621-0008
1.概述
隨著科學(xué)技術(shù)的發(fā)展，PLC在工業(yè)控制中的應(yīng)用越來(lái)越廣泛。PLC控制系統(tǒng)的可靠性直接影響到工業(yè)企業(yè)的安全生產(chǎn)和經(jīng)濟(jì)運(yùn)行，系統(tǒng)的抗干擾能力是關(guān)系到整個(gè)系統(tǒng)可靠運(yùn)行的關(guān)鍵。自動(dòng)化系統(tǒng)中所使用的各種類型PLC，有的是集中安裝在控制室，有的是安裝在生產(chǎn)現(xiàn)場(chǎng)和各電機(jī)設(shè)備上，它們大多處在強(qiáng)電電路和強(qiáng)電設(shè)備所形成的惡劣電磁環(huán)境中。要提高PLC控制系統(tǒng)可靠性，設(shè)計(jì)人員只有預(yù)先了解各種干擾才能有效保證系統(tǒng)可靠運(yùn)行。
2.電磁干擾源及對(duì)系統(tǒng)的干擾是什么？
影響PLC控制系統(tǒng)的干擾源于一般影響工業(yè)控制設(shè)備的干擾源一樣，大都產(chǎn)生在電流或電壓劇烈變化的部位，這些電荷劇烈移動(dòng)的部位就是噪聲源，即干擾源。
干擾類型通常按干擾產(chǎn)生的原因、噪聲的干擾模式和噪聲的波形性質(zhì)的不同劃分。其中：按噪聲產(chǎn)生的原因不同，分為放電噪聲、浪涌噪聲、高頻振蕩噪聲等；按噪聲的波形、性質(zhì)不同，分為持續(xù)噪聲、偶發(fā)噪聲等；按聲音干擾模式不同，分為共模干擾和差模干擾。共模干擾和差模干擾是一種比較常用的分類方法。共模干擾是信號(hào)對(duì)地面的電位差，主要由電網(wǎng)串入、地電位差及空間電磁輻射在信號(hào)線上感應(yīng)的共態(tài)（同方向）電壓送加所形成。共模電壓有時(shí)較大，特別是采用隔離性能差的電器供電室，變送器輸出信號(hào)的共模電壓普遍較高，有的可高達(dá)130V以上。共模電壓通過不對(duì)稱電路可轉(zhuǎn)換成差模電壓，直接影響測(cè)控信號(hào)，造成元器件損壞（這就是一些系統(tǒng)I/O模件損壞率較高的原因），這種共模干擾可為直流、亦可為交流。差模干擾是指用于信號(hào)兩極間得干擾電壓，主要由空間電磁場(chǎng)在信號(hào)間耦合感應(yīng)及由不平衡電路轉(zhuǎn)換共模干擾所形成的電壓，這種讓直接疊加在信號(hào)上，直接影響測(cè)量與控制精度。
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Motortronics Inc ABC-10-480-N Electronic Brake Module
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Allen Bradley 1756-L1/A ControlLogix Processor w/ 1756-M1/A Rev R01
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
ABB 3BSC690141R1 S800 I/O Analog Input Module AI893 PR:C
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW ASCO JIS8316B354 Red Hat Solenoid Valve
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Schneider VX5A66U41N4 Replacement Drive Control Board
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW Siemens SIMATIC 6ES7 155-5AA00-0AC0 Interface Module FS:02 FW:V3 0 1
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Gould 100-0166 DNP II Axis Logic Board
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Trane X13650457-11 TCI-Com4/IPCB Module Rev M
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Westinghouse 4D33900G19 Ovation Auxiliary Power Supply Module Sub 13
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW Rosemount 3051CA2A22A1AB4I5L4M5 Pressure Transmitter 0-1000mm HG 150 PSIA
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
General Electric THLC234175 Circuit Breaker 175 Amps 480VAC
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
International Cybernetics Corporation 100-0315 Control Board 0100-0036
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Westinghouse 4D33865G03 PCD I/O Auxiliary Power Supply Module Sub 09
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
AMC Power Tempering Air CAMM Combustion Airflow Management Module
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
AMC Power Hot Air CAMM Combustion Airflow Management Module
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
AMC Power Hot PA CAMM Combustion Airflow Management Module
Pre-Owned
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW Bindicator RFO0G1A RF Series Level Probe Module
2 258 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Parker C3S063V2F11 I20 T11 M00 Compax3 Brushless AC Servo Drive
Pre-Owned
2 223 97
Free Shipping
3 Watching
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW Rollway NU324EMC3 Cylindrical Roller Bearing
2 223 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Westinghouse HM2P4XWS10 Circuit Breaker 400A 600V
Pre-Owned
2 223 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Westinghouse Emerson 5X00106G01 Ovation Analog Input Module New Style
Pre-Owned
2 213 54
Was: Previous Price 3 162 20
Free Shipping
30% off
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
General Electric PLE3ESBG13 Power Leader Power Meter 3-EL "Y" Universal
Pre-Owned
2 189 22
Was: Previous Price 3 127 45
Free Shipping
30% off
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Mahr Federal Size 32 3040mm Snap Gage OP#370 4792743-LH / 4792744-RH
Pre-Owned
2 189 22
Free Shipping
Only 1 left!
1 Watching
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Allen Bradley 1791-0A32 Block I/O Module Ser B Rev B01 No Covers
Pre-Owned
2 189 22
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW MRC 319M Single Row Roller Bearing
2 189 22
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Sony LH20-C Magnescale Digital Display / Control Unit
Pre-Owned
2 189 22
Was: Previous Price 3 127 45
Free Shipping
30% off
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Liebert 02-786497-01 Snubber / Charger / S S Assembly Rev E P/L I
Pre-Owned
2 119 72
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Lincoln Electric Automation Division Welding Feeder Control Box
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
General Electric LA3600F Circuit Breaker 600A Frame 600VAC 400 Amp Trip
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW Bently Nevada 330102-00-36-10-02-00 Proximity Probe
2 084 97
Free Shipping
Only 1 left!
1 Watching
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Sanyo Denki 65AA030VXR03B Servo Amplifier Card PRS-1929E
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Sanyo Denki 65AA030VXR01E Servo Amplifier Card PRS-3002
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Sanyo Denki 65AA030VXR01B Servo Amplifier Card PRS-1929E
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW Dayton 6K637M Capacitor Start Industrial Motor 1/2 HP 1725 RPM 115/230V
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Square D HGL36080 PowerPact Shunt Trip Circuit Breaker 80 Amps 600VAC
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW McJunkin Blind Flange 13-1/2" O D 12" Bolt-to-Bolt
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
GMF Robotics NE8400-010-0031 Excitor-Counter Servo Amplifier Card Rev C
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Yokogawa YS170-001 Programmable Controller Style S2
Pre-Owned
2 084 97
Free Shipping
Only 1 left!
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
GE Fanuc HE697THM160G Series 90-70 Thermocouple Input Module
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Westinghouse 1P00000G01 Ovation Analog Output Card 13QAO9 Rev E
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Krauss Maffei LV200 AE9 Control Board PCB
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Krauss Maffei LV200 AE4 Control Board PCB
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Milltronics AO-15 Isolated Analog Output Module ML10L1295
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW United Conveyor Corporation 1802-25 6" Soot Intake Valve
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
GE Fanuc IC697CPU781G Series 90-70 CPU Module CPU781
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW Qty 4 Anvil 171S 2" Solder End Bronze Ball Valves
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
Edstrom Watchdog System 6100-9001-010 Local Processor Unit Rev B
Pre-Owned
2 084 97
Free Shipping
Watch
Get fast shipping and excellent service when you buy from Top-rated sellers
Item image
NEW Rahn 14236 2159 33 Flange Assembly with Stub Ends 11-3/4" Bore
2 084 97
