Panasonic KX-TSC14B - Connecting a Communication Device

3.2.3. If you use the unit only as a single-line telephone
- For this connection, you can only use LINE 1.
3.3. Connecting a Communication Device
After connecting the telephone line cord to a two-line telephone jack, you can connect a
communication device (computer, modem, fax, answering machine, etc.) through this unit using
the LINE 2/DATA jack (—Data Port).
6