Panasonic KX-TVA594 Installation Manual page 141

c)
Set the amount of time that passes before a call is considered "unanswered" and therefore
forwarded to the VPS (Intercept Routing No Answer timer).
1)
Go to the "System-Timers & Counters-CO / Extension" screen.
2)
Assign the "Intercept Timer" parameter.
3)
Click "Apply" to save the changed data.
5.3 KX-TDA and KX-TAW Series PBX Programming for Inband Integration
Installation Manual 141