AT&T 7406BIS - Manual (Page 39)

Intercom (Automatic/Dial)
To make a call to your 1 Press [ Icom Auto xxx ] (while off-hook)
predetermined
Automatic Intercom
● Intercom ring is sent
partner
[ringback tone]
To dial a call to a
member of your Dial
Intercom group
1 Press [
Icom Dial xxx
] (while on-hook) [dial tone]
2 Dial group member’s 1- or 2-digit code [ringback tone]
● Intercom ring is sent
To answer any 1 Pick up handset and press [ Icom ]
intercom call
●
You are connected to call
Note: If you are active on another call, first press
[ Hold ], then press flashing [ Icom ].