描述
根据存放信息的性质不同,在PLC中常使用以下类型的存储器:
1.只读存储器(ROM)。只读存储器中的内容由PLC制造厂家写入,并永久固化,PLC掉电后,ROM中内容不会丢失。用户只能读取,不能改写。因此ROM常用于存放系统程序,系统程序具有开机自检、键盘输入处理、用户程序翻译、信息传递、工作方式选择等功能。
2.随机存储器(RAM)。随机存储器又称为可读写存储器。信息读出时,RAM中的内容保持不变;写入时,新写入的信息覆盖原来的内容。它用来存放既要读出,又要经常修改的内容。因此RAM常用于存人用户程序、逻辑变量和其他一些信息。掉电后,RAM中的内容不再保留,为了防止掉电后RAM中的内容丢失,PLC使用锂电池作为RAM的备用电源,在PLC掉电后,RAM由电池供电,保持存储在RAM中的信息不消失。
3.可擦写、可编程只读存储器(EPROM、EEPROM),EPROM是只读存储器,失电后,写入的信息不丢失,但要改写信息时,必须先用紫外线擦除原信息,才能重新改写。一些小型的PLC厂家也常将系统程序驻留在EPROM中,用户调试好的应用程序也可固化在EPROM中。EEPROM也是只读存储器,不同的是写入的信息需用一个较高的电压擦除。
欧美品牌停产的,常用的“PLC”备品备件
我司产品应用于以下领域:
1,《发电厂DCS监控系统》
2,《智能平钢化炉系统制造》
3,《PLC可编程输送控制系统》
4,《DCS集散控制系统》
5,《智能型消防供水控制系统》
6,《化工厂药液恒流量计算机控制系统》
7,《电气控制系统》造纸,印染生产线,变电站综合自动化控制系列
本特利,英维思,伍德沃德,福克斯波罗、西屋、瑞恩、施耐德莫迪康、ABB、AB、西门子、摩托罗拉、GE发那科、安川、博世力士乐,ACSO,力士乐等各大品牌的DCS系统配件,机器人系统配件,大型伺服系统备件。
Semitool 50 Wafer Carrierless Rotor
ESI PFA Pure Chamber&PFA cap ES-2100-5472
Air Products Plis Interface Box 0010-30002
Cyonics,LASER POWER SUPPLY 120VAC 2.4AMPS,2114-20SLK
Olympus BH Microscope
PALL Megaplast G2 w/Chemraz O-Rings PFGF1P12H12
Green Tweed HDP,L-Motion,Bonded SV,5641A-1282-SC63?9
ENVIRCO PERFORMANCE MACH 10 HEPA FILTER,69506-018
MRC Eclipse Control Board PCB 884-13-000
PALL TRINITY FILTER HOUSING 25UPS1G,4HD4886-2316
BRUSHLESS DC MOTOR SERVO,RATIO 1/80 T61105-59
NT INTERNATIONAL TRANSDUCER ACID 1/2 FLR 0-60 PSI 4210-
EUROTHERM POWER SUPPLY,661/01/00
Swagelok Process out stick 809-470314915A
APPLIED MATERIALS ION/TC BOX CONTROLLER,01-81911-00
LAM ASSY,PCB,ADIO-AO,810-017031-004
Leitz Wetzlar PL Fluotar 50x/0.85 567013
GRANITE MICROSYSTEMS COMPUTER,1 GHZ,256M RAM
FURON VALVE 3-WAY PNEUMATIC MOB3-122HP
Entegris Pressure Transducer 41501-110G-F04-?B12-A-S3
Entegris 1″PFA Hand Valve,DS16-2ML-16F
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SIMCO Ionization Kit 4009012
SIMCO Ionization Kit 4008899
Fortrend Model F8225 Wafer Transfer Unit
Microvision MVT 1080 Wafer Inspection Station,used
Acopian DC Power Supply A75HT560 MRC Eclipse Star
DNS Hot Plate Assembly For Model 60A,150mm
CUTLER-HAMMER CIRCUIT BREAKER,HFD3175L
D SQUARED TRANSFORMER,45T3HFI5NLP
BLOWER In Great Condition
Front End Load Port
MICROPUMP HEAD L15368,2170/56C
USHIO UV LAMP SUV-2002NIL
USHIO UV LAMP SUV-2011NI
White Knight AP-200 Pump Rebuild Tool Set KC-AP20-170
Schumacher ELOI Overlay,1495-3174
Air Products,Spill alarm cable assembly,2103-3615
AXIOMTEK COMPUTER ASSEMBLY BOARD SBC8360/73300-33
FUJI CIRCUIT BREAKER 150A 3PL GFI ELB EG203B
Mykrolis Stainless Steel Filter Housing KC-YY55P8000
HYTEC FLOW SYSTEMS ULTRAPURE HEAT EXCHANGER HFS-062/3
BALZERS QUARTZ GLASS MANTEL,BK221252
Air Products Cable Assembly Spill Detector 2103-0397
Applied Materials 0020-89990
NESLAB CHILLER,MODEL FTC-350A
NT INTERNATIONAL TRANSDUCER PRESSURE FLOW THRU 3/4″
Immersion Heater 4.8KW 208V 8.83X8.83 W/O TOP670217JS
Tosoh Honeywell Endura 5500 Target
SEMITOOL LINEAR RAIL ENCODER TAPE 62.75″T73311-02-0627
Swagelok Gas Hard Line Pigtail 1/2″FVCR 1495-3154A
Schumacher,Mother controller board,1730-3005
Pneutronics Interface System
Air Products Pigtail Outlet,1/4in MCVR 1495-3104A
KLA Instruments X-Interpolator PCB 710-658177-20 Rev C0
KLA Instruments Y-Interpolator C Ph.3 710-658172-20
KLA Instruments X-Interpollator Ph.3 710-658177-20
KLA Instruments Y-Interpolator C Ph.3 710-658172-20
KLA Instruments Interface 1 Ph 3 710-658086-20 Rev E0
TEL Tokyo Electronics Cup 11851250-001
Semitool Rotor Kit PMR0333-01
MASTR III AUXILIARY RECEIVER
FLUKE 8500A DIGITAL MULTIMETER
KLA Inst Memory Controller Assy Ph 3 710-658232-00
SENSARRAY PROCESS PROBE WAFER,1501A-8-0425
EUROTHERM POWER SUPPLY,661-01-00
Semitool Rear Bowl Seal
Kalrez Rear Bowl Seal 4079
Mykrolis FIlter Microgard UPX.05um 10″CWUZ01P01
SensArray Corporation K-TYPE TC WAFER REFLOW 1630A-8-00
Fujikin Inc.3/4 Auto Valve Stainless N.C.KC-FPR-71-19
Pentagon Tech Exclusion Ring,DC10046
GREEN TWEED o-ring,barrel 8528002139SD653
KLA Instruments Processor PCB 710-658046-00
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PROCESS TECHNOLOGIES HEATER IMERSION KIT,HXOL4205CX
KLA Inst.Alignment Processor(API)Ph.3 710-658036-20
PHOENIX CONTACT INTERBUS-S IBS 24 DI/32