When you have defined the program code for your program, you need to configure it so that the system can execute it. To do this, you need to use the various Execution settings, the Trigger setting and the Execution Queue Size setting. Depending on your selections, the system will execute the program:
- At regular intervals
- When its inputs are processed
- When it detects changes to the values of its inputs
- When it is triggered by a change to a value in the database (only applicable Logic programs that have an On Interval execution method)
- When there is a change in the quality of any of its inputs (only applicable to Logic programs that have an On Input Processed execution method).
To define the execution settings for a Logic Program:
- Display the configuration Form for the relevant program (see Configure an ST Program, Ladder Diagram, SFC or FBD).
- Select the Logic tab.
- Define the following execution-related settings:
- Priority—Use to define whether the Logic program is executed in preference to other Logic programs (see Define the Priority of a Logic Program)
- Execution Method—Use to define whether the Logic program is executed on a time basis or when its inputs change (see Define the Execution Method for a Logic Program)
- Interval—Use to define how often timed execution of the Logic program takes place (see Define the Interval Settings for a Logic Program).
- Interval Offset—Use to define the start time for the first timed execution (see Define the Interval Settings for a Logic Program).
- Interval Offset Time Zone—Use to define the time zone to be used when calculating the time for the first timed execution (see Define the Interval Settings for a Logic Program).
- Input Change Detection—Use to define whether the Logic program is executed when it detects a change in the value of one of its inputs (see Define whether a Logic Program Executes when the Value of an Input Changes)
- Execute on Quality Change—Use to define whether the Logic program is executed when it detects a change in the quality of one of its inputs (see Define whether a Logic Program Executes when the Quality of an Input Changes)
- Allow Manual Execution—Use to control the availability of the Execute action that is used to manually execute the Logic program (see Define whether a Logic Program can be Executed Manually)
- Trigger—Use to set the Logic program to execute in response to a change in the value of a selected property of a specific database item (see Associate the Execution of a Logic Program with a Property in the Database)
- Execution Queue Size—Use to define the maximum number of values (reported by an outstation) that can be stored in the execution queue. The default setting of 250 is usually appropriate (see Define the Maximum Number of Executions that can be Queued).
- Save the configuration changes you have made.