Dialogic M7324 Manual De Usuario

To complete a call (supervised or blind), press the transfer key again with 
dx_dial(&), where & acts as a key press of the transfer key. The application 
must handle the on-hook state after completing the transfer. 

A transferred call can be aborted at any time (prior to completing the transfer) 
by pressing the appropriate appearance key where the original call resides. 
The application can perform this only in a supervised transfer mode. For 
example, if the original call resided on the first appearance (Feature Key 00), 
dialing dx_dial(<ESC>KA) will bring the original caller back to an active 
state. 

An application answers a call and plays a greeting message prompting the 
caller to enter the extension they wish to reach (the caller enters 221). Using 
the dx_dial( ) function with the dial string (&,221), the application attempts to 
transfer (supervised) the call to extension 221. Call progress analysis is used 
to determine if extension 221 is answered, busy, or there is no answer. If 
extension 221 answers, the application needs to use dx_dial( ) to press & 
again to complete the transfer and hang up after the transfer is complete. If the 
extension is busy or not answered, the application reconnects to the incoming 
call and plays a message asking the caller to choose between accessing voice 
mail or transferring to the operator.