Panasonic KX-TDE100 Features Manual page 197

1.17 Optional Device Features
2.8.16 [2-8-2] Ring Tone Patterns—Call from Doorphone
2.8.18 [2-9] System Options—Option 3—Confirmation Tone—Tone 1 : Doorphone / Called by Voice
2.11.1 [5-1] Doorphone
PT Programming Manual
[720] Doorphone Call Destination
[729] Doorphone Number Reference
User Manual References
1.10.1 If a Doorphone/Door Opener is Connected
Feature Guide 197