This one, if you click the squarer on the left it will give a 7.83 Hz for 3 seconds between each frequency in your programs. Default is zero and the squarer is not clicked, so it depends on your choice. I would guess that if it is not the default "0" then it is probably part of your programs so I would click the squarer on the left and enable it, but it is up to you. If the squarer is not clicked then it is disabled so the 7.83 will do nothing as if it was "0". You can read more in the manual - page 106.
For more details, please check the link: