Panasonic KX-TD500 Installation Manual page 122

Installation
Paralleled Telephone - DPT
Any Single Line Telephone can be connected on a parallel with Digital Proprietary Telephone
as follows:
To DHLC card
122
Modular
T-Adaptor
4-conductor
wiring cord
Digital Proprietary Telephone
KX-T7220 KX-T7431
KX-T7433
KX-T7230
KX-T7235 KX-T7436
KX-T7250
KX-T7420
KX-T7425
Panasonic KX-J66
or
USOC RJA2X
2-conductor wiring cord
Single Line Telephone
Installation Manual