A button set to this function allows the user to operate the system's contact closure 2 connection. The user must be a member of the contact closure group.

If an extension already has a button set to this function, creating another button with this function automatically clears the setting from the existing button.

To access this function without a programmable button:

On DS and ETR phones, press FEATURE and dial 42.

On BST phones, press FEATURE and dial 9*42.