The ability for the DuraFon to receive Visual Message Waiting Indication signals was added to all serial #121xxxxxx items and higher for PRO. By default, this feature is turned OFF on the PRO model.
This feature was also added to all DuraFon 1x ser#121xxxxxx and higher and default is ON.
The signal needs to be FSK (Message Waiting Indication), either provided by the PBX or from your phone carrier (if a PBX is not used).
To turn this feature on with PRO: From any registered handset, press Menu, star, pound, pound, star, then choose the base ID (00), then choose 4 (B EEP).
Go to the address 0005 and change the data to 0A01. (So ADDR = 0005, DATA = 0A01). Then power cycle the base station to make the changes active.
Details of what a handset does when the FSK signal is received:
When a handset receives the signal, it will double beep and an envelope icon will appear on the display. When the message is cleared the PBX or provider will send another FSK signal denoting the change - and the icon will then go away.