ok the pref line out part of the system simply put is ....what you want the phone to do when you lift the handset.
in most cases this is set to intercom
reason when you lift the handset you would most likly want to ring somone inside the building if it is your customers intent to use the handset as a hotline then your fault may be that the handset is set with a no: programed into it.
to explain lets say your cus has a phone set to ring an outside no when lifted.this no may be 9-045 898611
in the above the system dials 9 first (give me an outside line)
if you have pref line set to line them the no being dialed is really 99-045 898611
if your cus doesnt have a line no: set in pref line out and if the system is set to intercom then the handset when lifted is looking for an ext with the no: 9-045898611 which it cant have thus the display "Not Valid" ...
so in short if you want to get a outside line when you lift the handset you must tell the system which line or group of lines to pull.
things that would help us to help you ...
1. what is the model of the phone system ver also if known or age.
2.what does the customer whant to happen when he lifts the handset.
3. when the customer dials 9 or 0 to get a outside lin(dependnt on where you are (does he get one.
peter doyle (www.novacomms.net