6SL3352-1AE41-4FA1

6SL3352-1AE41-4FA1

6SL3352-1AE41-4FA1

6SL3352-1AE41-4FA1

PLC上电后，X000、X002常开点就会闭合。即逻辑值为“1”Y0=(Y0+X001)×X000×X002只要按下启动按钮SB1后，X001的逻辑值为“1”，Y0逻辑值就为“1”。松开启动按钮SB1，X001的逻辑值为“0”但Y0逻辑值为“1”，Y0与X001是或的关系，保证了Y0逻辑值始终为“1”，即自锁。直至按下停止按钮或出现过载 (FR0动作），Y0的逻辑值才变为“0”。

通过上面的简单示例可知，新手可能还未弄懂外部为常闭输入时，经PLC内部输入电路后逻辑值发生了“非”的变化。以及继电器电气控制固有思维影响，老手是出于疏忽。这虽然是低级错误，也易发生在程序编制过程中。

Siemens SBS 2500 SBS 4025 SBS4025 F 2500 A Amp SB25TLSI

GE 7700 Series 6" Breaker Feeder MCC Bucket 2-Wire 20A

Bussmann JCL-2R 70A Fuse JCL2R 5.08kV R-rated Buss NIB

GE 7700 Series 6" Breaker Feeder MCC Bucket 2-Wire 15A

GE 7700 Series 6" Breaker Feeder MCC Bucket 3-Wire 20A

Allis-Chalmers LA-1600A 1600 Amp A Air Circuit Breaker

Westinghouse Hagan Ring RB-3003 Circular Chart Recorder

Square D GC-DSP Ground Fault Display for GC-200 GCDSP

Square D Circuit Breaker FAL FAL22100WB 100Amp 100A Amp

GE General Electric TED TED134030 30 AMP 30Amp 30A A

General Electric GE QMR366 Disconnect Switch 600 Amp

Square D I-Line FCB24040BC FC24040 40 Amp 40Amp 40A A

Bussmann LAR-H02 Fuse K KL LA LARH02 LARHO2 Buss A6KC

Allen Bradley AB 509-FOA Size Sz 5 Starter 270A 240V

Square D Circuit Breaker KAL26200WBB 200Amp A 200A Amp

General Electric GE 763B406G28 QMR Switch 600 A Amp

Allen Bradley 1734-OE2C Analog Output Module AB NEW/NIB

Mitsubishi Breaker NF-SF3100 NF 100 Amp 100Amp 100A A

SOLA SCP30 S15-DN 15V 2.0 A Power Supply SCP30S15DN NIB

Crompton VA-SFSF DC Volts Meter 0-500VDC 237-01 VASFSF

Northern Telecom QPC444A Conf Conference Communication

Square D Schneider Masterpact NW12L 1200 A CRADLE NIB 

Mitsubishi Breaker NV100-SB NV 100 Amp 100Amp 100A A

Zenith 1200 A Amp ZBTSD121E 480 V 3 PH Transfer Switch

Mitsubishi Breaker NV100-SB NV 50 Amp 50Amp 50A A

Acopian A24H1200M Regulated 24VDC Power Supply A24H1200

Hitran Transformer 51 kVA 460/230Y/133 51kVA 3 PH 230 Y

Square D Mini Power Center 5 kVA with 20 Amp Main

Foxboro CFT50-B1EADBZ Mass Flowmeter CFT50B1EADZ

Acopian TD15-850 Dual Tracking Power Supply TD15850

ITE LKM-2 Current Transformer 4000:5 401739-K10 LKM2 5A

Hitran Transformer 8 kVA 460/230 V 1 PH 8kVA 230 1PH

ITE LKM-2 Current Transformer 4000:5 401739-K10 LKM2 5A

Acopian TD15-850M Dual Tracking Power Supply TD15850M

Square D I-Line Breaker FA26100AC FA 100 Amp A 100A

Square D QED MP50H1 Breaker Panel 5000 Amp A 4W Ground

Allen Bradley AB Powerflex 400 Drive 22C-D072A103 50 HP

ASCO 1200 Amp G9623120097XC Transfer Switch 480/277 4W

Allen Bradley AB size 0 509-AOXD Motor Starter A0D 18A

AB Allen Bradley 960182 PCB Control Board

ASCO 100 A Amp Transfer Switch 208/120 V B940310049C 

Toshiba Tosvert VT130H1U4270BOH Inverter Drive 25 HP