Panasonic KX-T7730 ring problem

[5n1663r]

Hi
We have a KX-TEM824 + KX-T7730 System
and some intercom lines and 3 outlines are connected to it.
the problem is when we are speaking with the phone , if another line get to ring the phone just flashes the correspond button and there is no ringing, so sometimes we miss calls .
How can I make phone to ring even while speaking with it?

Thank you

 

[LkEErie]

After you program the phone to ring, from the intercom dial 7311# and 7321#. The first turns CW CO on, the second CW Intercom/doorphone. It's done from each phone that you want the cw signal on. and 0 turns it off.

LkEErie

 

[5n1663r]

Thank you very much.