The DS7420i is compatible with the DS7400, DS7400X or DS7400Xi, however its telephone wiring connections to the DS7400 or DS7400X are different than to the DS7400Xi. When using the DS7420i with the DS7400 or DS7400X, wire terminals 21 through 24 as follows:
- Terminal 21 to Terminal 14 Control Panel Line Ring
- Terminal 22 to Terminal 13 Control Panel House Ring
- Terminal 23 to Terminal 16 Control Panel House Tip
- Terminal 24 to Terminal 15 Control Panel Line Tip
All other wiring connections shown in the DS7420i Installation Instructions are correct for all panels.
