Variable Definition
As part of creating a template, variables can be used in many different areas in place of literal values. These variables are placeholders whose values can be specified by the user as part of generating a report on demand.
Every variable that is used in the template is automatically assigned an input method that is shown when the On Demand Reports application is run for that template. The following describes the default input method for certain variable types used in the template.
Date and Time Variables in Data Groups
If date or time variables are detected in groups they are assigned to the Date Calendar panel. If a variable is used for the end date, a limit is imposed on overall time period of the Date Calendar panel. The limit is determined as follows:
Data Groups from Historical Data
The limit is determined based on the Interval setting for the Time Period. If the Interval is time based (e.g., Every 5 minutes or Every 1 hour), the following rule is followed based on the unit:
Seconds
The limit is 1 day.
Minutes
If the Interval is a variable, the limit is 30 days; otherwise, the limit is 1 day.
Hours and Days
The limit is 30 days.
Weeks
The limit is 4 weeks.
Months
The limit is 3 months.
For all other Interval Types, the limit is 30 days.
Data Groups from Databases
The limit is 30 days.
Tag Variables in Data Groups
If variables are detected for tags in Data Groups from real time or historical data sources, they are assigned to the Tag panel with the Source and Connector set based on the connector of the group.
Other Variables
If no specific input can be determined for the variable, it is added to the Parameter panel with a text box input.
Report Date and Report Time
Report Date and Report Time are special variables which allow user input to any parameter in the template that is based around a relative date or time using a calendar control.
For example, a template set up to run daily to retrieve values from a historian. The History Data Group for this template would be set up with the Time Period as Relative with a Duration of 1 day and Start at 00:00:00.
When this template is updated by the Scheduler the report date is read from the operating system clock. However, to run this report in an On Demand Reports client or the Web Portal, the user selects the date manually using the calendar control.