IC693PIF400 輸入采樣階段

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

IC693PIF400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掃描用戶程序（梯形圖）。在掃描每一條梯形圖時，又總是先掃描梯形圖左邊由各觸點構成的控制線路，并按先左后右、先上后下的順序對由觸點構成的控制線路進行邏輯運算；然后根據(jù)邏輯運算的結果，刷新該邏輯線圈在系統(tǒng)RAM存儲區(qū)中對應位的狀態(tài)，或者刷新該輸出線圈在I/O映象區(qū)中對應位的狀態(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，只有輸入點在I/O映象區(qū)內(nèi)的狀態(tài)和數(shù)據(jù)不會發(fā)生變化，而其他輸出點和軟設備在I/O映象區(qū)或系統(tǒng)RAM存儲區(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)行結果會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)只能到下一個掃描周期才能對排在其上面的梯形圖起作用。

IC693PIF400 

RELIANCE ELECTRIC GV6000 AC DRIVE 7.5HP

RELIANCE ELECTRIC 6MB40007 DRIVE MD65 460V IP20 7.5HP 

Reliance Electric SP500 AC Drive Module ISU41001

One-day shipping available

Reliance Electric AutoMate 20 Controller 45C20

Expedited shipping available

Reliance Electric 57C403/57C-403/0-57C403 SEALED!!!!

One-day shipping available

Reliance Electric AutoMate Programmer 45C94

Expedited shipping available

RELIANCE ELECTRIC 45C66A OR 45C-66A OUTPUT MODULE

**FS** Reliance Electric Analog Input 61C542A 

Expedited shipping available

RELIANCE ELECTRIC AUTOMATE PROGRAMMER MODEL 45C94

One-day shipping available

NIB RELIANCE ELECTRIC 45C60 115V OUTPUT MODULE CONTROL*

RELIANCE ELECTRIC 14C102 FLEXPAK PLUS DC DRIVE,NEW 

RELIANCE ELECTRIC C56H1590H ? HP FRAME FB56C MOTOR, NIB

Reliance Electric OHMITE Renewal 63803-13CP 18.2 K OHM

New Reliance Electric Remote Operator Adapt Kit 14C220

Expedited shipping available

RELIANCE ELECTRIC P44G0362N 125 HP FR. 444TS MOTOR NEW

RELIANCE ELECTRIC P44G0362N 125 HP FR. 444TS MOTOR NEW

RELIANCE ELECTRIC MODEL 501 20 GAL. WATER HEATER

Enlarge

Reliance Electric Motor P56H1301H 3/4HP 3PH 1725RPM

**NIB** Reliance Electric Input Module 61C501

Expedited shipping available

Reliance 30 Gallon self cleaning electric water heater

RELIANCE ELECTRIC A51A0627 AC MOTOR BRAKE,UNIBRAKE 

NIB Reliance Electric AutoMate Input Module 45C40

Expedited shipping available

RELIANCE ELECTRIC CHANNEL INPUT MODULE 57400-A 115V

Reliance Electric Output Module 57C403

Reliance Electric Spindle Drive Type S3R Service Manual

Reliance Electric Spindle Drive Type S3R Service Manual

Reliance Electric AutoMate 45C40 Module AC/DC 115V NEW 

Expedited shipping available

Reliance Electric Spindle Drive Type S3R Service Manual

RELIANCE ELECTRIC 57408 POWER MODULE INTERFACE (NIB)

3/4HP Rockwell Electric Motor 1140RPM Reliance Electric

Reliance Electric Brake Motor #6 (2 AVAILABLE)

NIB Reliance Electric Position Module 65C500

One-day shipping available

Reliance Electric 45C60 Card 59012-13RD

Reliance Electric 2V4451 GV3000 2HP AC Inverter **LNC**

Reliance Electric VS Drive SP 500 M/N 1SU41001

RELIANCE ELECTRIC 5 HP MOTOR 

Enlarge

RELIANCE ELECTRIC 57408-D POWER MODULE INTERFACE (NIB)