Panasonic KX-TD1232NE Programming Manual page 186

2.5 CO Line Programming
• For the KX-TD1232, port number 01 through 06 are for the Master System and 07
through12 are for the Slave, if available.
• This programme becomes available whien "MSN" is selected in programme [420/
429] ISDN Ring Service Assignment — Day / Night.
Feature References
Integrated Services Digital Network (ISDN)
Multiple Subscriber Numbers (MSN) Ringing Service
186 General Programming