1）可编程控制器有继电器输出、晶闸管输出、晶体管输出三种形式。可编程控制器（plc）具有结构灵巧，硬件配置灵活方便、可靠性高、抗干扰能力强，易学易用的特点，已作为普遍的自动化控制器件广泛应用于各行各业。《plc原理及应用》课程已成为工科院校一门覆盖面较广的***课，作为学校如何培养出高素质应用型plc人才，这成为社会、学校、教师与家长关注的焦点。根据多年的教学实践，就影响plc人才培养的各个因素的提高与协同系统的设计结构合理，采用多圈值编码器采集水位，以可编程控制器为控制核心，提高了系统的自动化程度，保证了系统运行的可靠性；硬件、软件模块化设计具有良好的扩展性和灵活性，可根据现场实际需求更改系统的配置规模。该系统在福建水东电站现场运行表明工作稳定，在监视报警、综合计算、信号输出等各方面满足电站的运行要求，取得了很好的效果，有较高的推广价值与个人计算机相比，plc在标准化方面作得较差：plc的软、硬件体系结构是封闭的而不是开放的；绝大多数plc使用专用的总线、专用通信网络及协议；各种plc产品的编程语言在表示方式、寻址方式和语法结构上都不一致，使得它们互不兼容。国际电工***会的iec6113l-3《可编程序控制器的编程软件标准》为plc编程的标准化铺平了道路。不少厂家正在开发以pc(个人计算机)为硬件平台、在WINOOWs操作系统下、符合iec61131-3国际标准的新一放体系结构的plc。相对于国际的plc厂商而言，国内公司的plc应用业绩较少，用户对国产plc的性能、产品质量和技术支持持怀疑态度xl3025minarikdrivespeedcontrolsiemenssimatics56es5752-0aa126es5752-0aa12e:4fkfd578-2mturckinboxsen***co***etu-04621fkfd578-2mu04621fkfd5782mamat0140-00754harnessassembly,mfup/lowpanelinterlockwatlowd8,d880-0000-1000,amat3930-00234temperaturecontroller,398232nibcutlerhammeran16an0ac3pole,9amp,an16anoac,an16an0,c306dn3numatics153ss415k000030solenoidvalve4-way,110-120v/50-60hz.12ampboscha24/2-eplc050635-20271070050634-2101070050634-210moduleboardhydepark***851a-24-00ultrasonicsen***receiver***851a2400bearing22219w33snr22219-w33oememersonyorkcolemanluxairecondenserfanmotor1/10hp230vk55hxmay-0353mano-contactdbg/tb/1teddingtoncontrols0.2/3.5bar3711dbgtb1mitsubiships11034intellimodmodule------lotof5estedwa***m500mfmonitormoduleintelligent***s8007aw005232revbcircuitboardwie***npb3allenbradley800t-pt16w800t-p16r800t-p16g*xlnt*turckbsv8151-0/pg9connector,m12male,fieldattachable,5pin,4-8mm,blacka***54-123806a69/aerafc-7800mfcmassflowcontrollerh2500sccm-ai-nonibsickflexisoftcpu2safetycontrollerfx3-cpu230002valcomvpc-a5-p-d-200kpaw-4-dnapressuregaugeinopenboxcsqgefanucinputmoduleic200mdl640cndsdomes2clec21.3"colorlcdmedicaldiagnosticmonitormoorenullmaticpressureregulatormodel44skflocalconditionmultilogmonitoringunitcmma9105-1allenbradley2090-xb33-16,brakemodulewithoutbox,oldstocknever.v600-ca1a-v2omroninboxrfidcontrollerv600ca1***2highspeed4portusb2.0usb2.0expansionhubasphoto.z/zx610honeywell51401496-100fanassemblypcbcirclesealcontrolsv04-25solenoidvalvebentlynevada72961-01wiringterminalboardplcbentley72960-011747296101lotof2mueller#26bootredinsulator26-2forbu-242525cfreeshippinghoneywell51401477-100bclassicbackpanel51401475-100bplcchassisrackxycom70201-002circuitcardxvme-201frev.1.170201002cylinderboschrexroth0-822-240-0370822240037oemcarrierbryantpaynesquirrelcageblowerwheella22la18618.5x15x17/16dell/emcnx4ax4storageproces***oldstock!martin23tooth3/4"sprocket60b23oldstockparkerrepairservicepackkit11113x01050believetobecompleteneclt156projector-partslotof(99)oldstock!weidmullerwdu-2.5terminalblocks1020000000allenbradley800t-fxjqh13ra1seriestredpushbuttonbi***allenbradley280-mtr22-m3serapatchcordarmorstartmotorcablemale90niballenbradley1336-sn-sp9a10a11a74101-363-51spkinvertersnubberboardkiminverteromronra***i3g3mvpfi3020-e3phasefilterswagelokss-600-3ttmteemalebranch3/8swx3/8swx1alumalifte20-473-01-000acceltubecradlevariane19009720wikapressuregaugew/diaphragm0-200kpa4-1/2"advantechpca-6114p4rev.a1.01backplane1902611430xc6vlx130t-2ffg784cxilinxicfpgavirtex6128k784ffgbga(1per)l17-b00-opdanorgreninboxlubricatorl17b00opdal17-b00-0pdafz1200r25kf1infineon1200a,1600v,n-channeligbttransistor(1per)mitsubishiadc-02inductosyna/dconverter,s/n133748,sporlanb14p2solenoidvalve1/2"odfsolderconnecti***lesscoilinboxelatron4549.09.01gasflowcontrolboard87047605011445499001i***320-rm1aremotemultiplexercard320rm1ad-16-12-258repairedbartoninstrumentsystemsprime002nc7analoginputmonitorw/wa20inputmodulenibomrons82k-10024powersupplymodule24vdc4.2as82k10024traneastandardfurnaceinducermotorblw887blw00887sunrisetelecomsunsetmttw/t1modulessxdsl-22fascofurnaceexhaustinducermotor7062-4639706246397062-415970624159reliancerefurbbedrelianceelectriccontrolcardboard846935-rallen-bradley22-him-a3vfddigitaloperatorterminalseriesaboxof6haworthduplexigrtancubiclepanelrecept***es8190-0405-20yaskawacacr-sr03sz1ss-y223servodrivetestedwithwarrantytexasinstrumentss-10pprogrammerforti405plcomronn°1srt2-ad04parkerh2-62couplingquickdisconnect1/4"female)