PLC作用：

PLC是多數(shù)工業(yè)控制和工廠自動(dòng)化系統(tǒng)的核心組成部分，通常被稱(chēng)為工廠的“大腦"，PLC 通過(guò)接收和處理來(lái)自傳感器和機(jī)器的數(shù)據(jù)來(lái)實(shí)現(xiàn)廣泛的功能，然后使用這些數(shù)據(jù)來(lái)控制和制動(dòng)外部設(shè)備。除此之外，成功的設(shè)計(jì)必須具備可靠性、系統(tǒng)穩(wěn)定性以及與連接的自動(dòng)化系統(tǒng)的互操作性。

現(xiàn)在工業(yè)上使用可編程邏輯控制器已經(jīng)相當(dāng)接近于一臺(tái)輕巧型計(jì)算機(jī)，甚至已經(jīng)出現(xiàn)集成個(gè)人計(jì)算機(jī)(采用嵌入式操作系統(tǒng))與PLC結(jié)合架構(gòu)的可編程自動(dòng)化控制器(Programmable Automation Controller，簡(jiǎn)稱(chēng)PAC)，能透過(guò)數(shù)字或模擬輸入/輸出控制機(jī)器設(shè)備、制造處理流程及其他控制的電子系統(tǒng)。

1、用于開(kāi)關(guān)量控制

目前，PLC的首要目標(biāo)，也是別的控制器無(wú)法與其比擬的，就是它能方便并可靠地用于開(kāi)關(guān)量的控制。用PLC進(jìn)行開(kāi)關(guān)量控制實(shí)例是很多的，冶金、機(jī)械、輕工、、紡織等等，幾乎所有工業(yè)行業(yè)都需要用到它。

2、用于模擬量控制

模擬量，如電流、電壓、溫度、壓力等等，它的大小是連續(xù)變化的。工業(yè)生產(chǎn)，特別是連續(xù)型生產(chǎn)過(guò)程，常要對(duì)這些物理量進(jìn)行控制。用PLC實(shí)現(xiàn)模擬量控制是*可能的。

PLC進(jìn)行模擬量控制，要配置有模擬量與數(shù)字量相互轉(zhuǎn)換的A/D、D/A單元。它也是I/O單元，不過(guò)是特殊的I/O單元。

3、用于運(yùn)動(dòng)控制

實(shí)際的物理量，除了開(kāi)關(guān)量、模擬量，還有運(yùn)動(dòng)控制。PLC可接收計(jì)數(shù)脈沖，加上PLC有數(shù)據(jù)處理及運(yùn)算能力，若再配備相應(yīng)的傳感器(如旋轉(zhuǎn)編碼器)或脈沖伺服裝置，則*可以依NC的原理實(shí)現(xiàn)種種控制。

4、用于數(shù)據(jù)采集

隨著PLC技術(shù)的發(fā)展，其數(shù)據(jù)存儲(chǔ)區(qū)越來(lái)越大。PLC還可配置上小型打印機(jī)，定期把DM區(qū)的數(shù)據(jù)打出來(lái)。PLC也可與計(jì)算機(jī)通訊，由計(jì)算機(jī)把DM區(qū)的數(shù)據(jù)讀出，并由計(jì)算機(jī)再對(duì)這些數(shù)據(jù)作處理。這時(shí)，PLC即成為計(jì)算機(jī)的數(shù)據(jù)終端。

5、用于信號(hào)監(jiān)控

PLC自檢信號(hào)很多，內(nèi)部器件也很多，多數(shù)使用者未充分發(fā)揮其作用。其實(shí)，*可利用它進(jìn)行PLC自身工作的監(jiān)控，或?qū)刂茖?duì)象進(jìn)行監(jiān)控。

STI RM-4 43860-0010 SAFETY CURTAIN CONTROLLER

STI MS4348B-2 48" LIGHT CURTAIN RECEIVER

STI MINISAFE/FLEXSAFE TEST PROCEDURE WITH CABLE 4300B-2

STI MINI-SAFE B LIGHT CURTAIN CONTROLLER LR-MS4400B-2 SERIES

STI MINI SAFE 4600 SERIES SAFETY LIGHT CURTAIN MS46-30-870-Q1-X

STI MINI SAFE 4600 SERIES LIGHT CURTAIN TRANSMITTER MS46-X-2095-30

STI MINI SAFE 4600 SERIES LIGHT CURTAIN TRANSMITTER MS46-30-2095-X

STI MINI SAFE 4600 SERIES LIGHT CURTAIN RECEIVER MS46SR-30-2095-Q1-R-NC-FN

STI MICROSAFE SENSOR BANNER LIGHT CURTAIN MC4228XE

STI MICROSAFE MC4200 SERIES RECEIVER MC4244RE

STI MICROSAFE 115/230VAC .5A/0.25A CONTROLLER, MC42DMISSING BOARD*

STI MEGA SAFE 4600 SERIES MG46SR-20-610-R-D1-GM1  

STI MEGA SAFE 4600 SERIES MG46-20-610-X-D1-GM1

STI LIGHT CURTAIN CONTROLLER 70010-1136 MS4324B2... / 70011-1001 MS/FS43CNTRL...

STI FLEXSAFE SERIES RECEIVER FS4316BR-3

STI 4600 SERIES SAFETY LIGHT CURTAIN EMITTER MS46-14-870-Q2-XNICKS*

STI 115VAC 30VA C CONTROLLER 70027-1000 / LCC-FB-AC1-U

STI SAFETY CURTAIN RECEIVER MS4432R

STI MINISAFE RECEIVER MS4320BR

STI MEGASAFE 46000 SER LIGHT CURTAIN RECEIVER MG46CL-20-785-R-D3-C

STI MEGASAFE 4600 SERIES TRANSMITTER MG46-30-520-X-A1-FD2

STI LIGHT CURTAIN TRANSMITTER MG46-30-870-X-A1-FD2

STI LIGHT CURTAIN 49.5'' MS46-30-1215-R-FN

STEWART-WARNER 150 PSI 3 FOOT PUMP 324429-3

STEWART WARNER THOR 500RPM MOTOR 11637A

STERLING PROMEASURE SYSTEM DV202,  

STERLING ELECTRIC GEAR REDUCER 2175FHR00500102 5:1 RATIO 1750RPM 1.703HP

STERLING 3PHASE TYPE 1K FBK1 1725RPM ELECTRIC MOTOR B0014FAF2A1

STEARNS STYLE 5 CFCBC 90VDC 27W CLUTCH-BRAKE 2-13-4241-00-LJ

STEARNS 230V 60HZ BRAKE 108773101 QG REV D

STEARNS 1 087 021 000 56 SOLENOID ACTUATED SELF ADJ DISC BRAKE,

STATE SOLUTION 1 POWERFILL SELECT 4+2 CLEANER DEGREASER REMOVER 108158

STARRETT HEIGHT GAGE 755

STARRETT 14" TO 15" MICROMETER PARTS OR REPAIR

STAR LINEAR BEARING BLOCK 4671-81X-10 / AA02K

STAR CUTTER VP7L1C-3525-BA  

STAR 2-3/4" X 1-5/8" GEAR CUTTING TOOL 40078175*

STANLEY IN-LINE ELECTRONIC NUTRUNNER E40MF2XXG-55LISTING #2*

STANLEY F30L21TA-23 " CROWSFOOT OPEN END PNEUMATIC RATCHET, USED

STANLEY ELECTRONIC NUTRUNNER ES40-081

STANLEY ELECTRONIC NUTRUNNER E40MFA3XXG-43LISTING #1*

STANLEY BetaFSC TORQUE CONTROLLER ACFAF4-01XXX-11411

STANLEY AIR TOOLS PNEUMATIC NUTRUNNER NO LABEL

STANLEY A40LA-6 3/8" DRIVE ANGLE PNEUMATIC NUT RUNNER

STANLEY 5/8IN DRIVE RIGHT ANGLE ELECTRONIC NUTRUNNER E40MFA3XXG-43LISTING #2*

STANLEY 5/8IN DRIVE IN-LINE ELECTRONIC NUTRUNNER E40MF2XXG-55LISTING #1*

STANLEY 1/2IN DRIVE RIGHT ANGLE ELECTRONIC NUTRUNNER E40LRA3XXG-43

STANLEY 1/2IN DRIVE RIGHT ANGLE ELECTRONIC NUTRUNNER E40LRA3XG-32

STANLEY 1/2" DRIVE RIGHT-ANGLE REVERSING NUTRUNNER E40LRA2XXG-17

STANDARD PUMP INC. 100 PSI AIR MOTOR A2 FOR DRUM PUMPS

STANDARD LOCKNUT N056

STACKFLOW 17" LONG WITH 1-1/4" THREAD CONNECTION STACKVALVE FLOW