IBM Workload Automation & Workload Scheduler

I'm curious what the refresh rate of the file dependency check is.  Or how often is goes back to the defined directory to check for the defined file. 

I know with the "File Creation" Event Rule event, you are able to provide a duration on how often the system checks for your file.  However, I don't see anything similar to that in the File Dependency option when you use that on a job within a stream.  I'm curious how often the system checks, as that may be a more streamline way of doing thing rather than the Event Rule checking and kicking off streams.