西门子PLC基本指令功能介绍

　　一、标准触点 LD、A、O、LDN、AN、ON、

　　LD，取指令。表示一个与输入母线相连的常开接点指令，即常开接点逻辑运算起始。

　　LDN，取反指令。表示一个与输入母线相连的常闭接点指令，即常闭接点逻辑运算起始。

　　A，与指令。用于单个常开接点的串联。

　　AN，与非指令。用于单个常闭接点的串联。

　　O，或指令。用于单个常开接点的并联。

　　ON，或非指令。用于单个常闭接点的并联。 

　　二、正、负跳变 ED、EU 

　　ED，在检测到一个正跳变（从OFF到ON）之后，让能流接通一个扫描周期。

　　EU，在检测到一个负跳变（从ON到OFF）之后，让能流接通一个扫描周期。 

　　三、输出 =

　　=，在执行输出指令时，映像寄存器中的指定参数位被接通。 

　　四、置位与复位指令S、R

　　S，执行置位(置1)指令时，从bit或OUT指定的地址参数开始的N个点都被置位。

　　R，执行复位(置0)指令时，从bit或OUT指定的地址参数开始的N个点都被复位。

　　置位与复位的点数可以是1-255，当用复位指令时，如果bit或OUT指定的是T或C时，那么定时器或计数器被复位，同时当前值将被清零。 

　　五、空操作指令NOP   

　　NOP指令不影响程序的执行，执行数N（1-255）。

　　公司主营产品有:AB,ABB,GE,西门子,力士乐，施耐德,福克斯，等工业自动化控制配件及各种停产备件。诚信经营，质量可靠，请放心购买，我们将竭诚为您服务！

　　TURCK NI14-M18-AP6X-H1141 PROXIMITY SWITCH QUICK DI

　　TURCK NI30U-M30-VP44X-H1141 PROXIMITY SENSOR UPROX + 10-55VDC 200MA

　　TURCK NI3-G08-AN6X PROXIMITY SENSORS, VALVE POSITION SENSORS AND MATING ACC.

　　TURCK NI3-G08-AN6X PROXIMITY SENSORS, VALVE POSITION SENSORS AND MATING ACC.

　　TURCK Ni5-K11-AN6X/S327 INDUCTIVE SENSOR 10-30VDC PLASTIC SMOOTH BARRELL

　　TURCK RSC RKC 5722-10M CONNECTION CABLE U8017-10

　　TURCK RSC-RKC-5711-1.2M CORDSET 5P MALE FEMALE STRAIGHT 1.2 METER

　　TURCK TS-500-LUUPN8X-H1141 TEMPERATURE FLOW SENSOR 18-30VDC 1PNP/NPN

　　TURCK VB 1003-*M/S1052 PICOFAST JUNCTION BOX CONNECTOR 10 PORT

　　TURCK VB 1003-0.6-BSMK 14/S653/S1055 MULTIBOX JUNCTION BOX CONNECTOR 10 PORT

　　TURCK WKC 8T-3-WSC 8T/S101 CORDSET CABLE U0923-32

　　TURCK WSC WKC 572-1.5M CONNECTION CABLE U2531

　　TURCK WSM WKM 5711-15M CONNECTION CABLE U2779-26

　　TURCK WSM WKM 5711-15M CONNECTION CABLE U2779-26

　　TV ELITE FFN-102M S/N 94-000598 TV/VGA SPLITTER WITH CORDS AND MANUAL

　　TWO CROUSE HINDS TB57 CONDUIT OUTLET BODY 1 1/2"

　　TWO IKO LWL12 BEARING BLOCKS WITH 10-7/8" LINEAR RAIL

　　TWO MISUMI SSXR 28 BEARING BLOCKS WITH 400MM RAIL 15 3/4" L 3/4" W 5/8" T

　　TWO NSK S20 SZ BEARING BLOCKS WITH 250MM RAIL 9 14/16" L 3/4" W 5/8" T

　　TWO SMC SYJ3333-5LOZ SOLENOID VALVES WITH MANIFOLD

　　TWO THK SR15 GUIDE CARRIDGES WITH 41" LINEAR SLIDE RAIL

　　TWO THK SR25 GUIDE CARRIAGE 3 IN X 2 IN X 1 IN WITH 39 IN LINEAR SLIDE RAIL

　　TYCHEM 125285XL PROTECTIVE COVERALL W/ HOOD X-LARGE

　　TYCO 700-TT-R-D2 DIGITRACE TEMPERATURE TRANSMITTER ENCLOSURE KIT

　　TYCO ELECTRONICS 53428-1 ELECTRICAL CONNECTORS BOX OF 500

　　TYCO ELECTRONICS P40P42D12P1-24 CONTACTOR 3 POLE 24VDC 40A INDUCTIVE 600V

　　TYCO LOT OF 100 66360-4 CONTACT PIN 18-14AWG

　　TYK RS-1000F LIQUID LEAK DETECTOR SENSOR

　　TYK RS-1000F LIQUID LEAK DETECTOR SENSOR

　　TYLAN GENERAL 2900 SERIES FM-3900V MASS FLOW CONTROLLER

　　TYLAN GENERAL FC-280S SAKZ MASS FLOW CONTROLLER 500 SCCM N2 KALREZ SS-4BK-VCR-1C

　　TYVEK FC 444 SGY 00 020000 FRICTION COATED BOOT COVERS

　　U E CONTROLS PRESSURE SWITCH PART# J120-555

　　U TECHNOLOGY USCO-18R18 COAXIAL LIGHT RED LUMINESCENT 24VDC

　　UBI MAXIBAR DL40 WEDGE BARCODE SCANNER

　　UC COMPONENTS C-1328-SVEP SS SOCKET HEAD CAP SCREW 1-3/4" BAG OF 20

　　UEHLING MODEL 03 TEL-FLO BUBBLING BOTTLE 3-1/2" ALUMINUM WITH CHECK VALVE

　　ULTEX 44MA ACTUATOR ULTRASONIC WELDING W/ DUKANE 43A400 UNIVERSAL ADAPTER

　　ULTRA TECH SPILL PALLET P1 PLUS UT 9606 WITH DRUM NO DRAIN

　　ULTRAFILTRATION TANGENTIAL FLOW FILTRATION SYSTEM

　　ULTRALUX ULHBT5-446 4-LAMP HIGH BAY AC 120-277V 216W 50/60 HZ 2.0A

　　ULTRAMATION INC 3B-6RUV LINEAR THRUSTER

　　ULVAC GP-IDA CONTROLLER PIRANI VACUUM GAUGE WP-01 HEAD

　　ULVAC SINKU KIKO DA-120S DIAPHRAGM VACUUM PUMP

　　ULVAC TECHNOLOGIES PLASMA SOURCE

　　UM ABRASIVES HON AN CUT 3/8 ACT22 FINE CUT CERAMIC MEDIA 10LB PACK

　　UM ABRASIVES HON AN CUT V 1/2 CYL POLSHING CERAMIC MEDIA 10LB PACK

　　UNIBLITZ MODEL SD-10 SHUTTER DRIVE TIMER

　　UNI-COUP UCR-65 327709 FLOATING JOINT COUPLING 0.54" X 0.98" KEYED BORES

　　UNIMEASURE EP-50-004-S2 TWO CHANNEL DIGITAL OUTPUT POSITION TRANSDUCER

　　UNIMEASURE EP-50-004-SE POSITION TRANSDUCER WITH MCRE-0-HHH-Q DISPLAY

　　UNIOP MD00R-02-0045 PROGRAMMER LCD DISPLAY

　　UNIPOWER CORPORATION MODEL EHPA-2C5D5H POWER SUPPLY 120/220-240V 12/8A 50-60HZ

　　UNIT INSTRUMENTS INC UFC 1500A MASS FLOW CONTROLLER

　　UNIT INSTRUMENTS UCO-550 MASS FLOW CONTROLLER COMPUTER INTERFACE

　　UNIT INSTRUMENTS UFM-8100 MASS FLOW CONTROLLER ELASTOMER SEAL 500 PSI MAX

　　UNITED ABRASIVES INC 58450 4 1/2" X 7/8" 50 GRIT 3Z ZIRCONIUM FIBER DISCS

　　UNITED ABRASIVES INC 58450 4 1/2" X 7/8" 50 GRIT 3Z ZIRCONIUM FIBER DISCS

　　UNITED ELECTRIC 105 SERIES B105-119 TEMPERATURE SWITCH

　　UNITED ELECTRIC ADJ PRESSURE SWITCH J21K 254 9545

　　UNITED ELECTRIC CONTROLS J6 156 PRESSURE CONTROL SWITCH

　　UNITED ELECTRIC E400-2BSB TEMPERATURE SWITCH

　　UNITED ELECTRIC E400-2BSB TEMPERATURE SWITCH

　　UNITED ELECTRIC J302 441 PRESSURE CONTROLLER 0-10" WC.15-6" WC 225 PSI

　　UNITED ELECTRIC PRESSURE CONTROL TYPE J402 MODEL 270 0-200 PSI 0-1400 KPA

　　UNITED ELECTRIC TYPE J7 PRESSURE SWITCH MODEL 6473 115/230 VAC 225 PSI 15A

　　UNITED ELECTRIC TYPE J7X PRESSURE SWITCH MODEL 258 M-6233 115/230 VAC 50 PSI

　　UNITED ELECTRIC UE J120-190 PRESSURE SWITCH FOR DIV 1&2

　　UNITED ELECTRIC UE PRECISION SENSORS PV48W-15 VACUUM SWITCH 5 TORR 5MM HG

　　UNITED LWT 304L STAINLESS STEEL HEAT EXCHANGER 2" PIPE DIA 46" L 2" OD FLANGE

　　UNITORQ R300-08-115 VALVE ACTUATOR R SERIES ELECTRIC

　　UNIVER E-0220P MINIATURE SPOOL VALVE AND COIL SYSTEM

　　UNIVERSAL FLOW MONITOR LL-AZMSF5SM-2U-20P1.0T80-X17WR-ST-1D FLOWMETER

　　UNIVERSAL FLOW MONITORS LL SERIES FLOWMETER

　　UNIVERSAL FLOW MONITORS, GAS / AIR FLOW METER W/ SWITCH

　　UNIVERSAL INSTRUMENT TSE-000323 SBEC II LOAD CONTROL

　　UNIVERSAL INSTRUMENT TSE-000347 CONTROL BOARD

　　UNIVERSAL INSTRUMENT TSE-000402 VME TO FUNCTION BUS INT

　　UNIVERSAL INSTRUMENT TSE-003548 WJ BUS/SWITCH INTERFACE