Binding development: how often is command RefreshType issued?

So I see OH can issue org.openhab.core.types.RefreshType to my handler and it’s issued on OH startup.

My question is: does the OH system issue this command periodically? Or is it up to my code to check item state every so often to ensure it’s current?

This is for my work on the panamaxfurman binding

Thanks!
Dave

Regular polling is up to the binding. RefreshType.REFRESH should be issued when a channel is linked to an item, that is why you see them on startup.