Close the door and verify view point status displays the door point as normal. If not using the D9210B door point, ensure a 1K EOL is connected to terminals 9 & 10 to satisfy the door point. At the end of the programmed Extend Time (default entry is 10 seconds) the tone will continue until the door point restores to normal. If the Extend time is set to 0 or blank the tone will be disabled.