# Tips for using the On event part

Tips for use:

- If the condition you have specified occurs while the flowchart is running, it will complete the run-through and then run again.
- When providing an expression to match against, you will usually want to enter a non-variable value (e.g., 'Start', 10, TRUE), but you may also enter a scene (global) variable. Local variables are not valid. See Variables, values and expressions for more details.
- If you provide a specific condition, the flowchart will only run the first time the condition is matched. The condition must become false again before it will match a second time. So, for example, a flowchart starting on the condition 'Temperature > 25' will run the first time the Temperature property goes above 25, but if it keeps going up, the flowchart will not run again; the property must first fall to 25 or below and then rise again for the flowchart to run a second time.

## See also:

- On event
- Variables, values and expressions