Chapter 5. Power Supply / CPU
5-12
5.4 Program
5.4.1 Program configuration
A program consists of all of the function elements that are needed to execute a particular control. It is to be stored in the
internal RAM of the CPU part or the EEPROM memory. The function elements are classified as below.
Function elements Processing Operation
Initialization program
• Executes when the power is applied or the CPU operation is transited to the RUN mode.
• Executes the initial/fixes data setting for execution of scan program and the initialization of
peripheral devices on special modules.
Scan program
• Processes the constantly repeated signals that are executed every scan.
Time driven task
Program
• When the following time conditional processing is required the program is executed
complying with the time interval setting.
- In case of the processing need a shorter interval than that of average scan processing time.
- In case of the processing needs a longer interval than that of average scan processing time.
- In case that the processing should be executed by the specified time interval.
Interrupt program
• A fast processing is executed for internal or external interrupt.
HSC interrupt program
• Executes when HSC Comparison Output occurs.
5.4.2 Program execution procedure
The followings explain the program execution procedure when the power is applied or the mode-setting switch of CPU part is
in the RUN status. Program operation processing is executed as the procedure given below:
Operation start
Initializing program
Scan program
END processing
External task program
Time driven task program
Executed only when
the condition has been
satisfied
.
y Executes when the power has been
applied or the CPU operation is in the
Run mode.
1
Internal task program
Executed only when
the condition has been
satisfied
.
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