IC646MPSS99***;IC646MPSS99***;IC646MPSS99***(4)来自信号线引入的干扰与PLC控制系统连接的各类信号传输线，除了传输有效的各类信号之外，总会有外部干扰信号***。此干扰主要有两种途径：一是通过变送器或共用信号仪表的供电电源串入的电网干扰，这往往被忽略；二是信号线受空间电磁辐射感应的干扰，即信号线上的外部感应干扰，这是很严重的。由信号引入干扰会引起I/O信号工作异常和测量精度大大降低，严重时将引起元器件损伤。对于隔离性能差的系统，还将导致信号间互相干扰，引起共地系统总线回流，造成逻辑数据变化、误动和死机。PLC控制系统因信号引入干扰造成I/O模件损坏数相当严重，由此引起系统故障的情况也很多。（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，既能电磁干扰的影响，又能设备向外发出干扰；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、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。例如电缆层必须一点接地，如果电缆层两端A、B都接地，就存在地电位差，有电流流过层，当发生异常状态加雷击时，地线电流将更大。此外，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，层内有会出现感应电流，通过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ALLENBRADLEY1785-LT2NSFP1785LT2ACMEELECTRICT-2-53616-1SUSPPT2536161SASEABROWNBOVERIDSQC-211USPPDSQC211TEXASINSTRUMENTSPLC945940-0001-ACUSPP9459400001ACTEXASINSTRUMENTS520C-1102SERIES500CONTROLLERREV2.6520C1102ASEABROWNBOVERIACH550-BD-180A​-4NSFPACH550BD180A4TEXASINSTRUMENTS5TI-1034-1,5TISequencerRepairedMITSUBISHILX6IC-BN624E25​2AUSPPLX6ICBN624E252​ATexasInstrumentVPU-500TEXASINSTRUMENTSPLC5TI-1013USPP5TI1013TEXASINSTRUMENTSPLC2490683-U13USPP2490683U13ASEABROWNBOVERI3HAB2242-1USPP3HAB22421MEASUREX51309223-125USPP51309223125TEXASINSTRUMENTSPLC500-2101NSFP5002101ASEABROWNBOVERI069829-001USPP069829001TEXASINSTRUMENTSPLC944935-15V/AEUSPP94493515VAEPanasonicACServoDriverMSDA043A1A#2FreeShipASEABROWNBOVERI57520001-CYUSPP57520001CYReturns:Acceptedwithin3daysCUTLERHAMMERLD3500USPPLD3500PanasonicACServoMQDB012AAD(V3)ASEABROWNBOVERI3HAB8101-8/14CUSPP3HAB8101814CTEXASINSTRUMENTSPLC505-4908USPP5054908SiemensTI565PLCMemoryCard560-2136SIEMENS1HU3104-0AD01-​ZUSPP1HU31040AD01ZPanasonic/NaisServoM***D042P1U+MBD​DT2210NIB!NewandOriginalPanasonicACServoDriverMSDA043A1AWITH60DAYSWARRANTYASEABROWNBOVERI57120001-HAUSPP57120001HAREXROTHVT-HNC100-1-21​/M-08-0-0USPPVTHNC100121M08​00TexasInstrumentsTIWAYI500-5039ALCATEL210SDMLAMNSFP210SDMLAMASEABROWNBOVERI503348NSFP503348ASEABROWNBOVERIS6HQ800BWAS4NSPPS6HQ800BWAS4SAJF//PANASONICAMKB200B10LAKACSERVOMOTORGEARREDUCTIONDRIVEUSEDTexasInstruments555-1103TexasInstruments500-5039ASEABROWNBOVERIHIEE300025R000​2NSFPHIEE300025R000​2TEXASINSTRUMENTSPLC575-2102USPP5752102TEXASINSTRUMENTSPLC500-5056NSFP5005056ASEABROWNBOVERIMHB63700LNSFPMHB63700LALLENBRADLEY2711-K6C8USPP2711K6C8TEXASINSTRUMENTSPLC128-1111USPP1281111TEXASINSTRUMENTSPLC505-3708NSFP5053708CONTROLOTRON994DN5GS-3NSPP994DN5GS3TexasInstruments500-5037APanasonicM***D082PJAACServoMotorBAILEYCONTROLSIMFBS-01NSFPIMFBS01GENERALELECTRICCR193C110L0070​80UNSFPCR193C110L0070​80PANASONICACSERVODRIVEMDDDT5540L011.5KWASEABROWNBOVERI006539960-KUSPP006539960KPanasonicACServoMotorMHMD042P1UNewinBoxFreeShipTEXASINSTRUMENTSPLCPM550-C-112USPPPM550C112TEXASINSTRUMENTSPLC560-2124NSFP5602124PanasonicACSERVOMOTORAMKA100B10KA0AMKA100B10KAOFreeShipASEABROWNBOVERI52700141NSFP52700141AYDINCONTROLS460-5045-501USPP4605045501ENDRESS&HAUSERFMR240-S3K1ALJ​AA4AUSPPFMR240S3K1ALJA​A4PANASONICACSERVOMOTORMFA024LA2NSJNEWASEABROWNBOVERIACS501-020-4-0​0P2USPPACS501020400P2TEXASINSTRUMENTSPLC505-4232USPP5054232ASEABROWNBOVERIEHDB520M2P-1LNSFPEHDB520M2P1LTexasInstruments500-5019ASEABROWNBOVERIYM222001NSPPYM222001TEXASINSTRUMENTSPLC560-2127USPP5602127DEMAG502001USPP502001ASEABROWNBOVERIACS800-U1-0011​-5NSFPACS800U100115TEXASINSTRUMENTS500-5056**SIEMENS6ES5-374-2AH21USPP6ES53742AH21ASEABROWNBOVERI57310001-CX/2USPP57310001CX2TexasInstruments555-1101PanasonicMSD021P1EACservodriver100V200WTEXASINSTRUMENTSPLC505-2590NSPP5052590ADEPTTECH10300-15520NSFP1030015520FujiHensokukiCOGeardMotorMT-9-5.4-002LAPanasonicACServoMotorMQMA022P2BSIEMENSTEXASINSTRUMENTS555-1103``XLNT``FASTSHIPPINGASEABROWNBOVERI57510001-AAUSPP57510001AAROBOTRON710-APUSPP710APTEXASINSTRUMENTS2601011*USED*)