可編程控制器(PLC)是一種數(shù)字運(yùn)算與操作的控制裝置。PLC作為傳統(tǒng)繼電器的替代產(chǎn)品，廣泛應(yīng)用于工業(yè)控制的各個(gè)領(lǐng)域。由于PLC可以用軟件來改變控制過程，并有體積小，組裝靈活，編程簡(jiǎn)單，抗干擾能力強(qiáng)及可靠性高等特點(diǎn)，特別適用于惡劣環(huán)境下運(yùn)行。

廈門岳航計(jì)算機(jī)工程有限公司

聯(lián)系人：李素云

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手機(jī)：18965423501

座機(jī)：0592-516550

當(dāng)利用變頻器構(gòu)成自動(dòng)控制系統(tǒng)進(jìn)行控制時(shí)，很多情況下是采用PLC和變頻器相配合使用，例如我廠二催化的自動(dòng)吹灰系統(tǒng)。PLC可提供控制信號(hào)和指令的通斷信號(hào)。一個(gè)PLC系統(tǒng)由三部分組成，即中央處理單元、輸入輸出模塊和編程單元。本文介紹變頻器和PLC進(jìn)行配合時(shí)所需注意的事項(xiàng)。

1.開關(guān)指令信號(hào)的輸入

變頻器的輸入信號(hào)中包括對(duì)運(yùn)行/停止、正轉(zhuǎn)/反轉(zhuǎn)、微動(dòng)等運(yùn)行狀態(tài)進(jìn)行操作的開關(guān)型指令信號(hào)。變頻器通常利用繼電器接點(diǎn)或具有繼電器接點(diǎn)開關(guān)特性的元器件(如晶體管)與PLC)相連，得到運(yùn)行狀態(tài)指令，如圖1所示。

Rittal ZZB835506 Vented Electrical Enclosure 53" x 12" x 12" w/ Fan & 40A Switch

Hoffman F44L48 Wireway 4" x 4" x 48" Length Top Open w/ Closer & Grounding Kits

New Square D LJ41 Wireway 4"x4"x12" Straight Section

Hoffman 4" x 4" Wireway Elbow Outside Open 2 Hinge w/ 1 Gasket *1 Hole*

Hoffman Wireway 4" x 4" x 6" Top Opening Gutter

Hoffman Wireway Tee 4" x 4" x 4" Top Opening w/ 1 Gasket

Hoffman 4" x 4" Wireway Elbow Outside Open 2 Hinge w/ 1 Gasket *2 Holes*

Hoffman F44LN2 Lay-In Wireway Nipple 4" x 4" x 2" Blue Color

Hoffman F44LN3 Lay-In Wireway Nipple 4" x 4" x 3" Blue Color

Hoffman F-66WFF Flexible Wireway 6"-Diameter, 7-5/8"x7-5/8"

Hoffman F66W120 Wireway 6" x 6" x 120" with Gaskets and Hardware

Rittal ElectroMate E66L36 Wireway 36" x 6" x 6"

Hoffman F-44WX Wireway, 11-3/4" x 4" x 4"

Hoffman F-22WN3 Wireway Fitting, 2-3/8" x 2-3/8" x 3"

Hoffman F-22WX Wireway 2.5" x 2.5" x 6"

Hoffman F-22WT Tee Wireway 2.5" x 2.5"

Hoffman F-66LE9A 90Deg Wire-Way Elbow 6" *Cosmetic Scratches* *No Kit/Seals*

Hoffman F-44WN1 Wireway 4" x 4" x 1" *No Screws*

Rittal Electromate 307B E66LN2 Wireway or Auxiliary Gutter, 6" x 6" x 2"

Rittal Electromate 307B E66LN3 Wireway or Auxiliary Gutter, 6" x 6" x 3"

Hoffman F-66WN6 Nipple Wireway, 6" x 6" x 6"

New in Box F66LE9B 90° Inside Open 6" x 6" Flat Sealing Plate

Lot of 5 New in Package Hoffman F-66GPA Panel Adapter

Hoffman F-44WN1 Wireway 1"L x 4"W x 4"H

Hoffman F-66LE9A 90Deg Wire-Way Elbow 6"

New in Bag Hoffman 19506097 Seal Kit

Hoffman F-88WE225 Wireway, Elbow 8" x 8" w/Hoffman 99411507 Bag Parts

New Hoffman F88LE9C 90° Elbow Wireway with Outside Opening 8" x 8"

New Hoffman 18506071 Lay-In Oil Tight Wire Way Kit

New in Bag Hoffman F-66LSGQR Quick Release Flat Sealing Plate *Factory Bag*

New Hoffman F88L12 Wireway Section with Open Top 8" x 8" x 12" Length

New Hoffman F88LTA Wireway Tee with Top Open 8" x 8"

New in Box Hoffman F88LE9A 90-Degree Corner Wireway Gutter Fitting 8" x 8"

New in Box Hoffman F-66LRE44 WireWay Reducer, 4" x 4" Inner, 5-7/8" x 5-7/8" Out

New Hoffman F88W36 Wireway 8" x 8" x 36"

New Hoffman F88WSC Swivel Nipple 8" x 8"

New in Bag Hoffman F88WW Wire-Way Gasket and Screws

New in Bag Hoffman F-88WG Gasket and Screws

New Hoffman F22WA Wireway Telescope1769-L20

1769-OA8

1769-OF8V

1769-OV32T

1746-A10

1756-DNB

1756-DNB

1756-ENBT

1786-RPA

2094-BC01-M01-S

MC-4/11/22/400

1394C-AM04

2711-K5A1

MC-4/11/03/400

MCS-20L

T8403

T8431

1305-BA03A

1746-A7

1746-HSRV

1746-HSRV

1746-HSRV

1746-IV16

1746-NI04V

1746sc-NO8i

1747-SCNR

New in Box Hoffman F22WN2 Wire-Way Nipple, 2-5/16" x 2-5/16" x 2" Inner

New in Bag Hoffman F-66WR44 Reducer Center, 4" x 4"

New in Bag Hoffman 14370 Wire-Way Reducer, 2-1/2" x 2-1/2" Inner

Hoffman F-66WSC Wire-Way Swivel Nipple, 5-7/8" x 5-7/8" x 2" Inner Dimensions

New in Bag Hoffman F-44LB Box Connector

New Hoffman F22W12 Wireway Straight Section 2" x 2" x 12"