DCS和PLC的设计原理区别较大,PLC是由摸仿原继电器控制原理发展起来的,70年代的PLC只有开关量逻辑控制,首先应用的是汽车制造行业。它以存储执行逻辑运算、顺序控制、定时、计数和运算等操作的指令;并通过数字输入和输出操作,来控制各类机械或生产过程。用户编制的控制程序表达了生产过程的工艺要求,并事先存入PLC的用户程序存储器中。运行时按存储程序的内容逐条执行,以完成工艺流程要求的操作。PLC的CPU内有指示程序步存储地址的程序计数器,在程序运行过程中,每执行一步该计数器自动加1,程序从起始步(步序号为零)起依次执行到最终步(通常为END指令),然后再返回起始步循环运算。PLC每完成一次循环操作所需的时间称为一个扫描周期。不同型号的PLC,循环扫描周期在1微秒到几十微秒之间。程序计数器这样的循环操作,这是DCS所没有的。OPHIR NOVA DISPLAY POWER METER + SENSOR 150C-Y-3/12 YAG
Rofin leistungsmessung Laser
FORCE SPARC CPU-8VT CPU-8VT/64-170-2 VME MAINFRAME CPU
Agilent 5086-7471 TBR Step Generator
Vision Engineering Oblique and Direct Viewer 360° Lynx
RVSI 63552 REV-A VME SLAVE PROCESSOR with TTM610-E
RVSI 53003 VME MASTER BOARD REV-B
RVSI 63551 X63551 VME MASTER BOARD REV-B
RVSI 63552 REV-B VME SLAVE PROCESSOR with TTM610-E - 11
Allen Bradley SLC 500 1747-L532 5/03 CPU 13 Slot Rack
FUJI 4800 VME-48108-00F-G Vision Processing Board
Agilent 5087-7020 Coupler with Bias Tee 50 OHM
FLOROD CORPORATION LCM-308 ABB 3HAC0129-1 LCM CONTROL PANEL
RVSI 51828 VME MASTER BOARD REV-A
GSI lumonics 6056049 P/N:6056049 Board
Motorola VME162-533A VME 162 533A SBC
Agilent 87206C Multiport Coaxial ABB 3HAC0129-1 Switch, DC to 26.5 GHz
Cognex In-Sight 5400 Smart Cameras With Cable
ZEISS EPIPLAN NEOFLUAR 50X/0.75 HD DIC OBJECTIVE LENS
Inb AXXSW1GB GIGABIT SWITCH MODULE "NEW"
LAMBDA EMI GEN 60-25 1500W Programmable Power Supplies
NetCom SmartBits 2000 WITH SX-7410B
Matrox IP-8/AT/1M IP-8/AT 0382-0302 Indutrial Video
Inb PRO/1000 PF Quad Port ABB 3HAC0129-1 Server Adapter EXPI9404PF
HP / Agilent 08563-60023 10.7MHz FILTER BOARD
Agilent E5847A 46-ch DRAM BGA probe to 90-pin cable
Agilent 87222E Coaxial Transfer Switch DC to 50 GHz
Agilent N1811-60009 4 port coaxial switch 50GHz
Matrox HELIOS XCL ODYSSEY XCL FRAME GRABBER
Delta Tau Data Systems PMAC-PC ABB 3HAC0129-1 602705-107 CPU + ram
AGILENT E1476A 75000 VXI Series C 64 Channel Mux
Agilent E6651A WIRELESS MOBILE WiMAX TEST SET PANEL