Rockwell-automation 1761 MicroLogix 1000 Programmable Controllers Manual de usuario descargar pdf (Pagina 79)

100

101

Programming Overview

4–3

With the logic program entered into the controller, placing the controller in the

Run mode initiates an operating cycle. The controller’

s operating cycle consists of a

series of operations performed sequentially and repeatedly, unless altered by your

program logic.

input

scan

program

scan

output

scan

service

comms

overhead

Operating Cycle













input

scan

– the time required for the controller to scan and read all input data;

typically accomplished within µseconds.

 program scan – the time required for the processor to execute the instructions in the

program. The program scan time varies depending on the instructions used and

each instruction’

s status during the scan time.

Note Subroutine

and interrupt instructions within your logic pr

ogram may cause

deviations in the way the operating cycle is sequenced.

 output scan – the time required for the controller to scan and write all output data;

typically accomplished within µseconds.

 service communications – the part of the operating cycle in which communication

takes place with other devices, such as an HHP or personal computer

 housekeeping and overhead – time spent on memory management and updating

timers and internal registers.

You enter a logic program into the controller using a programming device. The

logic program is based on your electrical relay print diagrams. It contains

instructions that direct control of your application.

Programming

1 2 ... 74 75 76 77 78 79 80 81 82 83 84 ... 421 422

Comentarios a estos manuales

Sin comentarios

Rockwell-automation 1761 MicroLogix 1000 Programmable Controllers Manual de usuario Pagina 79

Comentarios a estos manuales

Relacionado con productos y manuales para Equipo Rockwell-automation 1761 MicroLogix 1000 Programmable Controllers