廈門岳航計(jì)算機(jī)工程有限公司   A20B-3300-0410    
電話；0592-5085329               
咨詢熱線；18030132586（陳工）    
QQ;1151195663
傳真：0592-5165561(陳工）
郵箱：1151195663@qq.com
qq:1151195663
                                 
廈門市思明區(qū)湖濱東路湖光大廈8樓A座

【誠(chéng)信經(jīng)營(yíng)】【質(zhì)量可靠】【進(jìn)口原裝】【拆包防偽】
【超大庫(kù)存】【當(dāng)天付款】【順豐速運(yùn)】【歡迎搶購(gòu)】
PLC的發(fā)展歷程
A20B-3300-0410
    在工業(yè)生產(chǎn)過(guò)程中，大量的開(kāi)關(guān)量順序控制，它按照邏輯條件進(jìn)行順序動(dòng)作，并按照邏輯關(guān)系進(jìn)行連鎖保護(hù)動(dòng)作的控制，及大量離散量的數(shù)據(jù)采集。傳統(tǒng)上，這些功能是通過(guò)氣動(dòng)或電氣控制系統(tǒng)來(lái)實(shí)現(xiàn)的。1968年美GM（通用汽車）公司提出取代繼電氣控制裝置的要求，第二年，美數(shù)字公司研制出了基于集成電路和電子技術(shù)的控制裝置，次采用程序化的手段應(yīng)用于電氣控制，這就是代可編程序控制器，稱Programmable Controller（PC）。

    個(gè)人計(jì)算機(jī)（簡(jiǎn)稱PC）發(fā)展起來(lái)后，為了方便，也為了反映可編程控制器的功能特點(diǎn)，可編程序控制器定名為Programmable Logic Controller（PLC），現(xiàn)在，仍常常將PLC簡(jiǎn)稱PC。

    PLC的定義有許多種。際電工委員會(huì)（IEC）對(duì)PLC的定義是：可編程控制器是一種數(shù)字運(yùn)算操作的電子系統(tǒng)，專為在工業(yè)環(huán)境下應(yīng)用而設(shè)計(jì)。它采用可編程序的存貯器，用來(lái)在其內(nèi)部存貯執(zhí)行邏輯運(yùn)算、順序控制、定時(shí)、計(jì)數(shù)和算術(shù)運(yùn)算等操作的指令，并通過(guò)數(shù)字的、模擬的輸入和輸出，控制各種類型的機(jī)械或生產(chǎn)過(guò)程?？删幊绦蚩刂破骷捌溆嘘P(guān)設(shè)備，都應(yīng)按易于與工業(yè)控制系統(tǒng)形成一個(gè)整體，易于擴(kuò)充其功能的原則設(shè)計(jì)。

    上世紀(jì)80年代至90年代中期，是PLC發(fā)展*快的時(shí)期，年增長(zhǎng)率一直保持為30~40%。在這時(shí)期，PLC在處理模擬量能力、數(shù)字運(yùn)算能力、人機(jī)接口能力和網(wǎng)絡(luò)能力得到大幅度提高，PLC逐漸進(jìn)入過(guò)程控制領(lǐng)域，在某些應(yīng)用上取代了在過(guò)程控制領(lǐng)域處于統(tǒng)治地位的DCS系統(tǒng)。

    PLC具有通用性強(qiáng)、使用方便、適應(yīng)面廣、可靠性高、抗干擾能力強(qiáng)、編程簡(jiǎn)單等特點(diǎn)。PLC在工業(yè)自動(dòng)化控制特別是順序控制中的地位，在可預(yù)見(jiàn)的將來(lái)，是無(wú)法取代的。
INA CAM FOLLOWER BEARING, KR22-PP *NEW*

TIMKEN BEARING 301KDD

DODGE 7/8 INCH MOUNTED BEARING 205

INA ROLLER BEARING  RNA-NA 4911 NNB

NSK BEARING BLOCK LH25 NNB

IKO 14" LINEAR GUIDE RAIL LWH15 NNB

INA NEEDLE BEARING  BK3026 NIB

SKF BEARING 7205 BEY *NEW*

MCGILL CAMFOLLOWER CF-5/8-S *NEW*

FAFNIR BALL BEARING PILLOW BLOCK  RAKH 1-3/16"

SNR BEARING 6202.EEC3 NEW IN BOX LOT OF 5

UNKNOWN MFG * BEARING * 60SZ

INA NEEDLE BEARING HK3026 LOT OF 3  NIB

SEALMASTER * FLANGE BEARING * SFT 23

NDH DELCO 3L08 XR7A SUPER PRECISION BEARING ? SET, NIB

TIMKEN * NEEDLE BEARINGS NIB * FC-20

TIMKEN TAPERED ROLLER BEARING 07196 SEALED LOT OF 2

TSUBAKI BEARING  B-206

MARTIN COUPLING COVER, 5016COV *NEW*

SKF 5310 E BEARING REPLACES 3310 NIB

McGILL CAM FOLLOWER CF 5/8 SB *NEW IN BOX*

MCGILL 3/4" BORE BEARING MR-12 *NEW*

TIMKEN BEARING 18690 NNB

SKF BALL BEARING 6207 2RSJ NIB

MCGILL CAM FOLLOWER CFH 5/8 SB NIB

NTN 2.4"OD, 0.96"ID BEARING 6908 ZZ/2A *NEW*

NICE * BEARING * 7516

MCGILL CAM YOKE ROLLER CYR-1 NIB

NTN 3.1 INCH O.D, 0.96 INCH, I.D BEARING 6208LU *NEW/SEALED*

INA ZL 205 KRDU BEARING, NO BOX

CLARK BEARING-CONE D028-1797 NIB

HUB CITY B250X1 MOUNTED BEARING, NNB

FAG BEARING NIB XLS 2 1/4

TIMKEN / FAFNIR 5205K BALL BEARING, NIB

FAFNIR BOLT FLANGE BEARING SCJT1

TIMKEN TAPERED ROLLER BEARING, 72212C, NIB

SKF * ROLLER BEARING * 6012 RS

BEARING LOCKNUT STEEL SHAFT SPANNER NUT  AN-24

NTN 90MM OD, 50MM ID, 30MM W, ANGULAR CONTACT BEARING 3210

MCGILL CAMFOLLOWERS, CF1S, NIB LOT OF 10

INA NEEDLE ROLLER BEARING K100X107X21 NIB

ONAN * BALL BEARING NIB * 510-0047

GARLOCL KLOZURE OIL SEAL 21086 2723 53

TIMKEN * NEEDLE BEARING NIB * RCB-121616

INA THRUST BALL BEARING D9 NIB

TORRINGTON / FAFNIR MM208K CR SUPER PRECISION BEARING, NIB

SKF  21.56MM I.D, 52.44MM O.D. BEARING 7205 BEY *NEW*

INA * NATV 10 PP A BEARING NIB * 02/N3

BROWNING BEARING UNITS 2 1/2 VS-340 NIB

BROWNING 3/4" BORE FLANGED MOUNT BEARING, VF2S-112M *NEW*

SKF 1-1/2" BORE 2-BOLT PILLOW BLOCK BEARING HOUSING, SAF 509

MCGILL CAMFOLLOWER NIB CFE 5/8 SB

GENUINE ROTARY SEAL L42X55X10 NIB

INA BALL BEARING LR204NPPU NNB

DELCO NDH BEARING NNB 3208

MCGILL CAMROL CFH-1 1/4-S LOT OF 2 NIB

NSK 9-5/8" LINEAR GUIDE RAIL W/ 2 BEARING BLOCKS LH25 NNB

TORRINGTON * ROLLER BEARING * IR-1212

INA BEARING 14/20-XL X-LIGHT

MCGILL PRECISION BEARING MR52 SEALED

INA 100MM I.D, 135MM O.D THRUST NEEDLE BEARING AXK100135 *NEW*

SKF 3.125X0.687", 3.12-3.126" SHAFT RANGE, SPEEDY SLEAVE 99311 *NEW*

INA BEARINGS 7202-BE 2RS NIB

TIMKEN TAPERED ROLLER BEARING NIB 25821

SKF * CYLINDRICAL ROLLER BEARING NIB * NU 305 ECP

LOVEJOY 5/8" HUB 685441510

NTN BEARING 3/4" BORE ULTRA-CLASS PILLOW BLOCK BEARING, UELPL-3/4 *NEW*

ANCHOR FLANGE W4-24-24U *NEW*

SKF RADIAL SPHERICAL PLAIN BEARING, GEZ 100 ES *NEW*

NSK 13-5/16" LINEAR GUIDE RAIL W/ 2 BEARING BLOCKS LH20 NNB

McGILL NEEDLE BEARING MR 14 RSS NIB

TIMKEN 44150 TAPERED ROLLER BALL BEARING NIB

TIMKEN TAPERED ROLLER BEARING M802011 NIB

DODGE BEARING SC-50MM

FAFNIR 26MM OD 9MM ID BALL BEARING 9100KDD *NEW*

AMPHENOL RUBBER BUSHING 9779 513-10 LOT OF 12

SNR 1025.G15 BEARING NIB

INA 10MM ID, 14MM OD, 10MM W, NEEDLE ROLLER BEARING K10X14X10TN *NEW*

REXROTH 12-5/8" LINEAR BLOCK BEARING RAIL, *NEW*

TIMKEN 45MM BORE TAPERED ROLLER BEARING, 32009X-92KA1 *NEW*

NACHI TAPERED ROLLER BEARING E30206J

STAR BEARING 0602-025 NIB

NTN BEARING NATV6XLL NIB

SKF BEARING 6205 2RSJEN NIB

OSBORN HEAVY DUTY LOAD RUNNER FLR-2-10 NIB

NSK 34MM OD 16MM ID SINGLE ROW BALL BEARING 6003VVC3 *NEW*

MRC ANGULAR CONTACT BALL BEARING, 205RDU, NIB

TIMKEN TAPERED ROLLER BEARING, 28920, NIB

INA BALL BEARING INSERT, AY20NPPB, NIB LOT OF 4

TIMKEN BEARING 301KDD NIB

NTN ROLLER BEARINGS 6204 LLBC/5C NIB

INA THRUST BEARING TC1220 *NEW LOT OF 3*

DODGE 1-1/2" BORE 4-BOLT FLANGE BEARING, 124085, NNB

GRUVLOK 3 x 1/2" COUPLING 7045

AURORA 1-1/4" BALL BORE RIGHT HAND MALE ROD END, KM-20-1, NNB

IKO 1-1/4"OD NEEDLE ROLLER BEARING CR20UU *NEW*

TIMKIN ROLLER BEARING RA108RR+COL NIB

UNKNOWN MFG * PILLOW BLOCK BEARING   * UC208-12

TB WOODS SUPER-FLEX FLANGE 8S134 *NEW*

GARLOCL KLOZURE OIL SEAL 53X2900

DODGE 1" BORE 4-BOLT FLANGE BEARING UNIT, 124001, NNB

MCGILL BEARING MI-28 NIB

SKF 7208 CD/P4ADGA SUPER PRECISION BEARING SET, NIB

FAFNIR BEARING NIB 7206W

BARDEN SUPER PRECISION BEARING 208HDL G-75 SEALED

FEDERAL MOGUL OIL SEAL NIB 415437

CONSOLIDATED BALL BEARING 16012 NIB

MCGILL CF 1 S CAMFOLLOWER

TIMKEN TAPERED ROLLER BEARING. NIB 21212

BARDEN SUPER PRECISION BEARING 112HCDUL 0-11 SEALED

INA 47MM OD 29MM ID BALL BEARING 51106J *NEW*

MCGILL CAMFOLLOWER CFH 1 S *NEW*

FAFNIR PILLOW BLOCK 3/4 NNB

FAFNIR PILLOW BLOCK BEARING  1111 RR

TIMKEN TAPERED ROLLER BEARING A6162 NIB

TIMKEN TAPERED ROLLER BEARING L21511 NIB

DODGE TAPER LOCK BUSHING 117092 NIB LOT OF 2

INA * NEEDLE BEARING NNB * BCH812

FAFNIR ROLLER BEARING 1103KRR C2

FAFNIR BALL BEARING NIB 200KTD

SKF BEARING YSA 209-2FK NIB SEALED

IKO * BEARING * RNAFW405034

NSK ROLLER BEARING 63062

TIMKEN BALL BEARING 7205WN SU NIB

TIMKEN FAFNIR 1" BORE MOUNTED FLANGE BEARING, SCJT 1, NIB

INA 14MM ID, 18MM OD, 10MM W, NEEDLE ROLLER BEARING K14X18X10B *NEW*

TIMKEN TAPERED BEARING JH211710

SEALMASTER 20MM BRACKET FLANGE BEARING FB-204

DELCO BALL BEARING NIB 43311

MCGILL NEEDLE BEARING MR 24 RSS NIB, LOT OF 3

SEALMASTER 1-1/4" BALL BEARING FLANGE UNIT MSFT 20T NNB

SKF 7201 ACD/P4ADGA (1) SET BEARINGS, NIB SEALED

TIMKEN 13889 1-1/2" BORE 2.275" O.D. TAPERED ROLLER BEARING, NIB

0.9 BEARING  MDR00049 101

BOSCH REXROTH LINEAR RUNNER BLOCK R162281420 NIB

IKO * BEARING * RNA6907UU

SKF SINGLE ROW DEEP GROOVE BALL BEARING, 6011 2RSJEM, NIB

MOUNTED PILLOW BLOCK BEARING C-06-10

GARLOCK KLOZURE OIL SEAL 53X2732

GARLOCL KLOZURE OIL SEAL 210866 2225 53

TIMKEN TAPERED ROLLER BEARING NIB 21212

TIMKEN TAPERED ROLLER BEARING CUP, 2720, NIB LOT OF 2

NTN LOCKNUT BEARING S15 27/16 AN15

INA ROLLER BEARING NIB EW2-1/4

FAFNIR PRECISION BEARING 3MM9112WI

TIMKEN 05062 5/8" BORE TAPERED ROLLER BEARING, NIB

DODGE * FLANGE BEARING * SCM 2-B

RBC CAM FOLLOWER H20 *NEW* LOT OF 2

FAFNIR SUPER PRECISION BEARING 2MM9104WIUL NNB

GARLOCL KLOZURE OIL SEAL 53-2228

NSK 50MM BORE, 90MM OD, 20MM WIDTH, DEEP GROOVE BALL BEARING 6210ZZNR *NEW*

MISUMI LINEAR BUSHING LHFSWF20

BROWNING FLANGE 1-3/6

OSBORN  TIMKEN LM67000LA

NSK 39MM OD 16MM ID SINGLE ROW BALL BEARING 6203C3 *NEW LOT OF 2*

BALL BEARING SMN307K

SKF 35MM ID, 72MM OD, 27MM WIDTH, ANGULAR CONTACT BALL BEARING 5207 A *NEW*

WOOD'S FLANGE COUPLING MAX RPM 5250 7S X 178

FAFNIR SINGLE ROW BALL BEARING 208PP NNB

NTN 15MM I.D. 35MM O.D. TAPERED ROLLER BEARING, 30202 *NEW UNOPENED*

NSK 9" LINEAR GUIDE RAIL W/ BEARING BLOCKS LW21 NNB

THK BALL RETAINER NIB SHW-27CR

SKF BEARING S203 NNB

SKF NU 1010 MP ROLLER BEARING NIB

LINK-BELT BEARING 7/8" WP3-S214E NIB

SKF ROLLER BEARING 5305 A2ZNR C3

STAR KUGELFUHRUNGSWAGEN SIZE 20, RUNNER BLOCK / BALL RAIL 1694-894-10

RICHARD WILCOX TRUCK-CAGED ROLLER BEARINGS 3110.00001 NIB

TIMKEN TAPERED ROLLER BEARING NIB HM212011

32-1/8" LINEAR GUIDE RAIL UG5J68 NNB

TB WOODS SURE-FLEX SLEEVE 6 / 6E EPDM  2 PCS *NEW*

GENUINE ROTARY SEAL L32X45X10 NNB

REXROTH / STAR 1664-894-10 LINEAR BEARING BLOCK *NEW*

INA BEARING NK 32/20 SLOVAKIA 95 D04

SKF ROLLER BEARING NUP 205E NIB

MORSE SEAL MASTER BEARING INSERT NIB 2-115

FAFNIR ANGULAR CONTACT BEARING 7207WN NIB

UNKNOWN MFG * RAIL BEARING NIB * 1651-21X-10 X=4 AA11J

MRC 1.58" OD, .65" ID STEEL BEARING 203SZZG *NEW*

NTN 1-1/2"OD RADIAL BEARING 6203LLBC3/EM *NEW*

NSK LINEAR GUIDE LAH25BN NIB

RBC 38MM OD 24MM ID NEEDLE ROLLER BEARING SJ7194RS *NEW*

TIMKEN TAPERED ROLLER BEARING CUP L44610 NIB, LOT OF 2

NIPPON BEARING CO. SLIDE BUSH SM-40 *NEW*

SKF SIZE 20 11 IN. LONG RAIL GUIDE W/ 2 BEARING BLOCKS, LLBHR20 *NEW*

BALL & ROLLER BEARINGS LSS-16 HEIM 1 LOT OF 4

KAYDON REAL-SLIM BALL BEARING 52334001 0G2

MCGILL BEARING MI-28 NNB

CORE COVER GEARING HOUSING END 4CC41861 NNB

INA 44.40MM BORE, LINEAR BEARING KGNZ 24 PP

INPRO / SEAL 1000-A-19769-0 BEARING ISOLATOR, NIB

THK 8.19MM LINEAR BUSHING LMK20LUU *NEW*