Chapter 5 Programming Concepts
XBC E-Type Main Unit
5-1
Ver. 1
Chapter 5 Programming Concepts
5.1 Program Execution
5.1.1 Configuration of program
All functional elements needed to execute a certain control process are called a ‘program’. The program is
stored in the built-in RAM mounted on a CPU module or flash memory of a external memory module. The
following table shows the classification of the program.
Program type
Description
Initializing program
•
It will be executed till the specific Flag ‘INIT_DONE’ is on. And while the
initialization task is executed, cycle task, external interrupt task and internal
device task are not executed. I/O refresh, high speed counter and
communication are executed
Scan program
•
The scan program is executed regularly in every scan.
Cycle time interrupt
program
•
The program is executed according to the fixed time interval in case that the
required processing time condition is as below.
In case that the faster processing than 1 scan average processing time is
required
In case that the longer time interval than 1 scan average processing time is
required
In case that program is processed with the appointed time interval
External interrupt
program
•
The external interrupt program is executed on an external interrupt signal.
Subroutine program
•
Only when some condition is satisfied.(in case that input condition of CALL
instruction is On)
5.1.2 Program execution methods
Here describes the program proceeding method that is executed when the power is applied or key switch is
‘RUN’. The program performs the operation processing according to the configuration as below.
Start processing
Scan program
END processing
Subroutine program
External interrupt program
Cycle time program
Only when
initiated.
Initializing program
It executes up to execution of INIT_DONE instruction when initializing program is designated.
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