BSH0701T01A1A

3.PLC控制系统中电磁干扰的主要来源有哪些呢？

  (1)来自空间的辐射干扰

  空间的辐射电磁场（EMI）主要是由电力网络、电气设备的暂态过程、雷电、无线电广播、电视、雷达、高频感应加热设备等产生的，通常称为辐射干扰，其分布极为复杂。若PLC系统置于所射频场内，就回收到辐射干扰，其影响主要通过两条路径；一是直接对PLC内部的辐射，由电路感应产生干扰；而是对PLC通信内网络的辐射，由通信线路的感应引入干扰。辐射干扰与现场设备布置及设备所产生的电磁场大小，特别是频率有关，一般通过设置屏蔽电缆和PLC局部屏蔽及高压泄放元件进行保护。

  (2)来自系统外引线的干扰

  主要通过电源和信号线引入，通常称为传导干扰。这种干扰在我国工业现场较严重。

  (3)来自电源的干扰

  实践证明，因电源引入的干扰造成PLC控制系统故障的情况很多，笔者在某工程调试中遇到过，后更换隔离性能更高的PLC电源，问题才得到解决。

  PLC系统的正常供电电源均由电网供电。由于电网覆盖范围广，将受到所有空间电磁干扰而在线路上感应电压和电路。尤其是电网内部的变化，入开关操作浪涌、大型电力设备起停、交直流转动装置引起的谐波、电网短路暂态冲击等，都通过输电线路到电源边。PLC电源通常采用隔离电源，但其机构及制造工艺因素使其隔离性并不理想。实际上，由于分布参数特别是分布电容的存在，隔离是不可能的。

  (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侵入。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。

Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Panasonic MHMA302P1C Fast Ship
Brand New
   14  504  30
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-0235-B805 Tested in Good condition
Pre-Owned
   14  503  74
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-2230-B005 Tested in Good condition
Pre-Owned
   14  503  74
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New Siemens 6SE6440-2UE22-2CA1 2  2KW Fast ship with warranty
Brand New
   14  503  74
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New Siemens 6SE6440-2AD22-2CA1 2  2KW Fast ship with warranty
Brand New
   14  503  05
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Siemens 6SE6430-2UD37-5FB0 75KW Tested in Good condition
Pre-Owned
   14  496  79
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    makino T8G01-00 I/0 UNIT NO  1 TPB-H  VO Tested in Good Conditon
Pre-Owned
   14  494  71
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW ABB MODULE PP30012HS
   14  472  47
  
+   20  85 shipping
 Watch
From China
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW IN BOX Fanuc a16b-3200-0710 Fast ship with warranty
Brand New
   14  492  62
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    A20B-8101-0980 Fanuc motherboard Tested in Good condition
Pre-Owned
   14  489  84
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    WESTINGHOUSE 1C31232G02 INPUT MODULE Tested in Good condition
Pre-Owned
   14  484  35
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    HONEYWELL 80363972-150 Tested in Good condition
Pre-Owned
   14  482  89
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A16B-2201-0851 Tested in Good condition
Pre-Owned
   14  475  94
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New ABB DCS PM152 / 3BSE003643R1 Fast Ship
Brand New
   14  462  60
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW Siemens 6SE6420-2AC25-5CA1 MM420 5  5KW 220V
Brand New
   14  459  26
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New Fanuc A20B-3300-0670 Board Fast ship with warranty
Brand New
   14  458  57
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW IN BOX Fanuc A20B-8100-0161 Fast ship with warranty
Brand New
   14  457  87
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW HF-SP702BK HFSP702BK MITSUBISHI SERVO MOTOR
Brand New
   14  448  84
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW AGP3310H-T1-D24-RED PROFACE HMI GRAPHIC PANEL ORIGINAL
Brand New
   14  448  84
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Yaskawa servo drive SGDC-10ARA Tested in Good Condition Fast Ship
Pre-Owned
   14  393  93
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Siemens 6FC5370-0AA00-1AA0 Tested in Good condition
Pre-Owned
   14  389  76
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Siemens 6FM1706-3AB10+6ES5491-0LB11 Tested in Good Condition
Pre-Owned
   14  386  22
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
New in Original Box Schneider TSXP572823M PLC Module Fast Ship
Brand New
   14  386  15
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    ABB 3BHE024855R0101 Tested in Good condition Fast Ship
Pre-Owned
   14  384  20
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Yaskawa SGMJV-01ADD6S+SGDV-R90A01B002000 Fast Ship
Brand New
   14  379  34
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Mitsubishi HF154BS-A42 Fast Ship
Brand New
   14  379  20
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    ABB DCS DSDX 451 /5716075-K/DSDX-451 EXPANSION I/O MODULE Fast Ship
Pre-Owned
   14  379  20
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Panasonic MDME302GCG+MFDHTA390 Fast Ship
Brand New
   14  379  20
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Fanuc A05B-2518-C302#EGN Tested It Good Fast Ship
Pre-Owned
   14  375  45
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-6047-H201 A06B6047H201 Tested in Good condition
Pre-Owned
   14  371  69
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    CISCO ASA5540-BUN-K9 Firewall Tested in Good condition
Pre-Owned
   14  371  69
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    HORIBA SEC-N124MGM Tested in Good Condition Fast Ship
Pre-Owned
   14  363  35
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Siemens soft starter 3RW4047-1BB04 Fast Ship
Brand New
   14  358  35
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    WESTINGHOUSE 1C31233G04 INPUT MODULE Tested in Good condition
Pre-Owned
   14  332  29
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    HONEYWELL 51303982-400 CONTROL BOARD WITH 51304525-100 Fast Ship
Pre-Owned
   14  323  60
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    6RA22 Siemens C98043-A1200-L22 Tested in Good condition
Pre-Owned
   14  316  10
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    ABB DCS PM151 / 3BSE003642R1 Tested in Good condition Fast Ship
Pre-Owned
   14  310  88
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Emerson M155RGB14 CT Speed Regulator In Good Condition Fast Ship
Pre-Owned
   14  305  39
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Yaskawa SGMGH-30ACA21 Fast Ship
Brand New
   14  302  89
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New LEINE LINDE    862209126    768575-02   2500 ppr Fast ship with warranty
Brand New
   14  302  20
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW Siemens M430 6SE6430-2AD231-5CA0 15KW Fast ship with warranty
Brand New
   14  295  25
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW Cayee CNF101L Fast Ship
Brand New
   14  295  18
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Mitsubishi HF54BT-A42 Fast Ship
Brand New
   14  294  13
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Mitsubishi HF54BT-A51 Fast Ship
Brand New
   14  293  99
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Panasonic MSME202GCG+MEDHT7364 Fast Ship
Brand New
   14  288  85
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Cisco WS-SVC-IDSM-2 Tested in Good Conditon Fast Ship
Pre-Owned
   14  286  21
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Mitsubishi Q04UDVCPU Fast Ship
Brand New
   14  283  43
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A05B-2518-C212#EMH Tested In Good Condition Fast Ship
Pre-Owned
   14  281  90
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Siemens 6FC5210-0DA00-1AA0 6FC52100DA001AA0 Tested
Pre-Owned
   14  274  67
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC motor A06B-0246-B401 Tested in Good condition
Pre-Owned
   14  267  45
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Mitsubishi Inverter FR-F840-00620-2-60 Fast Ship
Brand New
   14  247  15
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-0571-B075 Tested in Good condition
Pre-Owned
   14  246  60
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Siemens 6RA7078-6DS22-0 Tested in Good condition
Pre-Owned
   14  246  18
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New Mitsubishi Servo Motor HC102T-A47 Fast Ship
Brand New
   14  244  58
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW IN BOX OMRON PLC CV2000-CPU01-V1 Fast Ship
Brand New
   14  243  68
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS SIEMENS NEW 6AV6545-0CC10-
Brand New
   14  236  87
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW Mitsubishi Servo Motor HC153T-SZ Fast Ship
Brand New
   14  236  73
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand New in Box Mitsubishi PLC MDS-R-V2-4040 (MDSRV24040) Fast Ship
Brand New
   14  231  45
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW Schneider PLC Module 490NRP25400 Fast Ship
Brand New
   14  227  76
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Siemens 6AV6545-0DA10-0AX0 6AV6 545-0DA10-0AX0 Tested Fast Ship
Pre-Owned
   14  219  35
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW IN BOX Fanuc A20B-8002-0220 Fast ship with warranty
Brand New
   14  216  02
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Brand NEW Mitsubishi Servo Motor HF-H104K-S1 Fast Ship
Brand New
   14  204  83
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A068-6105-H002 A0686105H002 Tested in Good condition
Pre-Owned
   14  200  73
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Fanuc A02B-0309-C242 Membrane Keypad Tested in good condition
Pre-Owned
   14  197  95
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS NEW IN BOX MITSUBISHI GT1450-QLBDE Fast Ship
Brand New
   14  192  39
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS Ruiyan RY-F600/RY-F600P Fiber Optical Fusion Splicer Optical Fiber Cleave
Brand New
   14  177  79
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS New Fanuc A06B-6111-H002#H550 Servo Amplifier Fast Ship
Brand New
   14  177  65
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    FANUC A06B-1404-B100 Tested in Good condition
Pre-Owned
   14  168  62
  
Free Shipping
 Watch
From Hong Kong
Get fast shipping and excellent service when you buy from    Top-rated sellers
Item image
1PCS    Fanuc A20B-8200-0709 PCB Board In Good Condition
   14  165  28