Vertical Communications DXP - Manual (Page 23)

3.5.3 Camping On At An Idle Station
And Waiting For An Automatic Callback
If you call another station and hear ringing but receive no answer, you
can press a button that will cause the system to ring your telephone
when the user at the called station initiates any telephone activity.
•
To camp on at a station for which you hear ringing but
receive no answer,
1. Dial ✳ 6.
Callback will occur after the user at the called station initiates
any telephone activity.
•
To cancel the camp-on condition at any time,
1. Press INTERCOM and dial # 6.
NOTE: If you make a call in the voice announce mode and receive no
answer at the called station, the CALLBK option is still
available to you.
GCA70-314 Making Calls
Non-LCD Station User's Guide 3–7