描述
除了执行用户程序外，在每次循环过程中，PLC还要完成内部处理、通信处理等工作，一次循环可分为5个阶段（见图1-5）。PLC的这种周而复始的循环工作方式称为扫描工作方式。由于计算机执行指令的速度极高，从外部输入-输出关系来看，处理过程似乎是同时完成的。
POE20U-560G PHIHONG 配件
RELIANCE ELECTRO-CRAFT S6100 / G&L SSM610 SERVO MOTOR
One-day shipping available
RELIANCE ELECTRIC 0-52808-2 OLVC CARD 0528082 NIB
RELIANCE 0-57407-4J PROCESSOR 57C407
Reliance 20 hp P25G5572C-G1-J2 Motor (MOT1999)
RELIANCE ELECTRIC GV3000 DRIVE 10V4140 460v 10HP VFD
One-day shipping available
RELIANCE ELECTRIC 418227-1A “NIB” 4182271A 74V DC COIL
RELIANCE ELECTRIC 0-51847-3 VLDD CARD
Reliance 0-52838
RELIANCE ELECTRIC 64418-WA USPP 64418WA
RELIANCE ELECTRIC 107075-012R USPP 107075012R
Reliance Electric Company 0-48652 Calibrator 048652
One-day shipping available
RELIANCE ELECTRIC DC MOTOR DRIVE 85014-29RA 0-51486-15A
RELIANCE ELECTROCRAFT SERVO CONTROLLER MMI PN 9078-0120
