Panasonic DBS576 Technical Manual page 164

Chapter 5. Key Telephone Features
In Version 3.0 and higher, directory numbers may be assigned to stations that are not installed,
provided the cabinet is installed. However, once the directory numbers have been assigned to a
particular slot, that slot is no longer available.
Figure 5-2. Example Directory Number assignments for Extension 200
When a caller originates a call, the call appears on the first available PDN key. If all PDNs are
unavailable, the call will select the EXT LED.
When calls come in to a DN, the call appears on the first available DN key. If the call is to your PDN
and no PDN key is available, the caller hears a busy tone.
Directory numbers may be assigned to FF keys 25-32. These are non-appearing keys.
Intercom voice calls only go to the PDN extension but light the corresponding NPDN keys red. A tone
call follows the appropriate ring status (immediate ring, delayed ring, etc.) for any extension.
5-40 DBS 576 (USA) issued October 2000
Section 700 - Operation
576-36-700