描述
5)来自接地系统混乱时的干扰
接地是提高电子设备电磁兼容性(EMC)的有效手段之一。正确的接地,既能抑制电磁干扰的影响,又能抑制设备向外发出干扰;而错误的接地,反而会引入严重的干扰信号,使PLC系统将无法正常工作。PLC控制系统的地线包括系统地、屏蔽地、交流地和保护地等。接地系统混乱对PLC系统的干扰主要是各个接地点电位分布不均,不同接地点间存在地电位差,引起地环路电流,影响系统正常工作。例如电缆屏蔽层必须一点接地,如果电缆屏蔽层两端A、B都接地,就存在地电位差,有电流流过屏蔽层,当发生异常状态加雷击时,地线电流将更大。
此外,屏蔽层、接地线和大地有可能构成闭合环路,在变化磁场的作用下,屏蔽层内有会出现感应电流,通过屏蔽层与芯线之间的耦合,干扰信号回路。若系统地与其它接地处理混乱,所产生的地环流可能在地线上产生不等电位分布,影响PLC内逻辑电路和模拟电路的正常工作。PLC工作的逻辑电压干扰容限较低,逻辑地电位的分布干扰容易影响PLC的逻辑运算和数据存储,造成数据混乱、程序跑飞或死机。模拟地电位的分布将导致测量精度下降,引起对信号测控的严重失真和误动作。
(6)来自PLC系统内部的干扰
主要由系统内部元器件及电路间的相互电磁辐射产生,如逻辑电路
互辐射及其对模拟电路的影响,模拟地与逻辑地的相互影响及元器件间的相互不匹配使用等。这都属于PLC制造厂对系统内部进行电磁兼容设计的内容,比较复杂,作为应用部门是无法改变,可不必过多考虑,但要选择具有较多应用实绩或经过考验的系统。
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。
SMC SOLENOID SY3120-6LZD-C4(LOT OF 3)
NEMA 34 Planetary Gearhead 518-43-010 Minarik Drives
Panasonic Servo Drive&Motor Set MUDS041A1A
Agilent HP 84000-60189 3.5mm Test Port Cable
SEALEVEL PCI RS-232 RS-422 RS-485 Interface 7202 rev C
OMRON VISION MATE CONTROLLER F350 F350-C10 F300-A20
Olympus WHSZ10X-H/22 Eyepieces
GE Fanuc S2K Servo Drive&MTR-3N31 Servo Motor Set
Interface PCI expansion interface module PCI-2724C 2724
PANTHER H12 Intelligent Motion System IMS
Agilent 11683A RANGE CALIBRATOR WITH OPTION H01
Delta Tau Data Systems PMAC-PC 602705-107 CPU+ram
NAIS M1T MICRO CONTROL UNIT PLC
Soder-Wick 50-4 25ft SIZE#4 QTY=5
Delta Tau Data Systems PMAC Lite 602402-105 602192-103
Delta Tau Data Systems Universal PMAC Lite 602402-105
Coherent FieldMaster Field Master Power Energy Meter
OMEGA DP25-S STRAIN GAUGE METER
FOculus FO442SB IEEE 1394 Digital CCD Firewire Camera
OPTEM 18-108 f/2.5 close 34-11-10 MACRO VIDEO ZOOM LENS
IDEC POWER SUPPLY PS5R-D24 PS5RD24 24VDC 2.1A Qty:3
OPTO 22 SNAP-PS5-24DC SNAP-PS5 SNAP I/O 5V 4Amp QTY:2
QUANTRONIX QS27-4SN-QX1 LIGHTWRITER SPE Q-SWITCH
National Instruments NI PXI-6031E DAQ Board
Agilent 08485-60005 3.5mm(f)-N(m)Adapter 50 MHz
MATROX Meteor II Multi-Channel METEOR2-MC/4
Agilent HP 8765B Coaxial Switch DC-20GHz with Opt 024
Agilent HP 87300C Coaxial Directional Coupler 1-26.5GHz
HP NC364T Quad Port Gigabit Server Adapter 436431-001
PIXERA 001226-001 Rev F PCI CARD
MATROX Meteor II Multi-Channel METEOR2-MC/4
MATROX Meteor II Multi-Channel METEOR2-MC/4/16F
PARKER COMPUMOTOR SX8 MICROSTEP DRIVE/INDEXER
MATROX METEOR2 CL/32 METEOR Camera Link Frame Grabber
TOTAL CONTROL QPI21100E2P QUICKPANEL 9″TOUCHSCREEN
Magnum ISA Bench Card 000-878004 050-878004 000-868704
Dell Latitude D410 Motherboard&1.6Ghz CPU G8336
Lot of 2 Gore ReadyFlex Microwave Cable Assemblie 18GHz
HUBER-SUHNER SUCOFLEX 104A 8120-4921 Cable 26.5GHz NEW
EDC BIOSYSTEMS LIQUID HANDLING PROCESS CONTROLLER PANEL
TRILLIUM HAND HELD CONTROLLER OT-30 PART#874-5242-01
HP Agilent 1NB7-8539
Agilent HP 08487-60001 2.4mm(f)-N(m)Adapter 50MHz
Agilent 5065-7021
Agilent HP E3614A 0-8VDC 6A DC Power Supply
Agilent 5065-6980
Agilent HP 10498-60001 10498A 8 CH Probe Lead Set
Lot of 3 TAKEX Fiber Optic Sensor FR2-Slim Type
KDI 64537 PQ-1846 Microwave RF Directional Coupler
HP Agilent 1NB7-8539
MITSUBISHI A1SJ71UC24-R2 RS-232-C UNIT NEW
MITSUBISHI A1SY41 OUTPUT MODULE NEW
YAMATAKE HONEYWELL MX100PT12 32PT TRANSISTOR OUT
Allen Bradley 1762-IQ8 MicroLogix DC Input Module QTY=2
Mitsubishi FX2N-80MR-ES/UL FX2N80MRESUL PLC
HITACHI KP-D50 DIGITAL COLOR CAMERA
JVC.TK-C1481BEG.LO-LUX CCTV COLOUR CAMERA
AVME-311AF AVME 311AF FUJI K2056D
Yamatake Honeywell MX250RV01 VME Interface Board
Texas Instruments 435 Complete PLC
Keyence LS-3101 Laser Scan Micrometer+Scanning Heads
COGNEX VISION SYTEM IN-SIGHT-3400 CAMERA MODULE
FUJI FH1016A VM1440A SIX CHANNEL COMMUNICATION BOARD
FUJI AVAL VME-520 MCIF-16 BOARD CARD
HITACHI ZOSEN HIMV-923A/924A HIMV-924A2 WITH 2M FLASH
Adept Technology 10332-12410 MI-6 VME BOARD STAUBLI
RKC FAREX SRM SR Mini HG SYSTEM
WYKO PCB 619-152 PCI Card
COGNEX 4400 VM13B REV T VISION PROCESSOR MODULE
GE FANUC 90-30 PLC 5 SLOT SYSTEM Stepper Motor
Agilent 20mm Torque Wrench 8710-1764
COGNEX CHECKER 101 807-0007-2 REV A VISION CAMERA
Lot of 2 CrystalFontz 634 CFA-634 LCD Dispaly
National Instruments NI GPIB PCIe PCIe-GPIB
AMD Turion 64 X 2 TL52 1,6 Ghz TMDTL52HAXSCT
Micro-Coax 26GHZ 84 inch Flexible Microwave Cable
NARDA POWER DIVIDER 4456-2 FROM 2.0 to 18 GHz
STORM TRUE BLUE 205 18GHZ 72 inch Flexible CABLE
Galil Motion Controls DB 1004 DAUGHTER BOARD Rev-C
Galil 6-AXIS Motion Controller DMC-1060 DMC1060 Rev G
BERKELEY PROCESS CONTROL BX I/O WITH INPUT&OUTPUT
Agilent 1250-1529 Adapter Type-N(f)to Type-N(f)75
KEYENCE KV-24DR PLC with KV-U2 POWER SUPPLY
Agilent 1250-1476 Adapter Type-N(m)to BNC(f)NEW
HP 44727A 4 Ch Voltage/Current DAC
HP 44705A 20 CHANNEL RELAY MULTIPLEXER
Sorensen DCS80-13E DC Programmable Power Supply
SUNX S link SL-T8J,SL-T16C1 and SL-TP16C1
CORECO PC-CAMLINK PCI UNIQ UP-2000CL CCD DIGITAL CAMERA
JSR Ultrasonics RP-U2 SONIX ECHO remote pulser
NAVITAR 6000 60095 Lens 1-60095 High Mag Zoom
LiNOS 4401-256-000-20 1064nm 2-8X Laser Beam Expander
QUANTRONIX LASER HEAD PUMP CHAMBER
QUANTRONIX 0201-03199 Cavity Assembly
QUANTRONIX SHUTTER Assembly 319 0103-00483 REV G NEW
Cognex In-Sight 5400 Smart Cameras With Cable
Vision Control PSO 90-100/125 deflectors 90 degrees