIAL Part # PANASONIC ERX5SJR39
RESISTOR METAL FILM, 0.33 OHM, 5%, AXIAL Part # PANASONIC ERX5SJR33
Replacement White Handset Cord 25 Ft. for Panasonic KX-T, KX-DT, KX-NT Phones
Replacement Black Handset Cord 25 Ft. for Panasonic KX-T, KX-DT, KX-NT Phones
QTY 4 - Panasonic ELF-18D428 33HH H Series Line Filter  
QTY (5) ECQU2A224MV PANASONIC .22uf 250V SUPPRESSION POLY FILM CLASS X2 ROHS
QTY (25) 3.3uf 80V 105c SMD ELECTROLYTIC EEV-FK1K3R3R Panasonic
QTY (10) - ZNR 10K201U Varistors
Printrelais 5 V/DC 1 A 2 Wechsler Panasonic TQ25 1 St.
Printrelais 24 V/DC 1 A 2 Wechsler Panasonic AGQ20024 1 St.
Printrelais 12 V/DC 1 A 2 Wechsler Panasonic AGQ20012 1 St.
Printrelais 12 V/DC 1 A 2 Wechsler Panasonic AGN20012 1 St.
PRINTER USB DATA CABLE FOR OKI Olivetti Panasonic Ricoh Samsung
PARTIAL REEL 3000+pcs PANASONIC ERJ2GEJ331X 330R 5% CHIP RESISTOR
PANASONIC,EEUED2W150,CAPACITOR, 15UF, 450V
PANASONIC,EEFCD0J100R,CAPACITOR, CASE D, 10UF, 6.3V
PANASONIC,ECWH8333HA,CAPACITOR, 800V, 33NF, 3%
PANASONIC,ECWF2684JAQ,CAPACITOR, 250V, 680NF, 5%
PANASONIC,ECWF2394JAQ,CAPACITOR, 250V, 390NF, 5%
PANASONIC,ECQV1563JM,CAPACITOR, FILM, 100V, 56NF
PANASONIC,ECA1VAM471X,CAPACITOR, 470UF, 35V
PANASONIC,ECA1HM470,CAPACITOR, 47UF, 50V
PANASONIC,ECA1CAM222X,CAPACITOR, 2200UF, 16V
PANASONIC, EZADT62AAAJ, RC NETWORK, SMD 1206, 1000R, 47PF
PANASONIC, EZADT61AAAJ, RC NETWORK, SMD 1206, 1000R, 22PF
PANASONIC, EZADT12AAAJ, RC NETWORK, SMD 1206, 22R, 47PF
PANASONIC, ETQP5MR68YGC, CHOKE, POWER, 15.0UH, +/-20%,
PANASONIC, ERZV20D112, VARISTOR, 20MM DISC, 1100V
PANASONIC, ERZV14D511, VARISTOR, 14MM DISC, 510V
PANASONIC, ELT3KN149C, COIL, V STEP-UP, 0.33MH, +/-10
PANASONIC, ELT3KN139C, COIL, V STEP-UP, 0.68MH, +/-10
PANASONIC, ELT3KN136C, COIL, V STEP-UP, 2.0MH, +/-10
PANASONIC, ELT3KN032C, COIL, V STEP-UP, 25MH, +/-40%
PANASONIC, ELL6SH8R2M, CHOKE COIL, POWER, 8.2UH, 1.4A
PANASONIC, ELL6RH2R7M, INDUCTOR, 2.7UH