*初，PLC主要用于开关量的逻辑控制。随着PLC技术的进步，它的应用领域不断扩大。
如今，PLC不仅用于开关量控制，还用于模拟量及数字量的控制，可采集与存储数据，还可对控制系统进行监控；还可联网、通讯，实现大范围、跨地域的控制与管理。PLC已日益成为工业控制装置家族中一个重要的角色。。
3.1用于开关量控制
PLC控制开关量的能力是很强的。所控制的入出点数，少的十几点、几十点，多的可到几百、几千，甚至几万点。由于它能联网，点数几乎不受限制，不管点都能控制。
所控制的逻辑问题可以是多种多样的：组合的、时序的；即时的、延时的；不需计数的，需要计数的；固定顺序的，随机工作的；等等，都可进行。
WARNER ELECTRIC BRAKE EM-9-051 NEW EM1802...
MAGNETEK/GEMCO SD-2842-C RESOLVER SD2842C
ELECTROL M-615 NEW 1/27 HP ELECTRIC MOTOR M615
13 1/2" STANDARD RESOLVER WITH 10 PIN CONNECTOR
GROVE GEAR BM218-3 NEW FLEXALINE 100:1 GEAR REDUCER BM2...
HONEYWELL M640A 1048 ACTIONATOR MOTOR M640A1048
MODICON 140DAI54000 REMAN
AJAX MAGNETHEMIC J-02-0334-05-A BOARD J02033405A
MODICON ASB832016 NEW AS-B832-016
COAX 5-VMK-H 20 NO NEW VALVE 5VMKH20NO
CUTLER HAMMER 10316H-10 SWITCH NEW 10316H10
PLACID INDUSTRIES PS-24-M POWER SUPPLY PS24M
RELIANCE ELECTRIC PC BOARD 0-52
RELIANCE ELECTRIC PHASE SEQUENCER 0-54349-2 054349...
BODINE ELECTRIC NSH-34RH NEW MOTOR NSH34RH
HONEYWELL SECURITRAM SB FF-SB14R064-S2 RECEIVER
MODICON AS-B824-016 MODULE REPAIRED ASB824016
GENERIC AUTOMATION BE-236-639-D BE236639D
CUTLER HAMMER 10316H186 NEW TYPE L SWITCH 10316H186C
EATON LEBOW 3173-1K LOAD CELL 31731K
SIEMENS 505-6660 POWER SUPPLY MODULE 5056660
VICKERS CT-06-B-50 NEW RELIEF VALVE CT06B50
SMC VFS 2000 SERIES 12 VALVE MANIFOLD ASSEMBLY
EMERSON K55HXFEG-1285 MOT02369 NEW K55HXFEG1285
WESTERN CULLEN HAYES 38-0050-600 RELAY NEW 380050600
NORDSON 273378E 10' HOSE
BARBER-COLMAN EA31 ELECTRIC ACTUATOR NEW
MINCO MULTI-ZONE TEMPERATURE MONITOR CT 124 CT124
HMS ABX-PDPM-EMBS GATEWAY NEW ABXPDPMEMBS
BOSTON GEAR ELECTRIC MOTOR CBC56-16A NEW 82907
THK BIF2512S-3RRGO+1015LC7-D NEW BIF2512S3RRGO105LC7D
FANUC A860-0360-V501 PULSECODER A8600360V501
BAUMER MY-COM D250/S35 NEW MICRO SWITCH MYCOMD250S35
LOAD CONTROLS INC PCR-1810 REFURBISHED PCR1810
MTS TEMPOSONICS R SERIES RHT0210MRG01A01 NEW
DELCO HIGH EFFICIENCY 3 PHASE AC MOTOR 1G1154C2 NIB
ASCO RED HAT SOLENOID VALVE 8215C63 NEW
ELECTRA GEAR 7718897 PJ NEW 7718897PJ
ALLEN BRADLEY 1747-L514 NEW PROCESSOR UNIT 1747L514
DONGAN A10LA2X NEW IGNITION TRANSFORMER A10LA2X
FANUC A14B-0076-B001 INPUT MODULE A14B0076B001
SAMES # 22-642 BINKS ELECTROSTATIC CONTROL UNIT NIB
LINCOLN SSF4S1 .5TCN61 ELECTRIC MOTOR NIB SSF4S1.5TCN61
LINCOLN SRF6S1TC61 ELECTRIC MOTOR NIB
SPANG POWER CONTROL 83414 NEW 11737E7365
SMC SLIDE CYLINDER NCDPX2N15-100B NEW NCDPX2N15100B
SITI TYPE MI50FPZ1 MOTOR NEW
