Panasonic DBS-2.3-400 Programming Manual page 321

Section 400-Programming
Terminal Type: FF3 (ExtPort)# 2#
Notes
Hardware Requirement For Distinctive Ringing. The SCC-B card is
required in CPC-B configurations to support distinctive ringing on digital
phones (in which the ring pattern is programmed into the phone itself).
CPC-A and CPC-AII do not support distinctive ringing on digital phones.
However, with an AEC card, OPX Adapter, or SLT Adapter (these devices
determine the ring pattern), distinctive ringing can be supported for analog
SLT phones in any CPC configuration.
DBS-2.3/9.2-400 DBS Manual - Revised April 2000
Chapter 3. Extension Programming (FF3)
Page 3-47