View a program's core properties and modify its Object name and Description from the top level of the Programs application. Objects will automatically be given a unique name, description, and instance number upon creation, but these can be modified. Use the following procedures to view and modify a program's core properties:
- Click on the program you want to modify.
- The Properties pane will open.
- Modify the properties.
- Click to save. You will save each modified property individually.
You can use the same procedure to further customize a program’s properties by clicking on the program and viewing its standard objects. The program object will display at the top of the list.
Priority
The PPCL program priority property allows you run a program to meet the correct sequence of operation as defined in the Specification. If not specified, the program priority is set to Prio 16 by default. If you have more than one program commanding a single object, the program with the highest priority will command the object if the program commands overlap. Although you can modify this property for every program that controls a single object, it may become more difficult to track and troubleshoot the sequence of operation. This property can only be commanded via the web interface.
In the Properties pane, use the drop-down menu to choose a priority. Click to save.
Execution interval
The PPCL program execution interval property allows you to configure how frequently different programs run on the same device. Because of the variability in program sizes and the many other functions executing in a device, exact figures for program execution time cannot be guaranteed. Larger programs will always take longer to run than smaller programs because there are more statements to process. If all programs are configured to run at the same interval, smaller programs with fewer statements will run more frequently and will consume more processing time, even if those programs are not as critical to the application. Configuring the PPCL program execution interval property determines how often a particular program will attempt to run. This allows the prioritization of programs on the device so that programs that are most critical to the application get more processing time. Note that if a program takes longer to execute than the chosen interval, the program will always finish before restarting.
This property is set to Normal (5 seconds) by default.
In the Properties pane, use the drop-down menu to select an execution rate. Click to save.
Program cycle time metrics for different PPCL programs, such as Average cycle time (last 10 cycles) in ms, Highest cycle time in ms, and Lowest cycle time in ms can be seen by clicking on the respective program object in Application > My folder > Programs. This is useful for adjusting PPCL program execution rate properly.
Regardless of PPCL program execution rate property setting, the LOOP statement will execute at user defined second intervals. The system will ensure the user defined Sample time (st) is achieved.