描述

在輸入采樣階段，PLC以掃描方式依次地讀入所有輸入狀態(tài)和數(shù)據(jù)，并將它們存入I/O映象區(qū)中的相應(yīng)得單元內(nèi)。輸入采樣結(jié)束后，轉(zhuǎn)入用戶程序執(zhí)行和輸出刷新階段。在這兩個(gè)階段中，即使輸入狀態(tài)和數(shù)據(jù)發(fā)生變化，I/O映象區(qū)中的相應(yīng)單元的狀態(tài)和數(shù)據(jù)也不會(huì)改變。因此，如果輸入是脈沖信號(hào)，則該脈沖信號(hào)的寬度必須大于一個(gè)掃描周期，才能保證在任何情況下，該輸入均能被讀入。

(2)用戶程序執(zhí)行階段

在用戶程序執(zhí)行階段，PLC總是按由上而下的順序依次地掃描用戶程序(梯形圖)。在掃描每一條梯形圖時(shí)，又總是先掃描梯形圖左邊的由各觸點(diǎn)構(gòu)成的控制線路，并按先左后右、先上后下的順序?qū)τ捎|點(diǎn)構(gòu)成的控制線路進(jìn)行邏輯運(yùn)算，然后根據(jù)邏輯運(yùn)算的結(jié)果，刷新該邏輯線圈在系統(tǒng)RAM存儲(chǔ)區(qū)中對應(yīng)位的狀態(tài)；或者刷新該輸出線圈在I/O映象區(qū)中對應(yīng)位的狀態(tài)；或者確定是否要執(zhí)行該梯形圖所規(guī)定的特殊功能指令。即，在用戶程序執(zhí)行過程中，只有輸入點(diǎn)在I/O映象區(qū)內(nèi)的狀態(tài)和數(shù)據(jù)不會(huì)發(fā)生變化，而其他輸出點(diǎn)和軟設(shè)備在I/O映象區(qū)或系統(tǒng)RAM存儲(chǔ)區(qū)內(nèi)的狀態(tài)和數(shù)據(jù)都有可能發(fā)生變化，而且排在上面的梯形圖，其程序執(zhí)行結(jié)果會(huì)對排在下面的凡是用到這些線圈或數(shù)據(jù)的梯形圖起作用；相反，排在下面的梯形圖，其被刷新的邏輯線圈的狀態(tài)或數(shù)據(jù)只能到下一個(gè)掃描周期才能對排在其上面的程序起作用。

歐美品牌停產(chǎn)的，常用的“PLC”備品備件

我司產(chǎn)品應(yīng)用于以下領(lǐng)域：

1,《發(fā)電廠DCS監(jiān)控系統(tǒng)》

2,《智能平鋼化爐系統(tǒng)制造》

3,《PLC可編程輸送控制系統(tǒng)》

4,《DCS集散控制系統(tǒng)》
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5,《智能型消防供水控制系統(tǒng)》

6,《化工廠藥液恒流量計(jì)算機(jī)控制系統(tǒng)》

7,《電氣控制系統(tǒng)》造紙,印染生產(chǎn)線,變電站綜合自動(dòng)化控制系列

本特利，英維思，伍德沃德，福克斯波羅、西屋、瑞恩、施耐德莫迪康、ABB、AB、西門子、摩托羅拉、GE發(fā)那科、安川、博世力士樂，ACSO，力士樂等各大品牌的DCS系統(tǒng)配件，機(jī)器人系統(tǒng)配件，大型伺服系統(tǒng)備件。

Brocade Silkworm 3900 32Port Fabric Switch BR-3902-0001

Brocade Silkworm 2400 8 port Fibre Channel Switch

Brocade Silkworm 2800 Fibre Channel Switch

Brocade Silkworm 2400 8 Port Switch

Brocade Silkworm 12000 with 48 Port Dual Configuration

Brocade Silkworm 3900 2xFAN with Tray Hot Swap Module

Brocade 2 Gbit/sec SilkWorm 3900 32-Ports SAN FC Switch

Brocade Silkworm 2400 Fibre Channel Switch BR-2401-0000

Brocade SilkWorm 12000 24000 Power Supply 23-0000006-02

Brocade BR-4140 SilkWorm 4100 32-Ports SAN FC Switch

Brocade SilkWorm 3014 FC Switch PowerEdge 1855 SW3014
DELL T8560 PE1855 FC2 SWITCH MODULE

Brocade Silkworm 3850 16 Port Fibre Channel SAN Switch

Hp A5624-62001 Brocade Silkworm 2800 Fibre Chanl Switch

Brocade Hot-Swap Fan Module 60-0007000-04 Silkworm 3900

Brocade Silkworm 2800 16-Port Fiber Channel Switch

Brocade Silkworm Fabric Switch: IBM 2005-B32 & SAN32B-3

BR-SMEDPOD4-01 Brocade Silkworm 300 8 Port Upgd Option

Brocade SilkWorm 2800 Switch – Fibre Channel

Brocade SilkWorm 3900 Fan Assembly Tray New Pull

Brocade Communications Fibre Channel Silkworm 6400

Brocade SilkWorm 3250 8-Port Fibre Channel Switch New

Brocade SilkWorm 2800 Fiber Switch 16 Port NO PASS

BROCADE SILKWORM 3200 8 Port 1/2Gb/s FC-AL SWITCH

BR-48000-R0000 Brocade Silkworm 48000 Chassis cont, pwr

Brocade Silkworm 3900 3902 32-Port SG-XSWBRO3900 Fiber

Brocade silkworm 12000 250-006-900 BR-12000-0101 + GBIC

1 Year Brocade Silkworm Maintenance Support 200E Series

Brocade SilkWorm 2250 16 Port Fibre Channel Switch

Brocade Silkworm 4100 4120 32 Port ACTIVE 4Gb FC Switch

XBR-MIDRPOD-000?2 Brocade Silkworm 5100 8 Pt w/8 4GB SFP

BR-3802-0001 Brocade Silkworm 3800 16 ports, 2Gb SFPs

Brocade Silkworm 7500 16 Port Fibre Channel Switch NICE

Brocade 60-0000319-01 Silkworm Power Supply

Brocade SilkWorm SW 3014 Fibre Channel Switch T8560

Brocade 3800 Brocade 3800 Silkworm Fibre Channel Switch

Brocade Silkworm 12000 250-006-900 Br-12000-0101 + Gbic

BROCADE SILKWORM 3800 Fan Tray Assembly Module FJ00

SYSTEM BOARD BROCADE SILKWORM 2400 SWITCH 40-0000004-06

Dell Brocade Silkworm 3800 FanTray Module 7P241

Brocade Silkworm 1200 Control Processor 250-007-900

Brocade DCJ3002-01P Silkworm 3900 Power Supply New Pull

Dell Brocade Silkworm 3800 16-Port FC Switch Unit 2R411

Brocade 3800 SilkWorm Fantray FJ00 60-0001005-002

BROCADE SILKWORM 3250 8 Port 1/2Gb/s FC-AL SWITCH

Brocade Silkworm 2800 BP-2801 Fibre GBIC Network Switch

Brocade SilkWorm 24000 16-Port Blade 60-1002121-04

Brocade Silkworm 2240 Fibre Channel Switch 21H9837 GBIC

Brocade SilkWorm 24000 16-Port Blade 60-0002121-04

A5624-62001 Hp 16 Port Brocade Silkworm 2800 Fc SwitcH

Brocade SilkWorm 2800 Fan Tray 60-0110001-01 NEW

2 Qty Brocade Silkworm 3900 32 port Switch w sfp/rails

Brocade SilkWorm 24000 16-Port Blade 60-0002121-05

Brocade SilkWorm 3800 16-Port, Auto-Sensing FC Switch

Brocade SilkWorm 3200 Fibre Channel Switch BR-3200 Ref.

Brocade SilkWorm 3800 16 Port Fibre Channel DL-3802

Brocade Silkworm 3800 Fan Tray Assembly Module FJ00

Brocade SilkWorm 3200 8 Port 1Gbit/s 2Gbit/s FC SWITCH

Brocade Silkworm 2800 BR-2801 Fibre Channel Switch

Brocade 2 Gbit/sec SilkWorm 3800 32-Ports SAN FC Switch

BR-2802-0008 Brocade Silkworm 2800 1Gbps SAN Switch

Brocade SilkWorm 3900 System Board 40-0300505-03

1 Year Brocade Silkworm Maintenance Support 4900 Series

1 Year Brocade Silkworm Maintenance Support 5000 Series

Brocade Silkworm 3900 32Port Fabric Switch BR-3902-0001

Brocade Silkworm 4100 EMC DS-4100B 32 Port Fibre

Brocade SilkWorm 3900 System Board With Tray New Pull

Brocade SilkWorm 2400 – switch

Brocade, SilkWorm, AP7420, BR-7422-D0001 ~ USED

Dell Brocade Silkworm PowerEdge Fiber Switch N9473

BROCADE silkworm 4100 fiber Switch Warranty,Rails,?Cable

HP Brocade Silkworm 2400 8 port FC Switch A5625A

BROCADE SILKWORM 2400 BR-2402-0013 FIBER CHANNEL SWITCH

BR-360-1008-A Brocade Silkworm 300 8Gb 24 Ports

Brocade Silkworm-12000 * 128-port w/ GBICs

Brocade Silkworm 3900 SAN Fibre Switch 32-Port w/SFPs

Brocade SilkWorm 24000 16-Port Blade 60-1002121-04

Brocade Silkworm 4100 32 port 16 ACTIVE BR-4120 Switch

Brocade SilkWorm 3200 8 Port 1/2Gb/s FC Switch

Brocade Silkworm 3250 Fibre Channel Switch w/8 GBICs

Brocade Silkworm 3250 EMC DS-8B3 8-Port Fibre Switch 2G

Brocade BR-48000-R0000 Silkworm Chassis, 2 x cont,2xPWR

Brocade SilkWorm 3900 Enterprise Fibre Switch Refurb

BROCADE SILKWORM 3900 FAN 60-0007000-04

Brocade SilkWorm 2800 Fibre Channel 16 Port Switch

Brocade Silkworm 3900 32Port Switch BR-3902-0001

Brocade Silkworm 3850 / DS-16B3 Switch

BROCADE SILKWORM 3900 POWER SUPPLY 60-0000739-02

Brocade SilkWorm 3800 Power Sup 60-0000212-01, SP471-1A

Brocade SilkWorm 3800 FanTray, FJ00, 60-0001005-002

Brocade SilkWorm 3800 Fan Tray FRU Unit XBR-3800-0004

Brocade SilkWorm 3250 Fabric Switch

BR-5340 Brocade Silkworm 5300 80 Active 8Gb SFP’s

BROCADE SilkWorm 3250 Fibre Channel Switch w/8 GBIC

BROCADE SILKWORM 3200 8-PORT FIBRE CHANNEL SWITCH RACK

Brocade Silkworm 12000 16 Port XBR-12000-0101

XBR-MENTPOD8-01 Brocade Silkworm 5300 16 Port Upgrade

BROCADE Fan Silkworm 4100 Switch XBR-4100-R0004

Brocade Silkworm 3250 Switch, 8Port 8 SFPs

Brocade Silkworm 2800 Fiber Channel Switch FTR-8519P-5A
BR-2802-0008

Brocade Silkworm 3200 Fibre Channel Switch FC w/8 GBICs