Apple Final Cut Server - Manual (Page 213)

Chapter 14 Managing Automations 213
II
The Watcher window appears if you click the Create button.
The items that appear in the area on the left depend on the Watcher Type you choose.
The choices include poll and subscription.
 A poll watcher checks the device at timed intervals. This is the most common type
of watcher.
 A subscription watcher is for internal usage only.
Note: If you edit an existing watcher by double-clicking it in the Watcher pane, you
cannot change its Watcher Type setting.