128229-01本特利PLC的发展趋势
随着微处理器技术、超大规模集成电路技术和数字通讯技术的进步和发展,可编程序控制器也得到了迅速发展,其功能已远远超出了其定义所指的范围,其概念也日趋模糊,现代可编程控制器的发展趋势主要有以下几个方面:
(1) 用高性能器件,尽量缩小与工业控制计算机之间的差距。例如,德国FESTO公司的IPC(Industrial PC)由一系列符合工业标准的模块组成,它与微机兼容且具有PLC的功能。
(2) 丰富I/O模块,使PLC在实时性、精度、分辨率、人机对话等性能方面进一步得到改善和提高。
(3) 进一步强化网络功能,以实现信息管理自动化。例如IPC型控制器具备多种现场总线接口。如FESTO总线、Profibus、AS-I、CAN等,以及各种网络连接模块,如Novell等,从而使PLC与PLC、PLC与PC、PLC与现场设备之间建立通讯联网。
(4) 多种编程语言并存,互补不足。IPC型控制器除了采用梯形图、指令表编程以外,还可以用IEC1131规定的用于顺序控制的标准化语言以及C、Basic等计算机语言进行编程。
(5) 硬件结构集成化、冗余化。随着专用集成电路(ASIC,Application Specific Integrated Circuits)和表面安装技术
Thermolyne Type 7200 Stir Light P/N SL7225 7" x 7" Sur
Hamamatsu Hollow Cathode Lamp L233-29NB (Element Cu) A
Guard Master Minotaur MSR6R/T Safety Relay 110VAC
VWR Fisher Vortex Genie 2 (G-560) Mixer w Cup for Singl
VWR Fisher Vortex Genie 2 (G-560) Mixer w 3" Platform f
Pharmacia Gradient Programmer GP-250 (20-0002-02) 2 Av
Pharmacia Biotech Multiphor II Nova Blot
Euro DPC MicroMix 5 Without Power Adapter
VWR Block Module 24 Hole 10mm 13259-107 10.7 mm Well
Control Company Traceable Lab Controller 62344-701
Potassium (K) Hollow Cathode Lamp Max mA 10. Oper. mA
Copper Cu. Hollow Cathode Lamp Max mA 15. Oper. mA 5
3M Smart Battery Charger BC-210 For Use With Breathe E
GracePort Interface P-A2#2-F3RX-C10?C20 By Grace Engine
Orion ATC Glass Body Probe Cat No. 917002 New In Box H
Sonics & Materials VC 100 Vibra Cell Power Unit
Bellco 7766-20110 Dual Speed Quad Drive Master Control
Barnstead/Therm?olyne DB17615 Dri-Bath For One Block 11
Diagnostics Instruments SPOT SP401-115 Power Supply
VWR Standard Heatblock I Model 949030 Cat. 13259-030
Troemner 1 Kg. Class 2 Calibration Weight Last Calibrat
VWR Scientific SB20 SympHony pH Meter without Probe W
Thermolyne Nuova II Stirrer Model S18525
PolyVial Dionex Filter Caps for 0.5mL Vials Open Bag
Cole Parmer Microcomputer pH-Vision Meter Model 05669
Thermo 9990615 Filter Vapor Hyperclean Shandon Hypercl
Corning PC-353 Stirrer Somewhat dirty functional 5" x
Jenco Model 7001H Hand Held Digital Thermometer With Pr
CMA Microdialysis CMA/210 Power Supply (2 Units Availab
Allen Bradley 1489-A2C150 Breaker 15A 2P 15A 480Y |
 |
|