Sony PCS-3000 Operating Instructions Manual page 46

Setting the Answer Mode
2-10
Chapter 2 Settings
3
Set the answer mode you want from [ANSWER MODE].
Each time you select [ANSWER MODE], the answer mode switches
between AUTO and MANUAL.
Note
Do not change any other settings.
4
Select [EXIT].
The setting selected in step 3 becomes active, and the MAIN menu
appears.