To set preventive maintenance (PM) trigger scheduling, follow these steps:

1. Go to the maintenance page

2. On the left panel, find "preventive maintenance." 

3. On the preventive maintenance page, you will see a list of existing PM tasks. To add a new one, click on the button  "+ Preventive maintenance" available at the top right corner of the page.

4. On the new page you will find a form with various sections to fill in the required details for the new preventive maintenance task.

Trigger scheduling: Look for section 4, which pertains to trigger scheduling. In this section, you will find three options: schedule, alarm, and reading. These options determine how the PM task will be triggered.

1. Schedule: If you choose the schedule option, you will need to specify a date and time when the preventive maintenance task should be triggered. This could be a specific day and time or a recurring schedule (e.g., every Monday at 10:00 AM).

2. Alarm: If you select the alarm option, you will need to configure an alarm or notification that will trigger when the PM task is due.

3. Reading: The reading option is used when the PM task is triggered based on a reading or measurement. You will need to enter the parameter, threshold or criteria that will trigger the maintenance task.
   Note: You can select any one of these options or choose multiple options as per your preference.

5. Fill in required details: For the selected trigger scheduling option(s), fill in the necessary details.

6. Click on the "Save" button or a similar option to save the entry.