Rockwell-automation AutoMax Enhanced Ladder Language Reference Manual Uživatelský manuál stáhnout pdf (Strana 304)

100

101

DĆ2

D.1 Using the PreĆDefined Program Scan Variables

Use the following Boolean variables to execute logic based on the Processor's scan.

Only use these variables for input parameters (read only):

D first_scan

Use this variable to execute logic during a program's first scan. This variable is

true during the initial scan of the ladder rung and false during all other scans.

D second_scan Use this variable to execute logic during a program's second scan. This

variable is true during the second scan of the ladder rung and false during all

others.

D last_scan Use this variable to execute logic during a program's last scan. This variable is

true on the final pass of the ladder rung after you have selected TASK STOP.

This variable is not set when a STOPĆALL error occurs.

To use the last_scan variable, your program scan must be less than 0.5 s.

MPORTANT:

Do not use the last_scan variable in an eventĆdriven program. Because these

programs are based on the occurrence of an event, the last_scan variable may

never be executed when used in an eventĆdriven program.

1 2 ... 299 300 301 302 303 304 305 306 307 308 309 ... 351 352

Komentáře k této Příručce

Žádné komentáře

Rockwell-automation AutoMax Enhanced Ladder Language Reference Manual Uživatelský manuál Strana 304

Komentáře k této Příručce

Související produkty a manuály pro Zařízení Rockwell-automation AutoMax Enhanced Ladder Language Reference Manual