描述
當(dāng)PLC運行時,工作過程可分為三個階段:輸入采樣、程序執(zhí)行和輸出刷新。
(1)輸入采樣階段:PLC以周期掃描方式依次地讀入所有輸入狀態(tài)和數(shù)據(jù),并將它們存入I/O映像區(qū)中的相應(yīng)單元內(nèi),輸入的脈沖信號寬度必須大于一個掃描周期。
(2)程序執(zhí)行階段:在用戶程序執(zhí)行階段,PLC總是按南上而下的順序依次地掃描用戶程序。在掃描每一條梯形圖時,又總是先掃描梯形圖左邊由各觸點構(gòu)成的控制線路,并按先左后右、先上后下的順序?qū)τ捎|點構(gòu)成的控制線路進行邏輯運算,然后根據(jù)邏輯運算的結(jié)果,刷新各邏輯線圈、輸出線圈在映像區(qū)中對應(yīng)位的狀態(tài)。
(3)輸出刷新階段:當(dāng)掃描用戶程序結(jié)束后,PLC進入輸出刷新階段。CPU按照映像區(qū)內(nèi)對應(yīng)的狀態(tài)和數(shù)據(jù)刷新所有的輸出鎖存電路,再經(jīng)輸出電路驅(qū)動相應(yīng)的外設(shè)。
歐美品牌停產(chǎn)的,常用的“PLC”備品備件
我司產(chǎn)品應(yīng)用于以下領(lǐng)域:
1,《發(fā)電廠DCS監(jiān)控系統(tǒng)》
2,《智能平鋼化爐系統(tǒng)制造》
3,《PLC可編程輸送控制系統(tǒng)》
4,《DCS集散控制系統(tǒng)》
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5,《智能型消防供水控制系統(tǒng)》
6,《化工廠藥液恒流量計算機控制系統(tǒng)》
7,《電氣控制系統(tǒng)》造紙,印染生產(chǎn)線,變電站綜合自動化控制系列
本特利,英維思,伍德沃德,福克斯波羅、西屋、瑞恩、施耐德莫迪康、ABB、AB、西門子、摩托羅拉、GE發(fā)那科、安川、博世力士樂,ACSO,力士樂等各大品牌的DCS系統(tǒng)配件,機器人系統(tǒng)配件,大型伺服系統(tǒng)備件。
MKS INSTRUMENTS BARATRON,1 TORR,370HA
EMOTEQ CORP MOTOR ASSY PADDLE ACTUATING HS01001-A02-HGE
PATLITE SIGNAL TOWER,SL-402V
APPLIED CERAMICS,CERAMIC PLATE,200MM,716-028721-281
Cherry Electric exhaust vane switch 1491-3144
ASYS CONTROLLER,10052885
FURON 1/2″,2 way Valve,DIBPOL8PC
FURON OMNISEAL 3/16″X 12.375″70887-23
INSERT,INNER,MULTI-CHARGER/B?EAM TRAP MULTI-CHARGED
HATHAWAY/EMOTEQ MOTOR LIFT/TILT,BH02301A F04HBE
Micronix,I/0 board,PV-1648 Rev.3
Arcom,I/0 board,AIM104-ANALOG-I?/O
Air Products Comm.Controller board 287-607240
WESCO DISCONNECT SWITCH,NZM7-200-NA
Yaskawa AC Servo Motor,SGMP-01U314M
BIORAD 5″Cassette,QS600,013-5363-1
APPLIED MATERIALS FINGER LONG HOLLOW GRIPPER-AMI(SLO
FURON 1/2″,2 way Valve,WB-2W8P-C
LEYBOLD STRAIGHT THRU VALVE,428902
Air Products LCD Display 1730-7203
AP200 Shuttle adaptor kit,AP20-K-250
APPLIED MATERIALS PCB,SIGNAL CONDITION,ASSEMBLY
APPLIED MATERIALS ARC CHAMBER P19500
LAM RING,CLAMP-UPPER ELECTRODE
Trebor Model 85 Surge Suppressor
Finish Thompson/FTI Vertical Mag Drive VKC80VST336
Finish Thompson/FTI Vertical Mag Drive VKC80VST348
APPLIED MATERIALS INC.VANE,(MRS)P19500 AMI
Speedfam Load Cup
Lambda Power Supply,500W,24 VDC,FE050024RA
Applied Materials Gas Distribution Plate
DNS ELECTRONICS ARM,IH(2)-80A SCRUBBER
OMRON CAPACITIVE PROXIMITY SWITCH,E2K-C25MF1
Applied Materials 0020-82550 HOLDER(MRS)P19500
SMC VALVE SHUTTLE CAM PUMP F25 KT-PA2-38
Semitool OPTICAL BOARD ASSEMBLY 16730-01
APPLIED MATERIALS INC.HOLDER(MRS)P19500
Akrion Steag Valve PVDF610/15/D 7205A1 410200
APPLIED MATERIALS COVERING PIPE,0020-0930
DNA CERAMIC IH ARM L=110MM 2-F3-31399
DAIFUKU MOTOR,CONV.ORIEN.TRAVEL BODY
Watlow Din-A-Mite DB2C-2060-C050
Yaskawa Digital AC Servo Drive
Lambda Power Supply SC150U03
Lee ATMI Micropump LPVX0505600CA
Applied Materials 0020-81482
Applied Materials 0020-82822
TRIPP LITE UPS System SMARTINT700
ATMOS Air Handling Filter 2FM-22
Clean Room Products Air Handling Filter U3030A00ADACACA
Parker Motor MPC 1140X
Harowe Resolver 31BRCX-500-B1
Pacific Scientific Motor R63FSSA-HS-SS-N?V-04
POLYPURE BATH
SENSOR,SOG FLOW 3×2 N.C.ST215A
DYTEC VALVE,DUMP RINSER,QDV-400-PVDF-V
SMART UPS 1000VA BATTERY BACKUP
APPLIED MATERIALS HEATER BAND FOR TMS KIT,1410-01124
DWYER PHOTOHELIC GUAGE,KC-3003MR
APPLIED MATERIALS SHOWER HEAD,5B PUTTER ETCH 0020-09933
MIKRO ELEKTRONIK M34,M-Module,04M034-00
BALZERS ROLLE COUPLING,BB180942-T
EIT SENSOR STIK,0-25 PPM,SERIES 4500